…Heavy rain/flash flood threat continues today for portions of the Lower
Mississippi Valley and Southeast…
…A coastal storm will bring wind and rain to the Carolinas and
Mid-Atlantic over the next few days…
…A strong low pressure system will bring unsettled weather and well
below normal temperatures to the West with high-elevation snow in the
Sierra Nevada…
Francine’s remnants will linger over the southeastern U.S. early this week
as a nearly stationary frontal boundary sags south to the Gulf Coast.
Chances for locally heavy rain and isolated to scattered instances of
flash flooding will continue today for portions of the Lower Mississippi
Valley and Southeast. There is a Slight Risk of Excessive Rainfall (level
2/4) for parts of Mississippi, Alabama, and the Florida panhandle where
flooding will be most likely. Chances for showers and storms will persist
across this region over the next few days, but the risk of flooding will
gradually decrease, with only isolated flooding concerns expected Monday
and Tuesday.
Meanwhile, a separate area of low pressure will strengthen off the
Southeast Coast and gradually move north towards the Carolinas. This
system is likely to bring gusty winds, heavy rain, coastal flooding, and
dangerous beach conditions to the Carolinas and portions of the
Mid-Atlantic through mid-week. Strong high pressure over the Northeast
will slow the forward motion of this system, increasing the chance of
heavy rainfall totals and flash flooding. There is a Slight Risk of
Excessive Rainfall (level 2/4) for portions of the eastern Carolinas and
far southeastern Virginia with an embedded Moderate Risk (level 3/4) over
southeastern North Carolina where the risk of flash flooding will be
highest. The National Hurricane Center is also monitoring this system for
potential subtropical or tropical development, and has marked this area
with a 50% chance of tropical formation over the next 48 hours. There is
still quite a bit of uncertainty on the timing, intensity, and track of
this system, so regularly check for forecast updates over the next couple
of days.
In the West, an unsettled pattern is beginning to take root as upper level
troughing moves into the region. A deep upper low will move over the West
Coast today and Monday and push across the Intermountain West to the
Rockies on Tuesday. This will push a strong frontal system across the West
that will bring widespread precipitation chances and much cooler
temperatures to the region over the next few days. Precipitation will
mainly fall as rain, but temperatures will be cold enough in the high
elevations of the Sierra Nevada for some early season snow. A Winter
Weather Advisory is in effect for portions of the Sierra Nevada above 8000
feet where up to 4 inches of snow may fall tonight and Monday.
Precipitation chances will also increase across the Southwest/Four Corners
region today as tropical moisture streams north from Tropical Cyclone
Ileana, which will support monsoon-like showers and thunderstorms through
Tuesday.
Temperatures will have a large range across the United States over the
next few days. Forecast precipitation and cloud cover will keep
temperatures slightly below normal across the Southeast and Mid-Atlantic,
with highs from the mid 70s to the mid 80s. Well above average
temperatures are forecast for the Central U.S. and Northeast, with the
highest anomalies forecast to develop under high pressure in the Upper
Midwest/Great Lakes region. High temperatures will reach the 80s and 90s,
which will be 10-20 degrees above normal for some areas. Well below
average temperatures are forecast to spread across the West through
Tuesday under the deep upper low/trough, and high temperatures will be as
low as 15-25 degrees below normal. The coldest anomalies will be in
Oregon, Nevada, and California on Monday. Highs in the 50s will be common
in the Great Basin, and highs will likely only reach the 30s and 40s in
the Sierra Nevada.
Dolan
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
Leave a Reply