Mesoscale Discussion 678

Issued

May 18, 2021, 6:07 PM CDT (23:07 UTC)

Expired

May 18, 2021, 8:00 PM CDT

In force

113 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

The Lubbock radar (KLBB), 81 km from the middle of the area, began a volume at 23:09 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.

627 
ACUS11 KWNS 182307
SWOMCD
SPC MCD 182307 
TXZ000-190100-

Mesoscale Discussion 0678
NWS Storm Prediction Center Norman OK
0607 PM CDT Tue May 18 2021

Areas affected...The Texas Panhandle

Concerning...Severe potential...Watch unlikely 

Valid 182307Z - 190100Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated severe wind/hail will remain possible through the
late evening hours for portions of the Texas Panhandle as a line of
storms continues to move to the east.

DISCUSSION...Latest base reflectivity and velocity data from the TX
Panhandle show that an initial cluster of storms has now
consolidated into a semi-organized line. Relatively weak and
meridional flow over the region is limiting the overall severe
threat with this line as it slowly moves east via cold pool
propagation (as hinted by outflow boundaries noted west of KAMA).
While a robust MCS does not appear likely given weak bulk shear,
favorable low-level lapse rates near 8 C/km and sufficient
instability will continue to support a threat for isolated wind and
hail through at least sunset. Further south, a lone supercell will
likely persist for the next hour or two as it continues to move into
a more unstable air mass, and will pose primarily a wind and large
hail threat. Recent guidance suggests additional convection may
develop along a residual outflow boundary later tonight across parts
of west/northwest TX, but confidence in this scenario is somewhat
low. Regardless, the modest flow over the region suggests that a
more robust/widespread severe threat is unlikely, so a watch is not
anticipated.

..Moore/Grams.. 05/18/2021

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

ATTN...WFO...LUB...AMA...MAF...

LAT...LON   33640295 34470260 35180236 35670228 35920149 35800085
            35360070 34700063 34010073 32720111 32580193 33280292
            33640295

Mesoscale Discussions in Texas, 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.