Weather Prediction Center

National Oceanic and Atmospheric Administration

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
133 AM EST Sat Feb 14 2026

Valid 12Z Sat Feb 14 2026 - 12Z Mon Feb 16 2026

...A cold front sweeping across the Southern/Central Plains into the East
Coast will bring a threat for heavy rainfall and severe storms this
weekend...

...The next storm system enters the Pacific Northwest and brings
beneficial rainfall to coastal zones and valleys and snowfall to the
mountain ranges...

...Above average temperatures continue across much of the country...

The surface low that sits over the Southern Plains will continue to trek
east-northeast into the Southeast by Sunday. As the system moves into the
lower Mississippi Valley, the trailing cold front will interact with
lingering Gulf moisture, increasing chances for widespread showers and
thunderstorms stretching into the Southeast. Locally heavy rainfall will
be possible where storms train along the boundary, particularly across
portions of the the lower Mississippi Valley into Tennessee/Ohio Valley.
With the chance for higher instability and heavy rainfall, parts of
ArLaTex to the Mid-South have been placed under a Slight Risk for
Excessive Rainfall with a chance for flash flooding for Saturday into
Sunday. In addition, Storm Prediction Center has also issued a Slight Risk
for Severe Thunderstorms with possible isolated hail and damaging winds,
stretching from east Texas into the lower Mississippi Valley. On Sunday,
the system continues to move northeast into the Mid-Atlantic bringing
widespread showers and possible thunderstorms. Parts of the Southeast and
the Mid-Atlantic still remains under a Marginal Risk for Excessive
Rainfall from Sunday into Monday.

The frontal passage from the Gulf of Alaska continues to move inland
bringing precipitation chances across the Pacific Northwest and
Intermountain West. Light to moderate snow may develop over the Northern
Rockies as the moisture continues to move eastward on Saturday. On Sunday,
as the trough deepens over California and a surface cold front approaches
the California coast, chances for rain activity will increase, especially
over the coast and interior Northern California. As the moisture moves
over higher terrain, moderate to heavy snow is expected to develop over
the Sierra for Sunday into Monday.

Above normal temperatures will continue over much of CONUS, especially
across the Plains where high temperatures will be 15-30 degrees above
average. Across central U.S. into the Mid-Atlantic will see temperatures
in the 50s and 60s, while areas within Southern Plains into the Southeast
may see up to 70s and 80s. Over into the Northeast, temperatures will
remain near normal, with highs between 30s-50s, while the West Coast will
see 50s and 60s.


Oudit


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
251 AM EST Sat Feb 14 2026

Valid 12Z Tue Feb 17 2026 - 12Z Sat Feb 21 2026


...Widespread Rain/Snow Pattern returns to the West and downstream
Heavy Snow/Ice Threat for the North-Central U.S/Midwest next
week...

...General Overview...

An expansive upper level ridge builds in from the southern Plains
to the Midwest going into Tuesday, with widespread above normal
temperatures and breezy conditions accompanying it, and this ridge
then reaches the East Coast by Wednesday with a return to warmer
temperatures after prolonged cold weather. Out West, a pattern
change will be taking place with a large upper trough with embedded
shortwave energy building into the region, bringing badly needed
moisture after the recent dry spell, with moderate to heavy
rainfall for the California coast, and heavy snow from the Sierra
Nevada to the central and northern Rockies. An organized low
pressure system is expected to develop across the Midwest and Ohio
Valley to close out the work week.

...Guidance/Predictability Assessment...

The 00Z model guidance suite is generally in good overall agreement
on the main synoptic scale pattern through the middle of the week,
with the normal level of mesoscale differences among the models,
except for a slower offshore solution with the CMC regarding the
exiting low off the East Coast. The UKMET is on the northern side
of the guidance with the surface low and front across the Upper
Midwest and Great Lakes region, but all guidance agrees this low
weakens by Thursday as the next surface low evolves over the
Central Plains. The CMC is slower with this second low and makes it
stronger by the end of the forecast period, whereas the GFS/GEFS
are generally more progressive. The ensemble means were increased
to about half by next Saturday.

In terms of the NBM, the winds are likely too low from western
Texas and Oklahoma northward to eastern Wyoming for Tuesday into
Wednesday, so both sustained winds and gusts were increased to
better represent the expected synoptic set-up with strong
southwesterly winds ahead of the ejecting western U.S. trough.
Temperatures during the afternoon were also slightly raised along
with lowered dewpoints given the increased potential for fire
weather conditions, particularly near the Texas Panhandle region on
Tuesday.

...Weather/Hazards Highlights...

A potent shortwave trough moving inland across the Desert Southwest
is expected to bring moderate to locally heavy rainfall for the
lower elevations from near San Francisco to the greater Los Angeles
and San Diego metro areas. A Marginal Risk will remain valid for
these areas on Tuesday south of Monterrey, and lighter showers on
Wednesday when no risk areas are currently warranted. Additional
rainfall is likely going into the end of the week for the Pacific
Northwest, but does not appear to be heavy at this time in the
forecast. Snow levels are expected to fall quite a bit with the
shortwave and cold front moving inland, with multiple feet of
snowfall expected for the Sierra Nevada through next week, and 1 to
2 feet of snowfall is probable for the higher ranges of the
Intermountain West and the central/northern Rockies. This snowfall
will greatly help with the deteriorating drought situation across
much of the Colorado River basin.

The strong upper shortwave trough ejecting out over the Plains will
spur surface cyclogenesis over the western High Plains by Tuesday
afternoon across eastern Wyoming. This low should generally track
across the Midwest and then reach the Great Lakes and weaken going
into Thursday. A strong pressure gradient south of the low will
generate enhanced winds from western Texas to Wyoming, and combined
with anomalous warmth and low humidity will likely result in
elevated fire weather potential on Tuesday and perhaps into
Wednesday as well. To the north of the surface low will be a broad
corridor of mainly stratiform precipitation from the Dakotas to
Michigan, with snow on the northern edge. A second surface low is
likely to develop across Kansas by Thursday, but likely less
impactful than the first storm system.

Temperatures will feel more like late March and April across a
large portion of the Plains and the Midwest with the amplified
upper ridge in place and downsloping winds from the Rockies. Highs
are expected to be up to 30 degrees above mid-February averages
across portions of Nebraska and Iowa, with the potential for a few
record highs to be set. Except for New England, the eastern U.S.
will also get a welcomed warm-up after an extended period of very
cold weather the past couple of weeks going into Wednesday and
Thursday, as the warmth from the Plains builds eastward with a warm
front lifting north. It should remain cold closer to the Canadian
border as a strong surface high builds in behind a cold front, but
no arctic air mass intrusions are expected. Colder than average
conditions will generally be the rule across much of the West given
the upper trough and more clouds and precipitation keeping daytime
highs in check on most days.

Hamrick




Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
244 AM EST Sat Feb 14 2026

Valid 00Z Sun 15 Feb 2026 - 00Z Sun 22 Feb 2026

Upper ridging will be in place for several days across the state
which will be conducive for tradewinds and upslope shower
activity. A brief rise in shower intensity and coverage may be
possible Sunday into Monday as a modest surge in moisture will be
noted from the northeast. Breezy to windy conditions are also
likely in response to the pressure gradient between the high to
the northeast and a broad surface low/trough of low pressure south
and west of the archipelago. Winds should veer with time early to
mid next week as a surface high pressure area exerts more
influence from the north...which starts to draw deeper moisture
northward around the southwest periphery of the ridge.

The latest guidance continues to depict an upper level trough and
associated frontal system to track from the Papahanaumokuakea
Marine National Monument towards the main Hawaiian Islands. Trends
suggest that a secondary upper level trough/low will develop to
the northwest of the island toward the end of the end of the
week. There is a fair amount of spread in regards to whether this
will be a drier or wetter period for the western part of the
state.




Campbell/Roth

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1100 AM EST Sat Feb 14 2026
Day 1
Valid 16Z Sat Feb 14 2026 - 12Z Sun Feb 15 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM NORTHEAST
TEXAS TO THE MID-SOUTH...

1600Z Update...

Based on the new 12Z HREF guidance and recent HRRR solutions along
with satellite and radar trends, the Slight Risk area has been
pulled southward a bit into northeast TX, mainly from the DFW metro
area eastward to the Arklatex. This will accommodate concerns for
at least some brief/episodic convective training concerns as
convection grows upscale in an organized fashion out ahead of
strong shortwave energy/height falls ejecting east across the
southern Plains and Lower MS Vallety region. Increasing boundary
layer instability and a strengthening of thew low-level jet should
favor increasing rainfall rates capable of reaching 1 to 2
inches/hour, and with some training potential. Localized swaths of
3 to 4+ inches may occur. Since we are likely to have basically a
QLCS evolution going into tonight across the South, the Marginl
Risk area has also been extended southward to the Gulf Coast.
Overall, most areas should see any flash flooding concerns be
isolated to scattered, and mainly for urban areas.

Orrison

Previous discussion...

A positively tilted upper trough will pivot across the Southern
Plains, while a low pressure system develops at the surface today.
Mid-level diffluence will shed lobes of vorticity over parts of
the Southern/Central Plains and Lower/Middle Mississippi Valley,
providing ample forcing for convection to develop. Thus, showers
and thunderstorms are likely to increase in coverage this afternoon
starting over north-central Texas, into central Oklahoma and
spreading eastward into the Lower Mississippi Valley tonight. The
associated surface wave should strengthen into a rather anomalous
mid-latitude cyclone by tonight, which is when a line of convection
may initiate over east Texas and begin to propagate east across
the central Gulf Coast.

Instability will be most robust (250-750 J/Kg) over east Texas,
southern Arkansas and Louisiana through tonight. 1-2" PWATs will be
2-3 stndv above average and could produce 0.25"-0.75"/hr rates
with higher rates possible within linear convective bands moving
through east Texas and within any potential training/backbuilding
convection that occurs along a surface front draped over Arkansas.
Guidance is hinting at potential for slow moving cells to generate
an isolated flash flood threat over portions of Missouri this
afternoon.

Kebede


Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1100 AM EST Sat Feb 14 2026
Day 2
Valid 12Z Sun Feb 15 2026 - 12Z Mon Feb 16 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE MID-ATLANTIC AND SOUTHEAST...

The marginal risk area from yesterday's issuance remains mostly
the same, with the only change being an expansion northward in
Virginia. The potent low pressure system that will bring heavy
rainfall to the Lower Mississippi Valley today will continue to
spread moderate to heavy rainfall over parts of the Southeast and
Mid-Atlantic on Sunday. The heaviest rainfall is expected to occur
Sunday afternoon into evening in the Southeast, along the same
cold front responsible for potential linear convection over the
central Gulf Coast today.

MLCAPE will be modest at around 250-500 J/Kg, while PWATs hover
between 1-1.75" over the Southeast. Phasing of this southern stream
system with a northern stream one emerging from the Ohio Valley
could enhance precip. coverage over the Mid-Atlantic this afternoon
into tonight.

Kebede


Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1100 AM EST Sat Feb 14 2026
Day 3
Valid 12Z Mon Feb 16 2026 - 12Z Tue Feb 17 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
CENTRAL AND SOUTHERN CALIFORNIA...

A slight risk was introduced, in coordination with local offices,
across parts of the central and southern California Coast. A closed
mid-level low will weaken while shedding lobes of vorticity over
the West Coast on Monday. An upper-level jet streak (100-140 kts)
will gradually increase in intensity throughout the day as it sags
south from central to southern California. A surface wave will
develop and spread rain showers and isolated thunderstorms into the
central to southern coastal ranges below 6500-5000ft Monday
morning and into the early evening.

PWATs in the 0.5"-0.9" range within a relatively buoyant
atmosphere (100-200 J/Kg) and a 30-40 kt low level jet, could
support efficient rain rates especially within any convection that
develops. Burn scars will be especially susceptible to flash
flooding.

Kebede

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
251 AM EST Sat Feb 14 2026


A potent shortwave trough moving inland across the Desert Southwest
is expected to bring moderate to locally heavy rainfall for the
lower elevations from near San Francisco to the greater Los Angeles
and San Diego metro areas. A Marginal Risk will remain valid for
these areas on Tuesday south of Monterrey, and lighter showers on
Wednesday when no risk areas are currently warranted. Additional
rainfall is likely going into the end of the week for the Pacific
Northwest, but does not appear to be heavy at this time in the
forecast. Snow levels are expected to fall quite a bit with the
shortwave and cold front moving inland, with multiple feet of
snowfall expected for the Sierra Nevada through next week, and 1 to
2 feet of snowfall is probable for the higher ranges of the
Intermountain West and the central/northern Rockies. This snowfall
will greatly help with the deteriorating drought situation across
much of the Colorado River basin.

The strong upper shortwave trough ejecting out over the Plains will
spur surface cyclogenesis over the western High Plains by Tuesday
afternoon across eastern Wyoming. This low should generally track
across the Midwest and then reach the Great Lakes and weaken going
into Thursday. A strong pressure gradient south of the low will
generate enhanced winds from western Texas to Wyoming, and combined
with anomalous warmth and low humidity will likely result in
elevated fire weather potential on Tuesday and perhaps into
Wednesday as well. To the north of the surface low will be a broad
corridor of mainly stratiform precipitation from the Dakotas to
Michigan, with snow on the northern edge. A second surface low is
likely to develop across Kansas by Thursday, but likely less
impactful than the first storm system.

Temperatures will feel more like late March and April across a
large portion of the Plains and the Midwest with the amplified
upper ridge in place and downsloping winds from the Rockies. Highs
are expected to be up to 30 degrees above mid-February averages
across portions of Nebraska and Iowa, with the potential for a few
record highs to be set. Except for New England, the eastern U.S.
will also get a welcomed warm-up after an extended period of very
cold weather the past couple of weeks going into Wednesday and
Thursday, as the warmth from the Plains builds eastward with a warm
front lifting north. It should remain cold closer to the Canadian
border as a strong surface high builds in behind a cold front, but
no arctic air mass intrusions are expected. Colder than average
conditions will generally be the rule across much of the West given
the upper trough and more clouds and precipitation keeping daytime
highs in check on most days.

Hamrick

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
251 AM EST Sat Feb 14 2026


A potent shortwave trough moving inland across the Desert Southwest
is expected to bring moderate to locally heavy rainfall for the
lower elevations from near San Francisco to the greater Los Angeles
and San Diego metro areas. A Marginal Risk will remain valid for
these areas on Tuesday south of Monterrey, and lighter showers on
Wednesday when no risk areas are currently warranted. Additional
rainfall is likely going into the end of the week for the Pacific
Northwest, but does not appear to be heavy at this time in the
forecast. Snow levels are expected to fall quite a bit with the
shortwave and cold front moving inland, with multiple feet of
snowfall expected for the Sierra Nevada through next week, and 1 to
2 feet of snowfall is probable for the higher ranges of the
Intermountain West and the central/northern Rockies. This snowfall
will greatly help with the deteriorating drought situation across
much of the Colorado River basin.

The strong upper shortwave trough ejecting out over the Plains will
spur surface cyclogenesis over the western High Plains by Tuesday
afternoon across eastern Wyoming. This low should generally track
across the Midwest and then reach the Great Lakes and weaken going
into Thursday. A strong pressure gradient south of the low will
generate enhanced winds from western Texas to Wyoming, and combined
with anomalous warmth and low humidity will likely result in
elevated fire weather potential on Tuesday and perhaps into
Wednesday as well. To the north of the surface low will be a broad
corridor of mainly stratiform precipitation from the Dakotas to
Michigan, with snow on the northern edge. A second surface low is
likely to develop across Kansas by Thursday, but likely less
impactful than the first storm system.

Temperatures will feel more like late March and April across a
large portion of the Plains and the Midwest with the amplified
upper ridge in place and downsloping winds from the Rockies. Highs
are expected to be up to 30 degrees above mid-February averages
across portions of Nebraska and Iowa, with the potential for a few
record highs to be set. Except for New England, the eastern U.S.
will also get a welcomed warm-up after an extended period of very
cold weather the past couple of weeks going into Wednesday and
Thursday, as the warmth from the Plains builds eastward with a warm
front lifting north. It should remain cold closer to the Canadian
border as a strong surface high builds in behind a cold front, but
no arctic air mass intrusions are expected. Colder than average
conditions will generally be the rule across much of the West given
the upper trough and more clouds and precipitation keeping daytime
highs in check on most days.

Hamrick

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
332 AM EST Sat Feb 14 2026

Valid 12Z Sat Feb 14 2026 - 12Z Tue Feb 17 2026


...Cascades...
Days 1 & 3...

A broad upper-level troughing pattern off the Pacific NW coast
will continue to supply lingering low-mid level moisture that
allows for light snow through this morning. Snow levels will drop
to as low as 2000-3000ft today and into Saturday evening, bringing
snow to many of the passes over the WA Cascades. Following a lull
in snowfall Saturday night and into Sunday, another surge of
moisture will be supplied by a strengthening 500mb closed-low west
of British Columbia. Sharp height falls and excellent 500mb PVA
will be paired with an influx of 850-300mb mean-layer moisture to
produce periods of snow. Snow levels will plummet to as low as
800ft around the WA Cascades, while 2000 ft snow levels in the OR
Cascades will be more common. While these snow levels are getting
quite low, snowfall totals below 2,000ft in the WA/OR Cascades will
remain light. The heaviest snowfall will reside above 3,000ft
72-hour WPC probabilities show moderate chances (40-60%) for
snowfall totals >4" for both Snoqualmie Pass and Stevens Pass.
Given the long duration but lack of heavy hourly rates, WSSI-P
shows the chances for Minor Impacts are generally on the low side
(20-40%) with Monday having the best chances for some slick travel
conditions at pass level.


...California...
Days 2-3...

...Multiple days of heavy and disruptive snowfall to affect the
California mountain ranges beginning Sunday and continuing into
next week...

A pair of potent Pacific storm systems will work together to direct
copious amounts of moisture at the mountain ranges of the "Golden
State" starting Sunday. The first upper low west of California will
kickoff this multi-day heavy snow event on Sunday with snow falling
in the higher terrain of the Siskiyou, Shasta, and Salmon
Mountains. By Sunday night the upper low approaches, causing
heights to fall over CA and the strengthening IVT to direct
subtropical moisture at the state. Monday marks the beginning of
heavy snowfall along the Sierra Nevada with snow levels will
generally ranging from 4500ft to 6000ft from north to south
initially, then fall below 3000ft across northern CA as the other
potent Pacific trough approaches from the northwest. In both cases,
the state will be placed ahead of a pair of 500mb jet streaks that
will generate excellent upper-level divergence aloft, along with a
barrage of Pacific moisture and strong topographically-enhanced
snowfall rates. Heavy snowfall is expected as far south as the
Transverse Ranges above 6,000ft with WPC probabilities showing
moderate chances (40-60%) for snowfall totals >8" in the peaks of
the San Gabriel and San Bernadino Mountains.

California's mountain ranges welcome the snow, although it will
come down fast and furious on Monday and continue into Tuesday.
Through the end of this discussion's timeframe (12Z Tues), multiple
feet of snow will have fallen above 6,000ft along the Sierra
Nevada. WPC probabilities show high chances (>70%) for >24" of
snow having fallen along the I-80 pass by 12Z Tuesday and more snow
still to come. The WSSI-P depicts a highly impactful snow event
along the Sierra Nevada with high chances (>70%) for Major Impacts
above 6,00ft, including the I-80 pass. In fact, for the higher
elevations above 8,000ft, the WSSI-P shows moderate chances (>50%)
for Extreme Impacts, suggesting the potential for significant
impacts to infrastructure. Travel will be dangerous to impossible
in the Sierra Nevada into Tuesday. Note that there are also high
chances (>70%) for Minor Impacts for I-5 around Mount Shasta,
signifying potential travel delays for I-5 in the more elevated
terrain of northern CA.


...Intermountain West...
Days 1-3...

Pacific moisture ahead of the longwave upper trough off the West
Coast will spill over the Cascades and Sierra Nevada and reach many
ranges across the Intermountain West this weekend and into early
next week. With a lack of a frigid airmass ahead of this healthy
moisture source, snow will largely be confined to many of the
taller mountain peaks that sorely need beneficial snowpack. The
heaviest snowfall will reside in the Bitterroots, the Lewis Range,
Sawtooth, and the Blue Mountains whee 72-hour WPC probabilities
show moderate-to-high chances (50-80%) for snowfall totals >8".
Localized amounts ranging between 12-24" are most likely to occur
along the remote reaches of the Lewis Range and peaks of the Blue
Mountains. Farther south, most accumulations in the Great Basin,
the Wasatch, Uinta, Mogollon Rim, and CO/NM Rockies will be on the
lighter side. The peaks around Zion Nat'l Park on north along the
Wasatch sport moderate-to-high chances (50-70%) for snowfall totals
>4". Otherwise, most mountain ranges are likely to see 1-4" of
snowfall, with additional snowfall still to come on Tuesday.


...Northeast...
Day 2...

The last 24 hours have seen some model guidance (GFS/ECMWF)
gradually creep north with the precipitation shield. This is due to
the approaching 500mb shortwave over western PA coming in
stronger, thus leading to healthier PVA aloft and more 250mb jet
streak enhancement aloft. While boundary layer temperatures along
I-95 south of Philadelphia remain quite marginal on Sunday,
elevated terrain north and west of the Delaware River are likely to
have better chances to see wet snow Sunday afternoon. As the upper
trough in the Carolinas spawns low pressure over the NC Outer
Banks Sunday evening, 850-700mb WAA to the north of the low will
support narrow banding of snow from eastern PA and northern NJ to
the NYC metro, Long Island, and coastal southern New England. There
remains notable spread in model guidance in the position of this
band, but trends in not only the GFS/ECMWF guidance but also their
AI counterparts are showing additional support for a ribbon of
light snow. WPC probabilities show low-to-moderate chances (30-50%)
for snowfall totals >1" from the Delaware and Lehigh Valleys on
east to Long Island, but probabilities for >2" of snowfall are
<20%, showing that most totals are minor and likely to range
between a coating-2". There is the potential for additional
changes to this forecast in the next 12-24 hours.


The probability of significant icing across the CONUS is less than
10 percent.


Mullinax

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
251 AM EST Sat Feb 14 2026

Valid 12Z Tue Feb 17 2026 - 12Z Sat Feb 21 2026


...Widespread Rain/Snow Pattern returns to the West and downstream
Heavy Snow/Ice Threat for the North-Central U.S/Midwest next
week...

...General Overview...

An expansive upper level ridge builds in from the southern Plains
to the Midwest going into Tuesday, with widespread above normal
temperatures and breezy conditions accompanying it, and this ridge
then reaches the East Coast by Wednesday with a return to warmer
temperatures after prolonged cold weather. Out West, a pattern
change will be taking place with a large upper trough with embedded
shortwave energy building into the region, bringing badly needed
moisture after the recent dry spell, with moderate to heavy
rainfall for the California coast, and heavy snow from the Sierra
Nevada to the central and northern Rockies. An organized low
pressure system is expected to develop across the Midwest and Ohio
Valley to close out the work week.

...Guidance/Predictability Assessment...

The 00Z model guidance suite is generally in good overall agreement
on the main synoptic scale pattern through the middle of the week,
with the normal level of mesoscale differences among the models,
except for a slower offshore solution with the CMC regarding the
exiting low off the East Coast. The UKMET is on the northern side
of the guidance with the surface low and front across the Upper
Midwest and Great Lakes region, but all guidance agrees this low
weakens by Thursday as the next surface low evolves over the
Central Plains. The CMC is slower with this second low and makes it
stronger by the end of the forecast period, whereas the GFS/GEFS
are generally more progressive. The ensemble means were increased
to about half by next Saturday.

In terms of the NBM, the winds are likely too low from western
Texas and Oklahoma northward to eastern Wyoming for Tuesday into
Wednesday, so both sustained winds and gusts were increased to
better represent the expected synoptic set-up with strong
southwesterly winds ahead of the ejecting western U.S. trough.
Temperatures during the afternoon were also slightly raised along
with lowered dewpoints given the increased potential for fire
weather conditions, particularly near the Texas Panhandle region on
Tuesday.

...Weather/Hazards Highlights...

A potent shortwave trough moving inland across the Desert Southwest
is expected to bring moderate to locally heavy rainfall for the
lower elevations from near San Francisco to the greater Los Angeles
and San Diego metro areas. A Marginal Risk will remain valid for
these areas on Tuesday south of Monterrey, and lighter showers on
Wednesday when no risk areas are currently warranted. Additional
rainfall is likely going into the end of the week for the Pacific
Northwest, but does not appear to be heavy at this time in the
forecast. Snow levels are expected to fall quite a bit with the
shortwave and cold front moving inland, with multiple feet of
snowfall expected for the Sierra Nevada through next week, and 1 to
2 feet of snowfall is probable for the higher ranges of the
Intermountain West and the central/northern Rockies. This snowfall
will greatly help with the deteriorating drought situation across
much of the Colorado River basin.

The strong upper shortwave trough ejecting out over the Plains will
spur surface cyclogenesis over the western High Plains by Tuesday
afternoon across eastern Wyoming. This low should generally track
across the Midwest and then reach the Great Lakes and weaken going
into Thursday. A strong pressure gradient south of the low will
generate enhanced winds from western Texas to Wyoming, and combined
with anomalous warmth and low humidity will likely result in
elevated fire weather potential on Tuesday and perhaps into
Wednesday as well. To the north of the surface low will be a broad
corridor of mainly stratiform precipitation from the Dakotas to
Michigan, with snow on the northern edge. A second surface low is
likely to develop across Kansas by Thursday, but likely less
impactful than the first storm system.

Temperatures will feel more like late March and April across a
large portion of the Plains and the Midwest with the amplified
upper ridge in place and downsloping winds from the Rockies. Highs
are expected to be up to 30 degrees above mid-February averages
across portions of Nebraska and Iowa, with the potential for a few
record highs to be set. Except for New England, the eastern U.S.
will also get a welcomed warm-up after an extended period of very
cold weather the past couple of weeks going into Wednesday and
Thursday, as the warmth from the Plains builds eastward with a warm
front lifting north. It should remain cold closer to the Canadian
border as a strong surface high builds in behind a cold front, but
no arctic air mass intrusions are expected. Colder than average
conditions will generally be the rule across much of the West given
the upper trough and more clouds and precipitation keeping daytime
highs in check on most days.

Hamrick




Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw