050
FXUS64 KJAN 011507 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1007 AM CDT Mon Jul 1 2024

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE...
Issued at 1000 AM CDT Mon Jul 1 2024

Mid morning surface analysis showed a dry cold front along our
Highway 82 corridor. This front has brought in slightly drier air
knocking dew points in the lower 70s. Surface dew points in the
60s are expected across our northern zones this afternoon as the
dry cold front continues to sag a little farther south into our
CWA. Along and south of the front, heat and humidity will continue
with the most oppressive conditions expected over our southwest
where an Excessive Heat Warning remains in effect. Wrapped around
the Excessive Heat Warning, a Heat Advisory remains in effect
today. No changes to the forecast were needed with this update.
/22/

&&

.DISCUSSION...
Issued at 420 AM CDT Mon Jul 1 2024

Today and Tonight: The upper-level ridge centered over East Texas
this morning is analyzed around 596 dam at 500mb - or near max
values for this time of year. Subsidence beneath this ridge will
be the main driver again for dangerous heat across the Gulf Coast
region today, but at least some drier air is moving into parts of
our forecast area behind a weak cold front. This may bring some
slight relief to areas around the US Highway 82 corridor or a
little south. It`s uncertain if the mid 70s dew points will hang
on around the Meridian area long enough for heat index values to
hit 105 this afternoon, but farther west and south the confidence
for 105-115 type heat index values remains high. Expanded the
Excessive Heat Warning along the Mississippi River up to around
Vicksburg and added a few more LA parishes and MS counties to the
existing Heat Advisory. A slight chance for showers or storms will
linger around the US Highway 84 corridor in our southern zones
today, but generally expect activity to remain in south Louisiana.
A surface low moving west from GA/FL this afternoon should
reinforce the subsidence and dry air advection into northern and
eastern Mississippi overnight, and low temps should fall to a more
comfortable mid and upper 60s range for about half the area
tonight. /NF/

Tuesday through Sunday:

High pressure and ridging aloft will gradually build east into
and through the region during the forecast period. Meanwhile at
the surface, high pressure will likewise slide further east of the
CWA, becoming wedged into the region from the east. As this
happens, the slightly drier airmass that was in place across the
forecast area at the beginning of the work week, will become old
news as it`s replaced by an abundance of moisture. This will also
result in increasing chances for showers and storms each afternoon
through mid and late week. These rain chances will be maintained
across the CWA over the upcoming weekend, as a frontal boundary is
currently advertised to drop into the region Saturday into
Sunday.

Throughout much of the period, dangerous heat stress will continue
to be a concern across much of the forecast area.  Temperatures will
be consistent and continue to warm into the mid and upper 90s each
day.  This, coupled with the aforementioned increasing moisture over
the area will result in afternoon heat index values ranging above
the century mark across much of the CWA.  This will especially be
the case Wednesday through Friday, when indices will be more in the
105-110 range.  Because of this, a "Heat Advisory" will likely be
required for portions of the CWA through Friday.  With the progged
frontal boundary expected over the weekend, some relief from the
heat could exist across the area.  However each afternoon through
the week, isolated to scattered convection will aid in some relief
from the oppressive heat. /19/

&&

.AVIATION...
(12Z TAFS)
Issued at 616 AM CDT Mon Jul 1 2024

Some FG and low stratus to start the TAF period - primarily impacting
KHEZ through 14Z today. VFR conditions and north winds of 5-10
kts expected to prevail at all TAF sites after 16Z today. /NF/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       95  71  97  78 /  10   0  10   0
Meridian      97  69  98  75 /   0   0  20  10
Vicksburg     95  71  98  78 /  10   0  10   0
Hattiesburg   97  74  99  77 /  20   0  40  10
Natchez       95  74  99  77 /  30   0  10   0
Greenville    92  68  98  78 /   0   0   0   0
Greenwood     94  68  97  78 /   0   0   0   0

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory until 8 PM CDT this evening for MSZ040>043-048-049-
     054>056-062>066-072>074.

     Excessive Heat Warning until 8 PM CDT this evening for MSZ047-
     053-059>061.

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

     Excessive Heat Warning until 8 PM CDT this evening for LAZ016-
     023>026.

AR...None.
&&

$$

NF/19/NF