977
FXUS64 KJAN 211126 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
626 AM CDT Fri Aug 21 2026

...New AVIATION...

.KEY MESSAGES...

- Dangerous heat stress conditions are expected across at least
  portions of the forecast area again today.

- Isolated to scattered severe storms capable of damaging wind
  gusts are possible again this afternoon into this evening.

&&

.DISCUSSION...
Issued at 257 AM CDT Fri Aug 21 2026

Today and tonight...

Hot and humid conditions will continue across the area today as
guidance continues to show the frontal boundary slowly sagging
southwards the Gulf Coast. This will help focus scattered diurnally
driven late afternoon/early evening showers and storms, especially
for areas along and south of I-20. CAM guidance from early this
morning is beginning to show scattered convection across southern
portions of our CWA later this afternoon so went ahead and bumped up
the PoPs to around 20-40% in order to better reflect the storm
coverage with slightly higher PoPs (around 45%) across the Pine
Belt. Although the overall organization of the storms will be pretty
weak due to the lack of vertical shear, the combination of the hot,
humid, and unstable boundary layer conditions and steep low lapse
rates will support damaging microburst winds. At this time no
changes have been made to the severe graphic for today and a
"Marginal" risk (Level 1 out of 5) will continue to be advertised
for areas along and south of I-20. The timing of these storms still
looks to be between 3pm-9pm.

Dangerous heat will continue to persist across our forecast area
today with afternoon highs in the upper 90s to low 100s and heat
indices in the 105-110 degree range. The heat advisory remains in
effect from 11 am to 8 pm this evening for portions of southeast
Arkansas, northeast Louisiana, and much of eastern Mississippi.
Likewise, the extreme heat warning remains in effect from 11 am to 8
pm this evening for areas that could see heat index values up to 115
degrees. These areas include portions of northeast Louisiana,
portions of central, south central, southwest, and west central
Mississippi. /CR/

The forecast messaging for the extended forecast period remains the
same with no major changes made. The frontal boundary will continue
to push southward out of our CWA an towards the Gulf Coast heading
into the weekend. Limited to elevated dangerous heat will occur
across much of the area Saturday and Sunday. Because of this
additional heat advisories/headlines will likely be needed these two
days. Please refer to the previous forecast discussion down below
for more information:

Weekend through early to mid next week: Global model guidance
indicate that a northwest flow pattern will evolve and persist
through the remainder of the forecast. A NW-SE oriented thermal
gradient will support the greatest heat stress over southwest
portions of the forecast area, but this doesn`t appear it will be
more than a limited to potentially elevated dangerous heat
situation. This pattern would support an occasional MCS threat, but
timing details are very uncertain, and overall rain chances are not
great in the mean. Unfortunately for those needing rainfall, there
are no strong signals for it at this point aside from a gradual
uptick in rain chances as we go later into next week. /EC/CR/

&&

.AVIATION...
(12Z TAFS)
Issued at 620 AM CDT Fri Aug 21 2026

The -RA at GTR wl end by 13Z. Elsewhere VFR conditions wl prevail
until isolated to scattered TSRA develop this aftn and begin
affecting TAF sites cntrl and south after 20Z. This activity wl
continue until around 03Z Sat before dissipating. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       99  73  99  74 /  20   0   0  10
Meridian      97  72  98  73 /  30  10   0  10
Vicksburg    100  73  99  73 /  20  10   0  10
Hattiesburg   98  73  98  73 /  50  30   0   0
Natchez      101  74 101  74 /  30  20  20  10
Greenville   100  73 100  73 /   0   0  10  20
Greenwood     97  71  98  71 /   0   0   0  20

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for MSZ018-019-025>039-044>046-050>052-056>058-065-066-073-
     074.

     Extreme Heat Warning from 11 AM this morning to 8 PM CDT this
     evening for MSZ040>043-047>049-053>055-059>064-072.

LA...Extreme Heat Warning from 11 AM this morning to 8 PM CDT this
     evening for LAZ007>009-015-016-023>026.

AR...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for ARZ074-075.

&&

$$

22/CR/22