048
FXUS64 KJAN 152344
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
644 PM CDT Mon Jul 15 2024

...New AVIATION...

.DISCUSSION...
Issued at 258 PM CDT Mon Jul 15 2024

Through Tonight:

Thunderstorms in northeast Mississippi around the Louisville-
Columbus area are currently the only focus for rain chances in our
forecast area this afternoon. Guidance favors anywhere in eastern
Mississippi through the early evening for additional rain chances,
and a disturbed field of cumulus clouds could yield an additional
few clusters or showers or storms. Brief isolated showers have even
appeared around northeast LA at times so far this afternoon, so will
keep the current forecast in place. Early onset of convection and
cloud development today appears to have limited peak heating
potential for our southwestern parishes and counties, with most obs
sites south of I-20 in the 93 over 73 range giving heat indices
around 103-105. Delta sites are the warmest with higher dew points
pushing heat indices closer to 108-110. With lift and southwesterly
flow aloft associated with trough axis overhead, rain chances will
linger into the evening. Warm and muggy conditions will continue
overnight with lows in the mid 70s typical of mid July. /NF/

Tuesday through early next week:

Dangerous heat stress will be the primary hazard to start off the
extended period as global guidance shows a broad high pressure
system stretching across the Southern Plains region. At the same
time, a 591dam upper trough will continue to extend southwards in
the Ozarks/TN River Valley towards the TN/GA state line.  This will
result in increasing low-level heights across the southeast CONUS
Tuesday/Wednesday as a low level ridge will start to build into the
region ahead of the next system. Southwesterly flow from the Gulf
Coast will unfortunately promote dangerous heat stress across our
forecast area around this timeframe. Afternoon highs will climb into
the mid to upper 90s across central MS, with a few spots across the
Delta potentially reaching 100 degrees. The combination of
southwesterly flow along with high afternoon temperatures will
yield heat indices anywhere between 105-115 deg range. We went
ahead and issued a Heat Advisory for the entire forecast area for
Tuesday from 10 AM - 8 PM Tuesday evening. A Heat Advisory will
likely be needed for Wednesday given the increased warming trends.
Given the heat indices for Wednesday, a couple of areas across
the Delta and across south and west MS will likely get upgraded to
an Excessive Heat Warning. No changes have been made to the heat
graphic for tomorrow, especially for areas where the Heat Advisory
is in effect. Could see some updates to the heat graphic for
Wednesday. Precipitation on Tuesday and Wednesday will range from
isolated to scattered especially in E/SE portions of MS.

Relief from the heat is on the way heading into Thursday as the
ridge will break down allowing for a broad positively tilted trough
axis to dip southward across the ArkLaMiss region. This will help
increase storm chances across the CWA and introduce more seasonable
temperatures through the weekend. PWATs will be abnormally high
along the coast, with values exceeding 2.5 inches at times. Because
of this, some storms could produce locally heavy rainfall at times
which could lead to some localized flash flooding in a couple of
areas. Forecast confidence at this point is low given the
uncertainty regarding the placement of the trough axis. We will
continue to monitor flash flooding potential for this weekend. Later
on Sunday, future guidance hints at low level ridging building in
from the Southeast US. This will allow for afternoon temperatures
to increase into the 90s heading into the new work week, with heat
indices climbing up to 105 degrees for areas in the southern
portions of our forecast area. With the frontal boundary hanging up
along the Gulf Coast, scattered to numerous rain/storm chances will
be possible through the new work week. /CR/

&&

.AVIATION...
(00Z TAFS)
Issued at 644 PM CDT Mon Jul 15 2024

SHRA & TSRA remain possible at southeast TAF sites of PIB & HBG
through around 16/01Z. Patchy fog/BR is not expected to be a
concern overnight. Low probs of light SHRA & isolated TSRA are
again psbl Tuesday aftn at east-central-southeast sites of GTR,
JAN, HKS, MEI, HBG & PIB, mainly between 16/19-23Z. Light
southwesterly & at times variable winds, less than 10mph & brief
higher gusts, are expected through the next 24 hours. /DC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       76  97  76  96 /  20  30  10  50
Meridian      73  97  74  98 /  20  40  10  60
Vicksburg     76  97  77  97 /  10  10   0  20
Hattiesburg   76  96  77  96 /  30  50  10  60
Natchez       75  95  75  95 /  10  20   0  30
Greenville    76  97  77  97 /  10   0   0  20
Greenwood     76  97  77  97 /  10  10   0  40

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory until 7 PM CDT this evening for MSZ018-019-025>027-
     034>036-040>043-047>066-072>074.

     Heat Advisory from 10 AM to 8 PM CDT Tuesday for MSZ018-019-
     025>066-072>074.

LA...Heat Advisory until 7 PM CDT this evening for LAZ007>009-015-016-
     023>026.

     Heat Advisory from 10 AM to 8 PM CDT Tuesday for LAZ007>009-015-
     016-023>026.

AR...Heat Advisory until 7 PM CDT this evening for ARZ074-075.

     Heat Advisory from 10 AM to 8 PM CDT Tuesday for ARZ074-075.

&&

$$

NF/CR/DC