Wind Chill Advisory 3, NWS Huntsville, AL

Area Forecast Discussion...UPDATED
National Weather Service Huntsville AL
1113 PM CST Tue Jan 16 2018

.UPDATE...
For 06Z TAFS.

&&

.NEAR TERM...(Rest of tonight)
Issued at 1012 PM CST Tue Jan 16 2018

The arctic airmass has dropped temperatures into the 8-15 degree
range which along with winds of 5-10 MPH has resulted in wind chills
between -3 to 5 as of the current hour. Still expecting a continued
drop in temperatures overnight as clouds continue to clear and the
remaining very light snowfall moves off to the Southeast. Due to the
exiting snowfall, did let the remaining counties in the winter
weather advisory expire at 9PM. One note, radar is showing a band
stretching across the I-59 corridor, but for the most part snow
appears to be largely sublimating before reaching the ground due to
dry air advection between the surface and 750mb (evident on LAPS
soundings).

However, black ice continues to be a problem on area roadways--
especially secondary roadways. Because of this, have issued a special
weather statement through 10AM for hazardous roads and kept wind
chill advisory in place for dangerous wind chills through 10AM
Wednesday as well. Made some minor trend adjustments to the ongoing
air temperature and dewpoint temperature forecast. This has resulted
in some wind chill values dipping below -10 over southern middle
Tennessee. So, may need to monitor for possible upgrade to wind chill
warning tonight. Otherwise, made additional probability of
precipitation and weather grid changes to reflect the snow's exit to
the southeast.

.SHORT TERM...(Wednesday through Thursday)
Issued at 222 PM CST Tue Jan 16 2018

Bitterly cold start Wednesday morning and wind chill values don't get
above zero until after 10am. Have extended the Wind Chill Advisory
by an hour to end at 10am due to longer period of below 0 values.
There may be a few low clouds lingering over the area at sunrise but
with the dry air should quickly dissipate leaving mostly sunny skies.
The sunny conditions might help to melt some of the snow but even
with full sun the very cold airmass lingers over the area and highs
will only make it to the mid 20s. Winds begin to dwindle through the
day as high pressure begins to build into the area.

With the high over the area Wed night/Thurs morning, light winds and
clear skies would support a good radiational cooling night. There
will be some recovery in dewpoints with values around 10-12 degrees
and those values will likely be where lows end up by sunrise
Thursday. The upside is that we won't have much wind to contend with
and so wind chills end up close to what the air temperatures will be.

.LONG TERM...(Thursday night through Monday)
Issued at 222 PM CST Tue Jan 16 2018

Medium-range models are in good agreement beyond Thursday (though
12Z runs came in a little less consistent than 00Z runs). Despite a
northern-stream shortwave ejecting across the Great Lakes and a
southern-stream wave moving across the Gulf, conditions will remain
dry, and increasingly zonal and increasingly seasonable for the rest
of the week. Temperatures will moderate back to around normal by
Friday.

A deep longwave trough carving along the Pacific coast will turn
flow more southwesterly, warming things up considerably for the
weekend (temperatures will rebound solidly into the 60s Sunday). As
the trough ejects into the Great Lakes, the associated surface low
will drag a front across the area late Sunday night/early Monday.
With all of the prefrontal S-SW flow, there will be more than enough
moisture for a solid shot of rain, but it will move fast. Low-level
winds ahead of the front will be strong with a great deal of
directional veering, but as of right now, temperature profiles are
not supportive of thunderstorms. Post-frontal conditions will not be
too frigid this time--a little above normal for mid-late January.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1112 PM CST Tue Jan 16 2018

Clearing trend will continue across the region, with low clouds
moving out of KHSV by 08z or so. Some passing high clouds will remain
through early/mid Wednesday morning, before giving way to a clear
sky. NNW to north winds will remain at 5 to 10 kts through the
remainder of the period.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Wind Chill Advisory until 10 AM CST Wednesday for ALZ001>010-016.

TN...Wind Chill Advisory until 10 AM CST Wednesday for TNZ076-096-097.

&&

NEAR TERM...SL.77
SHORT TERM...Stumpf
LONG TERM...BCC
AVIATION...AMP.24

For more information please visit our website
at weather.gov/huntsville.

Hazardous Weather Outlook...UPDATED
National Weather Service Huntsville AL
915 PM CST Tue Jan 16 2018

ALZ001>010-016-TNZ076-096-097-171300-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-De Kalb-Cullman-Moore-Lincoln-Franklin TN-
915 PM CST Tue Jan 16 2018

This Hazardous Weather Outlook is for north Alabama and portions of
southern middle Tennessee.

.DAY ONE...Tonight...

Light snow is possible along and near the I-59 corridor in far
northeast Alabama through midnight CST. Regardless of location,
roads will remain hazardous overnight due to the light snowpack and
black ice. In some areas, roads may be impassable. Travel is
discouraged unless it is absolutely necessary!

North winds in the to 5 to 15 mph range will combine with very cold
temperatures to produce wind chills below zero late tonight into
Wednesday morning. Most valley locations will drop into the zero to
10 below range, with 10 to 15 below zero possible atop the
Cumberland Plateau. A Wind Chill Advisory has been issued for the
entire area. Please refer to this product for additional details.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday...

A Wind Chill Advisory will remain in effect until 10 AM CST on
Wednesday.

.SPOTTER CALL TO ACTION STATEMENT...

Activation of storm spotters and emergency management personnel is
not anticipated at this time.