177
FXUS64 KHUN 260041
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
741 PM CDT Tue Jun 25 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 955 AM CDT Tue Jun 25 2024

Our post-frontal air mass continues to advect drier air into
northern AL and southern-middle TN for at least one more day.
With that, dewpoints should mix into the 60s across the TN Valley.
This, along with synoptic-scale subsidence, PoPs are nonexistent
today. Surface winds remain generally from the north at around 5
mph. Under mostly sunny to clear skies, highs are forecast to
soar to the upper-90s to near 100 across much of the valley. Heat
indices should remain near 100 as well. Make sure to take breaks
and drink plenty of water!

&&

.SHORT TERM...
(Tonight through Thursday night)
Issued at 1222 AM CDT Tue Jun 25 2024

Another relatively "cool" night is expected again tonight with lower
to middle 60s east and upper 60s to around 70 west. More hot
temperatures on Wednesday, although the higher dew points near 70
will reside in NW AL into middle TN where heat index values of
100-105 are expected, with lower 60s further east in northeast AL and
eastern portions of southern middle TN where heat index values may
stay in the 90s once again. A rather potent MCS will be dropping
southeast through the corn belt and into the OH Valley Wednesday as a
shortwave and cold front drive southeast as well. Whether the MCS
reaches all the way into southern middle TN or north AL is debatable
at this point, but peak heating and westerly advection of
moisture/Theta-E will likely help to generate new convection in
advance of the MCS and/or outflow boundary. Or, the outflow boundary
itself may help activate convection as well. In either case, still
looks like our best shot of showers and thunderstorms in a while. A
few strong thunderstorms will be possible due to moderate CAPE and
steep low level lapse rates. But thankfully, deep bulk shear values
will be modest at best. Convective chances will linger through
Wednesday night, but I suspect the loss of peak heating will signal a
decrease at least in more widespread activity until the front moves
through.

Thursday will be a nice break from the heat and added humidity that
arrives ahead of the front on Wednesday. Highs will be in the upper
80s to lower 90s.

&&

.LONG TERM...
(Friday through Monday)
Issued at 1222 AM CDT Tue Jun 25 2024

From Friday into the weekend, southerly flow will redevelop in low
levels, elevating dew points into the lower to perhaps middle 70s.
With highs staying in the lower to middle 90s, heat index values may
reach 105+ in some areas, mainly central and west both days. The good
news is, pulse afternoon convection is expected to develop Saturday
afternoon, and then another cold front undercuts the 5h ridge across
the region and arrives sometime Sunday depending on the model
solution. So, we may get breaks in the heat at times both days due
to thunderstorms. However, the front will be weakening and will
likely lift back north by late Monday.

&&

.AVIATION...
(00Z TAFS)
Issued at 741 PM CDT Tue Jun 25 2024

Conditions will remain VFR at the HSV/MSL terminals this evening
and overnight, with a notable increase in the coverage of high-lvl
convective debris clouds (originating from multiple clusters of
TSRA spreading east-southeastward from the Mid-MO Valley into the
Lower-OH Valley) anticipated during the early morning hours.
Although this will reduce the risk for nocturnal fog development,
some patchy BR/FG will still be possible btwn 8-13Z (but near
large bodies of water). Shortly after 12Z, we expect to see an
even greater increase in the coverage of mid/high-lvl clouds as a
developing MCS across southeastern MO begins to drop southward
thru the Mid-South region. Present indications are that the
eastern edge of this MCS may clip the western portion of our CWFA
(where moisture/instability will be greatest) tomorrow aftn, with
PROB30 groups for TSRA included at MSL/20-24Z and HSV/22-24Z. Lgt
NW sfc flow will back to SW later this evening, with prevailing
speeds increasing to arnd 10 kts tomorrow morning.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.

&&

$$

NEAR TERM...Serre
SHORT TERM...17
LONG TERM...17
AVIATION...70/DD