Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
359 AM EDT Thu Jul 28 2022

Valid 12Z Thu Jul 28 2022 - 12Z Sat Jul 30 2022

...Moderate Risks of Excessive Rainfall out for parts of the
Ohio/Tennessee Valleys where flash flooding, potentially both significant
& life threatening, is possible today...

...Steady stream of monsoonal moisture to cause daily rounds of excessive
rainfall and flash flooding across portions of the Southwest and
southern/central High Plains with Slight to Moderate Risks of excessive
rainfall...

...Heat wave to continue in the Pacific Northwest; stifling heat to stick
around in South-Central U.S. and Southeast the rest of the week; coolest
temperature anomalies in the Central Plains & Midwest...

The second half of the week continues to be headlined by a seemingly never
ending fire hose of monsoonal and Gulf of Mexico moisture that is
producing a conveyor belt of heavy rain and thunderstorms from the
Southwest to the central Appalachians. After multiple days worth of heavy
rainfall in parts of the Ohio/Tennessee Valleys and central Appalachians,
the prospect of additional heavy rain and thunderstorms makes these
regions more vulnerable to flash flooding, as well as rising creeks,
streams, and rivers. The steady onslaught of rich atmospheric moisture and
potential for training thunderstorms makes it likely that additional flash
flooding is anticipated in these areas. As a result, a Moderate Risk
(threat level 3/4) is in place for eastern Kentucky, southern West
Virginia, and far southwest Virginia. It is here where flash flooding is
not only likely to unfold at times today, but flash flooding could be
significant to even life-threatening in spots. The threat for flash
flooding extends as far west as the Middle Mississippi Valley and as far
east as the central Appalachians where Excessive Rainfall rates may lead
to flash flooding in these areas as well. By Friday, a cold front
approaching from the north will push this conveyor belt of rain and
thunderstorms a little farther south into the heart of the Mid-South, but
parts of West Virginia, eastern Kentucky, and southwest Virginia remain
under a Moderate Risk for flash flooding.

Farther west, the Southwest and southern High Plains will contend with
their own deluge of heavy rain and thunderstorms thanks to the steady
influx of rich monsoonal moisture being fed directly into the region.
Daily episodes of strong thunderstorms containing heavy downpours atop
areas with increasingly saturated soils are ripe for potential flash
flooding. Locations most at risk for flash flooding are in/near burn
scars, within slot canyons, and within more urbanized communities. The
region perhaps with the most favorable setup for flash flooding is in the
southern Rockies and High Plains, where a stalled frontal boundary and
copious amounts of atmospheric moisture will result in slow moving
thunderstorms capable of producing Excessive Rainfall rates. A Moderate
Risk for flash flooding has been issued in southern Colorado, northern New
Mexico, and portions of the Oklahoma and Texas Panhandles where
potentially significant flash flooding is possible. A Moderate Risk for
flash flooding is also out for parts of southeast Colorado, southwest
Kansas, and the Oklahoma Panhandle on Friday. Slight Risks (threat level
2/4) for flash flooding likely continue to be in the forecast for parts of
Arizona and New Mexico into the upcoming weekend.

Regarding the temperature forecast across the CONUS, a pair of upper level
ridges; one in the Pacific Northwest and one off the Southeast coast, are
responsible for sultry conditions in the Northwest and Southeast. The most
anomalously hot conditions will be in the Pacific Northwest where a heat
wave is forecast to continue through the end of the week. High temps from
the Columbia Basin on south into central Oregon and far northern
California will soar into the triple digits. Highs temps in and around the
Seattle and Portland metro areas look to routinely hit the mid 90s and
even make a run at the century mark through Saturday. Daily record highs
will likely be broken throughout the Northwest as daytime highs range
between 20-25 degrees above normal. In the Southeast, the hottest
temperature departures will be most commonly found in the Carolinas on
south into Georgia and the Florida Panhandle. High temps will still make a
run at triple digits in the Southern Plains as well. In addition, daytime
minimum temps remain quite warm with record warm minimums possible across
the South through Saturday morning. The coolest temperature anomalies the
second half of the week are set to be in the Central Plains, Midwest, and
Great Lakes.

Mullinax


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