Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
258 AM EDT Thu Apr 18 2019
Valid 12Z Thu Apr 18 2019 - 12Z Sat Apr 20 2019
...Risk of severe thunderstorms and flash flooding from the Gulf Coast to
the Ohio River Valley today, shifting to the East Coast on Friday...
...Warmer and generally dry over the West, with the next round of
precipitation arriving in the Northwest on Friday...
A low pressure system will move east from the Mississippi River Valley
today, to the East Coast by Friday Night. This will deliver widespread
rain to much of the eastern half of the U.S. over the next couple days
with many locations likely to receive over an inch of rainfall. The
primary surface low will shift from the Mid South, near Arkansas, today to
the central Appalachians later on Friday. A trailing cold front will sweep
across much of the Gulf Coast and Southeast. Ahead of the low and
associated cold front, a warm, humid air mass will push well inland,
supporting the development of thunderstorms as far north as the Great
Lakes and Mid Atlantic.
Some of the thunderstorms will be severe. The greatest risk of severe
weather is in the Gulf Coast states today, and in the Southeast Atlantic
Coast states from Virginia to Florida on Friday. The main threats with the
severe storms will be damaging wind gusts and several tornadoes; some of
the tornadoes in the South today and tonight could be strong. For more
detailed information on the severe weather threat, refer to Storm
Prediction Center forecasts.
The thunderstorms and areas of heavy rain will also pose a risk for flash
flooding over much of the eastern half of the U.S. in the next couple
days, gradually shifting east with the low pressure system. Flash flooding
will be most likely today in the Lower and Middle Mississippi River
Valley; some locations could receive several inches of rain in a few
hours. The risk of flash flooding on Friday should extend along most of
the U.S. East Coast, from the northern border with Canada south to Georgia.
Meanwhile, across the West, today should be relatively warm and dry with
the warmth continuing into Friday in most areas. Temperatures will be 10
to 20 degrees on a widespread basis. The next front will begin to arrive
in the Northwest tonight and Friday, with increasing chances of
precipitation. Fairly high snow levels will generally prevent snow other
than in the highest elevations behind the cold front.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php