Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
349 PM EDT Sat Jun 24 2023

Valid 00Z Sun Jun 25 2023 - 00Z Tue Jun 27 2023

...Oppressive heat continues for portions of the south-central U.S. this
weekend, expanding into the Southwest on Monday...

...Risk of severe weather and some flash flooding moves from the
Midwest/Lower Mississippi Valley Sunday to the Mid-Atlantic Monday...

...Rain chances continue for the northern High Plains as much of the West
sees below average temperatures...

The oppressive heat over portions of the south-central U.S. will continue
as an anomalous upper-level ridge remains in place over northern
Mexico/Texas. High temperatures Sunday and Monday will range form the low
100s for east Texas to upper 100s/low 110s for west Texas and southeastern
New Mexico. However, higher humidity closer to the Gulf Coast will lead to
heat indices in the 110-115 degree range for much of east Texas. More
daily record-tying/breaking high temperatures are possible, with
record-tying/breaking warm lows providing absolutely no relief from the
heat overnight. Anomalously warm temperatures will begin to spread into
the Desert Southwest Monday as the upper-level ridge builds northwestward,
with highs over 110 forecast for southern Arizona.

Showers and thunderstorms will begin to taper off for most of the East
Coast Saturday evening into early Sunday morning as a lingering frontal
boundary over the region dissipates. Another front pushing south from
Canada will keep the chance for some locally heavy rain up up over
portions of the Interior Northeast/New England. Further west, an
organizing low pressure/frontal system over the Midwest will moves
eastward over the next couple of days, bringing widespread showers and
thunderstorms and the risk of severe weather and some flash flooding from
the Mississippi Valley to the East Coast.  Rich gulf moisture flowing
northward ahead of the front will contribute to very strong CAPE as a
passing upper-level wave and increased winds aloft provide sufficient
deep-layer shear for severe storms on Sunday. The Storm Prediction Center
has issued an Enhanced Risk of severe weather (level 3/5) for portions of
the Ohio/Tennessee Valleys with a broader Slight Risk (level 2/5) in place
across the Midwest/Lower Mississippi Valley in anticipation of the mix of
some supercells as well as more organized clusters/lines of storms, with
the primary threat of damaging winds in addition to some large hail and a
few tornadoes. The rich moisture will also contribute to the potential for
heavy rainfall, with a Marginal Risk of Excessive Rainfall (level 1/4) in
place as clusters of storms may lead to some locally heavy rain totals,
but progressive storm motions should limit the areal extent of the threat.

Showers and storms will return to much of the East Coast on Monday as the
frontal system pushes eastward. Widespread convection is expected to
develop over the Mid-Atlantic, with portions of the area under a Slight
Risk of Excessive Rainfall (level 2/4). Locally heavy rain totals of 1-3"
over progressively wetter soils given the recent upward trend in rain the
past few days may lead to some scattered instances of flash flooding.
Strong CAPE over portions of central North Carolina may also lead to some
more intense thunderstorms capable of damaging winds and large hail, with
a Slight Risk of severe weather in place. Forecast highs will range from
the mid-80s to low 90s for much of the East. Hotter temperatures into the
mid- to upper 90s are expected Sunday over portions of the Lower/Middle
Mississippi Valley ahead of the frontal system and cooler temperatures in
the 70s will follow the passage of the system for the Great Lakes. 

Energetic upper-level flow over the northern tier of the Plains/West will
keep precipitation chances up over the next couple of days. Lingering
moisture over portions of the northern High Plains may contribute to some
locally heavy rainfall totals. High temperatures across the region will
generally be below average, with some areas as much as 10-20 degrees below
average. Cloudy and rainy conditions will keep highs in the mid-70s to low
80s for the northern High Plains. An upper-level trough lingering over the
West Coast will also keep temperatures down, with 60s to low 70s for
coastal California and upper-70s to mid 80s for the central valleys and
the Great Basin. Highs will be closer to average in the Pacific Northwest,
with 70s to low 80s for the I-5 urban corridor and mid-80s for the
interior.

Putnam


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