Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
345 AM EDT Wed May 03 2023

Valid 12Z Wed May 03 2023 - 12Z Fri May 05 2023

...Much below average temperatures and damp conditions expected across
Great Lakes and Northeast through the end of the work week...

...Cool and unsettled weather for California and Southwest on Wednesday
before expanding northward into Pacific Northwest on Thursday...

...Above-average temperatures to continue throughout northern
Intermountain West and High Plains through Friday...

...Showers and severe thunderstorms possible in the Southern Plains on
Thursday...

Unseasonably cool weather will continue through the end of the work week
across the eastern third of the country as an upper-low slowly meanders
eastward across the Great Lakes region. Wednesday will feature widespread
temperature departures of 15-25 degrees below average throughout the
Mid-Atlantic and Northeast, with daytime high temperatures remaining in
the 40s and 50s, resulting in the potential for numerous locations to
approach or break daily record low maximum temperatures. The cool weather
will continue into Thursday, albeit returning closer to normal as the
upper-low weakens and shifts offshore. Moreover, conditions will remain
damp as scattered showers remain possible through Friday throughout the
region.

On the opposite side of the lower 48, an upper-low churning off the
California coastline has led to a cool and unsettled weather pattern
spreading eastward across the West Coast. Daytime temperatures will remain
in the 50s and 60s across much of California on Wednesday and Thursday,
accompanied by increased chances of showers and high-elevation snow. As
the upper-low shifts eastward, as well as an attendant frontal boundary,
the below-average temperatures will expand northward into the Pacific
Northwest and Great Basin regions on Friday. Furthermore, the development
of showers and thunderstorms as shortwave energy rounds the base of the
previously mentioned upper-level trough will produce a broad swath of
0.25" - 0.75" of rain on Thursday throughout much of the Great Basin and
Pacific Northwest. This, in conjunction with snowmelt and already swollen
streams and rivers, may lead to isolated instances of runoff issues.

Further inland, gusty southerly winds and well above average temperatures
are anticipated for much of the Intermountain West, with warm weather
spreading into the northern and central Rockies and northern High Plains
by Thursday. Widespread temperature anomalies of 15-25 degrees above
average will be possible as daytime temperatures exceed 80F across much of
the region. As a result, areas experiencing river flooding due to snowmelt
across the Great Basin and Intermountain West can expect more significant
snowmelt this week. As the frontal boundary associated with the persistent
upper-level troughing pushes inland, showers and thunderstorms will begin
to overspread much of the Rockies late Wednesday into early Thursday.

In the southern Plains, a stationary front will remain draped across the
area through Thursday, then lift northeast as a warm front from Thursday
night into Friday. Conditions across the region will be favorable for
thunderstorms each day, and scattered severe storms will be possible on
Thursday afternoon and evening in parts of Texas and Oklahoma where the
Storm Prediction Center has issued a Slight Risk of severe thunderstorms.
Severe storms will be capable of producing large hail, damaging winds, and
a couple of tornadoes.


Russell/Dolan


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