060
FXUS64 KJAN 250525 AAC
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1225 AM CDT Tue Jun 25 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 707 PM CDT Mon Jun 24 2024

Isolated showers and a storm or two are possible the rest of this
evening but a worked over boundary layer south of Interstate 20
and loss of daytime heating elsewhere in the CWA are quickly
limiting the chance for additional convection this evening. Warm
and muggy conditions expected overnight, but did not make many
changes there at this time. Looking at latest guidance into
Tuesday afternoon, did add some isolated shower and thunderstorm
mention in the weather grids across most of the area for the
afternoon hours. Though greater PWAT values will be focused in our
southwestern zones, values of 1.6 inches or greater are expected
except in all but the Golden Triangle area. As an upper-level high
pressure center pivots translates eastward more over AL/TN
tomorrow, light southerly flow will reinforce the humid air in
support of isolated storm chances as well as dangerous heat
conditions. Latest guidance suggests an Excessive Heat Warning may
be needed for more of the area tomorrow as expected near-100 temps
and mid-70s dew points result in heat index values near 110
degrees apart from (or before) afternoon showers and storms. /NF/

&&

.DISCUSSION...
Issued at 250 PM CDT Mon Jun 24 2024

Tonight and Tuesday: Mid afternoon surface analysis had a 1016mb
high centered over the Tennessee valley that was pushing a weak
backdoor cold front into northeast Mississippi. Farther south across
our CWA between Interstate 20 and Highway 84, a prefrontal trough
was drifting south and local radars showed a broken band of showers
and a few thunderstorms associated with it. Both the cold front and
prefrontal trough will continue drifting south this afternoon and
evening. The cold front is expected to move into our northeast zones
this evening before the cold front stalls. The prefrontal trough
will be south of our CWA by this evening and end the rain chances
across our southeast zones. Over our delta region temperatures and
humidity have been greater than anticipated and prompted the
issuance of an Excessive Heat Warning as heat index values exceeded
110F and will continue above 110F for several hours this afternoon
before lowering this evening. Heat and humidity will remain a
concern Tuesday. The surface high to our northeast will shift east
allowing for a weak return flow by late afternoon. With temperatures
topping out a couple degrees warmer Tuesday than today, an Excessive
Heat Warning may be needed for our northwest again while the
remainder of the CWA remains in a Heat Advisory. During the
afternoon there will be isolated to scattered showers and
thunderstorms over our southern zones but these will provide little
relief from the heat. /22/

Tuesday night through next Monday...

By Tuesday night into Wednesday, an upper shortwave is expected to
dig into to northern MS, bringing a weak surface boundary across the
northern portions of the CWA. Along with this, deep layer moisture
will continue to be present, which will generate scattered showers
and some storms across the region on Wednesday afternoon into the
evening hours. Cloud cover and slightly lower dewpoints will
decrease dangerous heat across central and eastern MS, but look to
still flirt with Heat Advisory criteria. Elsewhere, Heat Indices
will continue to range between 105-100 degF. By Thursday, the
boundary is expected to migrate along central and southern portions
of the CWA, which will shift isolated to showers southeastwards,
with the greatest potential for precipitation in the Pine Belt
region. Heat indices are expected to be subdued on Thursday, with
indices struggling to meet Heat Advisory criteria.

By Friday into the weekend, deep ridging will begin to take place,
enabling W/NW flow into the region. In the mid-levels, a strong high
pressure looks to migrate into the Lower Mississippi River Valley,
increasing heights and allowing for a hotter airmass to dominate.
The surface boundary looks to deviate southeastwards into the Gulf,
which will confine precipitation chances east of I-55 and south of I-
20 on Friday afternoon. Elsewhere, drier air will begin to filter in
from the northwest. By Saturday into Monday, precipitation will
remain more diurnal in nature as daytime heating becomes more
efficient due to increasing temperatures and decreasing cloud cover.
Weekend temps will range from the middle to upper 90s, while heat
indices climb into the 105-110+ range. Excessive heat products could
be in the works as guidance becomes cohesive over the next several
days. Either way, it will be HOT, so continue to take precautions as
heat related illness will be likely. /AJ/

&&

.AVIATION...
(06Z TAFS)
Issued at 1225 AM CDT Tue Jun 25 2024

VFR conditions will prevail through the majority of the TAF
period. Isolated SHRA or TS are possible mainly during the Tue
afternoon hours, which may result in localized brief categorical
reductions. Winds will be light. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       98  77  94  74 /  20  10  50  30
Meridian     101  74  97  72 /  10  10  50  40
Vicksburg     97  77  95  74 /  20  10  40  30
Hattiesburg   99  77  95  75 /  30  10  60  30
Natchez       96  75  94  74 /  20  10  30  30
Greenville   100  79  96  74 /  20  10  50  30
Greenwood    100  77  95  73 /  20  10  50  30

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory from 10 AM this morning to 8 PM CDT this evening
     for MSZ018-019-025>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.

&&

$$

NF/22/AJ/DL