Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
130 AM EST Fri Dec 7 2018

Valid 12Z Fri Dec 7 2018 - 12Z Sun Dec 9 2018

...Winter storm to bring ice and snow from the southern plains to the
Appalachians, and heavy rain from eastern Texas to Georgia...

A strong storm system crossing the Desert Southwest early Friday morning
will take a southerly track across the southern plains to the Deep South
and then the southeast U.S. coast through the weekend.  Snow and freezing
rain is forecast to overspread eastern New Mexico and the Texas/Oklahoma
panhandles by late Friday, and continuing into early Saturday.  The
greatest snowfall accumulations through early Saturday are expected across
the southern High Plains from eastern New Mexico and across parts of the
Texas Panhandle, with amounts on the order of 3 to 6 inches and locally
higher.  In addition, ice accretion of about a tenth of an inch, perhaps
higher, will be possible on the southern edge of the heavier snow band,
roughly from Lubbock to Oklahoma City.

In the warm sector of the surface low, heavy rain is forecast across
southeast Texas in response to a deep surge of moisture from the Gulf of
Mexico.  The Weather Prediction Center currently has a Moderate Risk of
excessive rainfall for Friday and Friday night for much of southeast
Texas, with several inches of rainfall expected.  The rainfall rates are
expected to be high at times, increasing the threat of flooding.  Flash
flood watches are also in effect for this region.  A slight risk of
excessive rainfall exists through Saturday night for the central Gulf
Coast region as heavy bands of showers and thunderstorms develop in
conjunction with the surface low and a deep moisture surge ahead of it.

As the surface low tracks eastward roughly along the Gulf Coast through
late Sunday, a swath of accumulating snow and ice is expected to extend
from eastern Oklahoma to the southern Appalachians.  Winter storm watches
are now in effect from the Texas Panhandle to the Ozarks of northern
Arkansas, and also for the southern Appalachians and adjacent Piedmont
region.  Travel will likely be severely affected across much of these
areas, and some power outages are also possible. 

Elsewhere across the nation, some lake effect snow is likely across parts
of Michigan and New York for Friday and Saturday as cold northwesterly
flow crosses the warmer lake waters.  Showers and mountain snow returns to
western Washington and Oregon on Saturday as a cold front approaches from
the eastern Pacific.  Colder than normal temperatures are expected to
persist across much of the central and northern U.S. through Saturday with
a large Canadian surface high in place.

D. Hamrick


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