184
FXUS64 KJAN 171945
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
245 PM CDT Tue Sep 17 2024

...New DISCUSSION...

.DISCUSSION...
Issued at 244 PM CDT Tue Sep 17 2024

Today...

The forecast remains on track today: With our early morning fog
burning off throughout the CWA and showers expected to develop
across the southern half of the forecast area today. The primary
driving mechanism for the weather today has transitioned from
Francine remnants to the interaction between a continental ridge
and a deep retrograding low centered over the eastern parts of the
Carolinas. This pattern has created easterly flow in SFC-700mb
level which will dry out the northern half of the CWA, inhibiting
our rain chances in those areas. Conversely, the offshore
stationary boundary to our south will allow for a moderate amount
of isentropic lift, coupled with high amounts of surface level
moisture from previous rainfall totals, will provide enough of the
necessary ingredients for light showers south of I-20 today.
Nothing to get too excited about though as projected totals for
today are not expected to be that much.

High relative humidity values and moderate cloud coverage are
contributing to our smaller diurnal temperature swings, leading to
cooler highs in the mid 80s F and seasonable lows in the mid 60s F.
Winds are not expected to be particularly notable with generally
calm easterly conditions persisting throughout today.

Tonight through Friday Morning...

The main focus from tonight through the short term period will be
the formation and coverage of fog across the region. There is a
plethora of low level moisture and with our cloud coverage clearing
out a bit tonight, we will see more ideal conditions for radiational
cooling tonight looks to be our most favorable setup for fog (some
possibly dense) across the forecast area. While we have some
confidence in the fog develop, enough uncertainty exists to hold off
at this time on a dense fog advisory. We will message with a
graphic indicating the fog potential for tonight. Next shift will
evaluate and update accordingly.

As we move through the rest of the work week we will continue to see
a moderate amount of drying easterlies coming around the low over in
Carolinas. That drying will dampen our fog coverage for the rest of
the week, lowering density to an obscuration of between 3-5 miles
for the area.

Friday Afternoon through Tuesday...

In the long term an upstream ridge will begin to build into the
area, allowing for generally northerly flow and strong dry air
advection. This dry air will curtail any chance for fog or mist
development throughout the remainder of the period. In tandem with
lower level drying, the ridge will bring mostly clear skies and more
seasonal temperatures to the region: Highs in the low 90s F and lows
in the upper 60s. Next week looks to be the last time we
consistently breach 90s for the year as Autumnal climatology begins
to take hold afterwards./OAJ/

&&

.AVIATION...
(18Z TAFS)
Issued at 1237 PM CDT Tue Sep 17 2024

Morning low clouds and vis restrictions are improving, but we`re
still seeing some MVFR conditions hold for a bit longer. The
afternoon will be main VFR and only issues will be with areas
across the south half that could see some Iso/Sct showers. Evening
will be clear and focus will shift to fog potential. Guidance
seems bearish, but with solid rad cooling conditions and wet
ground and moist low levels fits with good conditions for fog to
develop. Due to this, will be having MVFR/IFR vis conditions
between 09-14z. Conditions could get worse and be more widespread,
so that`s something to watch. VFR conditions for Wed after 14z.
/CME/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       67  89  66  89 /   0   0   0   0
Meridian      65  90  64  90 /   0   0   0   0
Vicksburg     67  89  67  89 /   0   0   0   0
Hattiesburg   69  90  69  92 /  10  10   0   0
Natchez       69  88  68  89 /  10  10   0   0
Greenville    64  88  63  87 /   0   0   0   0
Greenwood     65  89  64  89 /   0   0   0   0

&&

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

$$

OAJ/CME