940
FXUS64 KJAN 241715 AAB
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1215 PM CDT Tue Sep 24 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 1002 AM CDT Tue Sep 24 2024

Today`s forecast looks to bring rain showers (30-50%) and cloudy
conditions associated with a weak frontal boundary pushing into the
area. Current observations distinguish the weak boundary laying
through the southeastern corner of Arkansas with temperatures and
dew points trending 4F lower behind it. The upper level dynamics
associated with the attendant low have begun to shift northward,
cutting off any major support and therefore chances for significant
deepening and subsequent strengthening of the feature remain
limited. Unsurprisingly, this cut off low, has lost a lot of
momentum and is projected to slowly amble its way through the region
today

Daytime heating is expected to provide just enough lift this
afternoon to begin to precipitate out the Mississippi moisture
profile, with current HRRR/GFS runs depicting rain totals averaging
under half an inch along the front as it meanders through this
afternoon. The line of showers is not expected to be completely
filled in, so some sites may not see any rainfall today. This line
will be located in the northwest quadrant and propagate through the
southeast by midnight. There is a possibility for isolated
thunderstorms embedded in the overall line of showers, but lapse
rates look to be generally unfavorable for widespread development.

This afternoon will be our last bout of temperatures breaking into
the low 90s F for the foreseeable feature as the front is expected to
bring widespread cloudiness over the CWA for the next few days. The
incoming regime will establish a more seasonal temperature profile,
with highs in the mid to low 80s F and lows in the low 60s F.

The 850mb front is expected to stall out over the region, and with
minor overnight retrograding, we will likely see a repeat of today`s
weather over the next few days with less coverage and intensity./OAJ/

&&

.DISCUSSION...
Issued at 343 AM CDT Tue Sep 24 2024

Through tonight: A cold front is currently making rather slow
progress into the region and will continue to do so through tonight.
Ahead of this front, scattered showers have been moving across
northeast LA and the ArkLaMiss Delta early this morning. This
activity is expected to lose steam as daybreak approaches. However,
with diurnal heating, redevelopment of showers is expected ahead of
the front this afternoon. Marginally supportive bulk shear and
sufficient instability will exist for isolated storms to develop.
However, relatively weak forcing, marginal mid level lapse rates,
and largely boundary-parallel flow should help temper intensity.

Tonight, a more vigorous upper disturbance is on track to move
across the area as it rounds a cutoff upper low pivoting into the
Mid-Mississippi Valley. Increased forcing associated with this
feature should yield greater coverage of showers and embedded
thunderstorms along and ahead of the front, even as we head into the
overnight. While rainfall amounts will average below a half inch in
most areas, locally higher amounts will be possible with HREF LPMM
suggesting max localized totals in the 2-4" range. Given current
ground conditions with these amounts, flooding is not a concern at
this time. Cooler and somewhat drier air will begin to move in from
the north tonight behind the front, with airmass change becoming
more noticeable in the following days. /DL/

Wednesday through Monday: Extended forecast remains on track as a
stalled frontal boundary keeps wet conditions across the area and
Potential Tropical Cyclone Nine (PTC 9) moves northward into the
southern Gulf of Mexico. Thanks to both the stalled frontal
boundary and increased cloud cover from the tropical system,
slightly below to near average high/low temps are expected.

A slow-moving closed low forms over the Ozarks/ArkLaTex region as a
blocking pattern comes into place and a stalled frontal boundary
is expected to remain situated over the CWA, continuing rain
chances (25-60%) for the area.

Turning to the tropics: a tropical disturbance (now PTC 9) is
expected to migrate northwards toward the Gulf of Mexico. Models are
in agreement in tracking and strengthening the system into a
hurricane in the eastern Gulf, affecting FL panhandle near
Thursday. Interaction between the closed-low and tropical cyclone
is expected to bring abundant moisture to the region. IVT and PW
values are expected to be near the 99th and maximum percentile,
resulting in possible heavy rainfall across the area through
Friday, especially in eastern and northern parts of the CWA. As
the remnants of the tropical cyclone absorb into the main flow and
the closed low moves out of the area, rain chances will begin to
decrease for majority of the area this weekend. Continue to check
back for updates as the event gets closer. /SW/

&&

.AVIATION...
(18Z TAFS)
Issued at 1213 PM CDT Tue Sep 24 2024

VFR flight conditions will persist across all sites for the
beginning of the TAF period. Expect southeasterly winds between
5-10 kts. -RA/VCTS will be possible this afternoon and evening.
As a result, MVFR/IFR flight categories will be possible towards
the end of the TAF period. /OAJ/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       68  83  64  80 /  60  50  30  30
Meridian      68  83  64  80 /  50  60  50  50
Vicksburg     68  83  62  80 /  50  30  20  20
Hattiesburg   70  88  68  83 /  20  50  40  40
Natchez       69  83  63  80 /  40  40  10  10
Greenville    64  79  60  78 /  10  30  10  20
Greenwood     65  81  61  80 /  20  30  20  30

&&

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

$$

OAJ/SW/OAJ