…Widespread showers and storms to bring scattered to numerous instances
of considerable flash flooding and severe weather to portions of the
Mid-South and the western and central Gulf Coast…
…Pesky weather pattern of showers and storm across much of the
Mid-Atlantic, Northeast, and Great Lakes should begin to taper off by
Thursday…
…Cooler, well below average temperatures persist across parts of the
Inter-Mountain West and central/southern Plains as the northern Plains and
Pacific West Coast see above average temperatures…
The upper-low over the Southwest and an accompanying surface low
pressure/frontal system emerging across the Plains this afternoon is
providing forcing for a line of heavy thunderstorms that are bringing
flash flooding and all hazards of severe weather to parts of the Deep
South and Gulf Coast. Multiple clusters of storms may affect these regions
for the remainder of Tuesday and Wednesday, particularly for coastal Gulf
cities from Houston to Pensacola. This is a result of the influx of
anomalously high Gulf moisture interacting with quasi-stationary front and
upper-low providing favorable atmospheric dynamics. A Moderate Risk of
Excessive Rainfall (ERO) is in effect for much of the Louisiana Gulf Coast
for tomorrow as the threat of considerable flash flooding will be
possible. A Slight Risk of Excessive Rainfall extends from Houston to
Mobile for a more scattered flooding potential. Bottom line, across the
next few days, heavy rainfall and locally strong thunderstorms will be
present. As much as 4-7 inches of rain is forecast across the central Gulf
Coast in the 48 hour period. Turn around, do not drown. As for the severe
side of the storms, the Storm Prediction Center has a Slight Risk across
eastern Texas and a Marginal Risk across the central Gulf Coast for the
hazards of isolated severe hail, strong winds, and a few tornadoes for
tomorrow.
Across the eastern U.S., another upper-level low and surface low is
funneling high precipitable water and moisture transport along the
Mid-Atlantic and Northeast. Additionally, cooler temperatures aloft
associated with the upper-low will continue to provide severe weather
potential through this evening for the main hazards of hail and strong
winds. Fortunately, another trough will begin to dip southeast towards the
east Coast and begin to slowly push the storm system out of the region.
Showers will linger across the region on Wednesday and Thursday as the low
pressure spins offshore, but rainfall amounts should be light and
instability will be limited on the cool side of the upper-low. There is
the potential for the return of heavy rain on Friday across the Northeast
with the next cold front, but the details are uncertain by this time
range.
Cooler temperatures will be present across New Mexico, Colorado, and the
Central Plains due to being north of the surface boundary across the Gulf
Coast and being underneath an upper-level low meandering across the
central part of the country. For Wednesday and Thursday, high temperatures
in the upper 50s, 60s, and some low 70s will range 10-15 degrees below
average for early May. Meanwhile, across the West, desert Southwest, and
the northern Great Plains, temperatures will be as warm as 20 degrees
above average.Temperatures out West will be in the 80s across the valleys
and in the 70s for most coastal and high terrain areas. The Desert
Southwest will warm up significantly as ridging builds in, and
temperatures warm back into the 80s and 90s for Wednesday and Thursday.
Friday could see the hottest temperatures of the year so far for the area
as low 100s appear. The Northern Plains will see daily temperatures in the
upper 70s and 80s by Thursday and Friday as ridging builds in across the
area behind a weak frontal boundary. The high variation in temperatures is
a result of the current Omega Block pattern !
Elsewhere across the country, the Pacific Northwest could see some rain
showers on Wednesday and Thursday as a weak system moves across the
region.
Wilder
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
