Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 14, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sat Dec 14 2024
Valid 12Z Sat Dec 14 2024 – 12Z Mon Dec 16 2024

…Atmospheric River continues to bring very heavy rain with the potential
for flooding, heavy mountain snow, and gusty winds to central/northern
California Saturday…

…Heavy mountain snow forecast for portions of the Great Basin and
northern Rockies Saturday…

…Wintry mix including accumulating freezing rain continues for portions
of the Upper Midwest Saturday, spreading into the central Appalachians
Sunday…

A Pacific storm system and accompanying strong flow of
moisture/Atmospheric River continues inland over the West this morning
(Saturday) bringing heavy rainfall, mountain snow, and gusty winds to
central/northern California and the Pacific Northwest. The heaviest
rainfall will continue to focus on portions of central/northern California
through Saturday morning where rainfall rates of 0.5″ to 1″ per hour will
lead to an additional few inches of rainfall over already saturated
ground. The greatest potential for flooding will be around the greater Bay
Area where a Slight Risk of Excessive Rainfall (level 2/4) is in effect.
Heavy snowfall will also continue for higher mountain elevations of the
Coastal Ranges and Sierra Nevada, generally over 5000 feet, where Winter
Storm Warnings have been issued for storm total snowfall of 1-3 feet.
Winter Weather Advisories are also in effect further north into the
Cascades where storm total snowfall of 8-12″, locally 18″, can be
expected. Gusty winds also continue this morning, particularly along the
coast, but all hazardous impacts from the system should begin to taper off
through Saturday afternoon.

The system will push further inland through the day Saturday, spreading
moisture and precipitation chances across the Great Basin and Northern
Rockies. A mix of rain and snow can be expected at lower elevations,
though any snow accumulations should remain limited. Heavier snow is
forecast in the mountains, particularly from central Idaho into western
Wyoming, where Winter Storm Warnings are in effect for snowfall of 5-10″,
locally 12″+. Precipitation chances will spread eastward into the northern
High Plains by Saturday night with a wintry mix expected. Some light ice
accretions will be possible through the day Sunday. Some gusty winds are
also likely along the Front Range of the Rockies as the system pushes out
onto the Plains.

Further east, an upper-level shortwave/accompanying surface frontal system
will help to trigger showers and thunderstorms across the Ohio, Middle
Missouri, and Lower Mississippi Valleys Saturday, with some moderate to
locally heavy rainfall possible. Storms will likely linger into Sunday
along a trailing frontal boundary, though with lighter amounts expected.
More impactful weather will continue further north as warmer, moist air
overrides colder air at the surface leading to a wintry mix across the
Upper Midwest and Great Lakes. Snow/sleet accumulations should remain
light, but freezing rain is also expected, particularly over eastern Iowa.
An Ice Storm Warning remains in effect through Saturday afternoon for
totals potentially exceeding 0.25″ and leading to tree and power line
damage. The system will continue east on Sunday bringing a wintry mix into
the Southern Appalachians. Similar to Saturday, snow/sleet accumulations
should generally remain light, but some ice accretions over 0.1″ will be
possible.

Elsewhere, some showers and thunderstorms can be expected this weekend
along the Atlantic Coast of the Southeast and Florida with a
quasi-stationary frontal boundary in place. Additionally, after a brief
break late Saturday/early Sunday, another system over the Pacific will
bring increasing precipitation chances back to the Pacific Northwest by
Sunday evening. Most of the country will see high temperatures at or above
average this weekend as conditions moderate following a cold frontal
passage across the South and with an upper-level ridge passing over the
central/western U.S. ahead of the next Pacific system. Some of the warmest
temperatures will be in the Southern Plains/Texas with highs in the 60s,
70s, and even some low 80s. Otherwise, temperatures generally range from
the 30s and 40s from the Pacific Northwest and Great Basin east through
the northern Plains, Great Lakes, and Northeast; the 50s and 60s for
California, the central Plains, Ohio Valley, and the South; and 70s for
the Desert Southwest and Florida.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.

NOAA Updates its ENSO Alert on December 12, 2024 – Will it be or not? – Published on December 13, 2024

Synopsis:   La Niña conditions are most likely to emerge in November 2024 – January 2025 (59% chance), with a transition to ENSO-neutral most likely by March-May 2025 (61% chance).

So we continue to be in ENSO Neutral but NOAA may not want to admit their forecast was wrong so they present it as waiting for La Nina. It is correct that we are in La Nina Watch but it is also correct that we currently still remain in ENSO Neutral.

On the second Thursday of every month, NOAA (really their Climate Prediction Center CPC) issues its analysis of the status of ENSO. This includes determining the Alert System Status.  NOAA now describes their conclusion as “ENSO Alert System Status: La Nino Watch”

The exact timing of the transition is now perhaps more clear but maybe not.  It should increase the reliability of the Seasonal Outlook to be issued next Thursday. But will it?

BTW this is the Copernicus view of the next three months.

 

The above is a consolidation of a number of models including one of the U.S. models but it is dominated by  European models. The format is different than what NOAA will present next week. It is more technical in nature. Basically this graphic shows the expected average storm track over the three-month period.  It also shows the expected deviation from normal of the level of the 500 MB ((Z500) of air- pressure which is pretty much the midpoint of the atmosphere. Z 500 is often the best way to forecast weather. Remember this is not a weather forecast but a forecast of the average air pressure for the three months.  It will vary from day to day and week to week but the storm track is expected to be further north which usually divides the cold and wet area from the warm and dry area but we are talking about anomalies. I suspect that the NOAA forecast which will be issued next Thursday will be similar to the above. It is suggesting a La Nina pattern.

We have included a very interesting ENSO Blog Post by Emily  Becker.

CLIMATE PREDICTION CENTER ENSO DISCUSSION (LINK)

The second paragraph is what is important:

“The dynamical models in the IRI plume continue to predict a weak and a short duration La Niña, as indicated by the Niño-3.4 index values less than -0.5°C. This prediction is also reflected in the latest North American Multi-Model Ensemble (NMME), which continues to predict slightly cooler SSTs and weak La Nina conditions.  The forecast team leaned toward predicting an eventual onset of weak and short-lived La Nina conditions, based on the model guidance and current atmospheric anomalies. Weak La Niña conditions would be less likely to result in conventional winter impacts, though predictable signals could still influence the forecast guidance (e.g., CPC’s seasonal outlooks).  In summary, La Niña conditions are most likely to emerge in November 2024 – January 2025 (59% chance), with a transition to ENSO-neutral most likely by March-May 2025 (61% chance).”

Below is the middle paragraph from the discussion last month.

“The IRI plume predicts a weak and short duration La Niña, as indicated by the Niño-3.4 index values less than -0.5°C. The latest North American Multi-Model Ensemble (NMME) forecasts are cooler than the IRI plume and predict a weak La Niña.  Due to this guidance and La Niña-like atmospheric circulation anomalies over the tropics, the team still favors the onset of La Niña, but it is likely to remain weak and have a shorter duration than other historical episodes.  A weak La Niña would be less likely to result in conventional winter impacts, though predictable signals could still influence the forecast guidance (e.g., CPC’s seasonal outlooks).  In summary, La Niña is most likely to emerge in October-December 2024 (57% chance) and is expected to persist through January-March 2025).”

We now provide additional details.

CPC Probability Distribution

Here are the new forecast probabilities. The probabilities are for three-month periods e.g. NDJ stands for November/December/January.

Here is the forecast from last month.

The analysis this month and last month are a bit different with again the transition to La Nina being slightly slower than thought last month. Also, the probabilities of a La Nina are lower than estimated last month. This seems to be a trend. The chart is clearer than the discussion in the summary report above.  The La Nina is a bit slower to arrive. I am not sure that we will actually have a La Nina.  However, one should read the Blog Post by Emily Becker, which is discussed later in this article.

Some will need to click on “Read More” to read the rest of this article.

Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 13, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Fri Dec 13 2024
Valid 12Z Fri Dec 13 2024 – 12Z Sun Dec 15 2024

…Atmospheric River to bring very heavy rainfall and possible flooding as
well as high elevation mountain snow to the West Coast…

…Heavy mountain snow forecast for portions of the Great Basin and
northern Rockies Saturday…

…Potentially impactful wintry mix with freezing rain expected across the
Middle Missouri Valley and Upper Midwest Saturday…

An Atmospheric River event will bring very heavy rain, mountain snow, and
gusty winds to portions of southern Oregon and northern/central California
Friday into Saturday. A Slight Risk of Excessive Rainfall (level 2/4) has
been issued along portions of the Coastal Ranges of northern California
where locally heavy rainfall rates of 0.5″ per hour and rainfall totals of
3-5″, with isolated higher amounts upwards of 7″, may lead to some
instances of flooding during the height of the event Friday
evening/overnight into Saturday morning. Very heavy mountain snow is
expected at higher elevations (generally over 5000-6000 feet) of the
Coastal Ranges and for the Sierra Nevada. Winter Storm Warnings have been
issued for forecast snowfall totals of 1-2 feet, locally higher. In
addition to the heavy precipitation, strong, gusty winds are also
expected, particularly for coastal locations. A broader area of more
moderate rainfall stretches across the Pacific Northwest and south along
coastal California. Some Moderate to heavy snow is also forecast further
north through the Cascades where 4-8″, locally higher, can be expected.
The system will continue eastward late Friday and into the day Saturday,
spreading moisture and precipitation chances further inland over the Great
Basin and northern Rockies. A mix of rain and snow can be expected at
lower elevations with snow, heavy at times, for higher mountain
elevations. Winter storm Watches have been issued for the mountains of
central Idaho where the heaviest snow is expected with forecast totals of
6-12″.

To the east, an upper-level wave passing from the Rockies and over the
Plains will help to organize a surface frontal system and encourage moist,
southerly return flow from the Gulf of Mexico. Showers and thunderstorms
are forecast ahead of an eastward moving cold front across eastern
portions of the central/southern Plains on Friday. More widespread storms
with moderate to locally heavy rainfall are expected on Saturday as the
system continues into the Middle Mississippi/Lower Ohio Valley. Some
potentially impactful winter weather is forecast further north across the
Middle Missouri Valley and into portions of the Upper Midwest where warm,
moist air overriding colder temperatures will lead to a wintry mix Friday
afternoon through Saturday. Snow/sleet accumulations should remain light,
but some freezing rain accretions are also expected. These accretions may
be greater than 0.1″ over eastern Iowa which could lead to some tree
damage and power outages. Regardless, the wintry mix will at least likely
lead to some travel troubles across the region.

Elsewhere, most lake effect snow will be tapering off Friday morning for
the Great Lakes except downwind of Lake Ontario where an additional 6-12″
can be expected through the day Friday. Some light to moderate snow
showers will also continue through the day Friday for the central Rockies
as a cold front moves through the region. High temperatures will remain
cold and below average for much of the north-central and eastern U.S.
following a frontal passage. Forecast highs range from the teens and 20s
for the northern Plains, Great Lakes, and interior Northeast; the 30s and
40s for the Ohio Valley and Mid-Atlantic/coastal Northeast; and the 50s
across the Southeast. Conditions will moderate closer to average Saturday
with highs generally running 5-15 degrees warmer. Forecast highs are
generally at or above average across the West, with 40s and 50s in the
Pacific Northwest, Great Basin, and Rockies; the 50s and 60s in
California; and the 70s in the Desert Southwest. Conditions in the
Southern Plains/Texas will be some of the warmest and most above average
compared to the rest of the country with highs into the 60s and 70s.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.

Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 12, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Thu Dec 12 2024
Valid 12Z Thu Dec 12 2024 – 12Z Sat Dec 14 2024

…Great Lakes heavy lake-effect snow expected to continue into Friday
especially along the Snow Belt of the lower Great Lakes…

…A couple rounds of heavy coastal rain and heavy mountain snow expected
to impact northern California into Sierra Nevada heading into the
weekend…

…Sub-zero temperatures expected over parts of the northern Plains and
upper Mississippi Valley for the next couple of mornings…

As a deep low pressure system races further northward into eastern Canada
and a potent cold front exits New England this morning, an arctic high
pressure system will take over the northern Plains and expand across the
entire eastern U.S. through the next couple of days. Maine will be the
last to clear out from the heavy rain early this morning followed by much
colder temperatures under blustery westerly winds. The resurgence of
arctic air is triggering a new round of heavy lake-effect snow across the
Great Lakes through today and tonight before gradually tapering off on
Friday. The Snow Belt of the lower Great Lakes can expect a foot or more
of new snow, with locations downwind from Lake Ontario possibly getting
more than 2 feet since these locations will be the last to clear out from
the snow late on Friday.

Along the West Coast, moisture ahead of the next Pacific cyclone is poised
to overspread much of the Pacific Northwest and a good portion of
California today. The heaviest precipitation is expected to reach
northern California in form of rain near the coast and lower elevations.
A quick round of moderate to heavy snow will then reach the high
elevations farther inland and then along the Sierra Nevada for much of
today. It appears that this latest around of precipitation will taper off
temporarily tonight before the next round of precipitation associated with
the next Pacific cyclone arrives on Friday. Northern California into
southwestern Oregon can expect heavy precipitation Friday night with a
marginal risk of excessive rainfall continuing into Saturday morning by
the end of the short-range forecast period. Lesser amounts of
precipitation are expected for the Pacific Northwest.

The arctic high pressure system that is forecast to bring sub-zero
temperatures for the next couple of mornings is forecast to strengthen and
slide east into New England by Saturday morning. This will allow
southerly flow to increase across the southern Plains along with moisture
returning from the Gulf of Mexico by Friday night. Meanwhile, residual
energy associated with the first Pacific system is forecast to exit the
southern Rockies and induce the formation of a low pressure system over
the central Plains by Friday night. Some thunderstorms along with heavy
rain could quickly develop and move across the central Plains early on
Saturday ahead of the new low pressure system. Colder air could support
areas of mixed rain and snow farther north across the north-central Plains
into the upper Midwest in advance of the low pressure center. In the
short-term though, dry, breezy and relatively mild conditions will support
elevated fire danger across the southern High Plains for today.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.

Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 11, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Wed Dec 11 2024
Valid 12Z Wed Dec 11 2024 – 12Z Fri Dec 13 2024

…Widespread heavy rain and severe thunderstorm treats spreading up the
East Coast today and through New England into tonight…

…A surge of cold air into the eastern U.S. today will be followed by a
reinforcing surge of arctic air into the northern U.S. through the next
couple of days…

…Another round of significant lake effect snow expected through the next
couple of days downwind of the Lakes...

The stage is set for a rapidly intensifying low pressure system to track
up the East Coast today. A potent cold front trailing southwest from the
center of this elongated low pressure system will be the focus for heavy
rain, blustery winds, and strong to severe thunderstorms. Ahead of the
front, warm and moist air streaming in from the nearby Atlantic and Gulf
of Mexico will interact more vigorously with a jet stream aloft to develop
and expand the coverage of showers and thunderstorms, first across the
Southeast and the Carolinas this morning, followed by the Mid-Atlantic
states during the day, and into New England this evening. The highly
dynamic nature of this front will likely trigger formation of strong to
severe thunderstorms. This is especially the case across eastern North
Carolina this afternoon, and into southern New England this evening, where
the Storm Prediction Center has issued a Slight Risk (level 2 of 5) for
severe thunderstorms capable of producing damaging wind gusts. Elsewhere
along the Eastern Seaboard, the main concern will be a period of heavy
rain with embedded strong thunderstorms and intense downpours. Despite
much of the region currently experiencing moderate to extreme drought
conditions, the rain, while mostly beneficial, could lead to some
localized instances of flash flooding. The more urbanized locations and
poor drainage areas would have the greater risk of flooding issues.

Behind the potent cold front sharply colder air will surge into the East
Coast from the north and northwest. A period of accumulating wet snow can
be expected to spread up the western slope of the entire spine of the
Appalachians from south to north today through tonight. Meanwhile, a
reinforcing shot of arctic air is plunging into the northern Plains and
will overspread much of the northern tier states through the next couple
of days. High temperatures the next couple of days will be roughly 10 to
as much as 30 degrees below normal.

Attention then turns to yet another round of significant lake effect snow
downwind of the Great Lakes through the next couple of days. The
aforementioned surge of arctic air will stream across the still relatively
warm Great Lakes and ignite intense bands of lake effect snow, initially
downwind of Lakes Superior and Michigan on today and then downwind of
Lakes Erie and Ontario tonight into early Thursday. By the time the snow
starts to taper off on Friday, snowfall totals of 1 to 2 feet are likely
in the favored Snow Belt across portions of northwest and western New York
State, far northwest Pennsylvania, far northeastern Ohio, the Upper
Peninsula of Michigan and the western portions of the Lower Peninsula of
Michigan.

Along the West Coast, moisture ahead of the next cyclone from the Pacific
is poised to overspread much of the region through the next couple of
days. Northern California will see heavy coastal rain by this evening,
followed by heavy mountain snow farther inland and down the Sierra Nevada
where a foot or more of new snow is forecast through Thursday. It appears
that this round of precipitation will mostly taper off Thursday night
prior to the arrival of the next Pacific system.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.

Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 10, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Tue Dec 10 2024
Valid 12Z Tue Dec 10 2024 – 12Z Thu Dec 12 2024

…Widespread heavy rain threat emerging across the central to eastern
Gulf Coast region today will spread rapidly up the entire East Coast on
Wednesday…

…Active Lake effect snows to begin Wednesday and continue through
Thursday downwind of the Lakes…

…Record warm morning lows likely along the east coast Wednesday
morning…

…Arctic air to surge south into the Northern Plains/Upper Mississippi
Valley region late Tuesday into Wednesday…

…Santa Ana winds along with critical to extreme fire weather danger
across portions of southern California…

The upper-level flow pattern across much of North America will undergo
significant amplification over the next few days, producing various types
of impactful weather across mainland U.S. The most active weather in
terms of precipitation and winds will be the primary focus along the East
Coast through the next couple of days. Precipitation currently falling
across portions of the Southeast is in its organizing stage ahead of a
developing low pressure wave over the Mid-South along a cold front. As
the cold air behind the front interacts with a rapidly amplifying upper
trough, rain and embedded thunderstorms will rapidly expand northeastward
during the day Wednesday and up the entire East Coast, producing a period
of widespread heavy rainfall from the central to eastern Gulf coast,
across the Southeast, Mid-Atlantic, Northeast and New England. With much
of these areas currently in moderate to extreme drought conditions, this
rainfall will be beneficial. Still, given the potential for periods of
heavy rains over a short period, there will be a threat of localized flash
flooding, especially in more urbanized regions.

The cold front associated with this rapidly intensifying system will
become rather potent as it sweeps across the East Coast during the day on
Wednesday. There is potential for some very strong thunderstorms to form
ahead of the front together with heavy downpours. Meanwhile, drastically
colder air behind the front is forecast to produce accumulating snowfall
up the western slopes of the Appalachians on Wednesday together with
blustery northwesterly winds. The snow will then sweep across interior
New England through Wednesday night into Thursday morning as a potent
elongated low pressure system races northward into southeastern Canada.

With a warm southerly flow strengthening ahead of this potent front, there
is the potential for widespread record high morning low temperatures on
Wednesday across the southern Mid-Atlantic, Mid-Atlantic and portions of
the Northeast. In the wake of this front, much colder air will stream
across the Great Lakes from west to east beginning on Wednesday. This will
ignite active lake-effect snows, initially downwind of Lakes Superior and
Michigan on Wednesday and then downwind of Lakes Erie and Ontario
Wednesday night into early Thursday. Before these lake-effect snows
diminish by early Friday, snowfall totals of 1 to 2 feet are possible in
the favored Snow Belt across portions of northwest and western New York
State, far northwest Pennsylvania, far northeastern Ohio, the Upper
Peninsula of Michigan and the western portions of the Lower Peninsula of
Michigan.

The above-mentioned lake-effect snows will be driven by arctic air that
will be first surging east southeastward late Tuesday into early Wednesday
across the Northern Plains into the Upper Mississippi Valley and then
eastward trough the Great Lakes into the Ohio Valley on Wednesday. While
there are not expected to be any records with this arctic outbreak,
temperatures will be much below average on Wednesday across the Northern
Plains into the Upper Mississippi Valley. These much below average
temperatures will then push farther southeast into the Great Lakes and
Ohio Valley region on Thursday. Across these regions, high temperatures
will be 10 to 25 degrees below average during the height of the cold
temperatures during Wednesday and Thursday.

In contrast to the wet and cold conditions across portions of the
north-central to eastern U.S., dry condition and milder temperatures are
in store across the West coast, Great Basin and Rockies region. The dry
air, low relative humidities together with the latest episode of Santa Ana
winds across southern California will produce critical to locally extreme
fire weather danger. These fire weather conditions will be most prominent
in the higher terrain areas to the north and east of the Los Angeles to
San Diego region. Winds of 35 to 45 mph in the valleys and gusts of 50 to
65 mph in the mountains will help fan any fires that do develop quickly
and may reduce visibility with blowing smoke and dust adding to travel
concerns in the region. Across these areas, red flag warnings are
currently in effect, affecting nearly 13 million people.

By early on Thursday, the next round of coastal rain and mountain snow is
forecast to reach northern California as the next Pacific cyclone arrives.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.

Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 9, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Mon Dec 09 2024
Valid 12Z Mon Dec 09 2024 – 12Z Wed Dec 11 2024

…Heavy rain threat across the central to eastern Gulf Coast region today
will expand and move up the East Coast late Tuesday into Wednesday
morning…

…Periods of mixed rain and snow linger across interior New England
through tonight…

…Snow/blizzard conditions across the northern High Plains will gradually
taper off later today…

…Strong Santa Ana winds prompting critical fire danger across Southern
California…

…Well above average temperatures will overspread the central and eastern
U.S. as cold air surges into the western and then central U.S….

Increasingly active weather will progress toward the eastern U.S. through
the next couple of days as a weather pattern reversal continues to unfold
across the mainland U.S. One of the ingredients of this pattern change is
manifested by an expanding area of moderate to heavy rain moving through
the Ohio and Tennessee Valleys this morning with embedded thunderstorms
across the Deep South. The associated jet stream aloft will send the rain
rapidly northeastward across the Mid-Atlantic states today, reaching into
southern New England tonight. Temperatures will be cold enough to support
snow across northern New England Monday night into Tuesday morning before
tapering off for the time-being Tuesday afternoon. Meanwhile, an
extensive surge of cold air into the mid-section of the country will
reinvigorate the jet stream across the Deep South on Tuesday, leading to
an expanding area of moderate to locally heavy rain from the Gulf Coast
into the Deep South and interior Southeast. Tuesday night into Wednesday
morning will likely see the rain quickly expanding up the Appalachians and
into the interior section of the Mid-Atlantic, and then up into New
England with some ice possible at the onset. Meanwhile, organized lines
of thunderstorms could form ahead of a potent cold front across the
interior Southeast early on Wednesday along with sharply colder
temperatures and blustery northwesterly winds behind the front.

Across the northern High Plains, colder air and gale force winds behind a
low pressure system have prompted winter weather advisories/warnings,
Blizzard Warnings, as well as wind advisories/high wind warnings this
morning. 4-7″ of snow is expected across the northern High Plains.
Meanwhile, strong onshore flow off Lake Superior will further enhance
local snow totals across the Arrowhead of MN range where 9-12″+ totals are
expected.

On Tuesday, a more intense surge of cold air will be funneled southward
from Alaska and western Canada into the Plains associated with an
intensifying arctic high pressure system. A ‘Blue Norther’ cold front
will be driving well through the Southern Plains into northern Mexico by
Tuesday night, dropping temperatures into the 30s into southern Texas by
Wednesday morning. Meanwhile, a reinforcing cold front will drop
temperatures below zero degrees over the northern Plains by then. High
temperatures will be about 5-10 degrees below normal across much of the
Rockies, Southwest and eventually into the Plains.

Across the western U.S., a cold surge directed through the Great Basin
into the lower Colorado River Valley today will bring very strong Santa
Ana winds into southern California by later today. Given dry/low humidity
conditions already in place, Red Flag Warnings have been issued for the
eastern Transverse and all of the Peninsular Ranges; as well as a Critical
Fire (level 2 of 3) from the Storm Prediction Center. Winds of 35 to 45
mph in the valleys and gusts of 50 to 65 mph in the mountains will help
fan any fires that do develop quickly and may reduce visibility with
blowing smoke and dust adding to travel concerns in the region.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.

Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 8, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sun Dec 08 2024
Valid 12Z Sun Dec 08 2024 – 12Z Tue Dec 10 2024

…Heavy rain threat emerges across the Deep South late Sunday into
Monday…

…Periods of mixed rain and snow linger from the Great Lakes to northern
New England through Monday night…

…Unsettled and windy weather spreading across the Pacific Northwest this
weekend will reach into the northern Plains as snow/wintry mix by Monday…

…Well above average temperatures will overspread the central and eastern
U.S. as cold air surges into the western U.S….

A major reversal of the weather pattern is forecast to occur across
mainland U.S. during the next couple of days. The remaining cold air
across the eastern U.S. originated from the recent arctic outbreak will be
dispelled by an eastward expanding mild air mass from the central U.S.
Meanwhile, the mild air across the western U.S. in recent days will be
dispelled by a surge of cold air currently advancing through the
northwestern U.S. The upper-level trough responsible for this cold surge
into the western U.S. will first spread mixed rain and snow through the
northern Rockies today behind a cold front along with windy conditions.
Daytime heating will keep the precipitation mainly in the form of rain as
it moves quickly across the northern Plains today. By tonight, colder air
from Canada is forecast to filter south from Canada behind a low pressure
system. This will bring periods of snow into the northern Plains and
areas farther west to the foothills of the northern Rockies through
tonight and into Monday, along with windy conditions. The higher elevations
will receive higher amounts of snow, with the highest snowfall likely near
the northern slopes of the Black Hills where more than a foot of new snow
is possible. Portions of the central Rockies into the Front Range of
Colorado and down into northeastern New Mexico can expect to receive a
period of snow from this system through Monday night into Tuesday morning.

Ahead of the cold front trailing south from the aforementioned low
pressure system, a jet stream sliding across northern Mexico will interact
with a coastal front and a low pressure wave near the western Gulf Coast
to bring an increasing threat of heavy rain farther inland across the
lower Mississippi Valley and then into the Deep South through the next
couple of days. Warmer and more unstable air arriving from the Gulf will
help trigger heavier showers and thunderstorms for the eastern portion of
these areas. The overlapping elements coupled with some recent rainfall
will result in the possibility of scattered instances of flash flooding.
The Weather Prediction Center maintains a Marginal Risk of Excessive
Rainfall across the central Gulf Coast region for Monday into early
Tuesday, with a Sight Risk area from southeastern Louisiana to southern
Mississippi.

Across New England, widespread snowfall is in progress today ahead of a
clipper system moving quickly eastward along a warm front lifting north
across the region. Widespread snowfall of up to 6 inches can be expected
from the Adirondacks eastward through Maine before the snow tapers off
tonight. More snow will then skirt the upper Great Lakes ahead of the
warm front associated with the northern Plains low pressure system, with
6-8 inches expected over the Upper Peninsula of Michigan and the Arrowhead
of Minnesota. A period of rain will sweep across the Ohio Valley Sunday
night, then the Appalachians and the northern Mid-Atlantic on Monday ahead
of the trailing front, followed by the next round of snow across northern
New England Monday night. Mild Atlantic air will keep the precipitation
as rain for southern New England into Tuesday morning.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.

Cloud Seeding to Enhance Precipitation – Economic Considerations – December 7, 2024

Global Warming and Population Growth, create a need for more water.

There are a number of different ways to address a shortage of water:

  1. Get equal value from less water  (Conservation)

  2. Find more water from surface and groundwater  sources

  3. Have more precipitation (Increase the velocity of water)

We previously addressed (2) based on an excellent presentation by an expert in that area. We will discuss conservation in the future, particularly with respect to agriculture. There are major opportunities to achieve increased water use efficiency in agriculture.

In this article, we discuss “Finding More Water by Using Cloud Seeding to Increase Precipitation”.

Recently I published an article on using cloud seeding to increase precipitation.  It is included (with some updates) in it’s entirety in Part II of this article.  But to define what we are talking about the next two images are important.

Weather modification with cloud seeding was discovered by General Electric at the Schenectady New York Laboratory.  Initially, on July 14, 1946, they used Dry Ice. Of course, prior to that time, there were other attempts at increasing precipitation. The science is discussed in Part  II of this article but the general approach is to assist clouds in converting the moisture in clouds to become snow (or in the tropics large raindrops) so that in both cases they are heavy enough to fall from the clouds to the ground.  Importantly, precipitation in general soon returns to the atmosphere so the water molecules are available to precipitate again and again. Cloud seeding speeds up the process slightly.

Cloud seeding can be used for three different purposes:  Precipitation enhancement, hail suppression, and fog dispersal.  In this prior article, I focused on precipitation enhancement. The discussion in Part I of this article would apply to all three purposes and most projects of any sort since it is general economic theory.

Part I

In this new article, I want to discuss the economics of cloud seeding to increase precipitation.  For a proposed cloud seeding project it is important to know whether or not it is economically justifiable and if implemented continues to be economically justified. We discussed that to some extent in the earlier article which is included in Part II of this article. We know that where conditions are appropriate,  cloud seeding can increase the precipitation over what is called the target area. The reason for this is that natural precipitation processes are very inefficient. That is why precipitation occurs in many parts of the world that are many miles from the source of the moisture that is in the atmosphere. The atmosphere can hold a lot of water.

Hydrologic Cycle

It is important to remember that water is a compound that is almost impossible to destroy.  States view the consumption of water in agriculture as a depletion of the state’s water resource but evaporation and transpiration of plants in the process of photosynthesis returns the water to the atmosphere where it can precipitate and benefit others in the same state or other states or other nations. This can be repeated over and over again. Precipitation over oceans or water run-off into oceans makes that water unusable {other than importantly marine life) unless it is purified. However, the water is not destroyed and can be recovered and used (usually in arid areas like Israel).  Most of our precipitation comes from clouds that form over large bodies of water. So it is best to view all of this as a hydrologic cycle. Moisture evaporating from bodies of water or the ground or from plants enters the atmosphere. Under certain conditions moisture forms clouds. Again, under certain conditions, some of the moisture in clouds precipitates. Precipitation often provides value to people and the environment but mostly  (groundwater is an exception that we do not cover in this article) rather quickly returns to the atmosphere to provide the moisture necessary to form clouds and another round of precipitation. This is a process that is called the “hydrologic cycle”.

Velocity of the Hydrologic Cycle

Cloud seeding speeds up the process which means that individual molecules of water end up providing benefits more times in a year.  This process is not widely understood by the general public. In a way, it is analogous to the money supply. If there is more economic activity.  For simplicity consider a situation where printed currency is the only form of money. When the economy is good, a given unit of currency  (for example a one-dollar bill) will pass through the hands of more people than when the economy is less good. So increasing the velocity of money is often a good thing.  Within narrow limits, we can increase the velocity of the hydrologic cycle and increase the contribution of water to society.

Selection of cloud seeding projects

We know that we can increase the process of precipitation from clouds and the water being used or wasted but either way returning to the atmosphere to precipitate somewhere else. The questions addressed in this article are when is the effort to do this both economical and easily recognized as being economical?

Some information on my background

Years ago, I taught a graduate-level course in Engineering Economics. The focus of the course was applications in information systems but the theory is the same for any endeavor. I did not wish to teach this course but the Vice President of the consulting firm from which I  derived most of my income was also the Dean of the Management School of a significant educational entity (which is now part of NYU) and he insisted that I teach this course (based on my educational background and much experience with doing economic analysis) and I pretty much had no choice but to do so. I enjoyed it but it meant that most of Friday and Saturday every other week was tied up traveling to a neighboring state to teach this course. Teaching the course made me realize that what is basic microeconomic theory is difficult for many people involved in technology development to comprehend.

So it is with some trepidation that I address the topic in this article.

Economic analysis of potential and operational cloud seeding  projects

Generally, projects that do not produce more value than the cost are non-economic. I  will not address the exceptions to this rule because it devolves into a semantic issue of how one defines value.

But even if the approach produces more value than the cost you still have to look at:

  • Who benefits and
  • Who pays

If the payor and beneficiary are different,  there can be problems. [In healthcare it is even more difficult because there is usually a third party involved i.e. the insurance company. That creates a very complicated situation which I addressed in a project done for the Robert Wood Johnson Foundation. There are some aspects of that three-way situation with cloud seeding also.]

There can be other factors which complicate the analysis. This is especially pertinent in the U.S. West where most cloud seeding takes place. In most cases, the allocation of the water supply is based on the Priority Doctrine (PD).  This means that with cloud seeding, the identity of the beneficiary is often not known.  If more water is available it goes to those who otherwise would not receive water because their priority would not have been high enough. Priority is usually determined by who put the water to use first. That may not seem to be an optimal way to do things but it tends to avoid violence since it is easier to determine who put the water to use first than to agree on which uses are better for society than other uses.

Often there is an exception namely that precipitation that falls on your land can be used by the land owner or the land owner’s designated (typically a renter of the land) as long as the water does not leave the boundaries of the property.  If it leaves the property it typically enters the public water supply and the Priority Doctrine takes over. However, the specific rules vary by state in the  U.S.

A  further complication is what are called interstate river compacts which are agreements among states concerning the distribution of the available water supply. The reason this is important concerning cloud seeding is the beneficiary may be in another state. Two important interstate river compacts are the Colorado River Compact and the Rio Grande River Compact. Both of these also have delivery requirements to Mexico. There are many other interstate river compacts. In general, each one has its own rules.

Thus there are two major categories of beneficiaries:

a. A  beneficiary who puts the additional water to beneficial use

b. A  governmental entity that is obligated to deliver water downstream for the benefit of other beneficiaries. This can be considered an indirect beneficiary or a facilitator.

Looking at things from a different perspective the major beneficiaries of water are:

  • Farmers
  • Ranchers
  • Municipalities especially with regard to their need to deliver water to people and for other uses within a municipality
  • Ski resorts (they need snow  that falls from clouds or water to make snow
  • Hydroelectric facilities to generate electricity.
  • Commercial and industrial users who are not getting their water delivered to them by municipalities.
  • Recreation
  • The environment

Some of the above consume the water and others simply use it and pass it on (hydroelectric and ski resorts). For those who from a legal perspective consume water, that water generally returns to the atmosphere or is treated and reused. So our use of language can be somewhat inconsistent with science when it comes to water.

Implications

In some cases, the payor/funder of a cloud seeding project is also the beneficiary. That is the simple case since the payor can decide if the cost is worth the benefit.

In many cases, the payor of a cloud seeding project is an indirect beneficiary. That is often the case with the interstate river compacts and it is generally difficult to get projects funded that assist states in meeting their compact obligations.

Further Discussion

The economics of cloud seeding are complicated. One way of looking at this is that cloud seeding often resembles infrastructure.  When a road or bridge is built it usually is not clear exactly who will benefit. Generally, the consideration is whether or not the community or state or the U.S. will benefit. If funded with tax money (or borrowing which usually translates into property taxes) some will have paid for something that does not benefit them but others, and some will benefit many times more than their taxes.

In many cases, cloud seeding is like that. But in some cases, the direct beneficiary can be identified. Perhaps the best example of that would be ski resorts. They benefit from more snow falling from clouds thus having to make less snow. Hydroelectric in some cases is much like the ski resort example. The hydroelectric utility or the users of the electricity generated benefit and they can often recognize the value of cloud seeding to increase the generation of electricity. But on the Colorado River, it is often unclear who would be the beneficiary of more cloud seeding since there are so many different beneficiaries of there being more water in the river. A special case is when the delivery requirements of the interstate river compact are not being met and the two alternatives are to find more water or use less water.

So there is often a combination of private and public funding of cloud seeding. As a general rule, the greater the distance of the cloud seeding project from the beneficiaries the more difficult it is to have taxpayers or local government entities see the value to them of such a cloud seeding project.

The Prior Article which explains Cloud Seeding now follows as  Part II.

Some will need to click on “Read More” to access the full article.

Weather Outlook for the U.S. for Today Through at Least 22 Days and a Six-Day Forecast for the World: posted December 7, 2024

This article focuses on what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term U.S. outlooks (up to four weeks) and a six-day World weather outlook which can be very useful for travelers.

First the NWS Short Range Forecast. The afternoon NWS text update can be found here after about 4 p.m. New York time but it is unlikely to have changed very much from the morning update. The images in this article automatically update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sat Dec 07 2024
Valid 12Z Sat Dec 07 2024 – 12Z Mon Dec 09 2024

…Periods of mixed rain and snow linger from the Great Lakes to northern
New England through the weekend…

…Heavy rain threat emerges across the Deep South late Sunday into
Monday…

…Unsettled and windy weather spreading across the Pacific Northwest this
weekend will reach into the northern Plains as snow by Monday…

…Arctic air across the eastern U.S. will give way to above normal
temperatures by Monday…

As an arctic high pressure system moderates and retreats across the
eastern portion of the country, unsettled weather will emerge and expand
across the Deep South as well as the Pacific Northwest. Moisture
returning behind the high pressure system today will begin to interact
with an upper-level trough and a coastal front just off the Texas coast.
This will result in expanding areas of light to moderate rain with
embedded thunderstorms across the eastern two-thirds of Texas today. The
entire system will shift northeastward on Sunday before evolving into a
heavy rain threat across the lower Mississippi Valley toward the Tennessee
Valley by late Sunday into early Monday. A couple of inches of rain is
expected in this general vicinity with locally higher amounts through
Monday morning.

Meanwhile, periods of mixed rain and snow are expected to linger across
the Great Lakes and into northern New England where a clipper low pressure
system is forecast to track along a nearly stationary arctic front. Up to
a foot of new snow is possible near the Canadian border in these areas.

The Pacific Northwest is entering a period of increasingly unsettled
weather as a rather dynamic upper trough arrives from the Pacific.
Low-elevation rain and high-elevation heavy snow can be expected for the
Cascades and northern Idaho as the weekend progresses with windy
conditions. The mountain snow and low-elevation rain will progress
farther inland into the northern Rockies early Sunday as a low pressure
system begins to develop across the northern High Plains into Alberta
Province of Canada. Winter Storm Warnings and Advisories are active
across the northern Rockies through Saturday where several inches of
snowfall and some icing potential will create hazardous travel conditions.
Meanwhile, much of the remainder of the western U.S. will remain dry and
milder than normal as high pressure dominates. By Sunday night into
Monday morning, a low pressure system is forecast to track across the
northern Plains with snow and wind. Mainly light snowfall amounts are
expected for North Dakota into Montana, with high amounts enhanced by
local terrains.

Low temperatures in the 20s as far south as the Florida Panhandle this
morning have prompted Freeze Warnings for portions of northern Florida
into Georgia. High temperatures will begin to moderate across the East by
Sunday as anomalously mild temperatures across the central U.S. shift
eastward into the region. Highs should be in the 60s and 70s Sunday across
the Southeast and 50s and 40s across the Mid-Atlantic and Northeast, while
50s and 60s will expand across the northern and central Plains Sunday
afternoon ahead of the developing low pressure system.

To get your local forecast plus active alerts and warnings click HERE and enter your city, state or zip code.

Learn about wave patterns HERE.

Then, looking at the world and of course, the U.S. shows here also. Today we are looking at precipitation.

Please click on “Read More” below to access the full Daily Report issued today.