Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
355 PM EDT Sat May 13 2023

Valid 00Z Sun May 14 2023 - 00Z Tue May 16 2023


...Much above-average temperatures expected to continue across the western
U.S., including record-breaking heat over portions of the Pacific
Northwest on Sunday...

...Additional heavy rain and flooding possible for parts of Texas and
Oklahoma into early next week...

...Severe storms expected for parts of the mid Mississippi Valley into
Saturday evening...

High pressure in the upper levels of the atmosphere will continue to
support well-above normal temperatures across the western U.S., with
record-breaking heat expected across portions of the Pacific Northwest. 
Heat advisories remain in effect for portions of western Washington and
Oregon, including the Seattle and Portland metro regions, where daytime
temperatures are forecast to once again reach 20-30 degrees above normal
on Sunday.  While temperatures are likely to remain well above average, an
upper level low drifting north into the region is expected to increase the
chance for showers and thunderstorms and bring some relief from the early
season heat wave on Monday.  Heat advisories are in effect into Monday for
California's San Joaquin Valley, where high temperatures are forecast to
reach into the mid to upper 90s each day.  

Farther to the east, a series of slow-moving upper-level disturbances will
help to produce areas of showers and thunderstorms and keep temperatures
much cooler across the southern and central  Plains through the weekend,
with well-below temperatures likely along the High Plains into the
foothills.  Flood Watches remain in effect for portions of Texas and
Oklahoma, where additional periods of heavy rain will remain possible
through the remainder of the weekend.

Flooding and severe thunderstorms are also possible farther to the north
across portions of the upper and mid Mississippi Valley.  Severe storms
are now developing over the region, with the threat expected to continue
into this evening.  These storms have the potential to produce damaging
winds, large hail, and a few tornadoes.  Heavy rain is also possible with
a Flood Watch in effect across southwestern Minnesota and a small portion
of northwestern Iowa.  By late Sunday, high pressure is forecast to bring
drier and more settled weather to the northern Plains and upper Midwest.

In the eastern U.S., a cold front will continue to drop south through the
Mid Atlantic into the Southeast, with showers and storms possible into
early next week across portions of the southern Mid Atlantic and the
Southeast.  Cooler and drier conditions are forecast for the Northeast on
Sunday,  with Frost Advisories in effect for Sunday morning for portions
of far northern New York and Vermont. 

Pereira

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