860
FXUS64 KJAN 131002
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
502 AM CDT Tue Aug 13 2024

...New DISCUSSION...

.DISCUSSION...
Issued at 501 AM CDT Tue Aug 13 2024

Today and Tonight...

Model consensus generally agree that a subtropical high will remain
centered over the southeast region today. With this in mind, the
stationary dry airmass will heat up beneath the high. This will
unfortunately raise heat stress levels into the 105F-110F deg range.
A heat advisory remains in effect today from 10 AM this morning
until 8 PM later this evening. Furthermore, the advisory has been
expanded further eastward in order to include portions of northwest,
central, south central and southeast MS. A few changes have been
made to the heat graphic for today and both the "Limited" and
"Elevated" risk for heat have been expanded further east. Aside from
a few mid/high level clouds, sky conditions will be generally clear
across the area. This combined with sufficient daytime heating will
help afternoon highs peak in the upper 90s with a spots reaching the
low 100s. A few isolated showers cannot be ruled out mainly for
areas along and south of the Hwy 84 corridor. Heading into tonight,
weather conditions will remain quiet as the subtropical high remains
in place over the region. HREF guidance is hinting at some patchy
fog potential across parts of Concordia and Catahoula parishes later
in the overnight period. Nighttime temperatures will drop in the low
to mid 70s areawide.

Wednesday through Tuesday...

Dangerous heat conditions continues to be the primary focus for the
extended period with no major adjustments made to the overall
forecast. There still remains secondary challenge regarding
rain/storm coverage and timing later in the week which will be
discussed further down below.

Hot and dry conditions will make a return to the forecast region by
mid day Wednesday. Because of this, heat indices will once again be
in the 105-110F deg range. A few areas along and south of I-20 could
see heat indices above 110F. Any ongoing Heat Advisories may need to
be expanded further east heading into Wednesday. A few isolated
showers cannot be ruled out Wednesday afternoon. Forecast confidence
is still low in regards to the precise orientation of this pattern
due to discrepancies with model guidance. At the moment, we are
still looking at chance for scattered showers and storms east of I-
55 with low end PoP chances hovering in the 15-25% range. Thursday
will see a continuation of hot conditions with areas east of I-55
seeing afternoon temperatures climb in the low 100s with the rest of
the area seeing highs in the upper 90s. Heat indices will be similar
to Wednesday with isolated areas south of I-20 and across the Delta
seeing heat indices above 110F. Additional heat advisories/warnings
may be needed heading into the late week with concerns for
significant heat stress increasing as well. With that being said,
areas along and east of I-55 could have a slight chance (around 15-
30%) for scattered showers and storms.

Moving along into the late week and into the weekend, Friday through
Sunday could have the best coverage of diurnally driven storms
especially for eastern portions of the area. Forecast confidence at
this point still remains low due to uncertainty with long term model
guidance variability in regards to the timing and strength of the
trough. Some of the more vigorous guidance (such as the GFS) does
show the trough digging faster into the MS Valley region on
Saturday, while the Euro is a touch slower into late weekend. If the
faster and more amplified scenario plays out, we could see
significant height falls and stronger northwest flow which could
support organized storms earlier in the weekend with some possible
severe weather potential during that timeframe. Trends will continue
to be monitored. As this trough continues to dig southward, a
frontal boundary will track south towards our CWA. The
aforementioned boundary will help initiate afternoon scattered
showers and t-storms, with the greatest coverage of low PoP chances
(around 25%) east of I-55. Although cloud coverage will start to
increase slightly, sufficient daytime heating will help afternoon
highs peak in the upper 90s, with a couple of areas west of the MS
River reaching low 100s. With dewpoints expected to climb in the low
to mid 70s around this timeframe, heat indices will once again be
near 105F-110F deg. Should start to see a downward trend in heat
indices by Monday to start the new work week. Can`t rule out an
isolated shower or popup storm around this timeframe, especially for
areas across southeast MS. Similar conditions could occur on
Tuesday as future guidance hints at the weak front shifting further
south towards the Pine Belt. /CR/

&&

.AVIATION...
(06Z TAFS)
Issued at 1252 AM CDT Tue Aug 13 2024

VFR flight categories & light & variable winds, northerly at
times & less than 10mph, will prevail at the TAF sites through
the period. Winds may be more variable in southern Mississippi
where a sea breeze could turn winds out of the south
Tuesday. /DC/NF/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       98  76 100  76 /  10   0  20  10
Meridian      98  74  99  75 /  10   0  20  10
Vicksburg     98  76 100  77 /  10   0  10  10
Hattiesburg   99  75 101  76 /  20  10  20  10
Natchez       97  75  99  76 /  10   0  10  10
Greenville    97  76  98  77 /   0  10  20  10
Greenwood     97  76  98  76 /   0   0  20  10

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for MSZ018-019-025-034>036-040>043-047>049-053>056-059>066-
     072>074.

LA...Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for LAZ007>009-015-016-023>026.

AR...Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for ARZ074-075.

&&

$$

CR/DC/NF