Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
442 AM EDT Tue Jul 19 2022

Valid 12Z Tue Jul 19 2022 - 12Z Thu Jul 21 2022

...Dangerous heat to continue through midweek across the south-central
U.S., building across the Northeast on Wednesday...-

...Severe thunderstorms possible from portions of the Upper Midwest into
the upper Great Lakes today and then the Ohio Valley on Wednesday...

...Monsoonal moisture to bring locally heavy rains and isolated flash
flooding across portions of the Southwest, Great Basin and Southern
Rockies...

Dangerous heat will continue to impact a large portion of the U.S. this
week, with now more than 100 million people under excessive warnings or
heat advisories.  This includes most the southern Plains and lower
Mississippi Valley, as well as parts of the central Plains and the lower
Missouri Valley.  Daytime temperatures today are expected to reach 100
degrees across much of this region and as high as 110 in some locations. 
While a cold front dropping south is expected to bring some relative
relief into the central Plains on Wednesday, the well above-average to
record-breaking heat is forecast to continue through midweek across the
much of the southern Plains into the lower Mississippi Valley.  Heat
advisories are also now in effect for Wednesday for portions of the
Northeast, including the I-95 corridor from Philadelphia to Boston, where
heat index values are forecast to reach near 100 degrees.

Across the north-central U.S., a cold front associated with a strong area
of low pressure is forecast to produce showers and thunderstorms as it
moves across the Upper Midwest into the upper Great Lakes today.  Some of
these storms may become strong to severe, with large hail and damaging
winds possible.  On Wednesday, the focus for showers and thunderstorms and
the potential for severe storms is expected to move east along with the
front into the Ohio Valley.

Behind the front, dry and windy conditions are expected to develop today,
resulting in elevated fire weather concerns across portions of the central
High Plains.  Red flag warnings currently extend from southeastern Wyoming
through western Nebraska, where strong winds and low humidity would likely
support the rapid spread of any fires that develop.

Monsoonal moisture will fuel another day of diurnal showers and
thunderstorms across the Southwest, Great Basin, and the central to
southern Rockies today before activity become more confined to eastern
Arizona into the Rockies on Wednesday.  While widespread heavy amounts are
not expected, locally heavy amounts are possible.  This may result in
localized instances of flash flooding, especially across vulnerable
wildfire burn scar areas.

Pereira

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