Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
356 AM EDT Mon Sep 05 2022

Valid 12Z Mon Sep 05 2022 - 12Z Wed Sep 07 2022

...Blistering heat continues over the next few days throughout the West
and into the northern/central Plains...

...Scattered to numerous flash floods possible early this week from
southern New England to the southern Appalachians...


Mother Nature has turned up the heat this Labor Day as record-breaking
temperatures continue across a large region extending from California to
the northern/central High Plains. An exceptionally anomalous ridge has set
up over the central Great Basin and is forecast strengthen even more by
midweek, resulting in well above average temperatures throughout the
region. Widespread high temperatures are expected to reach into the
upper-90s and triple digits, with 110s probable throughout the Southwest
and central valleys of California. Little relief is in sight through at
least Wednesday as both daytime highs and overnight lows remain
uncomfortably hot. To put this late-summer heat in perspective, over 100
daily high temperature records could be set between today and Wednesday,
with around 40 of those records potentially threatening September monthly
extremes. Death Valley, California (the hottest location within the United
States), is forecast to reach 125 degrees on Tuesday. Excessive Heat
Warnings and Heat Advisories have been issued for much of California and
Nevada, as well as parts of Oregon, Idaho, Utah, and Arizona. Residents
should continue to follow proper heat safety and check in on family
members and neighbors who may be more vulnerable to heat related illnesses.

From the Northeast to the Gulf Coast, heavy rain is likely to dampen many
outdoor cookouts and barbecues today as moisture continues to stream
northward out of the western Gulf of Mexico ahead of an elongated
upper-level low. A stationary boundary draped across the Northeast and
central Appalachians will provide a focus for more organized and
slow-moving thunderstorm activity. As a result, flash floods are
increasingly likely over northeast Pennsylvania, where a Moderate Risk
(level 3/4) of Excessive Rainfall has been issued. Scattered downpours are
also possible throughout parts of southern New England. Even though this
region is currently experiencing severe to extreme drought conditions,
several inches of rain falling in a relatively short period of time could
still lead to areas of flash flooding. The threat of intense rainfall
extends to the Ohio/Tennessee Valley and southern Appalachians as well,
where a Slight Risk (level 2/4) of Excessive Rainfall has been issued. The
aforementioned frontal boundary is anticipated to gradually sink southward
on Tuesday as a low pressure system develops just off the Mid-Atlantic
coastline. This will allow for additional chances for heavy rain along the
I-95 corridor from Washington D.C. to Providence, Rhode Island to kick off
the shortened workweek. Elsewhere, tropical downpours are also a concern
across far South Texas and along the central/western Gulf Coast. A
stagnant and soupy airmass over the region will help fuel thunderstorms
capable of containing torrential rainfall. However, most thunderstorm
activity is expected to remain scattered and only produce localized
flooding impacts.

Snell


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