656
FXUS64 KJAN 200556 AAC
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1256 AM CDT Wed Aug 20 2025

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 933 PM CDT Tue Aug 19 2025

Intense deep convection developed early this evening over the
upper ArkLaMiss Delta region in association with a boundary
pushing south into what is a very moist and unstable airmass. A
severe microburst resulted in the Greenville area where a good
bit of tree damage is being reported in addition the 51 kt gust
observed at GLH. Storms will continue for the remainder of the
evening as the boundary continues to push south, but less unstable
airmass farther south will not be as conducive to maintaining any
sort of strong/severe threat and expect there to be a diminishing
trend by the time we approach midnight.

Looking ahead to tomorrow, the same boundary will help to support
additional convective coverage with daytime heating, and this will
likely support another round of strong to severe storm potential
for locations roughly along/southeast of the Natchez Trace
Corridor. With high res guidance showing strong wind gust
potential, this may be a case for messaging a marginal severe
risk and we`ll be assessing that further tonight. Otherwise, the
heat advisory for tomorrow will continue. /EC/

&&

.DISCUSSION...
Issued at 102 PM CDT Tue Aug 19 2025

Tonight and Wednesday: The local radars were quieter early this
afternoon than they were at the same time Monday afternoon. Isolated
to scattered showers and thunderstorms are still expected across the
central and southern portions of the CWA this afternoon into early
evening. Although the storms are not expected to be as potent as the
Monday storms, a strong storm or two with gusty winds will be
possible. Heat and high humidity are the main threats this afternoon
leading to an Extreme Heat Warning in the west and a Heat Advisory
in the east until 8PM CDT.

Otherwise, the recent oppressive heat wave is expected to have
peaked today and less oppressive conditions are expected Wednesday.
As the large 598dam high becomes centered over the Four Corners
region lower heights and shortwave troughing will develop over our
region. This shortwave troughing from the north will also be
supporting a weak cold front. The cold front will remain to our
northwest Wednesday but help increase the chance for rain and
associated cloud cover over our CWA. This should help hold
temperatures down and result in lower heat indices. The peak heat
index values should rise above 105F for several hours before
convection kicks in and leads to rain-cooled temperatures. A Heat
Advisory has been issued for most of our CWA Wednesday. /22/

Thursday Onwards...

Little will change over the next week, as high pressure remains
anchored over the region. Isolated afternoon and early evening
showers/thunderstorms are expected every day. All indications at
this time point to non-severe characteristics for this convection
but there is still a chance for damaging winds should a cell or two
overachieve. A weak trough and an associated front will rotate
around the upper level ridge Thursday/Friday which will help
moderate our temperatures back down into the 90s, allowing for a
relief from our 105+ heat indices across the area. Upper level
troughing will continue over the area into the weekend, bringing
cooler temperatures and a slight increase in afternoon storm
coverage; with the greatest coverage along and south of I-20.

Over the weekend another front will push into the area from the
north. This will allow for marginal drying and an attendant drop in
precipitation both in coverage and intensity. That being said we
should see a continued drop in temps next week with highs in the
high 80s and lows in the 60s./OAJ/

&&

.AVIATION...
(06Z TAFS)
Issued at 1256 AM CDT Wed Aug 20 2025

Scattered convection early this morning will taper off over the
next few hours. However, redevelopment is expected Wed afternoon,
continuing into Wed evening, potentially resulting in brief
categorical reductions in TSRA or brief strong convective wind
gusts. Patchy fog cannot be ruled out around daybreak this
morning. Otherwise, VFR conditions will prevail through the TAF
period with mainly light wind. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       98  73  94  72 /  50  30  50  20
Meridian      96  73  92  72 /  40  30  50  20
Vicksburg     96  73  94  71 /  50  40  40  20
Hattiesburg   99  75  95  74 /  30  20  60  30
Natchez       96  73  92  72 /  40  30  60  20
Greenville    97  73  94  70 /  50  30  20  10
Greenwood     98  73  94  70 /  60  30  20  10

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for MSZ018-019-025>037-040>043-047>049-053>055-059>066-
     072>074.

LA...Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for LAZ007>009-015-016-023>026.

AR...Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for ARZ074-075.

&&

$$

EC/22/OAJ/DL