Severe Thunderstorm Warning 48, NWS Jackson, MS

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1155 AM CST Tue Mar 4 2025

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 1010 AM CST Tue Mar 4 2025

All is on track for severe storm timing today, and also for the
expectation of a lot of wind over the entire area, before and just
behind the storms. We are monitoring instability trends very
closely to determine the northward extent of any strong tornado
potential. Latest obs show the apex of richer moisture supportive of
more intense updrafts and tornadoes intersecting with the QLCS near
the I-20 corridor in western LA. The latest high res guidance shows
this instability axis (not much required given strength of shear)
will become slightly more suppressed as it encounters lower theta-e
air being advected greater easterly component winds, but the intense
low level jet (near 80kt) will squeeze every bit of moisture
northward that it can to maintain it. With all said, will continue
the mention of strong tornado wording and monitor for any shifts in
the axis.
/EC/

&&

.DISCUSSION...
Issued at 224 AM CST Tue Mar 4 2025

Today and tonight...

An intense low pressure system is currently taking shape in the lee
of the Rockies and will continue to push east/northeastward today
and bring along a surface cold front that will promote an onset of
severe storms this afternoon. Generally, little has changed in the
trends of what's expected.

A warm front will lift northward this morning in response to the
deepening low pressure system and carry with it a moist airmass
characterized by mid 60s dewpoints, nudging into the southwest.
remnant dry air results in a pinched off warm sector with severe
threat suppressed to the south where better moisture resides,
therefore the area of main focus appears to be along and south of
the HWY 84 corridor. A strong low level jet will overspread the area
and strong wind fields lead to large curved hodographs favorable
for tornadoes. A confluent zone is evident and backed surface
winds should increase tornado threat. This zone migrates along and
south of the HWY 84 corridor and should define greatest tornado
threat. As much as 500 effective SRH is evident in this zone,
supportive of tornadoes, some possibly strong. Storm mode may be a
bit messy in large part due to the intense lift and large scale
ascent. This could dampen instability. That said, any broken line
segments and/or embedded supercells able to tap into the
environment will have access to plenty of favorable shear to
produce all hazards including tornadoes, possibly strong. Tornado
threat should maintain even into the Pine Belt and areas southeast
as the low level jet arrives along with the arrival of a mid
level speed max this evening. The main question here is whether or
not the storms outrun the instability axis and become elevated
before exiting the area which is a possibility. Large curved
hodographs still support a tornado threat in this area should
storms remain surface based. Aside from the tornado threat,
damaging winds, possibly significant, is also a concern with very
strong wind fields and bowing line segments. With strong winds
aloft, even showers will be able to bring down damaging wind
gusts. Generally, the damaging wind threat is collocated with the
tornado threat but may spread further north. Damaging wind gusts
to 70 are possible with bowing segments, along with tornadoes and
hail. All this leads to continued messaging of an enhanced risk
for much of the area, except the northeast where moisture recovery
may be more difficult.

In advance of the severe weather, the deepening low will result in a
tightened pressure gradient across the area today ahead of the cold
front, with sustained winds 20 to 25 mph, and gusts to 40 to 50 mph.
Gust winds could onset as early as 4 to 5 am this morning in the
Delta. Elevated risk is highlighted areawide in HWO to capture this
and a wind advisory will continue, effective from 9 AM to 6 PM./SAS/

Wednesday through Friday: A low level cold advection pattern will
prevail in the wake of the front Wednesday, with considerable
cloudiness persisting as the mid/upper trough continues to pivot
across the area. This may also result in some sprinkles mainly along
and north of the Hwy 82 corridor. In addition, the surface pressure
gradient will remain fairly strong, so winds may gust in the 30-40
mph range at times. We will amend the current gradient wind threat
graphic to mention Wednesday as well. The gradient will begin to
relax overnight, but perhaps not enough for many areas to decouple.
Still, we may see sufficient cold advection for a low chance (10-30
percent) that portions of our north MS area dips below freezing
early Thurs morning. Otherwise, it'll be dry through the remainder
of the work week, but an active upper jet may keep considerable
cloudiness around. Temps will moderate more noticeably on Friday as
surface flow shifts back around to the south.

This weekend into early next week: Our next weather system will take
on a different look as upper flow is zonal to start out the weekend
and an upper low rolls across the Southern Plains and into the Deep
South. The more zonal configuration will result in a more west-to-
east oriented cold front that will shift southward across the area
from late Friday night through Saturday or Saturday evening. Some
guidance members depict a slower frontal passage with more
appreciable moisture and instability lifting into the area ahead of
the front on Saturday, a solution which would portend potential for
severe storms given the strong deep layer bulk shear. However,
ensemble cluster analysis suggests this solution is an outlier at
this time, with a greater percentage of members limiting greater
instability to the coast. Either way, we'll continue to keep an eye
on this time frame. Rain chances will end Saturday night into Sunday
behind the front with a brief cooldown Sunday before moderating
conditions into the new work week. /DL/

&&

.AVIATION...
(18Z TAFS)
Issued at 1149 AM CST Tue Mar 4 2025

The forecast remains on track with the biggest change to the
aviation forecast being the removal of wind shear. 850mb winds are
still forecast to be in the 65kt range, however; with surface
winds sustained of 25mph gusting to 45, we should remain just
outside the threshold for low-level wind shear. That being said
wind shear should warrant monitoring from aviators for the
daytime hours. Gusty south- southeast winds this morning will
shift to the south and increase to sustained around 25mph and
gusting upwards of 50 mph. Storms will move through the area from
west to east from around noon to 8 pm. Locally stronger wind gusts
are possible with storms./SAS/OAJ/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       47  59  36  60 /  50   0   0   0
Meridian      48  60  35  61 /  90   0   0   0
Vicksburg     46  59  35  60 /  10   0   0   0
Hattiesburg   51  66  38  65 /  70   0   0   0
Natchez       46  61  36  63 /  10   0   0   0
Greenville    45  54  34  55 /  10   0   0   0
Greenwood     46  55  33  57 /  40  10   0   0

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Wind Advisory until 6 PM CST this evening for MSZ018-019-025>066-
     072>074.

LA...Wind Advisory until 6 PM CST this evening for LAZ007>009-015-016-
     023>026.

AR...Wind Advisory until 6 PM CST this evening for ARZ074-075.

&&

EC/EC/OAJ