729
FXUS64 KJAN 071739 AAC
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1239 PM CDT Tue May 7 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 941 AM CDT Tue May 7 2024

A cold front currently situated from central TX through the
Missouri Valley will stall before reaching our area today.
However, ahead of it, a weak upper shortwave will provide
potential for scattered convection mainly later on today. This
activity will likely be focused along one or more surface
convergence zones evident on the latest visible satellite imagery,
the most prominent along remnant convective outflow extending
from the AR/LA border northeastward across the Delta. This will
shift eastward through the late afternoon, decreasing into early
evening. Seasonably warm and moist conditions will yield moderate
to marginally strong instability by this afternoon, and given
sufficient deep shear, a few of the storms could become severe
this afternoon into early this evening with damaging wind gusts
and lower end severe hail being the most likely concerns. The
marginal severe threat will be focused mainly north of I-20 where
coverage is expected to be greater and where the low level jet
will be somewhat stronger. /DL/

&&

.DISCUSSION...
Issued at 413 AM CDT Tue May 7 2024

Today through tonight: The primary weather concern in the near
term will be for a marginal risk of severe storms from later this
afternoon into the early evening hours. Height falls associated
with a shortwave trough crossing the Mississippi Valley will
mostly stay to the north of the forecast area, but there should be
just enough mid level ascent to initiate isolated storms in what
will be a very warm/moist and unstable environment this afternoon,
especially over northern/eastern portions of the area. Mid level
flow should be marginally sufficient for getting a few supercells
capable of damaging wind gusts and hail. We expect this activity
to diminish with loss of heating early this evening, and a quiet
and mild overnight is expected. /EC/

Wednesday through Monday: No major changes have been made to the
forecast for the long term period. Early morning global guidance
highlights a 996mb sfc low developing in the Central Plains early
Wednesday morning. Heading into Wednesday afternoon, this sfc low
will begin to track northeast towards the Great Lakes region. This
will allow for a cold front to push towards the southeastern
CONUS and interact with the warm/moist airmass around this
timeframe, thereby promoting the development of isolated showers
and thunderstorms. Wednesday night through early Friday morning
appears to be the best chance for any severe weather potential as
the frontal boundary pushes further south across central MS. With
the environmental parameters highlighting SBCAPE values between
3000 to near 4000 J/kg, bulk shear values of 50-60 kts, and strong
mid-level lapse rates we will continue to advertise a Slight and
Marginal risk for severe weather in our HWO graphics. Primary
hazards with these storms will be damaging wind gusts and hail up
to golf ball size, and a few tornadoes cannot be ruled out.

Furthermore, the westerly flow, increased wind shear, and high
moisture content will lead to several storms producing locally heavy
rainfall at times, thus localized flash flooding will be a concern
at times. Confidence has started to increase slightly as new model
data has started to come in, however there is still some uncertainty
regarding how further south the frontal boundary will setup in our
CWA heading into late Thursday night and early Friday morning, so
confidence in the severe weather/heavy rain threat beyond then is
low.

Any thunderstorm chances will come to an end Friday as the frontal
boundary surges further south out of our forecast area. Heading into
the weekend, a 1020mb sfc high will develop in the ArkLaTex region
before slowly pushing east towards our CWA. This will allow for
quiet weather to settle across the south with cooler-than-normal
temperatures expected. Some scattered to isolated showers and storms
will be possible heading into Monday. /CR/

&&

.AVIATION...
(18Z TAFS)
Issued at 1236 PM CDT Tue May 7 2024

MVFR stratus still linger at a few sites early this afternoon, but
most terminals have returned to VFR ceilings. Isolated to
scattered SHRA and TS will be possible this afternoon into early
this evening, with brief reductions and stronger wind gusts
possible in storms. Overnight, MVFR to locally IFR stratus will
return northward across the area and will persist into much of Wed
morning. Brief visibility reductions are also possible across
south MS around daybreak. VFR conditions will begin to return
around the late morning to midday time frame. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       72  89  72  88 /  10  20  30  50
Meridian      71  92  71  90 /  10  20  30  60
Vicksburg     73  90  71  89 /  10  10  30  40
Hattiesburg   73  91  73  91 /  10  10  10  40
Natchez       72  90  71  90 /  10  10  10  30
Greenville    74  89  71  87 /  10  10  60  40
Greenwood     73  89  71  87 /  20  30  70  50

&&

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

$$

DL/EC/CR