168
FXUS64 KJAN 261917
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
217 PM CDT Sun May 26 2024

...New DISCUSSION...

.DISCUSSION...
Issued at 211 PM CDT Sun May 26 2024

Through Monday: Warm and mostly dry conditions continue this
afternoon as a mid level capping inversion keeps a lid on convective
development across most of the area. However, later tonight a cold
front currently extending from the Ozarks southward into the Red
River valley will advance eastward toward the MS River overnight as
a potent upper shortwave swings across the Midwest and TN Valley.
These features may provide the needed forcing for convection to
initiate and move into the upper ArkLaMiss Delta late this evening.
While development may initially feature a few discrete cells,
convection is expected to evolve fairly quickly into more of a line.
It is with the earlier development, especially if things kick off a
bit earlier in the evening than currently anticipated, where storms
may be more likely to take advantage of steep mid level lapse rates
and produce larger hail up to golfball size. This is also when there
is some potential for a tornado to occur within modest low level
helicity before the low level jet begins to pull north and eastward
out of the area. As storms become more linear and cold pool dominant
overnight, damaging wind gusts will become the prevailing threat
with an even more limited brief tornado threat for any segments that
can surge more eastward within marginally supportive 0-3 km bulk
shear. Convection should lose intensity with time overnight as the
cold pool outpaces the forcing. It is worth noting that recent CAM
guidance casts some doubt over whether the forcing will be great
enough to overcome the cap, which could considerably limit
convective coverage tonight.

Forecast guidance has increasingly trended toward the cold pool from
overnight convection and/or outflows racing well south and eastward
into our area tomorrow morning, acting in effect as a cold front by
ushering in much drier air. This appears increasingly likely to
limit rain chances during the day across most of the area once any
showers clear early tomorrow morning. However, across south and east
MS and central/south LA, there is greater potential for either the
boundary to stall or retreat back into the area later in the day,
keeping greater moisture and instability around. This will result in
potential for isolated convection to redevelop Monday afternoon in
these areas. Highly conditioned on whether such redevelopment does
occur, any storms that redevelop in the afternoon could become
severe given the potential for moderate to strong instability and
marginally favorable deep shear. The window for this to occur
appears to be quite narrow, with the threat dwindling toward sunset.
Severe probabilities for the entire area during the daytime tomorrow
have been adjusted downward accordingly. /DL/

Monday night through Saturday night: Isolated storms could linger
into early Monday evening along/south of the Highway 84 corridor,
but quiet conditions are expected for the most part.

Looking ahead from mid/late week through the weekend, while the
sensible weather over the forecast area will be slightly cooler,
less humid, and more tolerable overall, this will not be reflected
in the QPF as we will keep rain chances around just about every
day. A deep trough digging southward over the eastern CONUS will
generally keep the frontal boundary draped to our west and south,
but with the upper level pattern expected to be progressive, a mid
level ridge will build over the Plains to MS Valley region, and
this will support a relatively moist deep layer airmass over our
area. A couple of rounds of convective rainfall will possible in
the late Tue to Wed time frame as a couple of minor perturbations
move across in northwest flow aloft, but convective paramaters do
not look impressive at this point and this should help keep
thunderstorm intensity below severe limits. Look for this weather
pattern to persist through late week and the weekend. /EC/

&&

.AVIATION...
(18Z TAFS)
Issued at 1240 PM CDT Sun May 26 2024

VFR conditions prevail across the region this afternoon. A cold
front will approaching the area overnight with a line or broken
line of TS, with some potential for 50 kt gusts mainly around
GLH/GWO/GTR. With this line, there will be a wind shift to the W
then NW by Monday morning. Low clouds will increase overnight with
MVFR across most of the area to locally IFR ceilings and patchy
MVFR fog possible in south MS. VFR conditions are expected to
return by mid to late Monday morning and drier air moves into the
area. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       73  93  69  92 /  40  10  10  10
Meridian      74  94  67  93 /  40  30  10  10
Vicksburg     74  93  70  93 /  40  10  10  10
Hattiesburg   75  95  70  94 /  30  40  20  20
Natchez       72  93  70  93 /  30  20  20  20
Greenville    74  92  70  92 /  50   0  10  10
Greenwood     72  91  68  92 /  60  10  10  10

&&

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

&&

$$

DL/EC/DL