Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Huntsville Alabama
540 PM CST Tuesday Nov 25 2014
for 00z tafs
/issued 238 PM CST Tuesday Nov 25 2014/
Current water vapor imagery depicts a broad upper level trough across
much of the Continental U.S.. meanwhile...at the surface a low pressure system
has developed across the northern Gulf...with an inverted trough
extending northward into Florida and Georgia. Cloud cover has
continued to stream across the area on the western periphery of
this low. This has kept conditions fairly mild across the forecast
area...with temperatures remaining in the middle to upper 50s.
As the surface low tracks northeast overnight...moisture will surge
to the north across the forecast area. Precipitation will enter
counties east of the Interstate 65 corridor after sunset
tonight...and then continue northward...before exiting the area by
sunrise on Wednesday. Given current model soundings...the vertical
temperature profile remains above freezing...and the moisture does
not quite reach the snow growth region in the upper levels.
Therefore...precipitation is expected to remain in liquid form.
The low will quickly move up the northeast coast...taking the
moisture out of the area on Thursday. Meanwhile...a shortwave will
develop in the longwave trough and move into the Tennessee Valley.
Moisture will accompany this trough...however it appears the most of
the deep layer moisture will remain north of the area. This will bare
watching because if more moisture does make it this far south...there
may be a brief period of wintry precipitation before sunrise on
The extended forecast will be dominated by an upper level ridge with
high pressure building into the eastern Continental U.S.. temperatures over the
weekend will be unseasonably warm...with highs reaching into the middle
60s by Sunday. Rain may enter the forecast area once again by Monday
afternoon...as several shortwaves begin to approach the area on the
northern periphery of the upper ridge. However...only kept low
chance probability of precipitation in for the extended.
for 00z tafs...
VFR conditions should continue for the next 24 hours. Middle and high
level ceilings will prevail over the region for much of the period.
Virga will be possible over the khsv area. Clearing should take
place after 07-09z. Another area of VFR clouds with bases around
10kft are expected to spread over the region Wednesday afternoon.
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