240
FXUS64 KJAN 250013 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
613 PM CST Sun Nov 24 2024

...New AVIATION...

.DISCUSSION...
Issued at 252 PM CST Sun Nov 24 2024

Through Tonight:

Warm, moist return flow on the backside of departing surface high
is evident in afternoon cumulus field spreading north and east
across portions of LA and far southern MS this afternoon. The
returning moisture will boost overnight humidity levels and could
be a concern for patchy fog especially where winds go light to
calm by early Monday morning. Latest HREF probabilities for fog
development favored the Pine Belt and areas northward into east
central Mississippi, where currently clear skies would support the
best potential for radiational cooling and moisture advection to
overlap. Added patchy fog wording to the river valley areas east
of Interstate 55 overnight, but may have to upgrade fog messaging
if confidence in dense fog increases.

Monday through Sunday:

An upper-level short-wave trough moving east from the Plains on
Monday will bring the next cold front into our area late Monday
afternoon into the overnight, though moisture return should be
minimal enough to limit thunderstorm potential. Can`t rule out a
few rumbles of thunder overnight with weak elevated instability,
but mostly a mundane frontal passage is expected.

What will have more significance is the next shortwave crossing
the Rockies Wednesday into Thursday. This wave should spin up a
low pressure system in the Southern High Plains that quickly moves
east along the Interstate 40 corridor, with more moisture
recovery and warming occurring over our area in advance of its
arrival. Latest model guidance remains in poor agreement with the
timing of this low-amplitude wave, but a corridor of warm, moist
advection along the Mississippi River Valley will increase
instability Wednesday into Thursday regardless. While the wave
will be positively-tilted and low-level flow will become more
south-southwesterly ahead of the approaching system`s cold front,
a strengthening upper-level jet streak associated with the system
will intersect the developing warm sector along the Gulf Coast.
Modest wind shear and decent instability will likely support at
least a Marginal chance for severe thunderstorms as the system
moves through our area late Wednesday into Thursday. This does
include the Thanksgiving Holiday, so area residents and visitors
should pay attention to changes in the forecast and updates to
timing for best thunderstorm chances.

Potentially stronger high pressure arriving behind the cold front
should give us another chance for frost and freeze conditions
heading into next weekend. While there is less confidence than
usual for the Wednesday/Thursday pattern, more substantial
disagreements with trajectory and strength of arctic air mass
coming south out of Canada introduces even more uncertainties for
our region next weekend. Peaking a little ahead into early the
following week, this signal for potentially cold air mass
affecting the region persists for a few days. Will keep an eye on
the trends regarding freeze potential in the region. /NF/

&&

.AVIATION...
(00Z TAFS)
Issued at 613 PM CST Sun Nov 24 2024

VFR flight categories prevail, with sfc winds winding into the
evening. Southerly sfc winds will linger at northwest sites of
GLH & GWO while light in southeast MS TAF sites (I-59 & Hwy 84
corridors). In addition, low-level wind shear (LLWS) >30kts can`t
be ruled out at GLH & GWO, with onset around 25/03-05Z Monday &
persisting through daybreak. Light winds & moisture advection,
especially nearby river valley corridors, could lead to some MVFR
patchy to areas of fog/BR. Can`t rule out brief sub IFR vsby near
daybreak. These flight restrictions last through mid-morning
25/14-16Z Monday. Southwesterly sfc winds will be predominant
after 25/15-17Z Monday, sustained up to 20mph & gusts around
25mph. Low probs of light rain showers will build in northwest TAF
sites near the end of the 00Z TAF period, so held off mention in
this TAF cycle. /DC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       56  78  52  65 /   0  10  80  10
Meridian      52  75  52  64 /   0   0  60  10
Vicksburg     58  80  49  64 /   0  10  50   0
Hattiesburg   54  79  58  69 /   0   0  50  10
Natchez       58  79  53  65 /   0  10  40   0
Greenville    58  77  44  59 /   0  20  40   0
Greenwood     57  77  46  62 /   0  20  60   0

&&

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

$$

NF/DC