Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Tue Apr 29 2025

Valid 12Z Tue Apr 29 2025 - 12Z Thu May 01 2025

...Strong to severe thunderstorms to impact the interior Northeast into
the Ohio Valley later today into this evening...

...An episode of heavy rain is expected to bring flash flooding concern
across the south-central U.S. through early Thursday...

An elongated low pressure system is currently moving fairly quickly
eastward across the upper Great Lakes into southern Canada.  Scattered
strong to severe thunderstorms forming ahead of the trailing cold front
will continue to advance eastward through the remainder of the Great Lakes
today before sweeping across the Northeast tonight.  Daytime heating under
a warm southwesterly flow across the eastern U.S. today will promote more
active formation of thunderstorms especially over the interior Northeast
later today into the evening hours when the dynamics associated with the
cold front are forecast to be the most vigorous.  The Storm Prediction
Center (SPC) maintains as high as an Enhanced Risk (level 3/5) of severe
weather for the interior Northeast into the Ohio Valley through tonight
with high winds and hail being the primary threats.  The front is expected
to clear the entire Northeast by Wednesday morning, ending the threat of
severe weather as gusty westerly winds usher much cooler and drier air
from the Great Lakes into the Northeast ahead of a high pressure system. 
The high pressure system will continue to settle into the Northeast,
bringing a chilly and dry morning into the region by Thursday morning.

Meanwhile, the trailing portion of the aforementioned cold front is
forecast to stall across the southern Plains through tonight before
beginning to lift northeastward on Wednesday as a warm front.  An episode
of heavy rain is expected to impact areas from northern Texas into a large
portion of Oklahoma toward the mid-Mississippi Valley as the front remains
nearly stationary.  Given the already saturated grounds from recent heavy
rainfall, and the potential for an additional 2 to 4+ inches of rain, the
Weather Prediction Center maintains a Moderate Risk (level 3/4) of
excessive rainfall for portions of the aforementioned areas through
Wednesday.  Numerous instances of flash flooding are possible by later
today, some of which could potentially be significant.  On Wednesday, the
focus for significant heavy rain and flash flooding shifts only slightly
east from the southern Plains toward the western Ozarks of Arkansas where
another day of a Moderate Risk highlights the concern for numerous
instances of flash flooding due to repeated training of strong to severe
thunderstorms for these areas.  The SPC maintains a slight to enhanced
risk of severe thunderstorms.  By later on Wednesday into Thursday
morning, a low pressure wave is forecast to form over the southern Plains
and then track toward the Midwest, ending the threat of severe weather
across the southern Plains as scattered shower and thunderstorms expand
into the Midwest and Ohio Valley ahead of a warm front.

The Pacific Northwest will see the latest round of unsettled weather
entering the region today before spreading into the northern Rockies in
the form of wet snow for the higher elevations on Wednesday.  The wet snow
in the mountains and lower elevation rain will dip into the central
Rockies and the Great Basin by early Thursday morning behind a cold front
and a developing low pressure wave over the central High Plains.

A strong ridge of high pressure extending across much of the
central/eastern U.S. will bring well above average warmth to much of the
region through midweek.  Forecast highs in the 70s and 80s will be common,
including for more northern locations like the Midwest and Northeast ahead
of the cold front.  Temperatures will begin to return back closer to
average over the West today, with highs generally ranging in the 60s and
70s, with 80s into the Desert Southwest.  Overall near average
temperatures continue for the West on Wednesday with above normal
temperatures continuing for much of the East.  The exceptions to the
warmth will be an influx of chilly air in the wake of the cold front
across portions of the Great Lakes and interior Northeast.

Kong/Miller


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