217
FXUS64 KJAN 201214 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
714 AM CDT Sat Jul 20 2024

...New AVIATION...

.DISCUSSION...
Issued at 434 AM CDT Sat Jul 20 2024

Today through Tonight...

Early morning water vapor/RAP analysis indicate perturbed
flow/trough axis centered over the MS Valley to Gulf Coast, with Rex
Block synoptic pattern locked in for the considerable future. The
main corridor of the vertically stacked low is analyzed over the
Hudson Bay. Deep ridging persists in the Desert Southwest, Rockies
to the Interior Plains/Prairie Provinces of Canada while subtropical
ridge remains in the southwestern Atlantic, Bahamas into the eastern
Gulf of Mexico to FL Peninsula. Stronger spoke of energy in the base
of the trough axis yesterday is now centered over the Mid-South &
progged to lift to the northeast through the day today. Expect
another day of active convection, with an early start ongoing
southeast of the Natchez Trace corridor. Light propagation, >90th
percentile precipitable water (PWs)/tropical airmass & deep warm
cloud depth >15kft, support slow-moving tropical downpours with
localized flash flooding. HREF prob match mean have lowered but
there remains some indication of potential for heavy rain mainly
along & south of a line from along the I-55 corridor in Grenada to
Yazoo in Warren in MS & westward to just south of the I-20 corridor
in Madison, Tensas to Franklin parishes in LA. In the wake of the
stalled boundary, there is some drier air around or < 1.5 inch PWs.
This potential will persist into the rest of the weekend.
Temperatures will remain seasonably cool today in the mid-upper 80s,
with seasonable lows in the low 70s this morning & again tonight.
Heat stress will remain in check today, but heat indices will be a
touch warmer in the mid-upper 90s, especially across the southern
half of the area. Some patchy fog is possible in areas this morning
& again into tonight, especially in areas that receive sufficient
rainfall. There remains scattered HREF probs for dense fog across
the Gulf Coast region but remains low confidence due to ongoing
cloud shield/stratus & redevelopment expected again in the I-59 to
Hwy 84 corridor tonight. Light westerly flow could organized some
storms into some isolated strong storms, severe storms are not
anticipated. /DC/

Sunday through next Saturday...

Not much has changed throughout the long term period as we remain
in this stagnant pattern of rain with tropical moisture and
multiple rounds of shortwave energy flowing into the southeastern
states.

Upper level troughing will persist through the mid/lower MS Valley
through much of central CONUS. This frontal boundary will often be
influenced by rounds of shortwave energy of a low pressure system
as it makes its way through the Mid-West to Great Lakes and
adequate moisture transport, diurnal heating and increased
convergence from boundary lifting to the northwest. With this
current weather regime pops will continue to be scattered to
numerous in coverage with some areas of heavy precip but generally
much of the same day-to- day throughout the period. Areas have
been seeing rainfall totals upwards of 2in constantly and the
limited flash flooding threat will remain in the graphical HWO for
a majority of the CWA through this weekend as some areas could
see upwards of 2-4in of rain, with locally higher amounts. Pops
have been adjusted slightly as the best moisture profiles trend
further south/southeast. Thus, portions of the ArkLaMiss region
will have been trimmed out of the flash floor threat graphic. As
for heat, consistent cloud cover and rain chances will keep the
heat in check keeping max temps well below climo for this time of
the year. /KVP/

&&

.AVIATION...
(12Z TAFS)
Issued at 713 AM CDT Sat Jul 20 2024

Deep moisture across the region is fueling ongoing scattered
SHRA, near MEI between through 20/14Z. A rumble of TS can`t be
ruled out through mid-morning. Low stratus & patchy BR are ongoing
& ceilings have worsened to MVFR-IFR this morning. LIFR has been
observed at GWO, PIB, HBG & HEZ. There have been some cases of
IFR vsby, even down to LIFR at PIB. Expect an improvement in
flight restrictions to VFR between 20/15-17Z. The best chance for
scattered-numerous SHRA & TSRA will be 20/19Z Saturday to 21/02Z
Sunday. Aftn SHRA & TSRA will wind down between 21/01-03Z. Winds
will be light & variable, below 10mph, through the TAF period. Low
ceilings & patchy BR are psbl after 21/08-10Z at MEI, PIB & HBG &
psbl at GTR. /DC/


&&

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

&&

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

$$

DC/KP/DC