112
FXUS64 KJAN 161740
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1240 PM CDT Mon Sep 16 2024

...New AVIATION...

.DISCUSSION...
Issued at 415 AM CDT Mon Sep 16 2024

Today through tonight: Primary weather concerns in the near term
include fog development (this morning and possibly again Tue
morning) and the potential for locally heavy rainfall over mainly
the northeast half of the area.

Concerning fog: Fog has developed as expected over mainly the
southwest half of the forecast area in the humid boundary layer,
and will keep the current limited dense fog graphic going as a
few observations of dense fog are being noted. May need a dense
fog advisory for some locations, but it seems overall, visibility
is remaining above a 1/4 mile. Given the persistent pattern and
weakening low level flow, another round of fog will be possible
early Tue morning.

Concerning rainfall: A persistent rex block type weather pattern,
anchored by a strong high centered over the Great Lakes/New
England areas and a low that has persisted over the Lower MS
Valley region, continues in the near term. The latest guidance
indicate that the low will fill and weaken as a potential tropical
cyclone near the South Atlantic coast takes over as the primary
low circulation in the rex block pattern. Before the weakening
fully takes place, a highly moist convergence axis (precipitable
water ~ 1.9 inches) in southeast low level flow will maintain a
band of showers over east central/north central MS. Highly
localized heavy rainfall rates are possible, but flash flooding
is generally not expected with weakening low.

Otherwise, given considerable cloud cover and areas of rainfall,
temperature ranges will be somewhat small and a below climatological
normal. /EC/

Tuesday through early next week: Early morning hi-res guidance
continue to show a stalled frontal boundary along the Gulf Coast.
This combined with the presence of tropical moisture will allow
for afternoon/early evening scattered showers/thunderstorms
generally south of I-20. Forecast confidence is much higher
compared to the previous day as the latest GFS/NAM holds on rain
chances through Tuesday evening. Current HREF guidance is starting
to hint at some widespread patchy fog potential across much of
our forecast area. Went ahead and added fog into the forecast for
Tuesday night/early Wednesday morning. Could see a Dense Fog
Advisory being issued around this timeframe if things pan out. Fog
trends will continued to be monitored as we get closer to Tuesday
evening.

Heading into Wednesday, global guidance continues to show a rex
block pattern evident of over the east CONUS which should keep our
forecast area dry and help suppress any rain potential. In addition,
temperatures could climb into the upper 80s with a few spots across
the NW Delta reaching in the low 90s. Went ahead and bumped up
temperatures slightly given 850 mb temps (between 14 and 16 deg C)
supportive of a slightly warmer solution. With the ground moist from
leftover rain and stagnant conditions expected, patchy fog is likely
for the next few days. By Sunday, warm conditions will make a return
to the area with slightly above normal temperatures near 90/70
returning to the area. Heading into the new work week, future global
guidance hints at a upper low pushing east across the Ohio River
Valley. On the southern periphery of the upper low is a cold front
that is forecasted to push east across the Southern Plains and
towards the southeast CONUS. This combined with limited tropical
moisture from the Gulf will re-introduce some low end rain chances
(between 15-20%) mainly for areas along and east of I-55 by
Monday afternoon. /CR/

&&

.AVIATION...
(18Z TAFS)
Issued at 1234 PM CDT Mon Sep 16 2024

Low CIGS are resulting in slowly improving flight categories
through 18Z today but overall, morning MVFR/IFR conditions will
continue to improve to MVFR/VFR through 09Z though scattered
SHRA/TSRA will persist through 02Z. After that time, ceilings will
have fallen across the area with patchy, intermittent fog
reducing CIG/VIS to MVFR/IFR. After 15Z, conditions improve and
VFR will prevail. Easterly winds prevail through the period, under
10kts through 02Z and under 5 kts thereafter. /86/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       68  85  67  88 /  60  30   0  10
Meridian      66  86  65  88 /  50  20   0  10
Vicksburg     68  85  67  87 /  40  20   0   0
Hattiesburg   70  86  69  90 /  70  50   0  20
Natchez       68  84  68  88 /  20  30   0  10
Greenville    66  85  64  86 /  50  10   0   0
Greenwood     66  87  65  88 /  30   0   0   0

&&

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

$$

EC/CR/LP