016
FXUS01 KWBC 020800
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Wed Apr 02 2025

Valid 12Z Wed Apr 02 2025 - 12Z Fri Apr 04 2025

...Life-threatening, potentially historic flash flood event begins
Wednesday for the Lower Ohio Valley and Mid-South...

...Tornado outbreak expected Wednesday for the Mid-South with
multiple intense tornadoes possible...

...Late season winter storm continues Wednesday for portions of
the Northern Plains/Upper Midwest with heavy snowfall expected...

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

...Critical Risk of fire weather for portions of the
central/southern High Plains and Southwest Wednesday...

A powerful Spring storm system will bring a barrage of
life-threatening weather including flash flooding and strong
tornadoes to portions of the Lower Ohio Valley and Mid-South
Wednesday, with the flash flood threat only the beginning of a
multi-day catastrophic and potentially historic event. A deepening
upper-level trough and accompanying strong low pressure/frontal
system over the Plains this morning will push eastward through the
Midwest, Mississippi Valley, and southern Plains Wednesday.
Extremely impressive dynamics given very strong upper-level and
lower-level wind fields, as well as a deep influx of boundary
layer moisture flowing northward from the Gulf, will help support
a broad warm sector featuring widespread, intense thunderstorms
stretching from the Great Lakes southwest through the Middle
Mississippi/Lower Ohio Valleys, Mid-South, ArkLaTex, and Southern
Plains. The Storm Prediction Center (SPC) has introduced a High
Risk (level 5/5) of severe weather across portions of the
Mid-South where the most favorable overlap of strong upper- and
lower-level shear and instability may lead to an outbreak of
tornadoes, including multiple intense tornadoes, as well as very
large hail and significant damaging winds. A broader at least
Enhanced level (3/5) severe threat covers the rest of the region
where a more scattered but still significant threat of tornadoes,
large hail, and damaging winds exists. Unfortunately, this severe
threat will be compounded by the beginning of a life-threatening
flash flood event. Strengthening upper-level ridging to the east
will help to slow the progression of the cold front through the
day Wednesday, increasing the chance of repeated rounds of storms
as they begin to move more parallel to the stalling boundary. The
blocked flow will also help to maintain a supply of plentiful Gulf
moisture helping to foster very-efficient, intense downpour
producing storms. There is a Moderate Risk of Excessive Rainfall
(level 3/4) Wednesday overlapping much of the SPC High Risk from
the Lower Ohio Valley southwestward into the Mid-South where the
greatest potential exists for several inches of rainfall and
scattered to numerous instances of flash flooding through the
evening and overnight hours. The front will become nearly
stationary across the region Thursday leading to an even greater
risk of significant heavy rainfall totals, with the probability of
more than 6" of rain over the two day period at 40-60%. The
repeated rounds of rainfall will lead to increasingly saturated
soils, and could bring additional rainfall over areas already
experiencing flooding. For these reasons, another Moderate Risk is
in place Thursday for the Lower Ohio Valley/Mid South to the
ArkLaTex with an embedded High Risk (level 4/4) for western
Kentucky, the Missouri Bootheel, northwestern Tennessee, and
extreme northeastern Arkansas where widespread, life-threatening
flash flooding is expected. The front will remain stalled into the
weekend with Moderate Risks already in place for Friday and
Saturday. This event will bring potentially historic amounts of
rainfall, with some locations possibly seeing as much as 10-15"+
of rain through the weekend. Communities throughout the area
should prepare now for the possibility of long duration and severe
disruptions to daily life given the expected extreme rainfall and
flood risk. Additional severe thunderstorms are also expected on
Thursday from the Mid-Atlantic southwest through the
Ohio/Tennessee Valleys and into the Southern Plains, with the SPC
maintaining a Slight Risk (level 2/5) for the threat of damaging
winds, large hail, and a few tornadoes.

Meanwhile, a winter storm continues Wednesday in the colder
airmass north of the system, with a band of heavy snow forecast
along and to the north of the surface low track from the eastern
Dakotas into northern Minnesota. Additional snowfall totals of
4-8", locally higher, are expected, with the heaviest totals most
likely along the northern shore of Lake Superior. Gusty winds may
lead to areas of blowing snow and very difficult travel
conditions. A wintry mix of snow, sleet, and freezing rain is
expected just to the southeast of the heavy snow from central
Minnesota east into northern Wisconsin and Michigan through at
least Wednesday morning. These areas of wintry precipitation are
expected to transition over to rain and even some thunderstorms as
a warm front lifts northward during the day Wednesday. A leading
shortwave ahead of the system will also bring wintry precipitation
to areas of the interior Northeast/New England Wednesday, with
some light to moderate snow and ice accumulations possible for
higher mountain elevations and portions of northern Maine.

Wintry weather continues across much of the Interior West as
embedded perturbations round the broad upper-level trough over the
region. Some moderate snow totals will be possible for higher
elevations of the mountain ranges across the Pacific Northwest,
Great Basin, northern/central Rockies, and Four Corners region
Wednesday. Western areas will see the snow taper off into Thursday
while the focus shifts to the northern/central Rockies and Four
Corners region. A frontal passage across the northern Rockies and
an area of low pressure east of the central Rockies will help to
enhance upslope flow and bring some heavier snow totals to the
mountains, with some snow also expected for adjacent portions of
the northern/central High Plains. Elsewhere, another day of
strong, gusty winds and low humidity across portions of the
southern High Plains and Southwest has prompted a Critical Risk of
fire weather (level 2/3) from the SPC.

An amplifying pattern with mean ridging building over the eastern
U.S. and the noted troughing over the central/western U.S. will
favor warmer, much above average temperatures to the east and
cooler, much below average temperatures to the west through at
least mid-week. Some of the greatest anomalies will be from the
Southern Plains eastward through the Southeast, where highs into
the 80s and low 90s may reach daily record-tying/breaking levels.
Well above average highs into the 70s to low 80s for the Midwest
Wednesday will fall into the 50s and 60s Thursday following a cold
front passage. Highs in the 50s and 60s for the
Mid-Atlantic/Northeast on Wednesday will warm into the mid-60s to
low 80s on Thursday as the ridge builds northward. Areas of the
Central/Northern Plains will remain cooler behind the cold front
with highs ranging from the mid-30s to the mid-50s. In the West,
forecast highs generally range from the 40s in the Interior West,
the 50s in the Pacific Northwest, the 50s and 60s in California,
and the 60s to low 70s in the Desert Southwest.

Putnam

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