702
FXUS64 KJAN 171658 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1158 AM CDT Tue Jun 17 2025

...New MESOSCALE UPDATE, AVIATION...

.MESOSCALE UPDATE...
Issued at 1157 AM CDT Tue Jun 17 2025

Rest of today...

Active morning continues with scattered convective coverage
increasing across the region. Shortwave trough axis extends across
the Lower to Mid MS Valley, with increased ascent, southwesterly low-
level jet and deep moisture (1.7 to +2 inches) across the Gulf Coast
region. This is leading to an early start to convective initiation
(CI) across the area, with early morning coverage across the MS
River corridor and LA Delta due to increased inflow/moisture
convergence and light east-northeast backbuilding vectors (less than
10kts). This led to some training and flash flooding in these areas.
This is waning, with most of the Theta E advection/convergence along
and southeast of the Natchez Trace corridor. This is where there
resides just enough flow for some marginally severe convection
generally along and east of a line from Natchez to Yazoo City to
Grenada. Gusty winds will be the main threat and small hail can`t be
ruled out. "Marginal" from SPC will be added to local HWO graphics
with minor adjustments in areal coverage to the west to southwest.
Sensible weather will be seasonable to slightly less, in northeast
MS (84-92F), with scattered to widespread rain coverage this
afternoon (55-90%), with highest coverage east of the MS River
corridor. Updates are out. /DC/

&&

.DISCUSSION...
Issued at 407 AM CDT Tue Jun 17 2025

The synoptic upper-level pattern continues to feature a weakness
between two ridges across the country. Ridges centered over the
Desert Southwest and off the US East Coast will allow for
shortwave troughs to pass through our region through around
Thursday. Fairly decent rain chances focused mainly in the
afternoon hours through that time will be widespread. And as seen
early this morning, the flow associated with these disturbances is
enough to sustain some chance for showers and thunderstorms in the
soupy air mass overnight. PWAT values in excess of 1.5 inches will
be supportive of heavy downpours with slow moving storms, and
localized flash flooding cannot be entirely ruled out especially
if heavier rain falls over more developed areas.

Friday onward, the pattern will shift with the southwestern ridge
translating east over the Mississippi and Ohio River valleys.
This will push best rain chances closer to the Gulf Coast, but
afternoon showers and storms remain possible into early next week.
The ridge aloft and continued warm, moist advection in the low
levels will push afternoon heat index values closer to or over 105
degrees than in recent days. Therefore will maintain the
"Elevated" threat for dangerous heat conditions across portions of
our area Friday into the weekend. Even in the lead-up, a few
spots of near-105 heat index can be expected. Heat Advisories may
be needed for portions of the area late this week into early next
week. Please remember to make sure friends and relatives have a
cooler location to spend the afternoon hours and warm overnight
hours. /NF/

&&

.AVIATION...
(18Z TAFS)
Issued at 1157 AM CDT Tue Jun 17 2025

A mix of VFR/MVFR/IFR conditions prevail at TAF sites as
showers/storms move across the area. Expect these conditions to
continue through the day as the chance for showers/storms continue
this afternoon into the evening hours. The storms should
dissipate this evening. By sunrise tomorrow IFR/LIFR conditions
will prevail at southeastern TAF sites PIB/HBG as BR will be
possible from 10Z-14Z. /KVP/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       88  72  91  74 /  80  20  30  10
Meridian      88  72  91  73 /  80  20  50  10
Vicksburg     90  73  91  75 /  70  10  20  10
Hattiesburg   90  74  92  74 /  80  20  70  10
Natchez       88  73  90  73 /  60  10  40  10
Greenville    88  74  91  75 /  60  10  10  30
Greenwood     88  73  91  75 /  80  10  10  30

&&

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

$$

DC/NF/KP