608
FXUS64 KJAN 151740
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1240 PM CDT Wed May 15 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 930 AM CDT Wed May 15 2024

An upper trough is departing this morning, pushing across the
midsouth,ushering in some drier air in the wake. Heights are
rising today as upper ridging begins to build in, which will keep
conditions quiet today. Temperatures should rise into mid 80s
across much of the area this afternoon under plenty of
sunshine./SAS/

&&

.DISCUSSION...
Issued at 331 AM CDT Wed May 15 2024

Today and Tonight:

Quiet weather is expected across the area today and tonight as
shortwave ridging aloft and a weak surface high pressure system are
centered over the area today. Winds will be variable as that high
slides through, and those light winds may allow for some patchy
light fog to develop either early this morning or early Thursday
morning. /NF/

Thursday through Tuesday:

An active period is expected for the beginning of the extended
forecast as a few shortwaves migrate across the area Thursday and
Friday, bringing potential severe weather and flash flooding to the
ArkLaMiss region. A weak cold front is expected push towards the
southern CONUS, helping clear out the shortwave disturbances by
Saturday evening. From Sunday into the new week, a warming trend is
expected as an amplified ridge build over the area.

As a longwave trough axis near TX Panhandle progresses eastward,
a developing low pressure and associated cold front embedded in
the longwave through is expected to push towards the southeast
region on Thursday. Ahead of the cold front, a few shortwave
disturbances are expected to traverse over the area, bringing
shower and thunderstorm potential for the CWA as decent moisture
and instability will be present. Current Euro/GFS models have come
into better agreement in showing the aforementioned shortwave
disturbances tracking across the area Thursday evening through
Friday evening.

In terms of severe weather potential, dewpoints in the upper 60s,
lapse rate near 7.0 C/km, bulk shear of 50-60 kts will help support
organized convection for both days. However Friday evening is
looking to be more favorable for severe weather as CAPE values
increase to 2000-3000 J/kg and dewpoints increase to the lower 70s.
As a result, SPC has outlook a "Slight" risk for parts of the CWA on
Friday. All modes of severe weather will be possible and the HWO
graphics will continue to highlight this risk.

In addition to possible severe weather, flash flooding potential is
increasing. With a moist airmass in place (dewpoints reaching lower
70s), PW values near 1.6 to 2.0 could help to produce some heavy
downpours. Along with PW values, IVT (integrated water vapor
transport) vectors are showing to be near the 98th percentile,
resulting in shower/thunderstorm activity moving over the same parts
of the area, creating a training effect and leading to possible
flash flooding in those areas. Rainfall totals are estimated to be
to 1-2.5in north of I-20 and 2.5-5in south of I-20 with possible 6-
6.5in near the Pine Belt. WPC has included a "Moderate" risk for
flash flooding on Thursday evening through Friday evening. An
updated "HWO" graphic will include these changes.

Come Saturday evening, the weak cold front is expected to exit the
area, bringing rain chances to an end and begin a drying period.
Post frontal passage, a ridge pattern will begin to build over the
area and gradually amplify heading into the next week. A warming
trend is expected as a result of the amplifying ridge, bringing high
temperatures into the lower 90s to close out the period. /SW/

&&

.AVIATION...
(18Z TAFS)
Issued at 1233 PM CDT Wed May 15 2024

VFR conditions will prevail through the period for most sites
under mostly clear skies. Some patchy fog is possible at HBG and
PIB but should clear quickly as the sun rises. High clouds will
begin to build into the area Thursday ahead of our next system.
Winds will be light from the NNW around 5 to 10 mph, shifting
Thursday to the SSE./SAS/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       62  88  66  83 /   0   0  70  80
Meridian      61  89  65  84 /   0   0  60  90
Vicksburg     63  88  66  83 /   0  10  80  70
Hattiesburg   63  89  68  85 /   0   0  60  80
Natchez       63  88  65  83 /   0  10  80  70
Greenville    66  88  68  83 /   0  10  70  70
Greenwood     63  88  67  82 /   0  10  60  80

&&

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

$$

NF/SW/SAS20