Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Birmingham Alabama
536 PM CST Tuesday Feb 9 2016
for 00z aviation.
Large closed low is weakening and pulling away from the southeast
this afternoon. With the longwave trough still situated over the
Tennessee Valley...a lobe of low level forcing rotating around the
back side of the trough will provide lift for continued isolated
to scattered snow showers through this evening. Moisture will
quickly pull away from the area tonight...with skies clearing.
With continued cool to neutral low level advection...clearing
skies and low dewpoints will help temperatures fall into the 20s
tonight. Winds will remain at 5-7kts...and we will not reach full
radiational cooling potential. Another cold day on tap for
Wednesday and Wednesday night.
Temperatures moderate Thursday as we finally have warm advection
at low levels. A shortwave will push a surface low southward
Thursday and Thursday night. Not much moisture to pull from and
expect only an increase in cloud cover. High pressure will drop
out of central Canada behind the surface low and cross the
central Appalachians Friday. Cold advection will return Saturday
as a stronger surface high moves into the Great Lakes region.
Temperatures 10-15f degrees below normal expected over the
weekend. The large surface high shifts eastward...setting up over
New England and extending down the Lee side of the Appalachians.
This will set up a wedge around the base of the mountains across
Georgia and into east Alabama. Easterly flow will reinforce the
cool and dry air across the area. Meanwhile...a shortwave will
drop through the plains and bring a return of moisture to the area
Sunday night into Monday...and the potential for another round of
Much uncertainty with this system as it is still 6-7 days out.
Model solutions continue to show differences in timing...strength
of The Wedge...and if low level warming occurs at the surface ahead
of the shortwave. All of which will have a significant impact on
00z taf discussion.
Skies should clear from SW to NE overnight with the gusts
subsiding and sustained winds becoming 5-10 kts. However some west-northwest
gusts up to 20 miles per hour will be possible again on Wednesday.
No fire weather concerns are expected at this time. A strong
upper level system will dominate the weather across the eastern
United States early this week and bring much colder temperatures
into central Alabama through Wednesday. Low precipitation chances
remains in the forecast tonight for northeast central Alabama...with
moisture pulling away from the area late tonight. Any additional
precipitation will be in the form of snow showers...and will not
be continuous. Light accumulations underneath a heavier shower is
possible. Northwesterly winds will remain elevated through
tomorrow. With drier air across the area...relative humidity values will drop
below 25 percent for a couple hours in localized area tomorrow and
Wind Advisory until 6 PM CST this evening for the following
Winter Weather Advisory until 9 PM CST this evening for the
following counties: Cherokee.