911
FXUS64 KJAN 251754
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1254 PM CDT Wed Sep 25 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 1040 AM CDT Wed Sep 25 2024

Mesoscale Update: Longwave troughing around a closed low progressing
through the lower Mississippi River Valley will continue to shift
east as a couple spokes of shortwave energy pivot through the area.
At the same time a weakening cold front will continue to progress
southward through the area today as showers and a thunderstorm or
two propagate along the front into this afternoon. As the cold front
clears the area rain chances will diminish with most of the area
remaining dry throughout the rest of the day. The best rain chances
will be this morning into mid-day with them diminishing into this
afternoon. We are currently seeing this trend come to fruition and
expect it to continue./KP/

&&

.DISCUSSION...
Issued at 326 AM CDT Wed Sep 25 2024

Today and Tonight: early morning water vapor imagery/RAP analysis
showed the circulation around a rather amplified trough extending
south across the ArkLaTex region from a closed low centered over the
mid Mississippi valley. Several subtle shortwaves were noted poised
to round the base of the trough and across our CWA within the
resulting southwest flow. One such shortwave was moving over our CWA
and helping to redevelop convection along and south of a weak cold
front that surface analysis had sagging into central MS. The 00Z Wed
JAN sounding still showed a warm moist airmass in place with a PWAT
of 1.87in. Hi-res models suggest the convection will continue to
increase this morning until the shortwave shifts northeast of
Mississippi later this morning. There will likely be a brief lull in
the convection around noon before the next shortwave combines with
daytime heating and the cold front to redevelop convection early
this is afternoon. The cold front is expected to be south or just
pushing south of our CWA by evening ending the rain chances. Dry
weather is expected by midnight and cooler and drier air will filter
into our CWA. This will lead to cooler than normal morning lows with
a few locations bottoming out in the upper 50s in our north. /22/

Long Term (Thurs-Tues):

Wet pattern continues for the ArkLaMiss region Thursday as a closed-
low situates over the Ozarks and a washed out frontal boundary hangs
around the area. In the southeast Gulf of Mexico: Tropical Storm
Helene is expected to become a hurricane/major hurricane before
landfall. Direct impacts from Helene is not expected for the CWA,
but will help transport tropical moisture into the region.

Both low pressure systems are expected to provide sufficient
moisture to the area to keep isolated/scattered showers in the
forecast through Saturday. Areas east of I-55 and north of I-20 has
the greatest potential (15-50%) to see rainfall. Post landfall,
Helene will absorb into the main flow and the closed-low will
gradually move towards the northeast Sunday. Drier conditions and
seasonal temperatures will settle in once the closed-low migrates
northward at the start of the new week. /SW/

&&

.AVIATION...
(18Z TAFS)
Issued at 1239 PM CDT Wed Sep 25 2024

Currently TAF sites will bounce around in category, varying cloud
bases and declining showery/storm activity in the region will
continue to impact TAF sites into early afternoon. By late
afternoon the front will have moved through the area and
conditions will improve, leaving all TAF sites in VFR/MVFR
conditions by 0Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       64  82  62  79 /   0  10  20  20
Meridian      63  81  62  80 /  10  20  30  20
Vicksburg     63  83  61  80 /   0   0  10  10
Hattiesburg   68  85  64  84 /  10  10  10  10
Natchez       63  81  61  80 /  10   0   0  10
Greenville    60  81  62  74 /   0  10  20  40
Greenwood     60  83  62  75 /   0  10  30  40

&&

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

$$

KP/SW/22