187
FXUS64 KJAN 161507
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1007 AM CDT Thu May 16 2024

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE...
Issued at 936 AM CDT Thu May 16 2024

The forecast remains largely unchanged. The southern jet continues
as the positively tilted trough axis across the southern plains is
currently helping propogate clusters of showers and storms across
Northeast Texas. Throughout the day expect mild conditions in our
area with partly cloudy skies prevailing. Expect cloud cover to
increase steadily throughout the day from west to east. Winds will
shift from southerly to southwesterly strengthening low level-
moisture by lifting the warm front north by tonight. Temperatures
will warm to the mid 80s to low 90s in the far southeast./KP/

&&

.DISCUSSION...
Issued at 406 AM CDT Thu May 16 2024

Today and Tonight:

As an positively-tilted upper-level trough remains situated over the
Southern High Plains, shortwave impulses ejecting eastward from it
remain the drivers of shower and thunderstorm activity across the
region. A jet streak nosing northeastward from central Texas today
will accompany one of these waves rounding the base of the trough,
lifting a warm front up from the central Gulf Coast through tonight.
PWAT values of 2.0 inches and a strengthening low-level jet
overnight will result in likely heavy rainfall and flash flooding in
the frontal zone. The latest suite of high-res guidance appears to
be handling the ongoing overnight convection to our west fairly
well. Following through the short-term projections, a west-east
oriented complex of storms over central Texas by this afternoon
should be spreading south-southeastward through unstable air.

Strong westerly deep-layer shear and the lifting warm front along
the Gulf Coast should facilitate a more eastward bend to the
complex`s movement overnight, which will result in the current
advertised Marginal Risk for severe thunderstorms across
southwestern and southern portions of our forecast area. The
potential for damaging wind gusts and possible tornadoes exists,
especially if the frontal boundary sneaks into the southern portions
of our CWA. Additionally, the heavy rainfall with these storms and
boundary-parallel flow support the current Elevated threat for flash
flooding. Current soil moisture saturation and derived flash-flood
guidance values suggest areas in our south will have trouble if they
pick up a quick 2 to 3 inches of rain. The threat for flash flooding
will continue into tomorrow with the next impulse, so any rainfall
tonight will be important to the evolving flood threat tomorrow. /NF/

Friday through Wednesday:

An active weather pattern will continue on Friday as additional
shortwaves traverse across the area, keeping the risk of severe
weather and flash flooding in the CWA. A weak cold front remains on
track to progress towards to the southeast region to help clear out
the shortwave disturbances by Saturday evening. The extended period
is expected to close out with a warming trend as a ridge amplifies
over the area, bringing above-seasonal temperatures by mid-week.

A low pressure center and weak cold front embedded in the longwave
trough near TX will continue to proceed towards the southeast CONUS
on Friday. Ahead of the frontal boundary, the shortwave disturbances
are expected to interact with the moist airmass (dewpoints in the
lower 70s) over the area. In addition to sufficient moisture: CAPE
values near 3000 J/kg, bulk shear values of 50-60 kt, and lapse
rates ranging from 6-7 C/km will help support organized convection
and possible severe weather Friday evening. Damaging winds, hail,
and tornadoes will be possible. The "Slight" risk is outlined in the
HWO graphics.

Along with severe weather, flash flooding continues to be of
concern. PW values remain between 1.6-2.0in; however, IVT vectors
have exceeded the 99th percentile in the latest NAEFS run. As a
result, training thunderstorms will be possible, leading to flash
flooding in areas that have already received rainfall. Rainfall
totals have lowered from yesterday`s model runs but 1 to near 4
inches of rainfall will be possible. Majority of the rainfall is
expected along and south of I-20 where 2-4 inches of rain will be
possible. Elsewhere, 1-2 inches of rainfall is expected. An
"Elevated" risk for flash flooding remains for Friday evening.

As the weak cold front exits the area Saturday evening, rain chances
will begin decreasing from west to east. Some lingering rainfall
will be possible post frontal passage but these showers aren`t
expected to pose a flooding threat. By Sunday, the area will begin
to dry out as a ridge migrates over the area. The ridge is expected
to amplify into the new week, bringing above-seasonal temperatures
(highs in the lower 90s). Rain chances are expected to return to the
area by the end and beyond the extended period. /SW/

&&

.AVIATION...
(12Z TAFS)
Issued at 655 AM CDT Thu May 16 2024

VFR conditions should prevail through at least 03Z, but increasing
chances for rain, thunderstorms, and low clouds will lead to
increasing chances for impacts to the TAF sites after 06Z. /NF/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       87  65  83  68 /  10  80  90  50
Meridian      89  64  84  67 /  10  70  90  60
Vicksburg     88  65  82  68 /  10  90  70  40
Hattiesburg   90  68  85  70 /  10  70  80  60
Natchez       88  64  83  67 /  20  90  70  50
Greenville    88  67  81  67 /  10  80  70  40
Greenwood     88  67  80  67 /  10  80  80  50

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Flood Watch from late tonight through Saturday morning for
     MSZ047>066-072>074.

LA...Flood Watch from late tonight through Saturday morning for
     LAZ015-016-023>026.

AR...None.
&&

$$

KP/SW/NF