468
FXUS64 KJAN 270545 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1245 AM CDT Mon May 27 2024

...New AVIATION...

.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 parameters 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...
(06Z TAFS)
Issued at 1239 AM CDT Mon May 27 2024

Regional radars showed a line of severe storms northwest of GLH
that will spread southeast through the night an affect the
northern and cntrl TAF sites. Across the south and cntrl MS MVFR
cigs will develop and prevail through 14Z before improving to VFR.
The chance for SHRA/TSTM activity will shift to the southern TAF
sites Mon aftn. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       69  92  68  84 /  10  10  10  30
Meridian      67  93  66  87 /  10  10  10  30
Vicksburg     70  93  68  83 /  10  10  20  40
Hattiesburg   70  94  68  89 /  20  20  10  30
Natchez       70  93  69  84 /  20  20  10  40
Greenville    70  92  69  82 /  10  10  20  40
Greenwood     68  92  68  82 /  10  10  10  30

&&

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

$$

DL/EC/22