761
FXUS64 KJAN 171515
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1015 AM CDT Wed Jul 17 2024

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE...
Issued at 1015 AM CDT Wed Jul 17 2024

No changes have been made to the forecast package for this morning.
Low-level heights will maximize across the southeast region today as
global model guidance continues to show a weak upper level trough
approaching the Lower Mississippi Valley. This will allow for low
level W/SW flow to intensify across our forecast area causing PWATs
to increase to -2.5 inches across the ArkLaMiss into the Gulf Coast
region. Current radar scans continue to show a decaying MCS moving
E/SE out of Arkansas and will bring showers and storms into the CWA
later this afternoon. Although severe weather is not expected, areas
in the northwest MS/AR Delta region could have the potential to
experience some strong storms today. A few of these storms could
produce locally heavy rainfall at times which could lead to isolated
flash flooding potential across the Delta region through this
afternoon.

Heat will once again be the main headline for today with afternoon
highs peaking in the mid to upper 90s. Heat indices are expected to
range in the 105-110 deg range, however if the rain comes in early,
the probabilities for long term heat stress will decrease through
the afternoon. At the moment, a Heat Advisory remains in effect for
the entire forecast area until 8 PM this evening. No changes have
been made to the "Elevated" heat graphic where the advisory is in
effect. /CR/

&&

.DISCUSSION...
Issued at 341 AM CDT Wed Jul 17 2024

Today and tonight...

Low level heights will maximize across the region today as weak
upper trough approaches the Lower Mississippi River Valley. Low
level W/SW flow will continue to intensify, which in return will
increase PWATs to ~2.5 inches across ArKLaMiss into the Gulf Coast
region. By late morning, a decaying MCS moving E/SE out of Arkansas
will bring showers and storms into the CWA. Although severe weather
is not expected, areas in the northwest MS/AR Delta region have the
potential to experience locally heavy rainfall and isolated flash
flooding potential through the late morning/afternoon.

The main headline will continue to be heat, with high temperatures
expected to maximize in the middle to upper 90s. Heat indices are
expected to range from 105-110 however if precipitation is early
onset, the probabilities for long term heat stress will decrease
through the afternoon. A Heat Advisory will be in effect from 10am -
8pm. By the evening into the overnight areas, isolated to scattered
precipitation is expected to continue, especially north of I-20 as a
frontal boundary approaches from the north. Expect rain chances to
increase overnight into Wednesday morning. Overnight lows will range
in the lower 70s. /AJ/

Thursday through next Wednesday...

By Thursday, the upper ridge is expected to fully break down as a
broad trough dips southwards, bringing a frontal boundary into the
region. Showers and storm potential will increase Thursday morning
into the afternoon hours as the front stalls across the CWA. As the
front stalls across MS and subtly moves towards the coast through
the weekend, PWATS will be abnormally high along the coast, with
values exceeding 2.5 inches at times. The potential for flash
flooding will continue to be monitored for this weekend, especially
for areas in the Pine Belt region.

By Sunday into the new work week, low level ridging will begin to
build in from the southeast, which will allow temperatures to begin
to increase into the work week. Highs will range in the lower to
middle 90s through Monday, with heat indices reaching up to 105 for
areas in the southern portions of the CWA. Rain chances will remain
scattered to numerous, as a frontal boundary hangs up near the Gulf
Coast and looks to keep a fairly moist, tropical-like layer across
the south through Wednesday. /AJ/

&&

.AVIATION...
(12Z TAFS)
Issued at 643 AM CDT Wed Jul 17 2024

VFR conditions prevail across the area this morning. Afternoon
SHRA and TS will be possible again mainly this afternoon, which
may result in brief categorical reductions and gusty wind.
Coverage of SHRA and TS is expected to increase tonight,
especially over the northern portion of the area around GLH/GWO,
as a cold front approaches the region. In addition, MVFR or
potentially IFR ceilings are expected to develop in these areas
through early Thursday morning. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       96  74  91  71 /  30  50  90  50
Meridian      96  72  93  70 /  40  50  90  70
Vicksburg     96  74  90  71 /  20  40  80  40
Hattiesburg   96  75  93  74 /  50  30 100  70
Natchez       94  73  90  71 /  30  40  90  60
Greenville    95  72  88  69 /  30  70  60  20
Greenwood     95  72  89  69 /  20  70  70  30

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory until 8 PM CDT this evening for MSZ018-019-025>066-
     072>074.

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

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

&&

$$

CR/AJ/AJ