Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Mon Jul 10 2023

Valid 12Z Mon Jul 10 2023 - 12Z Wed Jul 12 2023

...Heavy rain is likely to produce the potential for significant flash
flooding throughout parts of New England on Monday...

...Additional rounds of severe weather and flash flooding persist across
the Central/Southern Plains and Midwest...

...Anomalously hot weather continues for portions of the Florida
Peninsula, central and southern Plains, and the Southwest...

A slow-moving frontal system located over the Mid-Atlantic is the focus
for ongoing heavy rainfall as synoptic forcing and a very moist airmass
combine to create an environment ripe for flash flooding. Current radar
and observations show the heaviest of rainfall generally moving from south
to north across portions of New England, much of which is heavy,
persistent rainfall. Orographic lift will act to enhance rainfall in
regions of high terrain. Several additional inches of rainfall is expected
through Tuesday morning as this system slowly moves eastward. To make
matters worse, this region is sensitive to flash flooding due to recent
instances of heavy rainfall. For these aforementioned reasons, WPC has
issued a High Risk (level 4/4) of Excessive Rainfall for portions of
northern Vermont and the Champlain Valley. Residents and visitors are
advised to heed any warnings and never drive through a flooded roadway. If
driving is necessary, be sure to check current road conditions before
venturing out as over 50% of all flash flooding deaths occur within
vehicles. Where terrain is most susceptible, mud slides cannot be ruled
our across Vermont as well. The system should finally exit much of the
region by Tuesday morning and only offer a few remaining scattered shower
chances.

The severe weather and heavy rain threat is expected to ramp up across
portions of the Great Plains during the early part of the week. In the
southern Plains, confidence of the formation of a mesoscale convective
system (MCS) is increasing. Given the moist environment in place, these
thunderstorms may have the potential to produce localized instances of
flash flooding in addition to strong wind gusts. A more potent severe
weather event is expected across the Northern High Plains toward the
Mid-Mississippi Valley beginning on Tuesday. A cold front progressing
southward from the Canadian High Plains will become quasi-stationary
across the central Plains/Midwest and become the focus for heavy rainfall.
In addition, an MCS is expected to develop across the region on Tuesday.
This system has the potential to produce heavy rain for an extended
portion of the country. This system will move southeastward toward the
Mid-Mississippi Valley on Wednesday, with heavy rain impacts expected for
portions of the Mid-Mississippi Valley. Slight Risks of Excessive Rainfall
are in effect on Tuesday across the northern High Plains/Mid-Missouri
Valley and on Wednesday across the Mid-Mississippi Valley and Lower Great
Lakes.

Heat will continue early this week across much of the Southern Tier,
including the Southwest, Texas, and the Florida Peninsula. Widespread
highs of 100F+ can be expected across the southern High Plains and
Southwest, with higher temperatures possible over Arizona. The oppressive
heat in combination with high humidity may allow heat indices to exceed
100F across portions of the central Plains, with 110F+ heat indices
degrees throughout portions of South Texas and the Desert Southwest
throughout the early week. Dangerous conditions are possible if citizens
are unable to find relief in air conditioned buildings. On Wednesday, the
signal for heat increases, with widespread 100F+ heat indices expected
across much of the central Plains. In addition, High heat indices are
possible over portions of southern Florida early this week, where heat and
high humidity may near 110F.


Snell/Genz


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