Mesoscale Discussion 111

Issued

Feb 17, 2021, 3:22 PM CST (21:22 UTC)

Expired

Feb 17, 2021, 7:15 PM CST

In force

4 hr

Issued by

the Storm Prediction Center

Concerning

Heavy snow

The Memphis radar (KNQA), 49 km from the middle of the area, began a volume at 21:27 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.

824 
ACUS11 KWNS 172122
SWOMCD
SPC MCD 172122 
TNZ000-ALZ000-MSZ000-MOZ000-ARZ000-180115-

Mesoscale Discussion 0111
NWS Storm Prediction Center Norman OK
0322 PM CST Wed Feb 17 2021

Areas affected...southern/central Arkansas...southwest through
Middle Tennessee...and northwestern Mississippi

Concerning...Heavy snow 

Valid 172122Z - 180115Z

SUMMARY...Areas of heavy snow will continue across the discussion
area for several more hours.

DISCUSSION...Recent observations suggest that the heaviest of
snowfall in the discussion area (with rates likely exceeding 1" per
hour) was occurring in the general vicinity of Little Rock, Pine
Bluff, and Camden in central/southern Arkansas, with lighter, but
still moderate snowfall observed farther northeast toward Memphis
and Nashville in Tennessee.  The region continues to reside in a
regime characterized by appreciable lift due to isentropic ascent,
with strong low-level flow across central/southern Louisiana
impinging on a shallow cold airmass.  Though the general focus of
warm advection has begun to shift slightly to the east, additional
ascent from a mid-level wave apparent via water vapor imagery over
north-central Texas was also likely contributing to enhanced
snowfall rates in the region.  This general regime should continue
for at least several more hours (perhaps through 01-03Z or so)
before beginning to taper off from west to east in Arkansas later
tonight.  Beneath heavier precipitation bands, 2" per hour snowfall
rates cannot be ruled out.

..Cook.. 02/17/2021

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

ATTN...WFO...OHX...HUN...MEG...JAN...LZK...SHV...

LAT...LON   34809323 35289217 35799081 36128917 36198795 36248728
            36098677 35898669 35358700 34988795 34668913 34668913
            34418978 34209038 33789151 33429268 33509343 34029388
            34809323

Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Tennessee, 2021Mesoscale Discussions in Mississippi, 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.