Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
355 PM EDT Thu Jul 21 2022

Valid 00Z Fri Jul 22 2022 - 00Z Sun Jul 24 2022

...Dangerous heat to continue impacting portions of the southwestern,
south-central, and eastern U.S....

...Severe thunderstorms possible across sections of the East Coast and the
Southeast today...

...Monsoonal moisture to bring locally heavy rains and isolated flash
flooding across portions of the Southwest into the southern Rockies...

The bulk of the country will continue to see above average temperatures
through the end of the week, with a significant portion of the population
remaining under heat-related advisories and warnings. These areas include
the Southwest, where an Excessive Heat Warning for today and tomorrow
extends from southeastern California and western Arizona northward into
southern Nevada and southern Utah. Daytime temperatures are forecast to
soar well above 100 degrees across much of the region both days -- topping
110 in many lower elevation locations, and some record highs are possible.
Overnight lows are likely to remain in the 80s in many spots, providing
little nighttime relief.

From the southern Plains to the lower Mississippi and Tennessee Valleys, a
weak front that has dropped in the region could continue to bring
thunderstorms and some heat relief to parts of the region today compared
to previous days with record-setting heat. However, it will remain quite
warm and humid across the much of the region, and Heat Advisories continue
to cover portions of eastern Oklahoma and Texas eastward, with some
embedded Excessive Heat Warnings across parts of the lower Mississippi
Valley and Deep South. Temperatures are expected to remain above average
through the period, with daytime heat indices expected to climb well above
100 degrees across much of the region each day. Farther north,
temperatures are forecast to heat up through the end of the week across
northern and central parts of the Plains and Mississippi Valley, until a
cold front brings some notably cooler temperatures into the northern
Plains and the upper Midwest beginning Saturday.

Finally, Heat Advisories along with localized Excessive Heat Warnings in
eastern Virginia also stretch across parts of the East Coast with warm and
humid air in place ahead of a cold front. Though the cold front is
relatively weak in terms of temperature differences, it is helping support
ongoing severe weather that could continue through this evening from the
Carolinas northward across parts of the Mid-Atlantic and Northeast. Slight
Risks of severe weather and Severe Thunderstorm Watches are in place from
the Storm Prediction Center, and localized flash flooding is possible as
well where rain rates are high. Severe weather and excessive rainfall are
also threats over parts of the Southeast this evening as storms fire there
and could move slowly.

Monsoonal moisture is forecast to fuel daily showers and thunderstorms
from eastern Arizona into the southern Rockies mainly during the afternoon
and evening. While widespread heavy amounts are not expected, storms that
develop may have the potential to produce locally heavy accumulations,
with isolated flash flooding possible. Additionally, a couple of frontal
boundaries and low pressure systems will help support scattered
thunderstorms in the north-central U.S. over the next few days. Chances
for severe weather will increase there by the weekend, and the Storm
Prediction Center already indicates an Enhanced Risk over the Upper
Midwest Saturday.


Tate/Pereira


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