229
FXUS64 KJAN 020304
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1004 PM CDT Wed May 1 2024

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE...
Issued at 1002 PM CDT Wed May 1 2024

Rest of tonight...

Perturbed pattern persists across the western half of the nation,
with cold core low centered across northern MT/stronger longwave
jet progged to round the base of the trough in the Pacific
Northwest. Split flow exists across the southern half of the
nation, with shortwave moving into the region aiding in convective
development across eastern TX. With expected low-level southerly
return flow expected to pick up overnight on the western fringes
of the mean ridge, at the sfc/aloft, over the Carolinas/Atlantic
seaboard, low stratus/fog formation is possible across the
southern half of the area. HREF probs continue to indicate decent
probs for fog, >30% into the I-20 corridor. Added an "Elevated"
for probs of areas of dense fog while the "Limited" was expanded
to include the I-20 corridor. Held off on an advisory for now.
Updates are out. No major changes to sensible weather forecast,
with seasonably warm lows in the low 60s southeast of the Natchez
Trace corridor while mid-upper to the northwest & increasing
clouds. /DC/

&&

.DISCUSSION...
Issued at 314 PM CDT Wed May 1 2024

Tonight into Tomorrow:

The forecast remains tricky to nail down details even in the short-
term, because so much of what may happen in our forecast area will
depend on the mesoscale developments upstream to our west in Texas
and Oklahoma. No weather is expected the rest of this afternoon, but
building humidity and returning low-level flow tonight may bring a
better chance for fog to develop in southern Louisiana and
Mississippi by early tomorrow morning. HREF probabilities of dense
fog in the Pine Belt reach about 30-50% by sunrise, which combined
with the clear skies and southerly flow are usually indicative of
some dense fog developing in those areas. Have added a Limited
threat fog graphic for tonight and will monitor trends for any
widespread dense fog potential.

Then as mentioned, systems to our west will become a concern as we
near daybreak tomorrow. A southern stream shortwave trough lifting
across East Texas/western Louisiana tonight has been the focus of
recent model runs for generating a complex of storms that direction.
Latest HRRR and other high-res model guidance indicate an MCS or
broken line of storms moving into central LA by mid morning, and
possibly another focused area of storm development farther southwest
along the line scraping the Gulf Coast later in the morning into
afternoon. Regardless of exactly how it evolves, convection moving
east overnight will have favorable westerly flow and an instability
axis to propagate eastward along, so it seems reasonable that
organized strong to severe storms could move into our forecast area
tomorrow between mid morning and early afternoon time frame. A
bowing line could produce damaging winds, and a tornado could not be
ruled out. Therefore a Marginal Risk for severe thunderstorms has
been added for northeast LA, southeast AR, and Mississippi from
roughly the Greenville/Cleveland areas southeast toward Hattiesburg.
Showers and thunderstorms in general will be possible across the
forecast area by the afternoon and evening, though organized severe
weather is questionable by that time frame.

Friday through Wednesday:

Details remain tricky for the extended, but big picture forecast is
still for several shortwave disturbances moving east across the
country to trigger rounds of showers and thunderstorms into early
next week. Especially of interest in our area will be the fact that
waves will nudge a cold frontal boundary south toward the area, and
disturbances are likely to interact with the moist, unstable air
mass south of this front. Friday, Saturday, Sunday, and even Monday
have some chance for showers and thunderstorms in the forecast area
as it stands now. Where it is not raining, afternoon temperatures
will push the upper 80s to lower 90s. /NF/

&&

.AVIATION...
(00Z TAFS)
Issued at 711 PM CDT Wed May 1 2024

VFR conditions prevail across the region. Areas of IFR to MVFR
stratus will develop across parts of south MS & central LA, with
patchy dense fog possible in south MS at PIB & HBG. Timing is
expected between 02/08-13Z. Any dense fog is expected to diminish
by mid-morning, with ceilings rising back to VFR levels. By late
morning to afternoon, SHRA & TSRA are expected to spread east
across LA & AR then into western MS. Locally heavy downpours may
temporarily limit visibilities & ceilings may fall to MVFR levels
in some areas. Added some low probs for SHRA at central-western
TAF sites of GLH, JAN, HKS & HEZ before the end of the 00Z TAF
period. /DL/DC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       64  84  66  78 /   0  40  50  70
Meridian      62  87  66  83 /   0  10  30  50
Vicksburg     65  82  67  79 /   0  70  50  80
Hattiesburg   64  87  68  82 /   0  20  20  30
Natchez       66  81  66  77 /   0  70  40  70
Greenville    66  83  68  78 /   0  60  80  80
Greenwood     66  85  67  79 /   0  40  70  80

&&

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

$$

DC/NF/DL