271
FXUS64 KJAN 201112 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
612 AM CDT Sun Sep 20 2026

...New AVIATION...

.KEY MESSAGES...

- Dangerous levels of heat stress will build back in areawide
  through early next week before a front brings drier air and more
  pleasant temperatures late next week.

&&

.DISCUSSION...
Issued at 1210 AM CDT Sun Sep 20 2026

Another hot day is on tap for today as an H590 ridge continues to
prevail over the area. Highs will be in the mid 90s to around 100
across the area with heat indices ranging from 100-105. Expect
mostly dry conditions, but there could be a stray shower in the
southeast. /15/

Monday through next weekend...

The anomalous ridge responsible for recent record breaking heat
begins to break down early next week with the approach of a
shortwave trough. There is a subtle moisture return in response to
this, which will increase dewpoints back into the low 70s. This
should both increase dangerous heat as well as rain chances
beginning Monday and persisting through Tuesday. Heat indices will
range from 100-105+, with the hottest temperatures west of I-55. An
elevated heat graphic continues to be advertised. Would not rule
out a heat advisory for Monday and possibly Tuesday. Further east,
where low (20-30%) rain chances are focused, indices are likely
to remain below criteria (105), but there will still be a limited
heat threat. Isolated to scattered showers and thunderstorms, in
perhaps the first sign of the cool season, will not be strictly
diurnal, and should continue overnight ahead of a slow moving
frontal boundary. Since synoptic forcing is still weak, this
frontal boundary will slowly sag south over the course of
Wednesday and into Thursday as the shortwave rounds the midlevel
high. There is some difference among the guidance regarding the
timing of the main jet energy associated with the shortwave, but
there is good agreement, and it makes meteorological sense, that
shortwave ridging will be reinforced in its wake late next week
into the weekend. Dry conditions will return with a continuation
of above normal temperatures. /SAS/

&&

.AVIATION...
(12Z TAFS)
Issued at 611 AM CDT Sun Sep 20 2026

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

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       98  74  97  72 /   0   0  20  20
Meridian      98  72  97  71 /  10  10  30  20
Vicksburg     97  74  97  72 /   0   0  20  20
Hattiesburg   97  73  96  71 /  10  10  40  10
Natchez       98  74  97  73 /   0   0  20  10
Greenville    99  75  99  73 /   0   0  20  20
Greenwood     99  73  99  71 /   0   0  20  20

&&

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

$$

/15/22