Mesoscale Discussion 486

Issued

Apr 12, 2017, 11:04 AM MDT (17:04 UTC)

Expired

Apr 12, 2017, 1:30 PM MDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

60%

Counties Chaves County, NM, Eddy County, NM, Guadalupe County, NM, Lea County, NM, Lincoln County, NM, Mora County, NM, Otero County, NM, San Miguel County, NM, Torrance County, NM, Andrews County, TX, Brewster County, TX, Culberson County, TX, Gaines County, TX, Jeff Davis County, TX, Loving County, TX, Pecos County, TX, Presidio County, TX, Reeves County, TX, Ward County, TX, Winkler County, TX

The Holloman AFB radar (KHDX), 164 km from the middle of the area, began a volume at 17:03 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 141Apr 12, 1:05 PM MDT

146 
ACUS11 KWNS 121705
SWOMCD
SPC MCD 121704 
TXZ000-NMZ000-121930-

Mesoscale Discussion 0486
NWS Storm Prediction Center Norman OK
1204 PM CDT Wed Apr 12 2017

Areas affected...Parts of central/eastern New Mexico and southwest
Texas

Concerning...Severe potential...Watch possible 

Valid 121704Z - 121930Z

Probability of Watch Issuance...60 percent

SUMMARY...Increasing thunderstorm activity is expected near the
mountains of southwest Texas and central New Mexico through the 12-3
PM MDT time frame, accompanied by at least some risk for severe
weather.  Although stronger storm development may remain confined to
the vicinity of the higher terrain, and the potential for organizing
upscale convective growth seems small, a watch issuance for at least
southern portions of the region is possible within the next couple
of hours.

DISCUSSION...In the wake of an ongoing, sustained cluster of
thunderstorms, which developed across and northeast of the
Sacramento Mountains, persistent moist upslope flow and insolation
are contributing to weak to modest boundary layer destabilization. 
As this occurs, orographic forcing, aided by ascent associated with
an approaching low amplitude short wave trough, is already
contributing to increasing convective development across the higher
terrain, from near the Sacramento's northward toward the Sangre de
Cristo Mountains, and southward into the Davis Mountains area of
southwest Texas.  A gradual further increase and intensification of
thunderstorm activity seems probable through the 18-21Z time.

In the presence of weak to modest, but veering wind fields with
height, beneath 30+ kt southwesterly 500 mb flow, and thermodynamic
profiles characterized by steep lower/mid tropospheric lapse rates
with CAPE of 1000-1500+ J/kg, the evolution of a couple of sustained
supercells appear possible.  These are expected to be accompanied by
primarily a risk for severe hail, but a tornado may not be
completely out of the question by late afternoon.

..Kerr/Grams.. 04/12/2017

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

ATTN...WFO...LUB...MAF...ABQ...EPZ...

LAT...LON   31860523 32530638 33290644 34140622 35190638 35770549
            36030488 35080439 34720462 33670440 33210380 33000275
            32890258 32090261 31470290 30090252 29060322 29380396
            29850446 30600477 31860523

Mesoscale Discussions in Texas, 2017Mesoscale Discussions in New Mexico, 2017Every mesoscale discussion in 2017

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.