Area Forecast Discussion
Issued by NWS Huntsville, AL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS64 KHUN 252327

Area Forecast Discussion
National Weather Service Huntsville AL
627 PM CDT Tue Oct 25 2016

For 00Z TAFS.


.NEAR TERM...(Rest of Today)
Issued at 830 AM CDT Tue Oct 25 2016

Based on 12Z BMX RAOB this morning, 850 mb temps have warmed 4-5C
since last night. If we were to mix to a similar depth to Monday, we
could see highs soar into the 90s. Mixing depths should be a bit
less today (~875-900 mb), but that will still yield low to mid 80s.
Thus, have raised temps by a few degrees and will continue to
monitor. Surface winds will be veering to the southeast this morning.
Otherwise, no other sensible weather changes to the forecast needed
at this time.

.SHORT TERM...(Wednesday through Thursday)
Issued at 127 PM CDT Tue Oct 25 2016

Benign weather will continue through Wednesday as 850 mb high
pressure system will shift into the Carolinas. This will enable a
greater southerly fetch to develop which should increase dew points
and RH values on Wednesday. Temps will be milder tonight due to the
increased moisture, although typical cold drainage valleys in our
eastern counties will dip back into the 40s with lower 50s
elsewhere. Highs should once again reach around 80 degrees on
Wednesday at most valley locations.

Short range models continue to drop a rather distinct shortwave
southeast toward the region Wednesday Night. This wave outruns a cold
front rather quickly and may limit overall extent of precipitation.
However, there are run to run progs showing low level convergence
and moisture transport in eastern MS and western AL that help to
generate precip development late Wednesday Night into Thursday.
Elevated instability is marginal, but with an increase in dew points
into the 55-60F range, have opted to keep thunderstorms in the
forecast. These should shift southeast of our forecast area on
Thursday afternoon, and probably by late morning in southern TN and
northwest AL. Only modest lapse rates in low to mid levels which
limits CAPE values should keep storms rather ordinary.

.LONG TERM...(Thursday night through Monday)
Issued at 127 PM CDT Tue Oct 25 2016

A surface and upper level high pressure will be in place by Friday.
The departed frontal boundary is forecast to be in place over
southern Alabama and Georgia. Not much difference in air mass behind
the front, since the stronger cold air advection remains in the Mid-
Atlantic and northeastern states.

Temperatures should climb into the upper 70s to around 80 degrees on
Friday based on 850 mb temperatures. Lows will not drop much and
remain in the lower to mid 50s Friday night. Slightly higher 850 mb
temperatures and an upper level ridge on Saturday should allow
temperatures to warm in the 80 to 85 degree range.

By Saturday night, synoptic models are in fairly good agreement that
the upper level ridging weakens significantly. However, it does
remain in place over much of Georgia and Alabama. Could see some
passing clouds at times based on RH fields at various levels (due to
a disturbance well to our north over the Ohio Valley/western Great
Lakes region).

The cold frontal passage may produce winds of 10-15 mph around
daybreak Sunday. Cold air advection will be weak again with this
front. So, just a slight cool down is expected into early next week,
with highs in the upper 70s and lower 80s and lows of 50 to 55.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 620 PM CDT Tue Oct 25 2016

High pressure that has been situated over the area will shift east
towards the coast. This will winds to shift to the south and bring a
return of moisture into the area by Wednesday morning. Some guidance
is hinting at a possible low stratus deck advecting northward out of
southern AL/GA towards northern AL but believe this is overdone and
should remain south of the area.

So, have kept VFR conditions through the TAF period. Winds will be
light and variable but transition to the south and increase to around
10kts by late Wednesday morning.





For more information please visit our website
at is the U.S. government's official web portal to all federal, state and local government web resources and services.