Mesoscale Discussion 708

Issued

May 20, 2019, 5:08 PM CDT (22:08 UTC)

Expired

May 20, 2019, 7:15 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

60%

Counties Crane County, TX, Crockett County, TX, Glasscock County, TX, Midland County, TX, Reagan County, TX, Terrell County, TX, Upton County, TX

The Midland/Odessa radar (KMAF), 114 km from the middle of the area, began a volume at 22:10 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.

038 
ACUS11 KWNS 202208
SWOMCD
SPC MCD 202208 
TXZ000-210015-

Mesoscale Discussion 0708
NWS Storm Prediction Center Norman OK
0508 PM CDT Mon May 20 2019

Areas affected...Portions of Texas South Plains into the Big Bend

Concerning...Severe potential...Watch possible 

Valid 202208Z - 210015Z

Probability of Watch Issuance...60 percent

SUMMARY...Thunderstorms have initiated along the dryline west of
Midland, TX. Storms will pose a large hail and severe wind gust
threat, though the tornado threat should increase as storms move
northeast. Farther south, initiation is more uncertain. Large hail
and damaging wind gusts will be possible with any development. A new
watch may be needed for new activity south of WW 197.

DISCUSSION...Visible satellite imagery shows development of
thunderstorms along the dryline west of Midland, TX with large
MLCAPE values nearing 3000-3500 J/kg downstream. Initially, these
storms will likely pose a threat for very large hail -- long
straight hodographs per KMAF VAD and 18Z MAF sounding showing around
8 C/km mid-level lapse rates -- a severe wind gust threat given the
somewhat high surface dewpoint depressions. However, with time
storms will progress northeast as continued low-level theta-e occurs
and the 850 mb jet increases. RAP forecast soundings show improved
low-level hodograph curvature that would support an increase in the
tornado threat into the evening.

Farther south near the Big Bend, some CAM guidance shows new
thunderstorm development later this evening. Though initiation is a
bit more uncertain here, the cumulus development along the higher
terrain across the international border gives evidence to support
this scenario. However, surface dewpoint depressions in this region
are a bit larger. Large hail and severe wind gusts will likely be
the primary threats, though a tornado cannot be ruled out should any
potential development can tap into richer boundary layer moisture to
the east.

An extension of WW 197 will cover the threat in the MAF CWA. A new
watch may be needed should storm initiation become more certain
across the Big Bend and vicinity.

..Wendt/Guyer.. 05/20/2019

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

ATTN...WFO...EWX...SJT...MAF...

LAT...LON   31440261 31990233 32050157 31370107 30230106 29920160
            29830215 30000254 30990269 31440261

Mesoscale Discussions in Texas, 2019Every mesoscale discussion in 2019

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.