Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
323 AM EDT Sat Apr 29 2023

Valid 12Z Sat Apr 29 2023 - 12Z Mon May 01 2023

...Heavy rainfall and thunderstorms likely across Eastern Seaboard and
Gulf Coast through Sunday as strengthening system tracks along East
Coast...

...Localized, multi-day snowfall event for northern Wisconsin and Upper
Peninsula of Michigan this weekend; Widespread below-average temperatures
for Great Lakes & Midwest...

...Warm and dry conditions expected this weekend west of the Continental
Divide before cooler temperatures arrive Monday...

A deepening upper-level trough will continue to keep conditions cool and
unsettled across the eastern half of the country, with multiple rounds of
precipitation possible through the weekend. The main story will be the
developing low-pressure system in the Gulf of Mexico early Saturday
morning, which is expected to produce a multitude of weather hazards, with
rainfall chances increasing across portions of the immediate Gulf Coast as
warm, moist air streams northward behind a warm front. Several waves of
potentially heavy rainfall are expected from early Saturday into the
evening hours, leading to a Slight Risk of Excessive Rainfall issuance for
the Florida Panhandle, southeastern Alabama, and southern Georgia, as a
broad area of 1-2 inch rainfall totals and localized hourly rainfall rates
approaching 2"/hr are possible. Severe thunderstorms are also possible
along the Florida Panhandle, with damaging winds, large hail, and a few
tornadoes being the primary threats. Conditions are expected to improve
during the Sunday morning hours across the Southeast as the deepening
low-pressure system races northward along the Eastern Seaboard.

Sunday will be a wet and chilly day for the entirety of the Northeast and
Mid-Atlantic, as the surface low tracks just inland, allowing for
anomalously moist air to push onshore, increasing the chances for heavy
rainfall and producing region-wide rainfall totals of 1"+. Localized
areas, including central Pennsylvania and northern coastal New England,
may experience upwards of 2-3 inches, resulting in targeted Slight Risks
of Excessive Rainfall being hoisted. Severe thunderstorms will also be of
concern across eastern North Carolina, especially early Sunday morning,
when damaging winds and isolated tornadoes will be possible as the surface
low moves through the region. As a result, the Storm Prediction Center has
placed the area in a Slight Risk for Severe Thunderstorms.

On the backside of a stalled, anomalous upper-low, a multi-day snowfall
event will be possible this weekend throughout portions of northern
Wisconsin and the Upper Peninsula of Michigan, with as much as a foot of
snow falling through the early Monday morning hours. A broader area of
much-below-average temperatures (10-20 degrees F below average),
encompassing much of the Midwest and Great Lakes region, will also be
possible this weekend, with daytime highs struggling to reach 50 F on
Saturday and Sunday.

Elsewhere, conditions will start off pleasant and tranquil this weekend
across the West Coast, as persistent upper-level ridging supports
temperatures 15-25 degrees above normal for areas west of the Continental
Divide. Widespread high temperatures in the 80s are expected throughout
interior sections of the Pacific Northwest, while locations further south,
including California's Central Valley and the Mojave and Sonoran deserts,
reach the 90s and even 100s in localized areas. In fact, a few locations
along the West Coast and Southwest could challenge their daily
high-temperature records this weekend. The warm and dry conditions will
also combine with gusty winds to support an elevated fire risk area on
Saturday across portions of the Central Plains. However, a Pacific system
moving onshore late Sunday evening will bring an end to the unseasonably
warm temperatures on Monday as an attendant cold front pushes inland.


Russell


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