Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
410 AM EDT Fri Jul 14 2023

Valid 12Z Fri Jul 14 2023 - 12Z Sun Jul 16 2023

...Dangerous heat wave to stretch from the West Coast to the Gulf Coast;
at least 93 million people are under Excessive Heat Warnings and Heat
Advisories as of this morning....

...Friday features an expansive threat for Excessive Rainfall, highlighted
by a Moderate Risk for portions of the Northeast; severe weather likely in
the Central Plains...

...Saturday remains active with numerous heavy showers & storms in the
East; Slight Risk for Excessive Rainfall in the southern High Plains...

This weekend features no shortage of significant weather headlines that
are led by stifling heat, excessive rainfall, and severe weather. Shining
the spotlight on the heat first, a searing heat wave is set to engulf much
of the West Coast, the Great Basin, and the Southwest. This is the result
of an upper level ridge of high pressure over the southwestern U.S. that
is forecast to strengthen throughout the weekend. Friday will feature some
record heat in parts of the Southwest, but record-breaking heat expands
even more throughout the region on Saturday. Daytime highs by Saturday
will range between 105-115F from the Great Valley of CA to the Desert
Southwest. Some parts of the desert region of southern CA, southern NV,
and southern AZ could see daytime highs top 120F. Farther east,
oppressively hot and steamy conditions will persist from Texas and the
Lower MS Valley to Florida. Heat indices today look to range between
100-110F on average, with up to 115F readings possible along the immediate
cast of Texas and Louisiana. Expect similar heat indices in the South
Central U.S. and Florida on Saturday. In addition to the sizzling high
temperatures and heat indices, morning lows across the southern tier of
the U.S. will remain exceptionally warm, providing little in the way of
relief to these affected regions. Numerous Excessive Heat Warnings and
Heat Advisories have been issued from the West Coast to South Florida,
resulting in over 93 million Americans being placed under one of these two
heat-related hazards. For more information on the scope of the heat and
its impacts, please visit heat.gov for more information.

Elsewhere, a pair of frontal boundaries; one in the Northeast and another
crossing the Nation's Heartland will be the focus for widespread heavy
showers and thunderstorms. In terms of Excessive Rainfall, a few Slight
Risks (threat level 2/4) have been posted for portions of the Mid-South,
the southern Mid-Atlantic, and the Northeast. Flood Watches are in place
for parts of these affected regions early this morning. There is a more
serious Moderate Risk (threat level 3/4) in place for parts of southern NY
and central New England where the combination of torrential downpours over
the region's highly saturated soils make them particularly vulnerable to
flash flooding. There is also a threat for severe weather as the Storm
Prediction Center has issued a Slight Risk for the Central Plains and a
Marginal Risk that includes not only areas from the central High Plains to
the Great Lakes, but also the I-95 megalopolis from Richmond/Washington
D.C. to NYC and Boston.

By Saturday, most of the eastern third of the Lower 48 is under a Marginal
Risk (threat level 1/4). WPC's Excessive Rainfall Outlook also highlights
the southern High Plains with a Slight Risk. The Storm Prediction Center
indicates the best threat for severe weather is forecast to occur in the
eastern Great Lakes, Upper Ohio Valley, and central Appalachians where a
Marginal Risk has been issued. For those wanting to escape the heat this
weekend, the Upper Midwest and both the central and northern High Plains
will see a pair of cold fronts inject seasonally cooler temperatures from
Canada into these regions. Daytime highs will range anywhere from 5-15
degrees below normal there. The driest conditions are set to occur in the
western third of the U.S., the Dakotas, and along the western Gulf Coast.

Mullinax


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