447
FXUS64 KJAN 070551
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1251 AM CDT Tue May 7 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 1044 PM CDT Mon May 6 2024

Rest of tonight...

Evening water vapor/RAP/synoptic analysis indicate deep longwave
trough ejecting into the Plains, with the cold core/sfc low
occluding in the Dakotas. This environment has led to a ongoing
severe weather outbreak in the Plains. GOES East satellite imagery
indicates deep cold cloud tops, while over our region more benign
mean ridging/slightly above climatological norms in moist profiles
exists across the Gulf Coast (i.e. PWs around 1.5-1.75 inches).
A subtle shortwave provided the impetus for the aftn-early evening
showers & isolated storms but those have winded down for the
night under the suppression of the ridge at the sfc & aloft.
With southwesterly low-level jet expected to increase, warm
southerly return flow will support another night of seasonable
warmth (i.e. upper 60s east of I-55 to low 70s to the west), low
stratus & patchy fog in the Pine Belt. Updates will be out
shortly. /DC/

&&

.DISCUSSION...
Issued at 245 PM CDT Mon May 6 2024

This Evening through Tuesday:

Despite SBCAPE values in excess of 3000 J/kg indicating an
unstable air mass across our forecast area, a shortwave ridge
aloft has been suppressing convection and limiting deep-layer wind
shear so far today. A trough however is apparent over East Texas
on water vapor satellite imagery, and this has helped at least a
few isolated storms develop to the west. Isolated to scattered
showers or storms are still possible through early this evening,
but organized severe weather is not expected at this time. Into
tomorrow, a trough swinging across the Plains is expected to shift
a plume of better instability into our area, and showers and
thunderstorms are expected mainly in eastern Mississippi during
the afternoon/evening hours. With increased flow aloft, there is a
Marginal Risk for severe thunderstorms to develop in this
activity. /NF/

Tues Night through Sunday:

Lingering rainfall from the daytime will gradually come to an end
for extreme northern and northeastern portions of the CWA as the
weak shortwave exits the area. Warm/humid conditions will begin to
filter in thanks to southerly flow, causing dewpoints to reach the
lower 70s and above-average high temperatures in the the upper 80s
to lower 90s and low temperatures in the upper 60s to lower 70s in
the mid-week.

A more active pattern is expected for Wednesday night through early
Friday morning. A low pressure center is expected to progress
eastward towards Great Lakes, in turn pushing cold front towards the
southeastern CONUS on Wednesday. Ahead of the frontal boundary, a
warm/moist airmass will be in place to help promote showers and
thunderstorms. Along with sufficient moisture (dewpoints in the
lower 70s), bulk shear values of 50-60 kts and Surface CAPE values
of 3000 to near 4000 J/kg will help support organized convection and
severe weather potential Wednesday night through Thursday night. A
"Slight" and "Marginal" risk for severe weather will continue to be
advertised in the HWO graphics.

The aforementioned cold front is expected to push through the CWA on
Friday, bringing rain chances to an end by the afternoon hours. To
close out the extended forecast, post frontal passage along with a
surface high pressure center will bring below-seasonal to seasonal
temperatures and drier air to the area through the weekend. /SW/

&&

.AVIATION...
(06Z TAFS)
Issued at 1246 AM CDT Tue May 7 2024

Have maintained forecast for widespread MVFR/IFR category stratus
through early morning in this persistent, warm/humid, southerly
flow pattern. Given the stronger boundary layer winds being
observed and forecast, fog is not expected to be a significant
threat. All sites should observe sub-vfr conditions until mixing
brings improvements later in the morning. VFR conditions will
prevail Tuesday aftn/evng at all sites, but a few TSRA will be
possible and could have brief impacts, especially the GTR/MEI
corridor. /EC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       71  90  71  87 /   0  20  30  50
Meridian      70  92  70  90 /  10  20  30  60
Vicksburg     71  90  70  87 /   0  10  30  40
Hattiesburg   72  90  73  91 /   0  10  10  40
Natchez       71  90  71  88 /   0  10  20  30
Greenville    73  89  71  85 /  10  20  70  30
Greenwood     72  89  70  85 /  10  30  70  40

&&

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

&&

$$

DC/NF/SW/EC/