970
FXUS64 KJAN 181749 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1249 PM CDT Fri Sep 18 2026

...New AVIATION...

.KEY MESSAGES...

- Hot temperatures continue this afternoon, but lower humidity
  will help to reduce heat stress, with dangerous levels of heat
  stress confined to north of Interstate 20.

- Dangerous levels of heat stress will build back in areawide this
  weekend through early next week before a front with drier air,
  lower dewpoints and pleasant temperatures/less heat into late
  next week.

&&

.DISCUSSION...
Issued at 219 AM CDT Fri Sep 18 2026

Through mid-late next week (Thursday)...

Through this weekend: The Gulf Coast states remain entrenched
under a sprawling high at the surface and aloft (598 to 600DM).
RAP analysis/water vapor imagery indicate the center of mid level
high pressure gradually shifting westward today, leading anomalous
warmth, some 8-15F above normal (95F to 101F). Drier air is
evident in GOES East total PWs (0.9 to 1.3 inches) moving across
the Gulf Coast region as the mid level high shifts westward. While
it will remain hot, dangerous heat stress will be somewhat
decreased and shifted northward. Lows will be seasonably warm, a
touch cooler this morning in the mid to upper 60s to the southeast
(66-70F along and southeast of the Natchez Trace) while low 70s
(71-74F) to the northwest into the Delta, before a touch warmer
tonight (69-74F).

Highs continue to moderate into the weekend, with an influx of
deeper moisture. A westward propagating upper low/surface trough
over the northeast Gulf will lead to an influx of deeper moisture
aloft and higher boundary layer moisture, which supports less
mixing and more concerns of dangerous heat. Highs will moderate
into the upper 90s to around 100F (97-102F), with 101-102F
possible, especially in northern observation sites. Added some
targeted heat graphics in the HWO for today into the weekend
(Limited north of Interstate 20 today, areawide Limited Saturday,
and Elevated west of Interstate 20 late week on Sunday). Holding
off on any heat headlines for now. Rain chances remain a low
chance (less than 15 percent), with any chances possible southeast
of the Natchez Trace into the Interstate 59 corridors. While the
official forecast indicate a low chance of rain (less than 15
percent), some consensus and synoptic pattern could support higher
coverage than indicated, as much as isolated/low chance rain and
storm coverage in the Pine Belt late weekend on Sunday (15-30
percent).

Next week (Through next Thursday): As the upper low weakens and
another shortwave/cold core low propagates into the Mid West
States through middle to late next week, the mid level feature
over the northeast Gulf is progged to lift northward. This feature
will become absorbed in the mean flow to the north, which may
become more amplified than previously anticipated (per deep cold
core over the Great Lakes in 18/00Z Euro). This will lead to less
focused moisture convergence but persistent deep moisture (PWs
around 1.75 to greater than 2 inches).There are continued
indications of weak front/convergence zone and northwesterly flow
sinking into the area early next week, with drier air and lower
dewpoints late week.

Dangerous heat concerns will persist into early week and will
continue to message Elevated HWO heat graphics for Monday, less
oppressive Tuesday and much more pleasant into late week. Combined
with the ridge less stout and centered over east TX, highs will
not be as seasonably warm later (10F to 16F above early week to 4F
to 12F above late week). Highs peak in the 96F to 101F range
early week to 88F to 96F by mid to late week. Rain and storm
chances remain in the isolated/low chance range (15-25 percent) on
average in east to southeast MS, with deep moisture/frontal
convergence possibly driving coverage a touch higher in the
scattered/medium chance range (20 to 40 percent range). There
could be some cooler thermal profiles aloft, with vertical totals
in the mid to upper 20s (26C to 28C); isolated strong storms
cannot be ruled out at times. /DC/

&&

.AVIATION...
(18Z TAFS)
Issued at 1243 PM CDT Fri Sep 18 2026

VFR conditions will prevail through the TAF period. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       96  71  98  72 /   0   0   0   0
Meridian      97  72  99  71 /   0   0   0   0
Vicksburg     96  71  97  72 /   0   0   0   0
Hattiesburg   95  70  98  72 /   0   0   0  10
Natchez       96  70  98  72 /   0   0   0   0
Greenville    99  73 100  73 /   0   0   0   0
Greenwood     99  72 100  72 /   0   0   0   0

&&

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

$$

/DC/22