Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
333 PM EDT Tue May 16 2023

Valid 00Z Wed May 17 2023 - 00Z Fri May 19 2023

...Heavy rainfall, flooding and severe weather are possible across the
Mid-Atlantic and Tennessee Valley this evening...

...Above-normal temperatures continue in the West...

...Cooler, drier air across Great Lakes, Ohio Valley and Northeast through
midweek in wake of potent cold front...

A multitude of weather hazards are expected through Tuesday evening as a
slow-moving frontal boundary positioned across the Mid-Atlantic and
Tennessee Valley continues to be a focus for heavy rainfall and severe
thunderstorms. Warm, moist air on the southern side of the boundary will
allow for the continued development of showers and thunderstorms that may
produce damaging winds, large hail, and isolated tornadoes, resulting in
the Storm Prediction Center issuing an Enhanced Risk of Severe
Thunderstorms for parts of the southern Appalachians. Furthermore, these
storms will have the ability to produce heavy rainfall rates, which may
also lead to isolated instances of flash flooding through the evening,
especially in areas highlighted by a Slight Risk of Excessive Rainfall
throughout southern West Virginia, eastern Kentucky, and portions of
Virginia and North Carolina. Conditions are expected to improve overnight
as the storms dissipate. However, as the frontal boundary pushes southward
on Wednesday, localized moderate to heavy rainfall will be possible along
the Gulf Coast and Southeast, with rainfall totals approaching 1-2 inches.

Further north, a well-defined cold front surging southward through the
Great Lakes region and interior Northeast will result in a sharp
temperature and dewpoint decrease, especially in areas along Lake
Michigan, including the Chicago Metro area. Daytime temperatures in the
upper 70s to low 80s will quickly drop into the low 50s and upper 40s on
Tuesday evening in the wake of the boundary. As the front moves southward
across the Ohio Valley and Northeast on Wednesday, high temperatures will
remain in the low-to-mid 60s across coastal portions of the region, while
areas further inland, especially in the interior Northeast and New
England, experience temperatures remaining in the upper 40s to low 50s.
Furthermore, several record lows are forecast to be approached or broken
on Thursday morning across the region as temperatures hover around the 32F
degree mark before rebounding into the 60s during the day.

West of the Continental Divide, above-average temperatures will continue
through midweek as an upper-level ridge persists, with widespread
temperature anomalies approaching 10-20 degrees above average. Warm air
will work its way from the West Coast into inland areas and the Great
Basin by mid-to-late week, with daytime highs in the mid-to-upper 80s
throughout the Pacific Northwest and Great Basin, while areas further
south across the Southwest and Southern California exceed the 90-degree
mark. Furthermore, widespread record-high minimum temperatures are
forecast across coastal and interior portions of the Pacific Northwest
through Thursday.


Russell

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