Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
306 AM EST Sun Nov 13 2022

Valid 12Z Sun Nov 13 2022 - 12Z Tue Nov 15 2022

...Widespread below-average temperatures across much of the lower 48
through Monday...

...Lake-effect snow downwind of the Great Lakes will produce light
accumulations through Sunday...

...Unsettled weather across the Southwest and Plains to start the work
week as an upper-level low tracks across the country...

...Santa Ana winds subside on Sunday in southern California...

The main headline over the next several days will be the anomalously cold
temperatures gripping nearly the entirety of the lower 48, with widespread
forecasts of highs 10-20 degrees below average. On the backside of the
potent storm system that swept through the eastern third of the nation,
much cooler and drier air will surge southward from Canada, resulting in a
drastic temperature change from the 60s and 70s observed this past week,
as maximum temperatures will struggle to eclipse the 50-degree mark across
the Northeast. Furthermore, locations as far south as the Gulf Coast and
Florida panhandle will dip into the 30s during the overnight hours of
Sunday and Monday. As a result, widespread Freeze Warnings are in effect
across central Texas and the Southeast through Sunday morning, as
nighttime temperatures are forecast to drop below freezing. Further north,
the cold air surging southward across the Great Lakes will lead to
lake-effect snow downwind of Lakes Superior, Michigan, Huron, and Erie
through Sunday afternoon, resulting in the issuance of Winter Weather
Advisories across these areas.

In the Western region, an upper-level low diving southward across the
Great Basin and Southwest will be the lower 48's next source of inclement
weather as it tracks eastward across the country. Light snow is forecast
to develop throughout the Great Basin early Sunday morning before shifting
southeastward into Arizona and New Mexico Sunday evening as the system
intensifies. By Monday, widespread light snow will develop across the
central Plains, with a stripe of mixed precipitation forecast to track
across the southern Plains and Ark-La-Tex region. Although uncertainty
remains high on the timing and location of accumulating snow, totals are
expected to remain light. However, reduced visibility and hazardous
driving conditions will still be a concern as the region experiences its
first wintry event of the season.

As the system continues tracking eastward, low-pressure is forecast to
develop along the Texas Gulf Coast, which will track along the coastline,
producing moderate to potentially heavy rainfall across southern Louisiana
on Monday afternoon into the evening. Precipitation amounts will remain
lighter further north in the cold sector of the system, with light rain
expanding into the Mississippi Valley and Southeast while mixed
precipitation and light snow overspread the Midwest and Ohio Valley.

Lastly, high pressure building into the Great Basin region behind the
southward-moving upper-level low will lead to strong Santa Ana winds
across southern California through Sunday morning due to an increasing
pressure gradient across the region. As a result, Wind Advisories have
been issued for the Transverse Ranges, where winds may gust as high as 50
mph, before lightening on Sunday as the shortwave pushes southeastward.
The re-emergence of the Santa Ana winds will be possible again on Monday
as the pressure gradient increases, although uncertainty regarding the
exact timing and intensity of the winds remains high.


Russell

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