Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
357 AM EDT Tue Sep 14 2021

Valid 12Z Tue Sep 14 2021 - 12Z Thu Sep 16 2021

...Nicholas to produce torrential rainfall, strong winds, and high surf
from the Upper Texas coast to southern Louisiana, with life-threatening
storm surge and flooding possible; High Risk of Excessive Rainfall in
southwest Louisiana today...

...Severe weather and heavy rainfall possible from the central High Plains
to the Great Lakes and Northeast...

...A hotter than normal mid-September in store across most of the
contiguous U.S....

Nicholas, which briefly reached hurricane status overnight, is hammering
the Upper Texas coast and southern Louisiana with heavy rainfall, strong
winds, and battering surf. Even as the storm returns to tropical storm
status this morning, life threatening flash and urban flooding remains
possible from far eastern Texas to the central Gulf Coast. A High Risk of
Excessive Rainfall is in place for far southwest Louisiana and along the
coastal areas of the TX/LA border. Meanwhile, the Moderate Risk area
extends as far north as central Louisiana and as far east as New Orleans.
Nicholas' slow movement will lead to a steady barrage of heavy rain in
portions of the Lower Mississippi Valley into Wednesday where a Moderate
Risk for Excessive Rainfall remains in place. Even as the storm weakens to
a Tropical Depression late Wednesday into early Thursday, heavy showers
and thunderstorms will continue to generate torrential rainfall rates
across the Deep South. In total, over a foot of rainfall is possible in
this area with much of southern and central Louisiana receiving anywhere
from 5 to 10 inches for the duration of this storm from far east Texas to
the central Gulf Coast.

Elsewhere, an area of low pressure in the Midwest will work in tandem with
an elongated frontal boundary extending as far east as the Northeast Coast
and a cold front swinging through the Central Plains to produce
strong-to-severe storms today. Locations most at risk for severe weather
are the Great Lakes where a Slight Risk has been issued for today. By
Wednesday the intensifying area of low pressure reaches Quebec while its
trailing cold front approaches the Northeast. Slight Risks for both severe
weather and Excessive Rainfall have been issued for portions of the
Northeast and Mid-Atlantic for Wednesday. As this frontal system exits off
the East Coast by Thursday morning, a new storm system looks to gather
strength over the Midwest bringing with it yet another round of showers
and potentially severe thunderstorms to the region.

There are very few signs of autumn across most of the Lower 48 as
temperatures remain above their seasonal averages through midweek. The
hottest conditions compared to normal are forecast to occur in the
Mid-Atlantic and the Southwest. Below normal high temps are anticipated
across the Deep South as thick cloud cover courtesy of Nicholas keeps high
temps as cool as 10 to 15 degrees below normal. If any region is feeling
most like autumn for mid-September it is the Pacific Northwest where below
normal temperatures will be most common, even into the second half of the
work-week.

Mullinax

Graphics are available at www.wpc.ncep.noaa.gov/basicwx/basicwx ndfd.php