474
FXUS64 KJAN 282018
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
318 PM CDT Sun Apr 28 2024

...New DISCUSSION...

.DISCUSSION...
Issued at 253 PM CDT Sun Apr 28 2024

As anticipated, weaker inhibition today is allowing for warm
advection showers to develop and spread north across the forecast
area today. Isolated thunderstorms are embedded with this
activity as well, but deep layer shear is not favorable for
organized updrafts. Expect quick moving, and short-lived storms
where they do develop. Regional radar mosaic showed the remnants
of last night`s convective line were all but washed out across
North Texas into Arkansas, but an organized cluster of storms has
re-fired east of Waco and Killeen in Texas this afternoon. High
res guidance has struggled with how to transition from last night
to today`s activity, but but they all generally get to the point
of one or more MCS segments drifting east through Louisiana and
Arkansas toward Mississippi late tonight. 06Z and 12Z HRRR were previous
fast outliers, but 18Z run has come into a little closer agreement
with consensus of HREF members regarding timing.

Southerly low-level jet winds and greatest instability located to
the south of any MCS activity will favor southward propagating
MCS activity by morning (or at least most intense MCS activity
farther south along any broken line). Forecast MLCAPE values over
1000 J/kg seem to favor MCS trajectory to be along or southwest
of a diagonal line roughly from Ruston, LA down Natchez, MS or so.
Depending on timing and placement of overnight storms, the
potential for severe storms could extend farther east to around
the Interstate 55 corridor. Bowing segments along any line could
lead to increased potential for damaging wind gusts and possible
spinup tornadoes. The Slight Risk for severe storms was expanded
to account for this wind and isolated tornado potential -
including southeast Arkansas, northeast and central Louisiana, and
far southwestern Mississippi. The Marginal Risk area extends
south through Mississippi generally along Interstate 55. In
addition to any severe threat, heavy rainfall could cause
localized flash flooding concerns. End timing is a little
uncertain, but an organized line will probably clear out earlier
in the day than anything disorganized. /NF/

Monday Night through Sunday:

A fairly progressive split flow regime sets up over the CONUS
through the rest of next week, driving a few potential periods of
showers and thunderstorms as shortwave troughs moving east and
interact with spring-like humid and unstable air masses across the
South. Nothing at this point looks to fully scour out the decent
moisture in the region, and PWAT values over 1.3 inches should
support air mass thunderstorms on any given day. When not
raining, afternoon high temperatures should push the upper
80s/lower 90s range. Glimpses of summertime are coming into view.
/NF/

&&

.AVIATION...
(18Z TAFS)
Issued at 1248 PM CDT Sun Apr 28 2024

The stratus deck has started to lift across central MS allowing for
VFR ceilings to occur across all TAF sites to start off the TAF
period. S/SE winds will remain gusty at times through the period
with gusts to around 30 kts possible. A brief period of low-level
wind shear will be possible across several eastern TAF sites from
03Z Monday through 07Z Monday. Similar to the previous day, another
round of MVFR/IFR stratus will expand across the area late tonight
into early tomorrow morning. Furthermore, a line of showers and
severe storms will enter the area from the west late tonight/early
Monday morning. Primary concerns with these storms will be large
hail, 50 kt wind, and a tornado cannot be ruled out. Storms will
continue across the area through Monday afternoon. Conditions will
begin to improve a little after 10Z Tuesday as storms start to clear
the area around this timeframe. /CR/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       68  78  63  83 /  20  80  60  20
Meridian      64  81  63  84 /   0  70  80  30
Vicksburg     69  77  63  84 /  40  90  40  20
Hattiesburg   67  81  64  84 /  10  70  70  40
Natchez       68  76  63  85 /  30  90  40  30
Greenville    68  75  63  82 /  50  90  40  10
Greenwood     68  76  63  83 /  20  90  60  10

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&

$$

NF/NF/CR