Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Wed Mar 22 2023

Valid 00Z Thu Mar 23 2023 - 00Z Sat Mar 25 2023

...Strong to severe thunderstorms will become a significant concern
beginning Thursday afternoon and continuing through Friday for portions of
the Southern Plains, Lower Mississippi Valley and the Mid-South...

...Widespread heavy rain and flash flooding will become increasingly
likely by Friday across portions of the Lower Mississippi Valley and Ohio
Valley from numerous rounds of showers and thunderstorms...

...Very warm temperatures will persist through the end of the week across
much of the South and the East...

...Unsettled weather and chilly temperatures with locally heavy mountain
snowfall to continue across the West...

While California should see a bit of a break in the very active weather
seen over the last couple of days, the weather should generally remain
unsettled across much of the West as the remnants of the most recent West
Coast atmospheric river continues to advance east and traverses the
Southwest, Great Basin and the central and southern Rockies through
tonight and Thursday. A new storm system and associated cold front will
then arrive in off the Pacific Ocean and advance into the Intermountain
Region on Friday. This will maintain a threat for locally heavy mountain
snowfall for the Great Basin and the central and southern Rockies, but the
new Pacific storm will also bring locally heavy rains to the coastal
ranges of the Pacific Northwest and heavy snowfall for the higher
elevations of the Cascades. The overall heaviest snowfall totals through
the end of week will be in the Cascades where as much as 2 to 3 feet of
snow can be expected. Additional amounts of 1 to 2 feet can be expected
elsewhere for the higher terrain of the Intermountain West. Given the
unsettled weather, abundance of clouds and additional precipitation, the
temperatures will be chilly and will be locally as much as 10 to 20
degrees below normal for daytime highs.

Meanwhile, a very active weather pattern will set up for the end of the
week across portions of the Southern Plains, Lower Mississippi Valley,
Mid-South and Ohio Valley. The remnants of the storm system that hit
California and continues to traverse the Southwest will advance east on
Thursday out across the Southern Plains, and will interact with a strong
cold front draped across the region and with an abundance of moisture
surging north from the Gulf of Mexico into this front. The result will be
developing areas of heavy showers and thunderstorms initially across the
Edwards Plateau and stretching northeast into the Red River Valley of the
South by Thursday night. Some of the thunderstorms may be severe and there
will be concerns for damaging winds, large hail, and a few tornadoes. The
Storm Prediction Center has depicted a Slight Risk of severe weather
across these areas. Some training of these showers and thunderstorms may
occur, and especially as the activity advances northeastward across the
Ozarks and into parts of the Ohio Valley by early Friday morning. As a
result, the stage will become set for excessive rainfall totals and flash
flooding. For the Thursday night and early Friday time frame, the Weather
Prediction Center has depicted a Moderate Risk of excessive rainfall for
the Ozark Plateau.

The overall greatest threat of severe weather and flash flooding though
will occur during the day on Friday and into Friday night as widespread
shower and thunderstorm activity impacts the Lower Mississippi Valley,
Mid-South and Ohio Valley as surface low pressure near the Red River
Valley of the South ejects northeast and strengthens. Widespread severe
weather is anticipated with damaging winds, large hail and tornadoes
expected including some particularly strong tornadoes. In fact, the Storm
Prediction Center has depicted an Enhanced Risk of severe weather for
Friday and Friday night from northern and eastern Louisiana through
southeast Arkansas and western Mississippi. A much broader Slight Risk of
severe weather is depicted across the Lower Mississippi Valley and the
Mid-South. Meanwhile, given a significant threat of seeing multiple
training rounds of showers and thunderstorms, several inches of rainfall
is expected, and there will be a likelihood of seeing areas of flash
flooding from portions of the Lower Mississippi Valley through the Ohio
Valley on Friday. Some of this flash flooding has the potential to be
significant. The Weather Prediction Center has depicted a Moderate Risk of
excessive rainfall with an emphasis on the Ohio Valley.

Elsewhere across the South and many areas of the East ahead of this
developing storm and associated front, very warm temperatures will be in
place with many areas seeing daytime highs well above normal. Many areas
of the Gulf Coast, Mid-South, and Southeast will see high temperatures
well into the 80s through the end of the week, and thus very springlike.

Orrison


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