445
FXUS64 KJAN 300541
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1241 AM CDT Sun Jun 30 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 1040 PM CDT Sat Jun 29 2024

No changes to the forecast at this time. Kept slight/chance pops
in the southwest for the next couple hours. There were some
lingering showers and an occasional thunderstorm moving south of
the area. Conditions were still warm and muggy with temperatures
near 80 and dewpoints in the lower to mid 70s. Overnight
temperatures were expected to be generally steady through the
morning. Apparent temperatures across the western portions of the
area were near 90, so it may be a miserable night for some.

&&

.DISCUSSION...
Issued at 229 PM CDT Sat Jun 29 2024

Tonight and tomorrow:  Dangerous heat continues to be the main
concern in the near term as dewpoints have held in the upper 70s
and even some spots with 80. Such dewpoints should only allow
temperatures to drop to the upper 70s to 80 overnight, furthering
heat stress. Hot and muggy conditions persist Sunday, so will
continue to carry heat headlines and messaging. Moisture pooling
ahead of frontal boundary could potentially push dewpoints even
higher tomorrow, with more widespread near 80/80 dewpoints. The
resulting heat indices will be in the 105-115 range. Sunday could
potentially be hotter than today given the CAMs tendency to hold
off convection until afternoon. Relief is in sight, albeit
temporary, as drier air ushers in in the wake of the cold front
early next week./SAS/

Sunday night through Friday night: Come Sunday evening wl still be
on the eastern periphery of a large 597dam ridge while a weak cold
front drops into the northern portions of our CWA. There will still
be the chance for rain along and ahead of the cold front during the
evening but model consensus is that it will be dry after midnight.
Come Monday morning the cold front is expected to be stalled across
the central portions of the CWA with drier air across our northern
zones. A surface high to the northeast will help maintain drier air
across our northern zones but the area south of Interstate 20 will
likely need a Heat Advisory as peak heat index values between 105F
and 110F are expected again. There will also be the chance of
isolated to scattered showers and thunderstorms during the afternoon
south of Interstate 20. This activity should end by early evening
and Monday night is expected to be dry. Tuesday the mid level ridge
is expected to become centered over north Mississippi and surface
ridging is expected to be nosing back across our CWA from the
northeast. This will lead to another day of hat and humidity,
especially across the southern half of the CWA where another Heat
Advisory will likely be needed. There will also be the diurnal chance
for convection across the southern half of the CWA.

Wednesday through Friday the mid level ridge will weaken and flatten
over our region. Afternoon highs will continue to be above normal
and combine with high humidity for heat index values above 105F each
day. As the mid level ridge breaks down there will be a greater
coverage of diurnally driven convection each day as well. /22/

&&

.AVIATION...
(06Z TAFS)
Issued at 1241 AM CDT Sun Jun 30 2024

VFR ceilings and conditions will prevail across central MS to start
off the TAF period as current radar scans show a few isolated storms
lingering across Lawrence County. The last remaining storms will
end by 06Z Sunday. Patchy fog will be possible at a few TAF sites
(HBG, PIB, & MEI) heading into the overnight period. Some amendments
to these TAF sites may be possible if visibility decreases. Quiet
countdowns will continue through 17Z Sunday with mid to high
clouds expected. By 18Z Sunday afternoon, convection will start to
develop along the Hwy 84 corridor around this timeframe before
becoming widespread around 19Z as the seabreeze slowly drifts
north. Added VCTS and SHRA to most zones with a short period of
MVFR to possible IFR ceilings for PIB, HBG, HKS, JAN from mid to
late afternoon. Rain activity will continue into the evening. By
06Z Monday rain chances will come to an end with VFR ceilings
prevailing across all TAF sites. /CR/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       95  76  94  72 /  40  20  30   0
Meridian      96  74  94  70 /  60  20  20   0
Vicksburg     95  76  94  72 /  50  20  20   0
Hattiesburg   95  77  97  75 /  80  30  50  10
Natchez       95  76  94  73 /  40  20  40  10
Greenville    97  75  91  69 /  60  10  10   0
Greenwood     95  73  93  69 /  60  10  10   0

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Excessive Heat Warning until 8 PM CDT this evening for MSZ018-
     019-025>027-034>036-040>042-047-053-059-060.

     Heat Advisory until 8 PM CDT this evening for MSZ028>033-037>039-
     043>046-048>052-054>058-061>066-072>074.

LA...Excessive Heat Warning until 8 PM CDT this evening for
     LAZ007>009-015-016-023>026.

AR...Excessive Heat Warning until 8 PM CDT this evening for ARZ074-
     075.

&&

$$

SAS/22/07/CR