Area Forecast Discussion Issued by NWS Huntsville, AL
000
FXUS64 KHUN 181726
AFDHUN
Area Forecast Discussion
National Weather Service Huntsville AL
1226 PM CDT Mon Mar 18 2024
...New AVIATION...
.NEAR TERM...
(Rest of Today)
Issued at 917 AM CDT Mon Mar 18 2024
A large area of mid level cloud cover continues to move southeast
this morning. The clearing line behind this cloud cover has made
it to near a Scottsboro, AL to Vinemont, AL line with some
scattered lingering cloud cover still west of this clearing line.
Temperatures near and south of this line are in the 41 to 45
degree range.
North of the front, strong cold advection is dropping temperatures
into the mid to upper 30s. One major question for the forecast is
whether additional afternoon cumulus will form early this afternoon.
The other is how much the sunshine will counter the cold air
advection. At this point, think cold air advection will win out
more than previous models thought.
Based on upstream airmass seen behind the front via BNA 7 AM
sounding, believe there is enough moisture between 900 and 700 mb
to warrant a more widespread cloud cover early this afternoon
produced by diurnal heating. RAP13 and HRRR hints at this. The
expected strong cold air advection behind the front pushing
southeast and some additional cloud cover later towards noon
(despite a higher sun angle) should keep highs a bit lower than
previously thought. Thus, trended down high temperatures into the
lower 40s in southern middle TN and 45 to 50 degree range further
south.
&&
.SHORT TERM...
(Tonight through Wednesday night)
Issued at 220 AM CDT Mon Mar 18 2024
Clearing skies coupled with diminishing sfc flow will then result
in temps falling into the mid/upper 20s later tonight, as high
pressure out of the Plains states pushes into the western/central
Gulf states. As such, a Freeze Warning remains in effect from 1AM
tonight thru 9AM Tue morning for all of the central TN Valley.
High pressure moving further into the Gulf Coast region will then
allow sfc winds to turn more to the WSW later in the day Tue, as
afternoon temps begin to rebound into the mid/upper 50s. The air
mass across much of the area will rebound further heading into the
middle of the week, as weak upper ridging builds eastward over
the Gulf region. With prevailing mostly clear/sunny skies,
overnight lows thru mid week will trend more in the mid 30s/40s,
while afternoon highs Wed climb into the upper 60s/near 70F.
&&
.LONG TERM...
(Thursday through Sunday)
Issued at 220 AM CDT Mon Mar 18 2024
By Thursday, a cold front will be located near the southern edge of
the forecast area, which should result in a cooler and mostly dry
forecast. Look for highs in the mid 60s with mostly cloudy skies. A
shortwave disturbance will dig into the Tennessee Valley by Thursday
night, bringing increasing rain chances overnight through Friday.
Models still differ slightly regarding the timing of this system, but
the consensus does show the main sfc low well over the Gulf of
Mexico, keeping the better thermodynamic environment well to our
south. Have kept thunder out of the forecast with dry conditions
developing Friday night.
The weekend will start off on the cooler side, with highs in the low
to mid 60s on Saturday and clearing skies. Radiational cooling will
allow lows to fall into the lower 40s Saturday night into Sunday
morning, but should warm up nicely Sunday afternoon as southerly flow
starts to return to the area. In fact, could not really ask for a
better forecast for Sunday, with mostly sunny skies and afternoon
highs near 70 degrees. Overall, nothing too impactful expected within
the long term period!
&&
.AVIATION...
(18Z TAFS)
Issued at 1226 PM CDT Mon Mar 18 2024
VFR conditions are expected throughout the TAF period. We will
have to see if any fog development may be needed to be added
towards daybreak on Tuesday. However, for now, think the airmass
will too dry for that to occur.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Freeze Warning from 1 AM to 9 AM CDT Tuesday for ALZ001>010-016.
TN...Freeze Warning from 1 AM to 9 AM CDT Tuesday for TNZ076-096-097.
&&
$$
NEAR TERM...09
SHORT TERM....KTW
LONG TERM....25
AVIATION...KTW