899
FXUS64 KJAN 141729 AAC
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1229 PM CDT Sun Jul 14 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 958 AM CDT Sun Jul 14 2024

Rest of Today...The forecast area sits just on the eastern fringe of
a mid/upper level trough.  This feature is responsible for the mid
and high cloud cover streaming northeast across a large portion of
the forecast area this morning, and continuing into this afternoon.
With an abundance of deep moisture over the area, hot and humid
conditions will persist across the CWA today, with locations mainly
along and south of the Interstate 20 corridor under a "Heat
Advisory" until 7 PM this evening.  In this area, with highs from
the mid to upper 90s and dew points in the mid 70s, afternoon heat
index values will range from the 106-110.  While it`ll be hot and
muggy across the entire CWA, the aforementioned cloud cover
currently looks to keep temperatures in-check just enough that heat
index values will be slightly lower and hover near 105 elsewhere.
The only relief overall from the heat will come in the form of
mainly afternoon and evening isolated to scattered showers and
storms, particularly across southeast portions of the CWA.

The ongoing forecast is currently in good shape.  Other than some
minor adjustments to hourly elements of the forecast based on
current trends, no major changes will be made on this morning`s
forecast update. /19/

&&

.DISCUSSION...
Issued at 314 AM CDT Sun Jul 14 2024

Another warm and humid day is on tap, with a few minor forecast
challenges. A shortwave mid/upper trough is draped from the Ohio
Valley southwestward into Texas. Deep layer moisture remains
plentiful ahead of this feature and over much of our area. A band
of mid and high clouds extends from east TX through northwest MS,
and the latest guidance suggests these could persist well into
the day, with potential implications on high temps/heat indices
and destabilization. With diurnal instability more likely to be
focused southeast of this cloud deck, highest rain chances are
expected to be across south/east MS later this afternoon into
early evening, with convection diminishing by mid-evening.

A Heat Advisory remains in effect for much of the southern half of
the area for today. With more clouds and somewhat lower max temps
expected over western portions of the area, some portions of the
advisory were removed. But Clarke Co was added in east MS. /DL/

Monday through the weekend...

Our area will remain under the influence of high pressure through
mid week. Temps aloft will support surface temps in the mid to
upper 90s, along with SW flow regime holding dewpoints in the mid
70s. Resulting heat indices should be around 105, but there is
potential for higher heat indices Tuesday and Wednesday with
greater moisture, but with daily afternoon convection, confidence
at this time is low.

By Thursday, a strong mid level high situated over the western
CONUS will drive a midlevel trough and associated surface cold
front south into our area. Ahead of this front, we will have to
watch for heat concerns, especially further south due to moisture
pooling and compressional heating. Rain and storms associated with
the front should begin to push south across the area early
Thursday morning, reaching the Pine Belt by afternoon and evening.
It is here where the front looks to stall out. In the wake of the
front, drier air in the northwest should limit rain chances
Friday. Cooler temps will provide relief from the heat. Some may
call it a midsummer treat, but look for below normal temps for
most areas Friday with highs only in the 80s. Yes, you hear that
right. Temperatures will slowly warm into the weekend, but should
remain near or slightly below normal.

By the weekend, moisture gradually builds back north amid SW
flow. The stalled boundary in the Pine Belt could serve as a focus
area for flash flood potential with PWAT around 2 inches and
boundary parallel flow. Corfidi vector ridge is also evident.
Obviously, this is far out at this time, but should trends hold,
messaging may eventually be introduced./SAS/

&&

.AVIATION...
(18Z TAFS)
Issued at 1227 PM CDT Sun Jul 14 2024

VFR flight categories will prevail at area TAF sites over the
next 24 hours. Isolated to scattered convection could result in a
brief degradation of flight categories to MVFR/IFR status between
now and 01Z this evening, namely at KMEI, KHBG, & KPIB. This
activity will quickly begin to dissipate after sunset this
evening. Winds this afternoon will have a westerly component
between 5-8 knots and will become calm to light this evening into
tonight. /19/

&&

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

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory until 7 PM CDT this evening for MSZ047>049-053>066-
     072>074.

LA...Heat Advisory until 7 PM CDT this evening for LAZ016-025-026.

AR...None.
&&

$$

19