Heat in Missouri, August 11, 2023

Area Forecast Discussion
National Weather Service Memphis TN
610 AM CDT Fri Aug 11 2023

...New AVIATION...

.SYNOPSIS...
Issued at 249 AM CDT Fri Aug 11 2023

Today through the weekend, excessive rain and thunderstorms
should not be as widespread as we have seen for the past few days,
but August heat is returning. We will likely need Heat Advisories
and possibly Excessive Heat Warnings through the weekend and
maybe on Monday before cooler temperatures return to the Midsouth.
We should see mostly dry conditions Tuesday through Friday with
high temperatures in the middle 80s to low 90s.

&&

.DISCUSSION...
(Today through Thursday) Issued at 249 AM CDT Fri Aug 11 2023

Abundant ground moisture from recent heavy rain, light wind, and
mainly clear skies above ~2,000 feet have resulted in prime
conditions for fog across the Midsouth. Visibilities below 1/4 of
a mile have already been observed at many locations and will
likely only become more widespread through sunrise. A Dense Fog
Advisory has been issues for most of the Midsouth and may need to
be expanded area wide now that clouds have moved out of northeast
Mississippi. After sunrise, fog and low clouds should dissipate
quickly and temperatures will skyrocket. A Heat Advisory has been
issued for east Arkansas, the Missouri Bootheel, Shelby county
Tennessee, and portions of north Mississippi. Heat indices may
approach 110 degrees.

We remain under weak northwest flow with a ridge building over
east Texas and Louisiana. The strengthening ridge will result in
much warmer conditions today through the weekend. Today should be
mostly dry, but we may still see a round or two of thunderstorms.
Thunderstorms should be mainly mainly confined to northern and
especially northeastern portions of the Midsouth tonight, Saturday
and Sunday as weak impulses track across Missouri and northern
portions of west Tennessee. A few strong to severe thunderstorms
are possible, but widespread hazardous conditions are not
expected. The higher likelihood of severe thunderstorms should
remain to our north where shear is stronger. The primary threat
for any severe storms in the Midsouth would be from damaging wind
and large hail today through the weekend.

Sunday into Monday, a deep midlevel trough will track out of the
northern Rockies and across the central Plains. This feature will
become oriented from the Great Lakes into the southern Plains by
Midday Monday. At the surface, an attendant cold front will move
quickly across the Midsouth on Monday. We could still see heat
advisory conditions(105-109 heat index) in north Mississippi and
east central Arkansas Monday afternoon ahead of the front, but
cooler conditions should arrive to all of the Midsouth by Tuesday.

Several days of mostly dry conditions is expected next week
beginning Tuesday. Below normal temperatures are expected Tuesday
and Wednesday. Expect highs mostly in the 80s and lows in the 60s.
As the ridge restrengthens to our southwest, gradual warming will
take place Thursday and Friday with high temperatures returning to
the 90s.

30/Sirmon

&&

.AVIATION...
(12Z TAFS)
Issued at 610 AM CDT Fri Aug 11 2023

Widespread FG, BR, and low CIGS start this period with LIFR
conditions. Gradual improvement will occur near sunrise before
lifting to VFR after sunrise. All sites should reach VFR status by
18z at the latest. Winds will be on the lighter side today
shifting back to NW flow 7 kts or less. There is a chance for
pop up showers and thunderstorms, but no direct impacts to the
terminals. Guidance was hinting at TUP having another round of BR
conditions tomorrow night.

DNM

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Dense Fog Advisory until 8 AM CDT this morning for ARZ009-018-
     026>028-035-036-048-049-058.

     Heat Advisory from noon today to 8 PM CDT this evening for
     ARZ009-018-026>028-035-036-048-049-058.

MO...Dense Fog Advisory until 8 AM CDT this morning for MOZ113-115.

     Heat Advisory from noon today to 8 PM CDT this evening for
     MOZ113-115.

MS...Dense Fog Advisory until 8 AM CDT this morning for MSZ001>017-
     020>024.

     Heat Advisory from noon today to 8 PM CDT this evening for
     MSZ001-007-008-010>012-016-017-020>024.

TN...Dense Fog Advisory until 8 AM CDT this morning for TNZ001>004-
     019>022-048>055-088>092.

     Heat Advisory from noon today to 8 PM CDT this evening for
     TNZ088.

&&

PUBLIC FORECAST...JDS
AVIATION...DNM