127
FXUS64 KJAN 301834
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
Issued by National Weather Service Shreveport LA
134 PM CDT Wed Jul 30 2025

...New DISCUSSION, AVIATION...

.DISCUSSION...
Issued at 1244 PM CDT Wed Jul 30 2025

The synoptic scale pattern this afternoon features a strong ridge
of high pressure in the mid and upper levels located across the
Southern Plains and extending into the Midwest and TN Valley.
Closer to the surface, high pressure can be found along the TX
Coast, with weak low pressure centered over the MS/AL vicinity,
with weak troughing located in its vicinity.

After isolated morning convection, visible satellite imagery
depicts a SCT cumulus field across the local area, with isolated
thunderstorms beginning to develop, mainly across western and
southern zones per latest MRMS imagery. Expect this convection to
increase in coverage provided the unstable environment in place
where MLCAPE values range from 2000-4000 J/kg, low level lapse
rates range from 7-8C/km, and precipitable water values range from
1.5-2 inches. Temperatures in the low to mid 90s with dewpoints
in the mid to upper 70s are largely responsible for this unstable
environment and generally expect thunderstorm coverage to increase
through the afternoon fairly quickly. A few of these storms may
briefly reach severe criteria with very heavy rain/localized flash
flooding and gusty winds the primary hazards. The greatest
thunderstorm coverage (and severe threat) is expected to be along
and south of the I-20 corridor where some additional aid from the
previously mentioned weak sfc low/troughing is expected to reside.
Convection will decrease in coverage quickly this evening with
loss of daytime heating and overall weakening of the residual sfc
trough. Outside of the thunderstorms/isolated severe threat, heat
will continue to remain the main headline, with heat indices
generally ranging from 110-120 degrees. The extreme heat warning
remains in effect.

A very similar weather day is in store for Thursday with extreme
heat remaining the primary forecast concern. By the afternoon
hours, heat indices will again climb to between 110-120 degrees,
warranting an area-wide extension of the extreme heat warning. It
will remain vital to take all heat related precautions through
the day Thursday. With the continued hot and humid airmass across
the area, scattered thunderstorms will develop by early afternoon,
potentially carrying the threat for severe wind gusts and
localized flash flooding.

Some good news in then in store for those growing tired of the
relentless heat. A somewhat unseasonal airmass will be moving
south on Friday, with eventual fropa expected across the CWA by
early Saturday. High temperatures will be cooler across far
northern zones on Friday, likely eliminating heat headlines.
Unfortunately, for remaining zones, the need for at least a heat
advisory still appears likely. Given that the frontal boundary
will be moving through the area from north to south on Friday,
convection is likely to fire along and ahead of it. The threat for
widespread severe weather currently appears unlikely, however, at
the expense of sounding like a broken record, the humid and
unstable airmass ahead of the front may allow for a few briefly
severe storms.

With frontal passage expected early Saturday, just about all
locations will notice a rather significant change in airmass in
comparison to the extended period of heat the previous week.
Dewpoints across the northern half of the area will fall into the
upper 60s, with highs in the upper 80s to lower 90s. Areas across
the far south will notice less of a change in airmass with
dewpoints remaining in the 70s with highs in the lower 90s.
Isolated afternoon storms will remain possible.

A gradual warming trend will then commence from Sunday through
early next week, despite the upper level ridge remaining to the
west of the Desert SW. While the extreme heat experienced the
previous week does not appear likely at this time, conditions
currently look hot enough to warrant heat advisory headlines.
Afternoon and evening convection will also remain possible.


&&

.AVIATION...
(18Z TAFS)
Issued at 1244 PM CDT Wed Jul 30 2025

VFR conditions to prevail through the TAF period. A SCT-BKN cu
field between 5-6kft expected, with a cirrus shield above.
Convection will be isolated for terminals north of I-20 and
scattered across terminals along and south of I-20. A TEMPO for -TSRA
has been added to TAF sites where higher confidence in afternoon
thunderstorms development currently exists. Convection will
diminish after sunset. Winds will be light at 5kts or less from
the N/NE through the rest of today, shifting more W/NW on Thursday
and remaining 5kts or less.

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       75  96  76  95 /  20  50  20  60
Meridian      75  96  74  95 /  30  60  20  70
Vicksburg     76  98  76  97 /  20  40  20  50
Hattiesburg   76  96  77  97 /  30  70  20  70
Natchez       75  96  75  97 /  30  50  10  60
Greenville    77  99  76  93 /  10  20  10  40
Greenwood     77  98  76  93 /  10  30  10  50

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&

$$

SHV/SHV/SHV