Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
339 AM EDT Sun Jun 26 2022

Valid 12Z Sun Jun 26 2022 - 12Z Tue Jun 28 2022

...Heavy rain and flash flooding possible across much of the Southwest and
southern Rockies over the next few days...

...Isolated severe thunderstorms are possible throughout the Lower Great
Lakes, upper Ohio Valley, and Tennessee Valley today...

...High heat and humidity to persist for one more day across the southern
Plains and the Gulf Coast states, with heat continuing to build throughout
much of the West...

Additional rounds of showers and thunderstorms are likely to impact the
Southwest and southern Rockies today as ample moisture remains in place
along with a settling stationary boundary extending from West Texas to
Arizona. Much of this region will gladly welcome more rain, given the
severe to exceptional drought in place, but too much precipitation in a
short period of time may lead to flash floods. A Slight Risk (level 2/4)
of excessive rainfall has been issued for much of central/northern New
Mexico and southern Colorado through tonight in order to highlight the
concern, with a smaller Slight Risk issued for Monday over north-central
New Mexico. Rainfall totals of 1 to 2 inches, with locally higher amounts,
could lead to rapid runoff and flooding concerns particularly near burn
scars. The threat of widespread shower and thunderstorm activity is
expected to gradually diminish and shift southward on Tuesday.

A cold front advancing across the eastern and southern U.S. will create
the potential for isolated severe thunderstorms today, with the greatest
threat extending from the Lower Great Lakes to the Tennessee Valley. A few
storms could contain damaging wind gusts, frequent lighting, and heavy
rain. Chances for isolated flash floods will also extend along much of the
cold front as it reaches the East Coast on Monday. Meanwhile, a hot and
sultry airmass across the Deep South and Southeast will be supportive of
scattered pop-up thunderstorms through early this week as the
aforementioned cold front loses forward speed and eventually stalls over
the region. Slow-moving thunderstorms will have the capability of
producing intense rainfall rates and isolated flash flooding. Farther
north, a system entering from south-central Canada will lead to
thunderstorm chances over the Upper Midwest on Tuesday, a few of which
could turn severe.

One more day of dangerous heat, humidity, and potentially record breaking
temperatures are forecast across the Deep South and southern Plains before
some relief arrives on Monday and Tuesday. Highs are forecast to reach the
upper 90s and low 100s today from central Texas to Mississippi, with heat
indices well into the tripe digits. Above average temperatures will also
stretch northeastward through much of the eastern U.S. and into northern
New England, with highs into the upper 80s and 90s. Cooler temperatures
will enter much of the central and eastern U.S. by Monday and Tuesday
behind a potent cold front. For the West, a building upper-level ridge
will allow for highs to surge into the 90s and near 100 degrees from
central California through the Intermountain West and into the Pacific
Northwest. This equates to around 20 degrees above average compared to
normal late-June highs. Heat Advisories have been issued for much of
eastern Oregon and Washington, as well as parts of California. The heat
will be relatively short lived over the Northwest, as an approaching storm
system ushers in cooler air by Tuesday.

Snell

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