809
FXUS64 KJAN 121756 AAB
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1256 PM CDT Sat Sep 12 2026

...New AVIATION...

.KEY MESSAGES...

- Heat and heat stress potential will increase across much of the
  area through early next week.

&&

.DISCUSSION...
Issued at 253 AM CDT Sat Sep 12 2026

Through Wednesday: An upper shortwave currently situated over the
Mid South will shift eastward into the Tennessee Valley today.
The trailing portion of this wave, extending across parts of
North MS to near the AR/LA border, will serve as a focus for
scattered convective development later today into early this
evening. Further south, typical warm season isolated to scattered
diurnal convection is expected. As we head into early next week,
upper level ridging will begin to limit convection with afternoon
showers and storms becoming more isolated.

With the building ridge, temps will trend upward again, with highs
in the triple digits possible across the Delta region Monday
through Wednesday. This airmass will remain seasonably humid,
though we expect to see increasing daytime mixing as we head into
next week with dewpoints dropping into the 60s during the
afternoon hours over much of the area. Still with conditions
being so warm, heat indices will approach critical thresholds as
early as today across northwest MS/north LA/southeast AR and over
much of the western half of the forecast area by tomorrow. For
today, it is expected heat advisory criteria will only be met
briefly in a few areas. However, advisories may be warranted
later on for a portion of our area. We will continue to highlight
the increasing heat stress concerns in graphical products.

Thursday through next Saturday: By mid week, low level flow will
become increasingly easterly thanks to the orientation of the
surface high, ushering in a relatively drier airmass. This airmass
will still support hot days, but with dewpoints dropping into the
60s - perhaps even the 50s as times during daytime mixing - it could
greatly alleviate heat stress danger through the end of the forecast
period. Deep layer moisture will begin to increase again late Friday
into next Saturday, with returning potential for diurnal convection.
/DL/

&&

.AVIATION...
(18Z TAFS)
Issued at 1254 PM CDT Sat Sep 12 2026

Afternoon thunderstorms expected along our northern corridor, with
showers/ts possible but unlikely elsewhere. VFR conditions will
prevail eschewing momentary dips attendant with convection at the
aforementioned sites./OAJ/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       73  95  73  97 /  20  20   0   0
Meridian      72  96  71  98 /  10  20   0   0
Vicksburg     73  95  73  97 /  10  20   0   0
Hattiesburg   72  94  72  96 /  10  20   0  10
Natchez       73  96  73  97 /  10  30   0  10
Greenville    74  98  73  99 /  10  10   0   0
Greenwood     72  97  71  99 /  20  10   0   0

&&

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

$$

EC/EC/OAJ