…Excessive Rainfall and severe weather throughout the Southeast to make
its way into the Mid-Atlantic this week…
…Showers and thunderstorms expected from the Pacific Northwest &
Northern Rockies to the Northern Plains…
…Record warmth expected in parts of the West & Midwest…
Multiple rounds of showers and thunderstorms engulfing the Southeast U.S.
over the next few days will begin to make its way north into the
Mid-Atlantic for the first half of the week. An upper-level low meandering
over the Deep South continues to direct copious amounts of Gulf moisture
northward while a stationary front also acts as a trigger for
thunderstorms each day. WPC maintains an expansive Marginal Risk (threat
level 1/4) for Excessive Rainfall that stretches from the Lower
Mississippi River Valley to as far east as the Mid-Atlantic coast through
Tuesday. Today, a Slight Risk (threat level 2/4) includes areas from the
central MS/AL border on east tor the Carolina coast. As the storm moves
east on Monday, so will the Slight Risk area which includes areas as far
south as South Florida and as far north as central Virginia. Look for the
Excessive Rainfall threat to persist into Tuesday over the Mid-Atlantic,
highlighted by a Slight Risk in parts of Virginia and northeast North
Carolina. In terms of severe weather, the Storm Prediction Center (SPC)
has highlighted a Marginal Risk from the central Gulf Coast to the Georgia
Coast today. The severe threat on Monday stretches south into the Florida
Peninsula and as far north as the southern Appalachians.
A troughing pattern over the western U.S. will direct a series of
disturbances at the Northern Rockies and High Plains this weekend. SPC has
issued a Slight Risk (threat level 2/5) for today from the Snake River
Valley of eastern Idaho through parts of the northern Rockies and High
Plains of northern Wyoming and central Montana. Severe thunderstorms
within the Slight Risk pose a threat for damaging wind gusts and large
hail. The pattern remains unsettled over the Pacific Northwest on Sunday
with numerous showers and high elevation mountain snow on Monday. A
passing cold front will introduce a chance for showers as far south as
southern California by Monday night. Sandwiched between the wet conditions
in the Southeast and Northwest is a mostly dry stretch of weather for the
Southwest, Midwest, and Northeast.
Extensive cloud cover is contributing to unusually cool temperatures than
normal for May in the southeastern U.S. Daily temperatures will be below
normal from eastern Texas all the way to the Carolinas. Lingering
northwesterly flow will keep temperatures cooler than normal in New
England today before warming up to more seasonal levels on Monday. Early
morning frost is also possible today in the northern most portion of
Michigan’s Mitten. In contrast, ridging over the Rockies and Midwest will
favor very warm temperatures for mid-May, making Mother’s Day Weekend feel
more like an early kick-off to summer in some locations. Record warm
minimum temperatures are forecast today in southern California, the Great
Basin, and in isolated parts of the Northern Rockies. The hottest
temperatures versus normal will be found in the Upper Midwest where
widespread record warmth for mid-May is expected from the Dakotas to
Minnesota through Tuesday. Temperature anomalies in the Midwest are likely
to range between 15-25 degrees above normal and will potentially approach
30 degrees above normal in the Dakotas into the first half of the week.
NWS’s HeatRisk does depict an expansive area of Moderate heat-related
impacts with scattered areas of Major heat impacts in parts of North
Dakota and northern Minnesota. Residents who are sensitive to heat,
especially those without effective cooling and/or adequate hydration,
should plan accordingly for a stretch of stressful heat that will persist
through at least the first half of the week.
Mullinax
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
