Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
354 AM EDT Wed May 24 2023

Valid 12Z Wed May 24 2023 - 12Z Fri May 26 2023

...Isolated to scattered locally heavy rain and severe thunderstorms to
impact parts of the Southeast, Great Basin, northern Rockies, and much of
the High Plains over the next few days...

...Well above average temperatures confined to the northern Plains through
Thursday, while much cooler temperatures are set to enter the Midwest and
Northeast...

A subtly active and stormy pattern will continue across much of the
country over the next couple of days, with multiple focus areas for
isolated flash flooding and severe weather chances. A frontal boundary
draped across the Florida Peninsula westward through the Southern Plains
will be the driver for some of these thunderstorms. Moist onshore flow
over the quasi-stationary front over Florida will help to trigger heavy
rain producing thunderstorms on Wednesday, with an isolated risk of flash
flooding. The front should shift far enough south and east to bring down
rain chances/rainfall totals on Thursday. To the west, very moist,
southeasterly upslope flow north of the front over the central/southern
High Plains will help to initiate heavy rain producing thunderstorms and
thunderstorm complexes that will propagate southeastward into the Southern
Plains. Some of these storms may initially be severe, and the Storm
Prediction Center has issued a Slight Risk (level 2/5) of severe weather
Wednesday as sufficient shear will be available for a few supercell
thunderstorms with the risk for large hail. Additional storms are possible
along residual outflow boundaries left across the region from the expected
convective complexes, keeping the chance for locally heavy rainfall and
some isolated instances of flash flooding over the region up but the exact
location and attendant level of risk a bit nebulous. High temperatures
will be a bit below average for late May behind the front with residual
storms and cloud cover around. Mid-70s to low 80s can generally be
expected, with warmer temperatures into the mid-80s to low 90s in the
Lower Mississippi Valley, away from the gloomier conditions, and south of
the front over portions of Texas. 

A slow moving upper-level trough over the West and attendant surface
boundary snaking through the northern Rockies and Great Basin will be yet
another trigger of stormy weather the next couple of days. The boundary
will help to initiate daily rounds of showers and thunderstorms, with
anomalously high moisture lingering over the region contributing to some
locally heavy rainfall. Some isolated instances of flash flooding will be
possible around terrain sensitive areas and over burn scars. Forecast
highs will be near to above average for most of the West, with 70s to low
80s for the Rockies, Great Basin, and Pacific Northwest and mid- to upper
90s for the Desert Southwest. One exception will be the California coast,
where onshore flow and cloudy conditions will keep temperatures cool and
in the 60s.

A cold front from Canada pushing south across the Great Lakes and
Northeast will spread much cooler temperatures through the region over the
next couple of days. Highs will remain in the 70s to low 80s ahead of the
front over the Northeast and Ohio Valley on Wednesday with temperatures
falling into the 40s and 50s behind the front across much of the Great
Lakes. Temperatures will fall into the 60s for the Northeast following the
passage of the front on Thursday, while conditions will moderate into the
60s over the Great Lakes. Some showers and thunderstorms will accompany
the frontal passage mainly over New England, with moderate to locally
heavy rainfall possible. Further west, highs will remain well above
average and early summer-like over the northern Plains under the influence
of an upper-level ridge, reaching into the mid-80s for many locations. 

Putnam


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