029
FXUS01 KWBC 071945
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
344 PM EDT Tue May 07 2024

Valid 00Z Wed May 08 2024 - 00Z Fri May 10 2024

...Severe thunderstorm and flash flood threat forecast across much
of the Midwest, Tennessee and Lower Mississippi valleys, as well
as into parts of the Southern Plains over the next few days...

...Heavy snow to impact the Northern Rockies with well below
average temperatures throughout much of the Rockies and
Intermountain West...

...Triple digit and potentially record-breaking heat over southern
Texas on Wednesday and Thursday...

A mature and vertically stacked low pressure system over the
Northern Plains, along with its attached frontal boundaries, are
expected to be the driving force behind much of the impactful
weather to affect the Lower 48 over the next few days. This low is
expected to begin weakening tonight and slide eastward into the
Ohio Valley by Thursday before approaching the Mid-Atlantic by
early Friday. As it eventually makes the trek eastward, several
chances for severe weather and heavy rain are possible from the
Midwest and Ohio Valley to the Southern Plains, Lower Mississippi
and Tennessee valleys. The threat this evening starts in the
Midwest, specifically over Indiana, western and central Ohio, and
northern Kentucky. A few storms in this region could produce large
to very large hail, damaging wind gusts, and a few (some strong)
tornadoes. Additionally, isolated flash flooding is possible from
downpours associated with the strong thunderstorms. By Wednesday,
the severe weather and heavy rain threat is expected to shift
southward along a gradually lifting warm front extending from the
mid-Mississippi to the Ohio Valley. The Storm Prediction Center
has issued a rather expansive Enhanced Risk (level 3/5) from
northeast Texas to far western Virginia, which includes much of
the lower Ohio Valley, Tennessee Valley, and middle to lower
Mississippi Valley. Scattered to numerous thunderstorms appear
likely in this region, with all modes of severe weather possible.
The greatest flash flooding threat also overlaps with the risk of
severe thunderstorms, centered over Kentucky and Tennessee as well
sections of neighboring states. Residents and visitors are advised
to have multiple ways of receiving warnings and never drive across
flooded roadways. As the cold front shifts further south on
Thursday the active weather will reposition to the Southeast and
Gulf Coast States, where additional rounds of scattered severe
thunderstorms and flash flooding are possible.

On the northwest and colder side of this system, winter-like
weather and gusty winds are possible across the Northern Rockies
and northern High Plains through Wednesday. Over a foot of snow is
forecast across the elevated terrain of western Montana and
Wyoming as strong moisture flux and favorable upslope flow
interacts with anomalously cold air aloft to produce snow.
Meanwhile, strong winds with gusts up to 65 mph on the western
side of the low throughout the northern High Plains are expected
through tonight, which has prompted High Wind Warnings and Wind
Advisories to stretch from northern Montana to South Dakota. Below
average temperatures also wrap around the western side of the
system underneath scattered clouds and northerly flow. Highs are
forecast to remain 10 to 20 degrees below average on Wednesday
until a return to near average temperatures (outside of the
Rockies) on Thursday.

Conversely, above average warmth is expected across the Southern
Plains and much of the eastern U.S., besides a cloudy New England.
Highs into the 80s and low 90s will be widespread on Wednesday,
with a few scattered record highs possible. For South Texas,
afternoon temperatures are anticipated to soar into the triple
digits, which could pose a danger for individuals with health
conditions or people spending time outdoors for long stretches.
Heat Advisories have been issued for this region.

Snell


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

$$