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000
FXUS64 KJAN 181748
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1248 PM CDT Thu Apr 18 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 1032 AM CDT Thu Apr 18 2024

Mesoscale Update: Through mid-morning fog/low stratus has mostly
cleared with only patchy spots in the far southeast remaining.
Already this morning a severe thunderstorm warning has been issued
for portions of southeast Ar stretching into the Ms Delta. This
is what is to be expected as a slight risk area has been added to
the far northern portions of the CWA followed by the existing
marginal risk area. Model/CAM analysis this morning continues to
show a favorable storm environment in the far north, however
guidance has evolved to show a band of higher wind/larger hail
probabilities thus the slight risk was added to the area. While we
still expect this to be scattered thunderstorm event, if storms
do form there is the possibility for supercell development which
could produce hail up to golf ball sized, damaging wind gusts and
a tornado cant be ruled out. /KP/

&&

.DISCUSSION...
Issued at 419 AM CDT Thu Apr 18 2024

Today through Tonight...

Today: Water vapor/RAP imagery indicate weakening cold core lifting
into the Great Lakes while another is diving over south-central
Canada. Quasi-zonal flow aloft has set up across the region. There
are a few radar returns across the region but most has dissipated.
With continued southwesterly return flow of warmth/moisture,
widespread clouds & low stratus are ongoing across the region.
Patchy dense fog remains possible in the Pine Belt in southeast MS
overnight, so ongoing HWO graphic is in good shape. Seasonably warm
temps are ongoing this morning, in the mid 60s east of the I-55
corridor to low 70s along & west of the I-55 corridor. As mean
longwave trough/cold core deepens over south-central Canada, a weak
sfc low to lift northeast into the Mid West, dragging a cold front
southeast towards the Mid South to ArkLaTex. Expect increased
chances of showers & some storms for areas along & northwest of the
Natchez Trace, with highest chances to the northwest & in the Hwy 82
corridor today. With steepening mid-level lapse rates/vertical
totals in the upper 20s to near 30 deg C & mean bulk shear around 20-
40kts, some isolated severe storms are possible. Main adjustment was
to focus the Marginal a touch further north & add timing, with some
potential as early as late aftn (4-6PM) but most probable after
that. Timing should end around midnight but could persist in the Hwy
82 corridor if any convective complex is going off to the northwest.
Main concerns are gusty winds & hail up to quarter size. Expect
seasonably warm highs in the low-mid 80s.

Tonight: Broad cold core/frontal system will extend from the Hudson
Bay region down towards the OH Valley & moving into the Mid South to
ArkLaMiss region this evening through daybreak Friday. Southwesterly
return flow will become more westerly into the overnight hours. Sfc
winds gradually shifting to the northwest in the wake of the front
in the extreme northwest ArkLaMiss Delta region around daybreak.
With isolated strong to severe storms winding down around midnight
or so, some rain & isolated storm chances will remain confined to
the Hwy 82 corridor. Another round of low stratus & patchy fog are
possible in the Pine Belt. HREF probs are low enough that limit
confidence in dense fog but patchy fog is possible southeast of the
Natchez Trace & into the Pine Belt. Held off any mention in the HWO
graphics but will need to be monitored. Expect another night of
seasonably warm lows in the mid-upper 60s, some 10-15 deg. F above
normal. /DC/

Friday through next Wednesday...

As day breaks on Friday, a cold front will be in the process of
dropping southeast into and through the CWA. This will again
maintain some rain chances across mainly northern portions of the
CWA Friday afternoon. However, early Saturday morning into Sunday,
a couple of disturbances will shift east across the region under
zonal flow. This will result in decent chances for showers, along
with some isolated thunder, across the forecast area Saturday into
Sunday as cooler drier conditions will advect into the region.

As this system exits the region late Sunday night into Monday,
northerly winds will persist as high pressure to the northwest
builds into the forecast area.  Quiet weather and drier air will
exist across the region Monday into Tuesday.  Winds will steadily
become more easterly Monday night and southerly on Tuesday, with
warming conditions expected Tuesday into Wednesday. /19/

&&

.AVIATION...
(18Z TAFS)
Issued at 1247 PM CDT Thu Apr 18 2024

VFR/MVFR conditions will prevail for a majority of the
forecast period. However periods of SHRA and VCTS will impact TAF
sites this afternoon through this evening causing categories to drop
down to MVFR IFR with possible LIFR for an hour or two. Beginning
around 10Z expect another round of patchy dense fog to impact
southeastern TAF sites through 15/18Z as high moisture and low winds
will make it east for fog development./KP/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       66  84  65  76 /  10  20  10  50
Meridian      65  86  64  78 /  20  20  10  50
Vicksburg     66  82  62  73 /  10  20  10  50
Hattiesburg   67  88  63  84 /  20  10   0  30
Natchez       66  86  65  78 /  10  10   0  30
Greenville    64  73  56  63 /  30  20  20  70
Greenwood     66  76  59  66 /  30  30  10  60

&&

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

$$

KP/NF/DC