Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
355 AM EDT Mon Jul 25 2022

Valid 12Z Mon Jul 25 2022 - 12Z Wed Jul 27 2022

...Excessive heat to continue across portions of the Southern Plains and
Lower Mississippi Valley early week; Pacific Northwest heat wave to
kickoff this week....

...Stormy and soaking weather pattern to setup from the Middle Mississippi
Valley to the central Appalachians...

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

The stifling heat that enveloped much of the Northeast and Mid-Atlantic
this weekend will be on its last leg today as daytime highs make one last
run at the low-mid 90s from central Virginia on north to southern New
England. Some areas could still see heat indices in the triple digits,
supporting Heat Advisories and Excessive Heat Warnings being posted in
portions of southern New England, the Philadelphia metro area, and on
south to the DelMarVa Peninsula. In the Heartland, an even larger
footprint of Heat Advisories and Excessive Hear Warnings are in place in
the Southern Plains and Lower Mississippi Valley today. Unlike their
neighbors in the Northeast, where a cold front will bring about the return
of more seasonal temperatures on Tuesday, sizzling temps will stick around
in the South Central U.S.. In the Northwest, a strengthening upper level
ridge over the northeast Pacific and western Canada sets the stage for a
heat wave to engulf the Pacific Northwest through mid-week. Daytime highs
will surpass the 90s each day and even eclipse the century mark in the
Columbia River Gorge and Columbia River Basin. This prompted the issuance
of numerous Excessive Heat Warnings/Watches and Heat Advisories throughout
much of the region. Daily record highs will likely be broken from northern
California to the Portland and Seattle metro areas on Tuesday. Record warm
minimum temps are also expected in similar parts of the Pacific Northwest
through Wednesday.

A quasi-stationary frontal boundary draped across the nation's mid-section
from the Central Plains to the Mid-Atlantic coast becomes the focus for
daily rounds of showers and thunderstorms. Southerly flow emanating out of
the Gulf of Mexico will provide storms with the necessary moisture to
produce copious amounts of rainfall from the Midwest to the Tennessee
Valley and central Appalachians. In response to this threat for heavy
rainfall, a pair of Slight Risks (threat level 2/4) for Excessive Rainfall
have been issued for parts of these regions today. In addition to the
flash flood threat in these areas, there is also a Slight Risk (threat
level 2/5) for severe weather up and down the Northeast/Mid-Atlantic I-95
megalopolis today with damaging winds the most prominent severe threat. By
Tuesday, the front does not make much progress across the Ohio Valley,
which is where a Slight Risk for Excessive Rainfall is in place. Come
Wednesday, the front shifts slightly to the south, but after multiple days
of heavy rain and another rich plume of moisture delivering more excessive
rainfall, a Day 3 Moderate Risk (threat level 3/4) has been issued for
much of West Virginia.

Meanwhile, in the Southwest, the monsoon remains in full swing with plenty
of moisture aloft and numerous showers and thunderstorms each afternoon
and evening. Both Monday and Tuesday, there are Slight Risks for Excessive
Rainfall in parts of the Four Corners region, which includes Arizona, New
Mexico, Utah, and Colorado. Areas most at risk for flash flooding are
areas near burn scars, within slot canyons, and in locations with
abnormally saturated soils. Elsewhere, a cold front tracking across the
Northern Plains Monday night and into the Upper Mississippi Valley on
Tuesday will spark scattered showers and storms across these regions. In
the Southeast, diurnally driven showers and thunderstorms will dot the
Gulf Coast on east to the Southeast coast today.

Mullinax


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