977
FXUS64 KJAN 190534 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1234 AM CDT Wed Aug 19 2026

...New AVIATION...

.KEY MESSAGES...

- Dangerous heat stress conditions are expected across at least
  portions of the forecast area through the end of this week.

&&

.DISCUSSION...
Issued at 130 PM CDT Tue Aug 18 2026

The persistent heat remains the main concern over several days
into early next week, but today the combination of heat and
humidity will aid in development of isolated strong to severe
thunderstorms. South of a stalled frontal boundary in the region,
pooled deep moisture and abundant sunshine have increased analyzed
SBCAPE values to around 3000-4000 J/kg this afternoon. Heating and
weak convergence in the frontal zone are expected to trigger
thundestorm development in the next 2-4 hours, with activity then
spreading south and east through the instability axis. Deep layer
wind shear is only around 15 kts, so severe storm activity may not
be highly organized. Damaging wind gusts and locally heavy
downpours are the primary hazards, but small hail cannot be ruled
out.

In case you forgot about the heat, it is still hot. Several sites
in the area have already reached 100 degrees again today, and
widespread heat index values in the 105-110 degree range are being
observed as of the current moment. A Heat Advisory remains in
place through this evening and picks back up again tomorrow. Rain
and the frontal boundary may keep max values just below Excessive
Heat Warning criteria, but will continue to monitor for any needed
upgrades.

Steepening northwest flow aloft, associated with a building ridge
over the western CONUS, will allow for a couple of disturbances to
bring rain chances into our forecast area through early next week.
Will also nudge temperatures slightly cooler, but still August-
level heat. /NF/

&&

.AVIATION...
(06Z TAFS)
Issued at 1228 AM CDT Wed Aug 19 2026

Isolated to scattered TSRA are psbl this aftn over the east and se
TAF sites and may bring lower flying conditions. Otherwise, VFR
conditions will prevail areawide through the end of the TAF
period. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       77  99  75  97 /  10  10  10  20
Meridian      75  98  74  96 /  10  30  30  40
Vicksburg     77  98  76  97 /  10  10  10  10
Hattiesburg   76  98  74  97 /  20  30  20  40
Natchez       76  99  75  99 /  10   0   0  10
Greenville    79 100  76  99 /  10  20  10  20
Greenwood     77  98  74  96 /  10  10  30  20

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory until 9 PM CDT this evening for MSZ018-019-025>066-
     072>074.

LA...Heat Advisory until 9 PM CDT this evening for LAZ007>009-015-016-
     023>026.

AR...Heat Advisory until 9 PM CDT this evening for ARZ074-075.

&&

$$

NF/22