Mesoscale Discussion 1960

Issued

Dec 5, 2021, 5:05 PM CST (23:05 UTC)

Expired

Dec 5, 2021, 7:30 PM CST

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch possible

Chance of a watch

40%

The Memphis radar (KNQA), 62 km from the middle of the area, began a volume at 23:04 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

• Severe Thunderstorm Watch 550Dec 5, 8:55 PM CST
• Tornado Watch 551Dec 5, 9:00 PM CST

620 
ACUS11 KWNS 052305
SWOMCD
SPC MCD 052305 
TNZ000-ALZ000-KYZ000-MSZ000-MOZ000-ARZ000-060130-

Mesoscale Discussion 1960
NWS Storm Prediction Center Norman OK
0505 PM CST Sun Dec 05 2021

Areas affected...Northeast Arkansas...Far Southeast
Missouri...Western Tennessee

Concerning...Severe potential...Watch possible 

Valid 052305Z - 060130Z

Probability of Watch Issuance...40 percent

SUMMARY...An isolated and marginal severe threat will likely
continue for the next few hours from northeast Arkansas into western
Tennessee. Weather watch issuance remains possible across parts of
the mid Mississippi Valley early this evening.

DISCUSSION...The latest radar imagery from Memphis shows scattered
convection to the northeast of Little Rock, with a second more
isolated area located to the east-northeast of Memphis. This
convection is located along an axis of moderate instability where
MLCAPE is estimated in the 1000 to 1500 J/kg range by the RAP. This
surface-based development is being supported by warm advection
associated with a low-level jet in the mid Mississippi Valley. The
diurnally warmed boundary layer is also likely contributing as well.
In addition, the WSR-88D VWP at Little Rock has 0-6 km shear at 45
Kt with substantial speed shear in the lowest 1 km. This should
support a marginal wind-damage and hail threat. The hodograph from
Memphis also has some curvature suggesting that a marginal tornado
threat will also be possible. The severe threat may slowly increase
as the low-level jet in northern Arkansas shifts southeastward. This
increasing potential is somewhat conditional because the loss of
daytime heating may negatively impact development further east. Over
the next couple of hours, weather watch issuance still remains
possible for this convection, especially if storm coverage ramps up
quicker than expected.

..Broyles/Guyer.. 12/05/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...OHX...HUN...PAH...MEG...LZK...

LAT...LON   34998804 35458753 35838742 36358755 36718795 36908909
            36579029 35999119 35489163 35039147 34909111 34868983
            34878893 34998804

Mesoscale Discussions in Tennessee, 2021Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Kentucky, 2021Every mesoscale discussion in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.