Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
312 AM EDT Mon May 15 2023

Valid 12Z Mon May 15 2023 - 12Z Wed May 17 2023

...Above-normal temperatures expand from West into Central U.S....

...Additional heavy rain and flooding possible for parts of the Southern
Plains and Mid-Mississippi Valley into Monday...

...Heavy rainfall threat moving east into the lower Ohio and Tennessee
Valleys on Tuesday...

Record breaking heat over the Pacific Northwest will expand into the
Rockies and Northern/Central Plains over the next few days. High and low
temperatures will be between 20-30 degrees above average in the Pacific
Northwest throughout this week. Additional low temperature records may be
broken across the West Coast tonight with readings likely failing to drop
below the mid 50s. Low temperature records will continue to be rivaled in
the Pacific Northwest through the rest of this week.

Shortwave energy spinning around south Texas will contribute to
thunderstorm activity beginning late this morning and continuing into the
early evening. An isolated storm may turn severe, but the main threat will
be from heavy rainfall. A Slight Risk of Excessive Rainfall leading to
Flash Flooding is in effect over south Texas, due in part to the heavy
rain associated with convection, but also because of the already over
saturated soils from the recent deluge. Another vort to the north will
contribute to more scattered thunderstorms across the Middle Mississippi
Valley today. There's a Slight Risk of Excessive Rainfall leading to Flash
Flooding in place over portions of northeastern Oklahoma, southeastern
Kansas, northern Arkansas and southern Missouri as a result of today's
convection.

The aforementioned piece of energy over the Middle Mississippi Valley will
shift eastward on Tuesday and phase with a descending zonal trough axis.
This will drive the organization of a surface low pressure system over the
Tennessee Valley region and get the once quasi-stationary front draped
across the Central/Southern Plains moving again. More organized convection
is likely to focus along the developing cold front over the Lower
Mississippi to southern Ohio and Tennessee Valleys on Tuesday. A Slight
Risk of Excessive Rainfall leading to Flash Flooding is in effect over
portions of southeastern Illinois, southern Indiana, Kentucky,
northeastern Tennessee, far western North Carolina, central-southern West
Virginia and southwestern Virginia due to a more moist and unstable
environment likely than previously forecast. The latest guidance has the
highest rainfall occurring along an axis of 1-2" extending from eastern
Kentucky through southern Virginia to Maryland's eastern shore on Tuesday.
Elsewhere, scattered showers and thunderstorms are possible over the
Southeast on Tuesday night. A low pressure system descending out of
Alberta Canada will produce scattered to isolated showers and
thunderstorms across the Northern Rockies/Plains on Tuesday night, as well.

Kebede

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