346
FXUS64 KJAN 140001
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
701 PM CDT Mon May 13 2024

...New AVIATION...

.DISCUSSION...
Issued at 316 PM CDT Mon May 13 2024

Tonight and Tuesday...A shortwave will slowly shift east from the
central plains states into the Ohio River Valley tonight through
Tuesday.  This will prompt a surface low to likewise shift east from
the plains into the Ohio River Valley, while dragging a weak cold
front through the CWA on Tuesday.  Ahead of this shortwave this
evening and into tonight, a disturbance embedded in quasi-zonal flow
will shift east through the Lower Mississippi River Valley.  This
will prompt showers and storms to develop and move east across the
forecast area this evening into tonight.

A "Marginal Risk" for isolated severe storms does exist across
mainly western and southern portions of the CWA during this time.
However, thanks to this morning`s convection, a frontal boundary has
become stationary along the gulf coast.  This is keeping ample deep
moisture and instability from surging northward into the CWA. On top
of that, this morning`s convection has essentially worked over the
airmass over the CWA.  While again, an isolated severe storm is
possible tonight over western and southern portions of the area,
where a combination of wind shear and limited instability reside,
the greatest threat for severe storms will be south of the forecast
area, and more along the gulf coast and offshore.  That said,
damaging wind gusts will be the primary concern with any isolated
severe storms.

Earlier there was a concern for heavy rainfall and flash flooding
over southern areas today through Tuesday morning.  This threat too
has been shunted south of the CWA along the aforementioned frontal
boundary and warm sector, where the deeper moisture exists and
likewise the higher rainfall rates.  As a result, I`ve cancelled the
Flash Flood Watch that was initially in effect for southern
locations through Tuesday morning, and I`ve removed all mention of
flash flooding from the HWO.  Any flash flooding that may occur with
tonight`s convection, will be very localized and limited to low-
lying and poor drainage areas.

Showers and isolated storms will continue to be possible into
Tuesday as the main upper trough and the cold front moves through
the region. Convection will steadily come to and end from west to
east through the course of the afternoon as both features exit the
region.  Skies will also gradually clear from west to east as high
pressure quickly build into the region heading into the Tuesday
night period.  With clouds departing, look for highs to warm into
the low and middle 80s. /19/

Tuesday Night through next Monday...Overnight Tuesday into
Wednesday the main trough will have passed through the area along
with a weak shortwave. Expect a high pressure to begin to build
into the area overnight, following the preceding showers during
the afternoon and early evening Tuesday. Dry weather will ensue on
Wednesday as the upper trough moves east. During this time expect
winds to shift southwesterly as low level moisture begins to
increase. Come Thursday, several rounds of shortwaves will begin
to shoot across the area as chances for isolated and scattered
showers and storms become increasingly possible Thursday evening
overnight into Friday. This presents the best possibilities for
strong to severe storms as a negatively tilted trough axis over
the Southern Plains will send another shortwave and associated
cold front through our area. Persistent heavy rain seems to be the
primary risk associated with this event with flash flooding being
possible through the weekend. Wet conditions may linger into the
weekend as another shortwave will be possible however there isn`t
much model consensus right now. As of now, we expect excessive
rainfall products to be likely with possible 3-5 inches of
rainfall from Thursday night through Monday with 2-3 inches
possible Thursday into Friday. Locally higher amounts are
possible. /KP/

&&

.AVIATION...
(00Z TAFS)
Issued at 644 PM CDT Mon May 13 2024

Expect a general lowering of ceilings tonight with widespread
MVFR/IFR cateories through much of the morning hours before mixing
can bring back VFR categories by late Tue morning/afternoon. The
most intense TSRA will stay south of the area this evening, then
expect a few SHRA over mainly northern/eastern portions of the
area Tuesday in association with the upper trough. /EC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       65  83  63  84 /  70  30   0   0
Meridian      66  84  62  86 /  70  40   0   0
Vicksburg     66  84  62  86 /  60  10   0   0
Hattiesburg   65  85  64  88 /  80  50   0   0
Natchez       64  84  61  86 /  60  10   0   0
Greenville    67  82  64  84 /  70  20   0   0
Greenwood     67  82  63  83 /  60  40   0   0

&&

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

&&

$$

19/KP/EC