Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
333 AM EDT Thu Apr 18 2024

Valid 12Z Thu Apr 18 2024 - 12Z Sat Apr 20 2024

...Severe weather and isolated flash flooding for the Middle
Mississippi/Lower Ohio Valleys and Southern Plains Thursday...

...Showers, thunderstorms, and cooler weather for much of the Southern
Plains Friday; wintry mix into the central High Plains...

...Unseasonably warm conditions for much of the southern U.S.; chillier
weather expands across the northern Rockies/Plains and Upper Midwest...

A weakening system over the Northeast will bring some shower chances to
the northern Mid-Atlantic into New England Thursday. To the west, a much
broader area of showers and thunderstorms is expected ahead of a cold
front from the Middle Mississippi/Lower Ohio Valleys southwestward through
the Southern Plains. Sufficient shear and instability will be in place in
the Middle Mississippi/Lower Ohio Valleys for some organized
thunderstorms/line segments, with the Storm Prediction Center noting an
Enhanced Risk (level 3/5) for severe weather. Very large hail, damaging
winds, and a few tornadoes will all be possible. A Slight Risk (level 2/5)
extends southwestward along the front into Texas, with a more isolated
threat for some large hail and damaging winds. The prospect of widespread
storm coverage, especially for areas further north through the Middle
Mississippi Valley, and the potential for heavy downpours may lead to some
isolated flash flooding as well.

Shower and thunderstorm chances will progress eastward with the advancing
cold front into the Appalachians by Friday morning and eventually the East
Coast by Friday evening, though coverage and intensity looks to trend
downward during the day as the front approaches the coast. A few isolated
severe thunderstorms may occur over the Southeast. Areas of moderate to
rainfall will linger over portions of the Southern Plains along and north
of the cold front over Texas as it begins to slow and stall over the
region. Some isolated flooding will be possible. Post-frontal upslope flow
will also bring precipiation chances to the central High Plains and Front
Range of the Rockies, with a mix of rain and snow showers for lower
elevations and snow into the mountains. Any accumulations at the lower
elevations should remain minimal.

Forecast high temperatures remain rather warm to even hot across southern
portions of the country Thursday, with highs in the mid-80s to near 90
from Texas eastward through the Southeast, and even as far north as
portions of the Middle Mississippi and Lower Ohio Valleys. Areas of west
Texas and along the Rio Grande Valley will see mid- to upper 90s.
Conditions will be similarly hot in the Desert Southwest. The southerly
progression of the cold front will bring much cooler temperatures Friday
across northern Texas and into the Mid-South and Tennessee Valley as highs
drop into the 60s and 70s. Conditions will remain hot south of the frontal
boundary.  Further north, highs will range in the 50s and 60s across the
central Plains northeastward into the Great Lakes region, with 60s and 70s
from the Ohio Valley into the southern Mid-Atlantic. The northern
Mid-Atlantic into New England will be a bit chilly Thursday with highs in
the 40s and 50s, with temperatures expected to recover a bit Friday. Cold
temperatures will also expand in coverage across the northern
Rockies/Plains and Upper Midwest as high pressure settles in over the
region, with highs in the 30s and 40s. In the West, highs will range from
the 60s and 70s from the Pacific Northwest southward through coastal
California and inland across the Great Basin, with 80s for the central
California valleys.

Putnam

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