Area Forecast Discussion
Issued by NWS Huntsville, AL

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FXUS64 KHUN 211445

Area Forecast Discussion
National Weather Service Huntsville AL
945 AM CDT Fri Oct 21 2016

.NEAR TERM...(Rest of Today)
Issued at 945 AM CDT Fri Oct 21 2016

A broken deck of low clouds was continuing to move southeast through
middle Tennessee into the forecast area as of 1430z. Will continue
with a slow decrease in clouds by this afternoon, as drying in the
mid and upper levels will continue to move toward the region. Have
slightly lowered hourly temps through the afternoon to account for
the cold advection and temp trending. Forecast update will be

.SHORT TERM...(Tonight through Sunday)
Issued at 218 AM CDT Fri Oct 21 2016

After a cooler, blustery day, winds should diminish after sunset and
decouple. Although decoupling is anticipated, winds may still stay
up to 5 MPH overnight. Dewpoints are also expected to drop into the
upper 30s/low 40s and hold throughout the night. Thus, radiational
cooling from a clear sky and cold air in place, temperatures may
drop into the upper 30s to low 40s, but frost is not anticipated.

Ridge building will continue across the central and southern Plains
into the Southeast by Saturday with northwest flow aloft prevailing.
The sfc high pressure system that will have moved southeast from
MO/AR by Friday night will merge with a high pressure system over
the southern Plains this weekend. Meanwhile, on Saturday,
temperatures will once again be about 20 degrees cooler than the
past few days with daytime highs in the 60s due to the cold start
and slower modification of the airmass. Then, the surface high
pressure system will shift east across the Southeast bringing the
western flank of the surface high pressure system across the TN
valley. Because of this movement of the high pressure system, a
southerly fetch in conjunction with a sunny sky will bring weak warm
air advection back across the TN Valley. This will yield warmer
daytime highs, in the low to mid 70s. Closer to normal overnight
lows are then expected on Sunday night in the upper 40s to low 50s.

.LONG TERM...(Sunday night through Thursday)
Issued at 218 AM CDT Fri Oct 21 2016

Another streak of dry weather is once again expected through the
extended period. A fast moving shortwave will dampen the ridge
position over the Gulf states during the middle of next week, but it
is unlikely to produce measurable precipitation this far south. The
cold front associated with the wave now appears it may remain to our
north and essentially dissipate based on the GFS. Then southwesterly
low level flow (i.e. 850 mb) will redevelop through the latter part
of next week. Max temperatures during the period will be in the
middle to upper 70s and lows in the upper 40s to lower 50s. We may
need to include lower 80s by the end of next week or just beyond this
forecast package if the large thermal ridge over the southern Plains
continues to expand eastward through the Gulf states and mid South.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 600 AM CDT Fri Oct 21 2016

A south/southeast moving low MVFR cloud deck is affecting almost all
of northern Alabama and is fairly continuous to the north over KY/TN.
As a result, these clouds may remain in place for most of the morning
before breaking or moving off to the east after 21/16Z-21/18Z.
Northeast AL will be the area where the clouds will be the slowest to
recede. In addition, northwest winds of 10-15 kts gusting to 20 kts
are expected throughout the day as a high pressure system moves
closer to the region in the wake of a cold front. The winds should
diminish and clouds clear after 22/00Z.





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