Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
357 AM EDT Sun Jul 24 2022

Valid 12Z Sun Jul 24 2022 - 12Z Tue Jul 26 2022

...Over 85 million Americans are under Excessive Heat Warnings & Heat
Advisories today; Sultry Sunday from the Northeast to the Southern Plains;
increasingly hot conditions in the Pacific Northwest into next week....

...Severe thunderstorms capable of producing flash flooding in the eastern
Great Lakes and Northeast today; severe weather & flash flood threat to
stretch from the Middle Mississippi Valley to the Mid-Atlantic Coast on
Monday...

...Monsoonal moisture to cause daily rounds of excessive rainfall and
isolated flash flooding across portions of the Southwest and Southern
Rockies through Monday...

The steadfast ridging pattern over the Mid-Atlantic and Mid-South sticks
around to close out the weekend, resulting in dangerous temperatures
stretching from the Southern Plains to the Northeast. Numerous records
highs are forecast to be tied and/or broken today in the Northeast as
highs make a run at the century mark and heat indices range between
105-110 degrees. Stifling heat is also on tap from central Kansas and
Oklahoma to the Middle Mississippi Valley where a large swath of Heat
Advisories and a few Excessive Heat Warnings are in place. By Monday, an
approaching cold front will help to cool down the Great Lakes and
eventually the Northeast by evening, but the ridge remains entrenched over
the Lower Mississippi Valley through Tuesday, keeping abnormally hot
temperatures in place the first half of the week. Meanwhile, a building
upper level ridge in the northeast Pacific and along the British Columbia
coast is responsible for what will become a prolonged heat wave in the
Pacific Northwest starting today and peaking the second half of the week.
Daily record high temps are possible from northern California to the
Portland and Seattle metro areas by this coming Tuesday.

It is also a rather active period in terms of severe weather and potential
flash flooding. A strong cold front sweeping across the Great Lakes will
be the catalyst for strong-to-severe storms from northern New England on
south and west to the Ohio Valley. SPC does have an Enhanced Risk (threat
level 3/5) of severe weather in western New York, northwest Pennsylvania,
and northeast Ohio. There is also a Slight Risk (threat level 2/4) for
Excessive Rainfall in similar areas today but an elongated Marginal Risk
(threat level 1/4) extends from the Middle Mississippi River Valley to
northern New England. By Monday, the cold front pushes through the
Northeast and Mid-Atlantic, prompting SPC to issue a Slight Risk for
severe storms for the I-95 Northeast megalopolis. Farther west, the cold
front will slow down and become quasi-stationary from the central
Appalachians to the Middle Mississippi Valley, supporting the development
of numerous showers and thunderstorms. Slight Risks for Excessive Rainfall
are in place for parts of the Midwest, central Appalachians, and Tennessee
Valley on Monday due to the potential for areas of flash flooding.

In the Southwest, a seemingly endless feed of moisture as a result of
prolonged monsoonal flow will lead almost carbon-copy type forecasts the
next few days. Slight Risks are in place for portions of Arizona, Utah,
New Mexico, and Colorado today, Monday, and Tuesday. Strong and slow
moving thunderstorms containing Excessive Rainfall rates could lead to
areas of flash flooding. Locations most at risk for flash flooding are
near burn scars, in slot canyons, within urbanized areas, and atop overly
saturated soils. Even by the middle of the week, WPC's experimental Day 4
Excessive Rainfall Outlook contains a pair of Slight Risks in the
Southwest. This means the flash flood threat is forecast to linger through
them middle of the upcoming week and potentially into the second half of
next week. Elsewhere, diurnally-driven showers and thunderstorms will be
daily occurrences in the Southeast over the next couple days with the bulk
of the thunderstorm activity forming during the afternoon and dissipating
each evening.

Mullinax


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