Sig Silber

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Fri Jun 21 2024
Valid 12Z Fri Jun 21 2024 – 12Z Sun Jun 23 2024

…Record hot temperatures continue over portions of the Midwest/Ohio
Valley while expanding over the Mid-Atlantic…

…Heavy rain and flash flooding concerns across the Upper Midwest Friday
and Great Lakes Saturday…

…Risk for flash flooding in the Four Corners Region Friday…

…Heat building over much of the West heading into the weekend…

A stubborn upper-level high over portions of the eastern to south-central
U.S. will generally remain in place, continuing a heat wave over the
region with the focus for the most intense heat over portions of the
Midwest/Ohio Valley and expanding in the Mid-Atlantic. Forecast
temperatures generally in the mid-90s Friday will rise into the upper 90s
to 100 Saturday in the Mid-Atlantic, with record-tying/breaking
temperatures possible. Heat-related Advisories and Warnings are in place
as these temperatures, when combined with the humidity, will bring heat
index values into the 100-105 degree range, with values as high as 110
possible through the southern Mid-Atlantic on Saturday. Additionally,
overnight low temperatures will remain in the mid-70s for many locations,
at potential record-tying/breaking levels, providing little relief from
the heat overnight. The early arrival of this heat in the Summer season,
persistence over multiple days, and abundant sunshine will aggravate heat
stress on those without reliable air conditioning. Temperatures more
broadly from the East Coast to the central/southern Plains will be in the
low 90s Friday and mid-90s Saturday. Meanwhile, relief continues to the
north of a frontal boundary draped though southern New England, with highs
now mostly in the 70s and low 80s.

Meanwhile, areas of showers and thunderstorms will continue along this
frontal boundary to the north of the upper-high, as moisture from the Gulf
flows northward through the Plains and around eastward through the Upper
Great Lakes and into New England. The greatest threat for significant
heavy rainfall will be ahead of a surface wave over portions of the Upper
Midwest as overnight storm complexes help prime the soils Thursday
night/Friday morning ahead of another round of storms expected later
Friday. A Moderate Risk of Excessive rainfall (level 3/4) is in effect
Friday centered on southern Minnesota and adjacent west-central Wisconsin,
northern Iowa, and southeastern South Dakota, where the highest potential
for heavy downpours, several inches of rainfall, and scattered to numerous
instances of flash flooding exists. Additional scattered instances of
flash flooding will be possible more broadly across the Upper Midwest. A
few severe thunderstorms are expected as well, as the Storm Prediction
Center has included a Slight Risk of severe weather (level 2/5) for the
region, extending southwestward into the central Plains and the
northwestward into the central/northern High Plains. Damaging winds, large
hail, and a few tornadoes are all possible. An upper-level shortwave
approaching from the west will help to deepen the frontal wave and push
the system eastward on Saturday, bringing the threat for heavy rainfall to
portions of the Great Lakes southwestward into the Upper Mississippi
Valley. A Slight Risk of Excessive Rainfall (level 2/4) is in place
Saturday as an organized complex of storms is expected to follow the
system eastward, bringing additional locally heavy rainfall and scattered
instances of flash flooding. Some severe thunderstorms will again be
possible with a Slight Risk in place mainly for the threat of damaging
winds.

An upper-level trough moving over the Southwest will bring areas of
showers and thunderstorms to the Four Corners Region on Saturday.
Anomalously high moisture spreading into the region from the remnants of
former T.S. Alberto will help contribute to locally heavy downpours and
the threat for flash flooding, with a Slight Risk of Excessive Rainfall in
effect Friday. The focus for storms should shift more into portions of the
Desert Southwest on Saturday, with a lingering threat of some isolated
flash flooding. As this trough moves eastward, a ridge will begin to build
over the West in its wake, bringing and expanding area of hot, above
average Summer temperatures. Forecast highs in the 90s on Friday will soar
into the 100s on Saturday for portions of the Great Basin and central
California Valleys. Heat-related Advisories and Watches have been issued
for the central Valleys south into interior southern California beginning
Saturday. Conditions will also be notably hot over the Desert Southwest on
Friday, particularly over central Arizona where Excessive Heat Warnings
are in place, with highs into the 110s. The noted increasing
moisture/storm chances will help cool temperatures down a few degrees
Saturday. Elsewhere, a couple of waves of low pressure will pass over
portions of the Southeast/Florida as well as south Texas, with daily
thunderstorms chances Friday and Saturday.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Thu Jun 20 2024
Valid 12Z Thu Jun 20 2024 – 12Z Sat Jun 22 2024

…Heavy rain/flooding threats and gusty winds over South Texas gradually
decrease today as Tropical Storm Alberto makes landfall in Mexico and
dissipates…

…Heavy rain and flash flooding concerns increase across the northern
Plains to the upper Midwest later Thursday into Friday as scattered
thunderstorms could result in localized flooding issues from the southern
High Plains to the Four Corners…

…A heat wave will persist over the Great Lakes, Ohio Valley, and
portions of the Northeast into the weekend as heat intensifies in the
western U.S….

Tropical Storm Alberto centered over the southwestern Gulf of Mexico has
begun heading west toward northern Mexico early this morning. Organized
bands of heavy rain extending north from the center have already brought
close to 10 inches of rain locally near the mid-Texas coast. As the heavy
rain bands continue to steadily move west through the Rio Grande Valley
into northern Mexico today, the heavy rain and flooding threats will
gradually decrease across South Texas. Strong and gusty winds will also
gradually weaken with time. Some of the tropical moisture from Alberto
will be drawn northward and energize the scattered showers and
thunderstorms from the southern High Plains to the Four Corners heading
into the weekend. These showers/storms will be more numerous during the
late afternoon to early evening hours in these areas.

Meanwhile, the National Hurricane Center continues to monitor the
potential of tropical cyclone formation over the western Atlantic as a
tropical wave moves west-northwest in the general direction of
northeastern Florida and Georgia. Some enhanced rainfall with gusty winds
can be expected to reach these areas Thursday night and will likely linger
through much of Friday.

Across the northern tier states, relatively less active weather is
expected today as a high pressure system brings cooler and more stable air
from Canada. However, the next piece of energy exiting the central
Rockies will set up the next episode of heavy rain and strong to severe
storms across the northern Plains to the upper Midwest beginning tonight.
A couple rounds of heavy rain focusing just north of a nearly stationary
front across the region will result in slight to moderate risks of
excessive rainfall from eastern South Dakota, across southern Minnesota
into western Wisconsin through Saturday morning. Farther east, scattered
thunderstorms are likely across the Great Lakes region and the Northeast
near and north of the stationary front. Marginal to slight risks of
severe storms are delineated each day from the Storm Prediction Center
(mainly for the threat of severe wind but with some low chances for hail),
and marginal risks of excessive rainfall are in place as well.

All these rain and thunderstorm areas are taking place along the periphery
of an upper ridge/heat dome that edges from the Mid-Atlantic into the
Mid-South over the next couple of days and sustains a heat wave across the
Great Lakes, Northeast, and Mid-Atlantic. Afternoon high temperatures and
warm overnight lows will challenge daily records and even some monthly and
all-time records. Heat index readings are expected to peak from 100 to 105
degrees in many locations. Those without access to reliable air
conditioning are urged to find a way to cool down. Record warm overnight
temperatures will prevent natural cooling and allow the heat danger to
build over time indoors without air conditioning. Temperatures may be
lower and less hazardous closer to the coast if/where sea breezes form. By
Friday, conditions should improve over New England as cooler air dips a
bit farther south into the area behind a front, but temperatures well into
the 90s and higher heat indices are forecast to continue across the Ohio
Valley to Mid-Atlantic. Meanwhile, cooler than average highs are likely
into the southern High Plains with the clouds and rain forecast, but
temperatures over the West will gradually rise above normal Thursday and
Friday. In the western U.S., it appears that the heat will increase by
Saturday as triple-digit high temperatures are forecast for the Central
Valley of California and the Great Basin.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Wed Jun 19 2024
Valid 12Z Wed Jun 19 2024 – 12Z Fri Jun 21 2024

…Significant heavy rain/flash flooding threat with gusty winds well
ahead of Potential T.C. One expected to impact southern Texas today…

…A heat wave will persist over the Midwest, Great Lakes, Ohio Valley and
the Northeast into late week…

…Thunderstorms and heavy rain become less active across the
north-central today into Thursday but may reload across the northern
Plains Thursday night/early Friday…

With the last piece of the potent upper-level energy exiting into southern
Canada, the weather across the northern tier states will be less busy than
recent days. Meanwhile, Potential Tropical Cyclone One (PTC1) is making a
headline as the heavy rain and tropical-storm-force winds well north of
the center of circulation are poised to move onshore and head inland
across southern Texas today. It appears that the lower and middle Texas
coasts will be the locations that will most likely be impacted by the
heavy rain and gale force winds. A coastal front may enhance the heavy
rainfall just inland from the coast but how sharp this front will get
is uncertain at this point. Meanwhile, the strong Bermuda High that will
help sustain the heat wave across the Ohio Valley to the Northeast will
also help steer PTC1 westward toward northern Mexico today as PTC1 could
acquire tropical storm (TS) status before making landfall early on
Thursday. The heavy rain well north of TS1 will likewise move west across
southern Texas and into the Rio Grand Valley through tonight, resulting in
rainfall totals of 5 to 10 inches from northeast Mexico into South Texas
with maximum totals of 15 inches possible. Winds associated with TS1 will
weaken rapidly over northern Mexico as the heaviest rainfall is forecast
to move west of the Rio Grand Valley into northern Mexico and begin to
taper off early on Friday. Meanwhile, some of the tropical moisture from
TS1 is forecast to stream north and trigger showers and thunderstorms
across the Four Corners region by Thursday and into Friday.

As the aforementioned upper-level energy and associated low pressure
system moves farther into Canada, the thunderstorms and heavy rain from
the central Plains to the upper Midwest will become less active today.
The trailing front from the low will become nearly stationary from west to
east across the northern tier states during the next couple of days. The
next piece of upper-level energy ejecting from the central Rockies will
begin to interact with the stationary front late on Thursday and
reinvigorate heavy rain and strong thunderstorms across the northern
Plains and toward the upper Midwest into Friday morning.

Meanwhile, a heat wave will continue to impact areas from the Midwest into
much of the Ohio Valley, Great Lakes, Northeast and Mid-Atlantic through
the next few days. Afternoon high temperatures and warm overnight lows
will likely challenge daily records and even some monthly records. Heat
index readings are expected to peak from 100 to 105 degrees in many
locations. Those without access to reliable air conditioning are urged to
find a way to cool down. Record warm overnight temperatures will prevent
natural cooling and allow the heat danger to build over time indoors
without air conditioning. Conditions are expected to improve over New
England this weekend.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Tue Jun 18 2024
Valid 12Z Tue Jun 18 2024 – 12Z Thu Jun 20 2024

…Significant heavy rain/flash flooding threat with gusty winds well
ahead of Potential T.C. One expected to impact southern Texas on
Wednesday...

…More rounds of heavy rain and severe thunderstorms expected for the
northern Plains and upper Midwest today before shifting south into the
central Plains on Wednesday…

…A heat wave will persist over the Great Lakes, Ohio Valley and the
Northeast through midweek…

…Late-season wet snow continues across the high-elevations of the
northern Rockies today before tapering off early on Wednesday…

An active weather pattern continues across the U.S. mainland. This
weather pattern that features snow, heat, heavy rain, severe
thunderstorms, strong winds, and fire weather is now bringing Potential
Tropical Cyclone One in the midst. A low pressure system currently
intensifying along a frontal boundary is fostering another round of heavy
rain and severe thunderstorms across the northern Plains into the upper
Midwest early this morning. The potent upper trough and the associated
dome of cold air have continued to result in a round of late-season wet
snow across the higher-elevations of the northern Rockies together with
rather strong wind gusts. With less potent jet stream energy behind this
system, the low pressure system will quickly eject into southern Canada by
this evening, bringing the inclement weather across the northern Plains to
an end by Wednesday morning. However, a sharp front trailing south and
southwest from the low center will likely trigger an axis of heavy rain
and severe thunderstorms from the central Plains to the upper Midwest by
tonight into Wednesday morning. From Wednesday into Thursday morning, the
rain/storms should gradually become more scattered in nature across the
central Plains as a cool high pressure system passes to the north. This
high pressure system will also push the widely scattered showers and
embedded thunderstorms farther east into the lower Great Lakes and
interior New England through Thursday morning.

In stark contrast to the cool, windy, rainy and even snowy weather in the
West, a heat wave will settle and persist across the Great Lakes, Ohio
Valley and the Northeast through the next few days. Forecast highs today
and Wednesday will reach into the mid- to upper 90s, even the century mark
Wednesday and Thursday afternoon at the hottest locations in interior
northern New England. Widespread, numerous record-tying/breaking high
temperatures are possible. Additionally, morning lows will remain in
about the mid-70s, at record-tying/breaking levels, providing little
relief from the heat overnight. The early arrival of this magnitude of
heat, the duration, abundant sunshine, and lack of relief overnight will
increase the danger of this heatwave beyond what the exact temperature
values would suggest. This is especially true for those without adequate
air conditioning, which becomes more of a concern for locations further
north that are not as accustomed to periods of persistent heat.

Another big weather story over the next couple of days will be in the Gulf
of Mexico where the National Hurricane Center has already initiated
advisories on Potential Tropical Cyclone One. An elongated upper trough
digging into the southern Plains and northeastern Mexico has already drawn
a plume of tropical moisture northward into the central Gulf Coast region.
This upper trough will be instrumental in drawing the tropical moisture
well north of the center of PTC One into southern Texas mainly on
Wednesday as PTC One tracks west toward northern Mexico. An axis of very
heavy rain may develop just inland of the Texas coastline behind a coastal
front with dynamic support from the elongated upper trough. This pattern
could result in locally heavy rainfall in excess of 10 inches near or just
inland of the lower to middle Texas coast which would result in
significant flash flooding. The heavy rain is forecast to push farther
inland across the Rio Grande Valley early on Thursday. In addition to the
heavy rainfall, some coastal flooding along with tropical-storm-force
winds can be expected up the Texas coast on Wednesday. See the latest
advisory from the National Hurricane Center for additional detailed
updates. Meanwhile, fire danger across the Four Corners region should
gradually ease over the next few days with the arrival of slightly cooler
air followed by the arrival of moisture from the northern edge of
Potential Tropical Cyclone One.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Mon Jun 17 2024
Valid 12Z Mon Jun 17 2024 – 12Z Wed Jun 19 2024

…Heavy rain and severe thunderstorms possible today across the
north-central Plains, shifting north into the northern Plains and northern
Minnesota late tonight into Tuesday…

…Heavy rain and severe thunderstorms will shift farther south from the
central Plains to the upper Midwest Tuesday night to Wednesday morning…

…A heat wave will expand from the central Plains across the Great Lakes,
Ohio Valley and the Northeast today and remain across the Northeast
through midweek…

…Heavy rain threat emerging along the central Gulf Coast today,
following by an increasing heavy rain threat toward the Texas Gulf Coast
later Tuesday and especially Wednesday…

…Late-season wet snow will persist across the high-elevations of the
northern Rockies for the next couple of days...

A very active weather pattern will continue for the next couple of days
with additional cold air intrusion and jet stream energy traversing the
northwestern U.S. The battle zone will continue to be over the
north-central U.S. where a cluster of thunderstorms containing severe
weather and heavy rain is expanding across the northern Plains.
Meanwhile, a low pressure system is forecast to develop over the central
High Plains and intensify as it heads toward and reaches the upper Midwest
by Tuesday morning. The threat of heavy rain and severe weather will lift
farther north into the northern Plains and the upper Midwest on Tuesday.
By Tuesday night, while the low pressure center will rapidly eject into
southern Canada, a sharp front trailing south and southwest from the low
will likely trigger an axis of heavy rain and severe thunderstorms from
the central Plains to the upper Midwest from Tuesday night into Wednesday
morning.

The cold air intrusion and jet stream energy across the northwestern U.S.
will also bring a round of late-season wet snow across the high-elevations
of the northern Rockies through the next couple of days where Winter Storm
Warning and Winter Weather Advisories are in effect. In addition, this
energetic system will also bring quite a bit of wind across the Great
Basin and the northern Rockies today, reaching into the central Rockies
and northern Plains by Tuesday morning behind a sharp cold front.

In stark contrast to the cool/cold, windy, rainy and even snowy weather
across the Northwest, a heat wave is quickly emerging ahead of the low
pressure system from the central Plains, upper Midwest, and into the Ohio
Valley. The heat will surge into the Northeast by Tuesday where high
temperatures well up into the 90s are forecast as far north as Vermont and
New Hampshire. By Wednesday afternoon, some locations in interior New
England could see temperatures topping the century mark, which will break
daily records at certain locations. Across the Four Corners region,
critical fire danger conditions are anticipated today under persistently
dry conditions fueled by gusty winds with the approach of the sharp front.

Farther south from Central America across southern Florida and through the
western Atlantic, a plume of tropical moisture lurking across these areas
is beginning to head toward the central Gulf Coast region today. Showers
and embedded thunderstorms associated with this moisture plume are
expected to bring an increasing threat of heavy rain first along the
central Gulf Coast region during the next couple of days, with a gradual
westward shift in the heavy rainfall axis toward the western Gulf Coast
later on Tuesday and especially by Wednesday. Meanwhile, the National
Hurricane Center continues to monitor the potential for a tropical cyclone
to form over the southwestern Gulf of Mexico through the next few days.
It appears that east to northeasterly winds will gradually strengthen
especially along the Louisiana and Texas Gulf Coasts through the next
couple of days as pressure is forecast to fall gradually in the Gulf of
Mexico.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sun Jun 16 2024
Valid 12Z Sun Jun 16 2024 – 12Z Tue Jun 18 2024

…Multiple rounds of heavy rain and severe thunderstorms are expected to
impact locations from the northern Plains to the upper Midwest for the
next couple of days…

…Late-season wet snow is forecast for the northern Rockies Monday and
Tuesday…

…A heat wave will quickly spread from the Plains today, into the Great
Lakes/Upper Ohio Valley on Monday, and into the Northeast on Tuesday…

…A plume of tropical moisture will bring an increasing threat of heavy
rain and flash flooding to the central Gulf Coast late Sunday into Monday,
shifting toward the western Gulf Coast by Tuesday…

As a high pressure system brings fair weather and a fresh dose of cooler
than normal temperatures into the Northeast and Mid-Atlantic this weekend,
a heat wave is emerging across the Midwest into the Ohio Valley ahead of a
complex low pressure system developing over the northern Plains. A
thunderstorm complex containing severe weather is in progress early this
morning in association with the intensifying low pressure complex. The
thunderstorms will quickly move northeast into southern Canada today but
additional jet stream energy moving across the northern Rockies will help
develop a new low pressure system over the central Plains later today.
This system will rapidly develop and expand the next round of showers and
thunderstorms across the northern Plains tonight, and heading into the
upper Midwest on Monday. Severe thunderstorms with heavy downpours can be
expected to accompany this round of inclement over the upper Midwest after
the latest round of moderate to heavy rain and strong thunderstorms in the
same area early this morning diminishes and moves east into the upper
Great Lakes.

By Tuesday, yet another upper trough with an energetic jet stream will
move quickly into the Pacific Northwest. This system will usher a dose of
even colder air through the Pacific Northwest and northern Rockies, where
a round of late-season wet snow is expected to persist over the
higher-elevations of the northern Rockies Monday into Tuesday. A Winter
Storm Watch is in effect for these higher-elevations. In addition, Freeze
and Frost Warnings are in effect over portions of the interior Pacific
Northwest. This energetic system will also bring quite a bit of wind
across the Great Basin and the northern Rockies on Monday, reaching into
the central Rockies and northern Plains by Tuesday morning. As the low
pressure center over the central High Plains intensifies and heads
northeast across the northern Plains, a renewed round of heavy rain and
severe thunderstorms will likely develop and impact the same general
region of upper Midwest across north-central Minnesota by Tuesday morning,
where a moderate risk of flash flooding is anticipated.

In stark contrast to the cool/cold, windy, and even snowy weather across
the Northwest, a heat wave is quickly emerging ahead of the low pressure
complex from the central Plains, upper Midwest, and into the Ohio Valley.
The heat will surge into the Northeast by Tuesday where high temperatures
well up into the 90s are forecast as far north as Vermont and New
Hampshire.

Farther south from Central America across southern Florida and through the
western Atlantic, a plume of tropical moisture lurking across these areas
will shift westward into the Gulf of Mexico and begin to head toward the
central Gulf Coast region late Sunday into Monday. Showers and embedded
thunderstorms associated with this moisture plume are expected to bring an
increasing threat of heavy rain first along the central Gulf Coast region
during the next couple of days, with a gradual westward shift in the heavy
rainfall axis toward the western Gulf Coast by Tuesday. Meanwhile, the
National Hurricane Center continues to monitor the potential for a
tropical cyclone to form over the southwestern Gulf of Mexico through the
next few days. It appears that east to northeasterly winds will gradually
strengthen especially along the western Gulf Coast region by Tuesday
morning as pressure gradually falls in the Gulf of Mexico.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sat Jun 15 2024
Valid 12Z Sat Jun 15 2024 – 12Z Mon Jun 17 2024

…Multiple rounds of severe thunderstorms and locally heavy rain expected
to impact various locations in the northern and central U.S. through the
next couple of days…

…Late-season wet snow is forecast for the northern Rockies beginning on
Monday…

…A plume of tropical moisture is forecast to reach the central Gulf
Coast on Monday…

…A heat wave will quickly spread from the northern Plains this weekend
into the Great Lakes on Monday…

As a series of fronts pushes the showers and storms off the East Coast
early this morning, an active and changeable weather pattern will
establish across the Pacific Northwest. The unseasonably cold and
blustery conditions across this region will be in stark contrast with the
heat that is forecast to quickly spread from the northern Plains this
weekend, reaching into the Great Lakes on Monday. Areas in between these
temperature extremes will be under an active storm track where low
pressure systems will develop and move through in quick succession. The
first round of showers and storms associated with a leading system is
forecast to spark thunderstorm activity from the central Plains early this
morning to the upper Midwest by tonight. Multiple rounds of heavy rain
associated with these storms could lead to areas of flash flooding between
eastern Nebraska and northern Wisconsin. Additionally, a trailing and
stronger low pressure system is forecast to intensify and move quickly
across the northern Plains tonight. This system will help produce strong
to severe thunderstorms across parts of eastern Montana into North and
South Dakota. Unseasonably cold and windy weather will continue into
Sunday and Monday across the Northwest as yet another cold upper trough
reaches the Pacific Northwest. This system will reinforce the
unseasonably cold and windy conditions across the region on Monday along
with wet snow moving into the northern Rockies, therefore prompting the
issuance of Winter Storm Watches. Meanwhile, an area of rain and
thunderstorms is expected to develop and expand across the northern Plains
toward the upper Midwest where a stationary front strengthens ahead of a
developing low pressure system over the central High Plains.

Across the Florida Peninsula, the threat of heavy rain continues to
diminish as the main tropical moisture plume is forecast to swing farther
west and head toward the central Gulf Coast during the next couple of
days. Nevertheless, some thunderstorms that manage to develop over
southern Florida could result in local flooding issues given the already
saturated soil. By Monday morning, heavy rain associated with the
tropical moisture plume could begin impacting the central Gulf Coast
region. In contrast, a refreshingly dry airmass behind a cold front
should lead to beautiful weather this Father’s Day weekend throughout the
Northeast, Mid-Atlantic, and Ohio Valley.

The other main weather story this weekend will be the simmering heat
impacting areas from the Southwest to the Gulf Coast and Southeast. Highs
are forecast to reach the triple digits throughout much of the Desert
Southwest, with upper 90s stretching from the Southeast to parts of the
Southern Plains. Above average temperatures are also forecast across the
central Great Basin and northern Plains ahead of a cold front, with well
below average temperatures encompassing the Pacific Northwest. By Sunday,
an upper level ridge is anticipated to begin building across the Eastern
U.S., with anomalous heat starting in much of the Midwest, Central Plains,
and Tennessee Valley. Highs are forecast to reach the upper 90s, with
maximum heat indices near 105 degrees. When combined with warm overnight
lows, major heat risk could affect anyone without effective cooling and/or
adequate hydration. Be sure to remain weather aware and follow proper heat
safety!