Special Weather Statement, NWS Memphis, TN

Area Forecast Discussion
National Weather Service Memphis TN
1147 PM CST Sun Dec 5 2021

.UPDATE...

See 06Z aviation discussion below.

&&

.PREV UPDATE... /issued 921 PM CST Sun Dec 5 2021/

Updated to include a Severe Thunderstorm watch for portions of
northeast Arkansas, the Missouri Bootheel and far northwest
Tennessee. A line of thunderstorms has recently developed along a
cold front stretching from northwest Oklahoma into southeast
Missouri. Ample moisture in in place featuring PW's around 1.3
inches and dew points in the low to middle 60s and resulting in
CAPE in the 1000 to 1500 range. 0-6kt shear of 40-50kt to our
west should gradually shift across northern portions of the
Midsouth over the next several hours. Supercellular or quasi-
supercellular thunderstorms may result in damaging wind with a
slightly less threat of hail. 0-1 km shear between 225 and
250m^2/s^2 on the LZK 00z sounding suggest tornadoes cannot be
ruled out. Tornadoes would be most likely with any storms that
develop out ahead of the main line.

Additional watches may be needed farther south later tonight.

30

&&

.DISCUSSION... /issued 603 PM CST Sun Dec 5 2021/

Showers and a few storms have been ongoing this afternoon across
the Mid South. We expect a lull in the action for the next few
hours before a cold front starts to move into the region later on
tonight. The Storm Prediction Center continues to carry a Slight
Risk for severe weather tonight into Monday morning for a large
portion of the forecast area. We expect showers and storms to
develop sometime after 10 PM this evening along that front as it
moves south. The biggest question still remains is if any
convection will really take advantage of the kinematics that this
system would provide if storms can become surface based. Looking
at the soundings this afternoon an inversion is still being shown
for portions of the area as the best convection moves through.
That's not to say that this will be a non event, but there is a
conditional component to this event. The shear will not be a
problem and helicity will begin to pile up along the front as
well...embedded within the convection. This would point to a QLCS
type event with bowing lines and segments that could produce
damaging winds and a few tornadoes if it is able to take advantage
of the atmosphere in place. The best chances to see severe
weather look to be mainly north of I-40 and as the system moves in
the profiles become less favorable for deeper convection. The
good news is that this system should be out of the area after 10
AM...and we will clear out for the afternoon and evening hours.
The active pattern continues through the week. The next impulse
looks to move through by mid week. As of now it looks like most of
the precip will be off to the south and east of the area. Have
maintained some light POPs during that time frame as well.
Southwesterly flow aloft will develop late in the week, with
deeper moisture return and warm advection showers possible by
Friday...and another system bringing the chance of some
thunderstorms again by Saturday.

&&

.AVIATION...

06Z TAFs

Pre-frontal showers are pushing across the CWA this evening. The
main line of storms, IFR CIGs, and reduced VSBYs (3-4SM) is fast-
moving and approaching from the west. The line will reach JBR by
08Z, MEM and MKL by 09Z, and TUP by 11Z. Carried VCTS at all sites
except TUP which I capped at VCSH due to the line weakening as it
gets farther south and east. Winds ahead of the front will be
strong and southwesterly around 15-20kt, gusting to up to 25kt as
the line of storms passes. Winds behind the front will also be
strong, but N/NW around 15kt with higher gusts possible. A few
showers and low clouds may linger post-FROPA for a few hours,
especially at TUP. VFR conditions return by the morning and winds
calm down to NE around 10kt.

CAD

&&

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

Hazardous Weather Outlook
National Weather Service Memphis TN
104 PM CST Sun Dec 5 2021

ARZ009-018-026>028-035-036-048-049-058-MOZ113-115-MSZ001>017-
020>024-TNZ001>004-019>022-048>055-088>092-062115-
Alcorn-Benton MS-Benton TN-Calhoun-Carroll-Chester-Chickasaw-Clay-
Coahoma-Craighead-Crittenden-Crockett-Cross-DeSoto-Decatur-
Dunklin-Dyer-Fayette-Gibson-Greene-Hardeman-Hardin-Haywood-
Henderson-Henry-Itawamba-Lafayette-Lake-Lauderdale-Lee AR-Lee MS-
Madison-Marshall-McNairy-Mississippi-Monroe-Obion-Panola-Pemiscot-
Phillips-Poinsett-Pontotoc-Prentiss-Quitman-Shelby-St. Francis-
Tallahatchie-Tate-Tippah-Tipton-Tishomingo-Tunica-Union-Weakley-
Yalobusha-
104 PM CST Sun Dec 5 2021

This hazardous weather outlook is for portions of East Arkansas...
the Missouri Bootheel...North Mississippi...and West Tennessee.

.DAY ONE...This Afternoon and Tonight

There is a Slight Risk for severe thunderstorms late tonight and
early Monday morning over most of the Midsouth, specifically,
north of a line from Charleston to Oxford to Savannah. Primary
severe weather threat will be damaging winds. Secondary threats
include brief tornadoes and flash flooding. Additionally, a
secondary threat for large hail will exist over northeast Arkansas
and the Missouri bootheel in the early overnight.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There is a Marginal Risk for severe thunderstorms Monday morning,
over east central Arkansas, most of north Mississippi, and
portions of southwest Tennessee near the Tennessee River. Primary
threat will be damaging winds. Secondary threat will be flash
flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed late tonight.

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