Drought in Tennessee, December 1 to 31, 2023

Area Forecast Discussion
National Weather Service Memphis TN
1136 PM CST Thu Nov 30 2023

...New AVIATION...

.UPDATE...
Issued at 852 PM CST Thu Nov 30 2023

01Z surface analysis places a 1002 mb surface low over central
Oklahoma. A warm front extends east-southeast into east Texas and
into Louisiana with an occluding cold front located in the Texas
Hill Country. Meanwhile, an inverted surface trough is located
over southern Arkansas and east Arkansas, resulting in rain
showers across most of the Mid-South. Temperatures as of 8 PM CST
range from the middle 40s to the middle 50s.

Short-term model trends indicate the aforementioned surface low
will move northeast tonight into west central Missouri. Additional
rain showers are expected to develop and move across the area
overnight and gradually tapering off by late Friday morning.

The potential for elevated winds remains somewhat high while the
potential for sustained winds reaching Wind Advisory criteria is
low at best. 00Z KLZK upper air sounding showed a rather stout
inversion between 950-925 mb with boundary layer winds approaching
30 kts. This strong inversion also showing up in short-term model
soundings may ultimately prevent stronger winds mixing down to
the surface to meet the 25 mph sustained criteria. Operational
model and NBM MOS guidance continues to indicate sub-advisory
surface winds into early Friday. Some minor adjustments will be
made to the forecast for the remainder of the night. An early
cancellation of the Wind Advisory may be considered in the next
few hours unless trends begin to suggest otherwise.

CJC

&&

.SYNOPSIS...
Issued at 125 PM CST Thu Nov 30 2023

Shower and thunderstorm chances will continue to increase tonight
ahead of a deep low pressure system. Sustained winds 20-25 mph
with wind gusts up to 40 mph will be possible across most of the
area overnight. A Wind Advisory is in effect from 10PM tonight
through 7AM tomorrow. A secondary cold front will move through
Saturday, increasing rain chances again and cooling temperatures
down a bit. Expect cool and mostly dry conditions next week.

&&

.DISCUSSION...
(This evening through next Wednesday)
Issued at 125 PM CST Thu Nov 30 2023

NQA radar is showing some light precip returns this afternoon that
will gradually increase in coverage and intensity throughout the
day. This is ahead of a deep occluded surface low currently
centered over the TX/OK Panhandles. While the instability corridor
will most likely remain well displaced to our southwest, a few
rumbles of thunder cannot be ruled out overnight as the bulk of
the precip moves through. The period with the highest PoPs
(80-90%) looks to be between midnight tonight and sunrise
tomorrow. Expect QPF values just under an inch from now through
tomorrow afternoon, especially along and north of I-40.

While the aforementioned surface low approaches, the pressure
gradient across the CWA will continue to tighten throughout the
day. In addition, a 60 kt 925 mb jet will materialize across the
MS Delta shortly before midnight. These two features in
conjunction will contribute to elevated surface winds overnight
with sustained winds up to 25 mph and wind gusts up to 40 mph. A
Wind Advisory is in effect for much of the area, excluding parts
of northeast MS, from 10PM tonight to 7AM tomorrow. The presence
of a very steep inversion prominent on several observed and
forecast soundings may make it difficult for these elevated winds
to mix all the way down to the surface. This caveat is the main
factor limiting the confidence in actually meeting Wind Advisory
criteria (25 mph sustained winds) overnight.

As the low pulls away from the Mid-South, a reinforcing cold
front looks to arrive late Friday night, bringing a secondary
round of showers and perhaps a few thunderstorms for much of the
day Saturday. Ensemble probabilities of CAPE > 500 J/kg are
essentially negligible everywhere except for portions of northeast
MS, so if we do see a few rumbles of thunder, it would likely be
in the Tupelo area on Saturday morning. In the extended forecast,
a fairly nondescript surface pattern will set up under a 170 kt
upper level jet. Barring any shortwave features ejecting from the
central Plains, the remainder of the forecast period next week
looks benign with cool and mostly dry conditions.

CAD

&&

.AVIATION...
(06Z TAFS)
Issued at 1123 PM CST Thu Nov 30 2023

LLWS and IFR CIGs will be the main concerns this period as a low
pressure system moves across the Mid-South. LLWS of 45-55 kts at
FL020 will continue through the early morning hours. The exact
magnitude of surface winds will depend on how much mixing occurs,
but overall expect strong southeast winds gusting to around 20
kts.

Conditions will begin improving by midday as showers push out of
the region. By the end of the period, gusty winds will cease and
CIGs will return to MVFR/VFR.

ANS

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&

PUBLIC FORECAST...CAD
AVIATION...ANS