Excessive Heat in Missouri, August 1, 2024

Area Forecast Discussion
National Weather Service Memphis TN
658 AM CDT Thu Aug 1 2024

...New AVIATION...

.SYNOPSIS...
Issued at 310 AM CDT Thu Aug 1 2024

One final day of oppressive heat, with multiple heat headlines in
effect for today. Frontal passage tomorrow will aid in keeping
temperatures a little closer to normal through the weekend. Hot
conditions return next week, although it shouldn't be as humid as
this past week has been. Shower / thunderstorm chances remain low
through the forecast period, with the "best" (20 to 30%) coming
overnight and again tomorrow afternoon.

&&

.DISCUSSION...
(Today through Wednesday)
Issued at 310 AM CDT Thu Aug 1 2024

Clear conditions across the Mid-South early this morning with
another hot and humid day in store. Looking to our northwest,
there is a decaying MCS that will bring some scattered clouds to
the northern half of the area by mid-morning. Unfortunately that
is all that it is expected to do as temperatures will quickly
reach back into the mid to upper 90s today with widespread dew
point temperatures approaching the upper 70s. Many locations will
see heat index values over 105 with some locations over 110. As
such, heat headlines (Excessive Heat Warning and Heat Advisory)
will go into effect for the entire area at 10 AM until 8 PM.

Biggest question mark for the current forecast will be how the
frontal boundary that will move through the area tomorrow will
interact with some of the leftover energy from the aforementioned
MCS overnight tonight. Some CAMs have showers and thunderstorms
reaching our area from the north and approaching the I-40
corridor before fizzling out, while others have things fizzling
out before reaching out area entirely. If this line were to hold
together overnight, our environment could support a few strong to
borderline severe thunderstorms with damaging winds as the main
concern. My confidence in this is pretty low right now as we will
likely have a pretty large cap in place given the timing, but if
the frontal boundary can overcome this then certainly a few
storms on the stronger side will be possible. Frontal boundary
will finally move through the area tomorrow, aiding to bring
temperatures down a hair across TN and the MO Bootheel. We may
still need some heat headlines tomorrow across the AR/MS Delta, as
the boundary will not reach them until later in the day. Will
wait for another set of model runs before making that call, but
wouldn't be shocked if the Delta has another day of hot/humid
conditions. Luckily high temperatures and dew points will back off
for all Saturday and Sunday behind the frontal boundary, with dry
conditions for most of the area through the weekend.

Upper-level trough pattern will give way to a strengthening ridge
over the western U.S. as it drifts eastward over the plains by
Monday. This will allow high temperatures to creep back into the
mid to upper 90s Monday through at least the middle of next week.
The one good thing is that dew point temperatures do not look as
soupy as they have been this week, so heat index values should
remain between 100 and 105 for most of the area.

&&

.AVIATION...
(12Z TAFS)
Issued at 647 AM CDT Thu Aug 1 2024

This is essentially a persistence forecast as yet another decaying
MCS will approach the airspace after midnight. Confidence was too
low to go prevailing SH/TS at any of the terminals since CAMs are
relatively split on whether or not any of the convection will
actually hold together by the time it reaches the airspace. A
midlevel Cu deck is expected again with high cirrus to accompany
it. Generally southwest winds 5-10 kts should prevail.

CAD

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Excessive Heat Warning from 10 AM this morning to 8 PM CDT this
     evening for ARZ009-018-026>028-035-036-048-049-058.

MO...Excessive Heat Warning from 10 AM this morning to 8 PM CDT this
     evening for MOZ113-115.

MS...Excessive Heat Warning from 10 AM this morning to 8 PM CDT this
     evening for MSZ001-007-008-010>012-020-021.

     Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for MSZ002>006-009-013>017-022>024.

TN...Excessive Heat Warning from 10 AM this morning to 8 PM CDT this
     evening for TNZ001>004-019>022-048>052-088-089.

     Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for TNZ053>055-090>092.

&&

PUBLIC FORECAST...CMA
AVIATION...CAD