Mesoscale Discussion 821

Issued

May 31, 2021, 8:18 AM MDT (14:18 UTC)

Expired

May 31, 2021, 9:15 AM MDT

In force

57 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

5%

Counties Chaves County, NM, Curry County, NM, De Baca County, NM, Lincoln County, NM, Roosevelt County, NM

The Cannon AFB radar (KFDX), 123 km from the middle of the area, began a volume at 14:19 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 229May 31, 11:15 AM MDT

762 
ACUS11 KWNS 311419
SWOMCD
SPC MCD 311418 
NMZ000-311515-

Mesoscale Discussion 0821
NWS Storm Prediction Center Norman OK
0918 AM CDT Mon May 31 2021

Areas affected...southeast into east-central New Mexico

Concerning...Severe potential...Watch unlikely 

Valid 311418Z - 311515Z

Probability of Watch Issuance...5 percent

SUMMARY...Ongoing thunderstorms should persist for a few more hours.
Isolated large hail will be possible, but the sporadic nature of the
threat should preclude the need for a watch.

DISCUSSION...Thunderstorms continue to develop across southeast New
Mexico this morning will periodic indications of large hail per
MRMS. Origins of these thunderstorms appears to be weak
southwesterly warm-air advection rooted around 700 mb with
additional large-scale ascent downstream of an upper trough moving
into central New Mexico. Forecast soundings have effective-layer
shear on the order of 40-50 knots and modest lapse rates in the
700-500 mb range (around 7.5 C/km), which despite being close to the
base of the updrafts, should be sufficient to support isolated large
hail with the strongest updrafts. 

The overall thermodynamic environment is still recovering from
widespread convection yesterday, with surface temperatures across
east-central New Mexico still in the 50s F. Farther southwest, where
cloud cover is absent, surface temperatures have warmed into the 70s
F across south-central New Mexico, with surface dewpoint
temperatures in the low-to-mid 50s, yielding most-unstable CAPE
values around 1000-2000 J/kg. 

Given an unstable source region and the approach of large-scale
ascent, thunderstorms across southeast New Mexico should continue to
percolate through the morning before weakening later this morning as
they move east-northeast, farther away from the unstable source
region and into an increasingly stable environment. 

Later this morning into early afternoon, more robust convection is
anticipated farther west, within more unstable environment.

..Marsh/Hart.. 05/31/2021

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

ATTN...WFO...MAF...ABQ...

LAT...LON   33700549 34320554 34760500 34930379 34620316 33230315
            32830353 32840481 33100501 33700549

Mesoscale Discussions in New Mexico, 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.