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515
FXUS64 KJAN 231921
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
221 PM CDT Sun Jun 23 2024

...New DISCUSSION...

.DISCUSSION...
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Issued at 221 PM CDT Sun Jun 23 2024

Tonight and Tomorrow...

Global guidance shows the mid/upper level high drifting further west
towards the Carolinas. With the high shifting westward, this will
allow for a weak frontal boundary to sink into our forecast area
heading into the overnight period. Because of this, areas along the
far northern portions of our CWA could see some isolated showers by
early Monday morning. With increasing clouds overnight, nighttime
temperatures will fall into the mid 70s to around 80. Heading into
Monday, moisture will continue to increase across the area thanks to
southerly flow aloft. As the aforementioned frontal boundary
continues to sag further south across central MS, global guidance is
highlighting a weak sfc front that will slop into northeast MS,
stalling through the day. Isolated showers will be possible heading
into Monday afternoon with slightly higher rain chances (around 30%)
south of the I-20 corridor thanks to sufficient daytime heating.

With the anticipated moisture heading into Monday afternoon,
dewpoints will climb into the upper 70s areawide as afternoon highs
peak into the upper 90s. This level of heat and humidity will result
in afternoon heat indices between 105-112 degrees. As a result, a
"Heat Advisory" has been issue for the entire CWA for this
timeframe. /CR/

Monday night through Saturday night: Heat and humidity still look to
be the main concerns through the period with Tuesday expected to be
the most oppressive day.

Come Monday evening our CWA will be on the eastern periphery of a
large 592dam high while a stalled and nearly diffuse cold front will
be just south of our CWA. A 1014mb high will be centered just
northeast of our CWA The surface high will continue shifting east
Monday night and Tuesday allowing for a light return flow back
across our CWA. This will allow low level moisture increase while
afternoon highs top out around 100F along our Highway 82 zones and
upper 90s elsewhere. The hot temperatures will combine with the high
humidity to result in peak heat index values between 105F and 110F
and a Heat Advisory will likely be extended for the whole CWA
Tuesday.

By Wednesday morning the large mid level high will have become
centered just south of the Four Corners region. A shortwave trough
topping the ridge will spill into our region during the day and lead
to a greater coverage of convection and perhaps an earlier start.
Greatest coverage is expected over the eastern half of our CWA and
the cloud cover associated with the convection is expected to help
hold temperatures a few degrees cooler than on Tuesday. This will
result in lower peak heat index values. The shortwave trough is
still expected to be dropping south along the Mississippi/Alabama
stateline Wednesday night helping to maintain rain chances over the
southeast half of the CWA until tapering off from the northwest
Thursday afternoon and early evening. Friday the mid level high is
progged to build east back across our region. This will lead to
warmer temperatures and raise the concern of heat stress again. Rain
chances Friday and Saturday afternoons will be limited to our
southern zones. /22/
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&&

.AVIATION...
(18Z TAFS)
Issued at 1208 PM CDT Sun Jun 23 2024

Quiet conditions will occur across all TAF sites over the next 24
hours with VFR ceilings prevailing. /CR/

&&

.PRELIMINARY POINT TEMPS/POPS...
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Jackson       76  96  75  97 /  20  30   0  30
Meridian      74  98  74 100 /  20  20   0  30
Vicksburg     77  96  76  97 /  10  10   0  20
Hattiesburg   76  96  76  99 /   0  40  10  50
Natchez       75  94  75  96 /   0  30  10  30
Greenville    78  99  78 100 /  20   0   0  10
Greenwood     77  98  76 100 /  20  10   0  10
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&&

.JAN WATCHES/WARNINGS/ADVISORIES...
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MS...Heat Advisory until 8 PM CDT this evening for MSZ018-019-025-034-
     035-040-041-047.

     Heat Advisory from noon to 8 PM CDT Monday for MSZ018-019-
     025>066-072>074.

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

     Heat Advisory from noon to 8 PM CDT Monday for LAZ007>009-015-
     016-023>026.

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

     Heat Advisory from noon to 8 PM CDT Monday for ARZ074-075.
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&&

$$

CR/22/CR