Posts by Sig Silber

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Fri Oct 18 2024
Valid 12Z Fri Oct 18 2024 – 12Z Sun Oct 20 2024

…Heavy snow expected for the central and southern Rockies through
Saturday…

…Heavy rain expected for the western High Plains on Saturday ahead of an
upper low over the Four Corners region…

…Sunny and pleasant conditions for much of the Eastern U.S. through the
upcoming weekend…

A weather pattern change is in progress across the Western U.S. as an
amplified upper trough supports the passage of a strong cold front across
the Intermountain West. This will result in widespread mountain snow
across the higher elevations of the Rockies on Friday, and persisting into
Saturday across the mountainous terrain of the Four Corners region as an
upper level low develops. The potential exists for 10-20 inches of snow
across portions of Utah and Colorado, mainly above 9000 feet elevation.
It will also be turning considerably colder compared to the recent warm
weather that most of the Western U.S. has experienced so far this month.
Highs will only be in the 40s and 50s for most valley locations to close
out the work week and going into Saturday, and below freezing at night.

With the upper level low developing over Arizona, there will be a plume of
increased moisture advection across eastern New Mexico and portions of
adjacent states that will likely result in enhanced rainfall going into
Saturday, where a Slight Risk of excessive rainfall is currently depicted
in WPC’s outlook. The potential exists for 2-4 inches of rainfall here,
and this could result in some instances of flooding. Some strong to
severe thunderstorms will also be possible. Another area of enhanced
rainfall will be across western Washington, where an atmospheric river
event will likely affect Vancouver Island and the Olympic Peninsula,
producing a few inches of rainfall across the windward terrain.

Elsewhere across the continental U.S., a sprawling surface high will be
anchored in place across the Eastern U.S. and will govern the overall
weather pattern through the upcoming weekend. The result will be sunny
skies across a wide expanse of this region, and pleasantly mild conditions
during the day and cool at night. There will be a moderating trend with
temperatures compared to the recent cold spell earlier this week, and
highs are expected to be above normal for many areas with readings well
into the 70s from the Midwest to the Northeast states. The downside is
the developing short term drought conditions for much of this region, with
no rainfall expected through early next week.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Fri Oct 18 2024
Valid 12Z Fri Oct 18 2024 – 12Z Sun Oct 20 2024

…Heavy snow expected for the central and southern Rockies through
Saturday…

…Heavy rain expected for the western High Plains on Saturday ahead of an
upper low over the Four Corners region…

…Sunny and pleasant conditions for much of the Eastern U.S. through the
upcoming weekend…

A weather pattern change is in progress across the Western U.S. as an
amplified upper trough supports the passage of a strong cold front across
the Intermountain West. This will result in widespread mountain snow
across the higher elevations of the Rockies on Friday, and persisting into
Saturday across the mountainous terrain of the Four Corners region as an
upper level low develops. The potential exists for 10-20 inches of snow
across portions of Utah and Colorado, mainly above 9000 feet elevation.
It will also be turning considerably colder compared to the recent warm
weather that most of the Western U.S. has experienced so far this month.
Highs will only be in the 40s and 50s for most valley locations to close
out the work week and going into Saturday, and below freezing at night.

With the upper level low developing over Arizona, there will be a plume of
increased moisture advection across eastern New Mexico and portions of
adjacent states that will likely result in enhanced rainfall going into
Saturday, where a Slight Risk of excessive rainfall is currently depicted
in WPC’s outlook. The potential exists for 2-4 inches of rainfall here,
and this could result in some instances of flooding. Some strong to
severe thunderstorms will also be possible. Another area of enhanced
rainfall will be across western Washington, where an atmospheric river
event will likely affect Vancouver Island and the Olympic Peninsula,
producing a few inches of rainfall across the windward terrain.

Elsewhere across the continental U.S., a sprawling surface high will be
anchored in place across the Eastern U.S. and will govern the overall
weather pattern through the upcoming weekend. The result will be sunny
skies across a wide expanse of this region, and pleasantly mild conditions
during the day and cool at night. There will be a moderating trend with
temperatures compared to the recent cold spell earlier this week, and
highs are expected to be above normal for many areas with readings well
into the 70s from the Midwest to the Northeast states. The downside is
the developing short term drought conditions for much of this region, with
no rainfall expected through early next week.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Thu Oct 17 2024
Valid 12Z Thu Oct 17 2024 – 12Z Sat Oct 19 2024

…Powerful Pacific storm to bring much colder temperatures and widespread
mountain snow throughout the Intermountain West and Rockies over the next
few days…

…Heavy rain and scattered flash flooding possible across the southern
High Plains on Saturday…

…Above normal temperatures and gusty winds forecast across the central
and northern Plains today, resulting in fire weather concerns…

As the calendar dives deeper into autumn, colder storm systems are
beginning to impact parts of the country along with wintry weather
conditions. The Intermountain West and Rockies will face the brunt of next
Pacific-bred storm system ushering in below average temperatures, gusty
winds, and heavy mountain snowfall. A cold front marching southeastward
will mark the sharp transition toward cooler temperatures and increasing
snowfall potential. This frontal boundary is anticipated to cross the
Intermountain West between today and early Friday before traversing the
central Rockies and stalling over the southern High Plains by Saturday.
Heavy snowfall is likely in the higher terrain (mainly above 7000-8000
feet) of south-central Montana, western Wyoming, Utah, and southwest
Colorado. As the system slows forward progress and increasing moisture
content surges up the southern High Plains, the potential for heavy
rainfall exists across eastern New Mexico into southeast Colorado.
Training north-south oriented lines of showers and storms could contain
intense rainfall rates while remaining over similar locations for a few
hours. This setup could produce scattered areas of flash flooding,
especially for poor drainage locations and urban regions. A Slight Risk
(level 2/4) of Excessive Rainfall has been issued for this part of the
country in order to further highlight the flooding threat. Additionally,
gusty winds are possible in the central Great Basin and Southeast as the
strong frontal boundary sweeps through over the next few days, this may
also lead to a strong offshore wind event throughout California. Wind
Advisories have been issued for parts of Nevada, Arizona, and California,
as well as Red Flag Warnings for parts of central and northern California
in order to highlight the fire weather danger.

Fire weather concerns also exist throughout much of the central U.S. today
as strong southerly flow aids in producing above average temperatures and
low relative humidity. Red Flag Warnings span from Kansas to Minnesota and
reiterate the potential for fires to spread rapidly. These weather
conditions throughout the Plains and Midwest are in relation to a potent
high pressure system situated over the Ohio/Tennessee valleys that is
expected to settled over the East by the end of the week. Underneath this
high remains below average temperatures and for some places the first
frost or freeze of the season. Low temperatures are expected to drop into
the 30s and 40s for a majority of the eastern U.S. outside of the Florida
Peninsula, but even northern parts of the Sunshine State may need to break
out the sweaters the next few mornings. Temperatures will begin to
moderate by Saturday as afternoon highs into the 70s become more
widespread.

Elsewhere, a separate Pacific system moving inland over British Columbia
on Friday will surge precipitation chances into western Washington.
Rainfall amounts over 2 to 3 inches are possible in the commonly-damp
Olympic Peninsula and northern Cascades.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Wed Oct 16 2024
Valid 12Z Wed Oct 16 2024 – 12Z Fri Oct 18 2024

…Significant pattern change begins today across the Pacific Northwest
and Intermountain West with much colder temperatures and the threat of
widespread mountain snow through the end of the week…

…Above average temperatures build across the central and northern High
Plains with the risk of fire weather increasing through Thursday…

…A chilly mid-October continues for much of the East with frost and
freeze concerns from the central U.S. to parts of the Southeast and
Appalachians…

After some early fall warmth experienced throughout much of the West and
Rockies over the last few days vastly different weather conditions are
expected through the end of this week. A pair of cold fronts traversing
the region are expected to usher in below average temperatures and
precipitation chances. Showers are already evident throughout much of the
Northwest early this morning and will continue to spread eastward today,
before heavier precipitation focuses over the northern/central Rockies and
the Intermountain West from Thursday night through early Saturday. The
greatest weather hazards associated with this strong cold front are
forecast to be from gusty winds and heavy mountain snowfall. Total
snowfall accumulation over 8 inches are likely across the highest ranges
of south-central Montana, western Wyoming, Utah, and southwest Colorado.
Gusty winds may increase the fire weather danger as well and has prompted
Red Flag Warnings to be issued across parts of central California, Nevada,
and western Utah.

Fire weather concerns are also apparent over the central and northern
Plains for the next few days as strong southerly flow surges ahead of the
western U.S. system. Above average temperatures with highs into the 70s
and 80s will produce low relative humidity values and increase wildfire
dangers. This has prompted the Storm Prediction Center to issue a Critical
fire weather area for this region through Thursday, spanning from Kansas
to South Dakota. Elsewhere, Red Flag Warnings are in effect throughout the
central Gulf Coast as strong northerly winds push dry air into the region
behind a potent cold front sweeping southward over the Gulf of Mexico.

This same cold front has helped an autumn chill settle over most of the
central and eastern United States, while a potent high pressure system
also anchors over the region. Low temperatures into the 30s and 40s are
forecast to be widespread and stretch from the Midwest and Northeast
southward to the lower Mississippi Valley and Southeast. This may create
the first frost and freeze concerns of the season for many, marking the
transition out of the growing season. High temperatures will also remain
below average for this time of year and remain in the 50s and 60s before
moderating closer to normal by the end of the week.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Tue Oct 15 2024
Valid 12Z Tue Oct 15 2024 – 12Z Thu Oct 17 2024

…Unsettled weather along with high elevation snow to impact parts of the
Northwest, Intermountain West, and northern Rockies over the next few
days...

…Below average temperatures forecast across the central and eastern
United States, while summer-like warmth remains over portions of Texas
today and the northern Plain by Wednesday…

The weather pattern over the Lower 48 remains under the influence of a
strong high pressure system forecast to span from the Midwest to Gulf
Coast this week, before gradually settling over the East to end the week.
This will allow for dry conditions over much of the central U.S. and
Southeast, with unsettled weather confined to the peripheries of the high
pressure system. A pair of cold fronts traversing the Northwest and
northern Great Basin will usher in shower chances and high elevation snow
over the next few days. The greatest chances for at least 4 inches of
snowfall currently exist across the Cascades, Yellowstone region of the
northern Rockies, and the northern Utah mountains. Elsewhere, scattered
rain and snow showers are likely throughout parts of the Great Lakes, Ohio
Valley, central Appalachians, and Northeast within potent northwest flow
aided by a strong low pressure system in southeast Canada. Light snowfall
chances are likely to be confined to the higher elevated regions of
northern New England as well as the Adirondacks and central Appalachians.

A mid-October chill will be noticeable across much of the central and
eastern U.S. over the next few days as highs struggle to reach above the
50s for most locations. Low temperatures are also expected to dip well
below average for this time of year and into the 30s, leading to
widespread frost/freeze opportunities between the Midwest and
Mid-Atlantic. These autumn conditions will also reach the Gulf Coast,
Southeast, and much of the Sunshine State by Wednesday as the cold front
sinks southward over the Gulf of Mexico.

Above average and summer-like warmth is expected to linger across parts of
the country as well, with highs into the upper 90s today threatening daily
records throughout central and southeast Texas. However, this warmth will
be short-lived as the aforementioned cold front sinks south and into
northern Mexico by midweek. Warmer temperatures will then shift to the
northern Plains ahead of the western systems and on the northwest side of
the large area of high pressure over the Midwest. This pattern will allow
for warm southerly flow and afternoon temperatures to reach the 70s and
80s (20 to 30 degrees above average for this time of year). The warm
temperatures and low relative humidity when combined with gusty winds and
dry terrain are also forecast to produce critical fire weather conditions
for parts of the central and northern Plains on Wednesday.

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

…Rain and snow showers forecast across the Northeast, Great Lakes, and
Pacific Northwest over the next few days…

…Well below average temperatures to chill much of the central and
eastern United States…

…Summer-like warmth continues over parts of southeast Texas, the
northern Rockies, and northern High Plains…

A relatively quiet weather pattern is anticipated to remain over the Lower
48 through midweek as a large and dominant high pressure system builds
into the Nation’s Heartland. Unsettled weather is forecast to occur on the
periphery of this high pressure system, which includes the Northeast and
Great Lakes, as well as the Northwest. For the Northeast, rain and snow
showers will be associated with a deepening low pressure system organizing
near the New England coastline today before racing northward into eastern
Canada. Strong gusty northwesterly flow will lead to favorable upslope
precipitation across the Adirondacks, central Appalachians, and northern
New England ranges, as well as lake effect showers over the next few days.
Measurable snowfall is most likely in the higher elevations of northern
New York, Vermont, and New Hampshire. Meanwhile, a pair of cold fronts
marching through the Northwest will offer light to moderate precipitation
chances into the northern Great Basin by midweek, with snow likely in the
Cascades.

The aforementioned potent high pressure system will also usher in a crisp
autumn airmass into much of the central and eastern U.S. through midweek
as highs only reach the 50s and 60s for most locations. Widespread low
temperatures will also dip below average for this time of year and into
the 30s, creating the potential for some places to see their first frost
or freeze of this fall season. This cool weather will be far-reaching and
reach the Gulf Coast and even northern Florida by Wednesday, albeit with
slightly warmer temperatures compared to northern areas.

Summer-like warmth is set to continue for parts of central and southeast
Texas over the next couple of days in advance of the sinking cold front as
high temperatures rise into the mid-90s. These readings could break a few
daily high temperature records, including for cities such as Houston,
Austin, San Antonio, and Corpus Christi. Broad southerly flow will also
allow for warmer temperatures throughout the Intermountain West, northern
Rockies, and northern High Plains. Highs into the 70s and 80s will be
widespread, which equates to around 15-20 degrees above average.

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

…Unsettled weather forecast from the Great Lakes and Ohio Valley to the
Northeast over the next few days…

…Record-breaking heat continues across parts of the Southwest and much
of the south-central U.S. today…

…Locally heavy rain possible across southeast Florida…

A deepening low pressure system progressing from the Lower Great Lakes
today towards southern New England by Monday morning along with a trailing
upper-level trough will bring unsettled weather to much of the Great
Lakes, Ohio Valley, and Northeast. Showers and thunderstorms are likely to
dampen outdoor activities along and north of a sharp warm front extending
from northern Pennsylvania to southern New England today. Meanwhile, an
attached cold front will sweep across the Ohio and Tennessee valleys by
this evening, with a few thunderstorms potentially turning severe and
containing damaging wind gusts from central Tennessee to eastern West
Virginia. The Storm Prediction Center has issued a Marginal Risk (level
1/5) of severe thunderstorms in order to highlight this potential. As the
area of low pressure strengthens further on Monday and Tuesday while
lifting northward into eastern Canada, cold air surging southward on the
backside of the system will allow for high elevation snow in the
Adirondacks and northern New England mountain ranges. Lake effect rain and
snow showers will also be evident as cold northerly flow persists through
midweek. An autumn chill will spread over much of the Midwest and eastern
U.S. following the passage of the aforementioned cold front this week as
high temperatures only reach the 50s and 60s, with widespread lows in the
30s and 40s.

One more day of record-breaking heat is expected across the south-central
and southwestern U.S. today as mild air lingers south of the advancing
cold front. Highs into the 90s are anticipated throughout much of the Lone
Star State and Lower Mississippi Valley, with triple digits possible in
central Texas. 100s are also possible once again in Arizona before a
long-awaited gradual cooldown commences by Monday. Well above average
temperatures reorient early this week and are most apparent over the
western Gulf Coast, northern Rockies, and High Plains.

Outside of the Northeast and Pacific Northwest, much of the Nation will be
void of notable precipitation over the next few days. However, another
localized area of heavy rain potential exists over southeast Florida today
before thunderstorm activity pushes east away from the Sunshine State on
Monday. A few thunderstorms may exhibit slow forward motion while
containing intense rainfall rates over the sensitive urban corridor of
southeast Florida, which may lead to localized flash flooding. A Marginal
Risk (level 1/4) of Excessive Rainfall is in effect to further highlight
this heavy rainfall threat.