Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
359 AM EDT Thu Mar 30 2023

Valid 12Z Thu Mar 30 2023 - 12Z Sat Apr 01 2023

...Strong storm system will result in severe thunderstorms and heavy rain
for the Plains/Mississippi Valley; Critical Risk of Fire Weather for the
Central/Southern High Plains...

...Heavy snow, blizzard conditions, and accumulating freezing rain
forecast for the Northern Plains and Upper Midwest Friday...

...Locally heavy mountain snow over the Intermountain West ahead over
another Pacific storm system impacting the Pacific Northwest Friday...

A deep upper-level trough over the West will begin to move out over the
High Plains Thursday, encouraging lee cyclogenesis in the Central High
Plains. This will lead to subsequent reinforcement/organization of a warm
front pushing northward over the Central Plains and Midwest, a Pacific
front moving east over the Rockies/High Plains, and a dryline extending
southward through the Central/Southern Plains. A warm, moist airmass will
surge northward over the Plains Thursday evening as a strong low level jet
develops. Some moderate to locally heavy rainfall is possible with storms
developing along the warm front, particularly as storms may have the
tendency to repeat over the same areas as motions remain oriented along
the front. A Marginal Risk of Excessive Rainfall (level 1/4) is in effect
for portions of the Upper Mississippi Valley into the Upper Great Lakes as
a few isolated instances of flash flooding are possible. A Marginal Risk
of Severe Weather (level 1/5) has also been issued by the Storm Prediction
Center over portions of the Central/Southern Plains for the chance of a
couple isolated supercells ahead of the dryline that could produce large
hail, damaging winds, and a tornado.

More widespread, impactful weather is expected Friday as a vigorous
upper-level jet moves out over the Mississippi Valley and higher moisture
from the Gulf has had a chance to flow northward. Numerous and widespread
storms are expected to develop ahead of and along the eastward moving cold
front. Moderate to strong buoyancy in the presence of intense upper-level
and low-level shear has prompted two Moderate Risk outlooks for Severe
Weather (level 4/5) from the Storm Prediction Center. One risk area
centers on the Upper Mississippi Valley, where storms will have the
potential to produce widespread, significant damaging winds along with
large hail and tornadoes. Another focus area will be on the Mid-South,
where very strong low level shear will increase the risk for strong,
long-track tornadoes in addition to large hail and damaging winds. A
lower, but still significant risk of severe thunderstorms will exist
outside these regions across the Mississippi Valley. While the front is
expected to remain rather progressive, anomalously high moisture leading
to very heavy rainfall rates and storm motions roughly parallel to the
front resulting in repeated rounds of rainfall may also lead to some flash
flooding concerns. A Slight Risk of Excessive Rainfall (level 2/4) has
been introduced from the Mid-South eastward into the Ohio and Tennessee
Valleys.

Further west behind the dryline, a tightening pressure gradient with the
deepening surface cyclone ahead of the Pacific cold front pushing eastward
will lead to very strong, gusty downsloping winds over the
Central/Southern High Plains. The Storm Prediction Center has issued a
Critical Risk of Fire Weather for both Thursday and Friday over the region
as temperatures soar into the upper 70s and low 80s, relative humidity
decreases, and gusts upwards of 50 mph will promote the risk for
wildfires. High temperatures overall will be unseasonably warm over much
of the central/eastern U.S. as the warm front lifts northward. Highs in
the 60s and 70s, and even some low 80s, over the Central/Southern High
Plains, Mississippi Valley, and Southeast Thursday will spread
northeastward into the Ohio Valley, Lower Great Lakes, and Mid-Atlantic
Friday.

Meanwhile, further north, a secondary cold front pushing south from Canada
will help to reinforce the cold air over the region as moisture streams
northward, leading to areas of heavy snow from the Northern Plains into
the Upper Midwest beginning late Thursday night. Winter weather-related
advisories are in effect from South Dakota east into Minnesota and
Wisconsin for the potential of snow totals generally between 3-6", with
locally heavier totals of 10"+ possible. In addition, gusty winds behind
the front upwards of 50 mph will lead to areas of blowing snow and
blizzard conditions, making travel treacherous to impossible. A wintry mix
is forecast along the southern end of the snow axis, with the potential
for some impactful ice accumulations. Temperatures will remain
unseasonably chilly with highs Thursday and Friday in the 20s and 30s.
Lows may dip into the single digits for some locations Saturday morning.
The cold front sliding southward over the High Plains Friday will drop
highs into the 30s and 40s for the Central High Plains. There will be
quite the stark contrast in temperatures between the frontal boundaries
draped across the region, with highs on Friday in Iowa forecast to reach
the low 70s and highs just to the northwest over South Dakota in the upper
20s and low 30s.

Snow will continue over the Intermountain West under the influence of the
deep upper-level trough and a frontal system pushing through the region.
Additional locally heavy accumulations of 6-12"+ are possible for higher
elevations in the mountain ranges of the eastern Great Basin and
Northern/Central Rockies Thursday into early Friday. Little to no snow
accumulations are expected for most lower elevation valley locations,
however some light accumulations will be possible over the Northern High
Plains. Another Pacific storm system will approach the Pacific Northwest
early Friday, bringing moderate to locally heavy lower elevation/coastal
rain and heavy snow accumulations to higher elevations of the Cascades.
Moisture will spread inland over the northern Great Basin/Northern Rockies
by Friday evening, with accumulating snowfall forecast for higher
elevation mountain ranges here as well. High temperatures will remain well
below average across the West under the influence of the upper-level
trough and behind the initial Pacific cold front pushing through the
region. Highs will generally be in the 30s and 40s for the
Northern/Central Rockies and Great Basin Thursday-Friday, with highs in
the 50s over the Pacific Northwest Thursday also dropping into the 40s
Friday. Highs in California will only be in the 50s for most locations
Thursday, with the potential for some record-tying/breaking low maximum
temperatures over southern California. The Desert Southwest will be in the
60s Thursday, with some low 70s possible Friday.

Putnam


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