116
FXUS64 KJAN 290531
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1231 AM CDT Fri Aug 29 2025

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 955 PM CDT Thu Aug 28 2025

Local radars were still lit up with convection nearly along and
east of the Natchez Trace. Models agree that additional
development is likely across the southwest half of our CWA. No
severe storms are expected but additional locally heavy rainfall
will be possible. /22/

&&

.DISCUSSION...
Issued at 1237 PM CDT Thu Aug 28 2025

Through the Weekend...

A much anticipated heavy rainfall event is currently unfolding
across the lower MS Valley region early this morning as a shortwave
trough approaches and enhances rainfall in an unseasonably strong
baroclinic zone extending from northwest to southeast across the
region. A long duration of warm advection and frontal ascent
combined with unseasonably strong upper jet support early on and
anomalous moisture will support widespread heavy rainfall totals
with 1 to 4 inches common along with a few locally heavier totals of
up to 5 inches.

That is how things look in the big picture, but there are some
details to iron out due to uncertainty in where the heaviest
rainfall and localized minor flooding threats will exist as there
are a wide range of solutions among both the global and CAM guidance
suites. The general consensus is that rainfall emphasis will
initially be on the frontogenesis and tropical moisture interaction
today through tonight before transitioning to a more convective
regime farther south as we go into late tonight and Friday. The
variance in guidance seems to be related to how quickly the precip
focus shifts away from the frontal forcing over northern portions of
the area to more convective centric over southwest portions.
Confidence is on the low side as a result as both slower and faster
scenarios are plausible. /EC/

While some of the rains mentioned are falling or have fallen already
this morning, midday guidance suggests it is a bit too early to make
forecast graphic adjustments. Areas in the highway 82 corridor would
likely be the first to be trimmed from the "limited" flood outlook
should shower and storm activity not become reinvigorated in that
area later today. Trends suggest the bulk of the activity may  be
transitioning south of there in the next few hours and should
confidence increase that these areas are becoming less likely to
receive additional possibly flooding rains, adjustments to the
outlooked areas would come at that time. /86/

Going into the weekend, it appears the heavy rainfall threat
should diminish greatly, but uncertainty with rain chances doesn`t
improve a whole lot as a good bit of guidance show solutions
ranging from dry to wet, especially along/south of the I-20
corridor, due to differences in how much subsidence pushes in
behind the Friday convective system. Total rainfall for the
Saturday-Monday period should be much lighter overall than what
will fall in the Thursday-Friday time frame. /EC/

Into Next Week...

We will remain under the influence of longwave troughing and
northwest flow aloft. With upper heights well below normal and the
incipient lower-level airmass being of more continental than
tropical origins as a surface high anchors across the Ohio Valley,
we likely will see only isolated to scattered showers and a few
thunderstorms that will be most likely during the afternoon and
evening hours. This troughiness will support a continued period of
somewhat lowered humidity (dewpoints ranging mostly from the 50s
F to 60s F) and near to below average temperatures (highs mostly
in the 80s F for most through much of the upcoming week). /86/

&&

.AVIATION...
(06Z TAFS)
Issued at 1231 AM CDT Fri Aug 29 2025

A mixture of MVFR/IFR and LIFR ceilings are occurring across several
TAF sites to start off this TAF period as current radar scans
continue to numerous SHRA and isolated -TSRA moving across the
region. Varying flying conditions will prevail across all TAF sites
through the period. Ceilings will begin to improve to a mixture of
VFR/MVFR starting around 20Z Friday afternoon. /CR/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       67  86  67  87 /  40  50  20  30
Meridian      66  85  65  86 /  50  50  20  30
Vicksburg     67  86  67  87 /  30  40  20  20
Hattiesburg   70  87  69  88 /  60  70  20  30
Natchez       69  84  68  85 /  40  50  20  30
Greenville    64  88  65  88 /  10  20  10  10
Greenwood     64  89  65  89 /  20  20  10  10

&&

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

$$

22/LP/CR