Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Tue Apr 01 2025

Valid 12Z Tue Apr 01 2025 - 12Z Thu Apr 03 2025

...Significant, life-threatening flash flood event begins Wednesday for
the Lower Ohio Valley and Mid-South...

...Severe weather threat shifts from the central/southern Plains Tuesday
to the Midwest and Middle/Lower Mississippi Valley Wednesday...

...Another late season winter storm for the Northern Plains into the Upper
Midwest/Great Lakes Tuesday into Wednesday with heavy snowfall expected...

...Unsettled weather continues over the West as an upper-level trough
passes over the region...

...Critical Risk of fire weather returns to the central/southern High
Plains and Southwest Tuesday...  

A potent Spring storm will bring the threat of significant,
life-threatening flash flooding, widespread severe weather, and a winter
storm to portions of the Plains/Mississippi Valley/Midwest this week. An
energetic upper-level trough will deepen over the western/central U.S. as
an accompanying surface low pressure/frontal system strengthens in the lee
of the Rockies through the day Tuesday. Intensifying moist southerly
return flow will lead to an increasing chance of thunderstorms ahead of a
lifting warm front and eastward moving cold front over the
central/southern Plains, especially by the late afternoon/evening hours.
Very strong upper- and lower-level dynamics given the strength of the wind
fields with the arrival of the upper-level trough and sufficient
instability with an increasingly moist boundary layer will bring the
threat of severe weather. The Storm Prediction Center has included an
Enhanced Risk (level 3/5) for the threat of very large hail, damaging
winds, and several tornadoes, some of which could be strong, especially
during the late evening hours. In addition, expanding storm coverage and
the potential for heavy downpours may also lead to some isolated instances
of flash flooding Tuesday night. Then, on Wednesday, the progression of
the system will begin to slow heading into the Midwest/Mississippi Valley,
especially with southward extent, as an upper-level ridge builds over the
southeastern U.S. More widespread storms are expected in the warm sector
ahead of the cold front with an increasing tendency for storms to
cluster/repeat over the same regions by Wednesday evening as the progress
of the cold front slows, most likely along an axis from the Lower Ohio
Valley southwestward through the Mid-South. Increasing moisture pooling
ahead of the cold front will also lead to more intense downpours following
another day of return flow. A series of Moderate Risks of Excessive
Rainfall (level 3/4) are in effect for the region as this will be the
beginning of a multi-day significant, life-threatening flash flood event.
The placement of the cold front and exact axis of heaviest rainfall is
likely to change as the event nears. However, there is high confidence in
several inches of heavy rain, with some locations potentially seeing
amounts in excess of 10" over the next 7 days. Widespread severe weather
is also expected Wednesday across much of the Midwest/Ohio Valley
southwest through the Mid-South and ArkLaTex. A broad Enhanced Risk covers
the region for the threat of very large hail, significant damaging winds,
and strong tornadoes.

Beyond the flash flood and severe weather threat, a late-season winter
storm is also forecast in the colder air to the north of the system across
portions of the Northern Plains and Upper Midwest. Snow has already begun
this morning and will continue to increase in coverage and intensity into
Tuesday evening, lasting through Wednesday night, as the system
intensifies and lifts northeastward through the region. An axis of heavy
snow totals is forecast along and to the north of the surface low track
from the eastern Dakotas east through central/northern Minnesota and into
northern Wisconsin. Storm total snowfall of 4-8 inches, locally higher, is
expected. Gusty winds may lead to areas of blowing snow and difficult
travel conditions. A wintry mix of sleet and freezing rain is expected
just to the southeast of the heavy snow from central Minnesota/Wisconsin
east into the LP of Michigan. A leading shortwave ahead of the system will
also bring wintry mix to the interior Northeast/New England on Wednesday
with precipitation beginning as snow/freezing rain before changing over to
mostly rain as warmer air reaches the region. Some light to moderate snow
and ice accumulations are possible for higher elevations and portions of
northern Maine.

In the West, coastal rain, an interior lower elevation wintry mix, and
heavy higher elevation snow continue as the noted upper-level trough
remains over the region. An influx of Pacific moisture has waned overnight
but some moderate to locally heavy rainfall will continue along the West
Coast, especially along the coastal ranges of northern California into far
southern Oregon. Precipitation across lower elevations of the interior
from the Great Basin east into the northern/central Rockies should remain
very light with little to no snow accumulations. Very heavy snowfall
continues across the regional mountain ranges, especially for the Sierra
Nevada and the northern/central Rockies. Additional snowfall totals of
over foot are expected, with 1-4 feet possible for the Sierra Nevada.
Snowfall should come to an end for California and western areas of the
Great Basin by Wednesday while lingering for the eastern Great Basin and
northern/central Rockies. The potent upper-jet accompanying the trough as
it dives south and eastward over the West and into the central U.S. will
also bring very strong winds with gusts upwards of 50-60 mph from southern
California and the Southwest east into the southern Rockies and the
Plains. Warm temperatures and very dry antecedent conditions on top of the
high winds have prompted the return of a Critical Risk of fire weather
conditions from the Storm Prediction Center for portions of the
central/southern High Plains and Southwest Tuesday and Wednesday. Dust
storms will also be possible. 

An amplifying pattern will bring increasingly warmer/above average
conditions across the south-central and eastern U.S. while temperatures
remain cooler and below average under the upper-level trough over the
West. Forecast highs in the 70s and 80s across the Southeast and
central/southern Plains Tuesday will spread into the Midwest by Wednesday,
with closer to average conditions and highs in the 50s and 60s for the
Mid-Atlantic. The northern tier will be much cooler, with 30s and 40s for
the Northern Plains/Upper Midwest and New England. Highs across the West
will generally be in the 40s for the Interior West, 50s for the Pacific
Northwest, 50s and 60s in California, and 60s to low 70s for the Desert
Southwest.


Putnam


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