521
FXUS64 KJAN 010921
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
421 AM CDT Mon Jul 1 2024

...New DISCUSSION...

.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...
(06Z TAFS)
Issued at 101 AM CDT Mon Jul 1 2024

VFR conditions to start the period at the TAF sites, however with
some rain that fell Sunday evening, some patchy BR is possible
before 12Z Monday. Additionally, some brief impacts from scattered
to broken MVFR ceilings are possible before 14Z as patches of low
stratus are pushed southward by a cold front. /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 from 10 AM this morning to 8 PM CDT this evening
     for MSZ040>043-048-049-054>056-062>066-072>074.

     Excessive Heat Warning from 10 AM this morning to 8 PM CDT this
     evening for MSZ047-053-059>061.

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

     Excessive Heat Warning from 10 AM this morning to 8 PM CDT this
     evening for LAZ016-023>026.

AR...None.
&&

$$

06/19