Mesoscale Discussion 643

Issued

May 17, 2016, 5:38 PM CDT (22:38 UTC)

Expired

May 17, 2016, 7:15 PM CDT

In force

97 min

Issued by

the Storm Prediction Center

The Laughlin AFB radar (KDFX), 73 km from the middle of the area, began a volume at 22:41 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.

444 
ACUS11 KWNS 172239
SWOMCD
SPC MCD 172238 
TXZ000-180015-

MESOSCALE DISCUSSION 0643
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT TUE MAY 17 2016

AREAS AFFECTED...PORTIONS OF SOUTHWESTERN TX

CONCERNING...SEVERE THUNDERSTORM WATCH 180...

VALID 172238Z - 180015Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 180
CONTINUES.

SUMMARY...A CLUSTER OF STRONG/SEVERE THUNDERSTORMS OVER THE EDWARDS
PLATEAU SHOULD CONTINUE MOVING SOUTHEASTWARD ACROSS WATCH
180...MAINTAINING A THREAT FOR LARGE HAIL/DAMAGING WINDS...AND
PERHAPS A TORNADO...THIS EVENING.

DISCUSSION...A CLUSTER OF SEVERAL HP SUPERCELL/MULTICELL STRUCTURES
CONTINUES TO EVOLVE ACROSS PORTIONS OF THE EDWARDS PLATEAU THIS
EVENING...WITH NEW DEVELOPMENT FOCUSED AT THE INTERSECTION OF A
SOUTHWARD-PROGRESSING OUTFLOW BOUNDARY AND CONFLUENCE BOUNDARY OVER
CROCKETT COUNTY. A SOUTH/SOUTHEAST PROPAGATION COMPONENT SHOULD
FURTHER DRIVE THESE CELLS TOWARDS WESTERN PORTIONS OF THE TX HILL
COUNTRY OVER THE NEXT FEW HOURS...AS THEY MOVE ALONG A SFC THETA-E
AXIS. WEAK LOW-LEVEL FLOW SUGGESTS THE TORNADO THREAT SHOULD REMAIN
LOW...BUT SOME VEERING WITH HEIGHT /IN ADDITION TO CELLS
ENCOUNTERING RICHER LOW-LEVEL MOISTURE/ COULD SUPPORT A BRIEF
TORNADO. LARGE HAIL SHOULD REMAIN THE PRIMARY THREAT THOUGH...AS
STEEP MID-LEVEL LAPSE RATES AND OVER 40 KTS OF EFFECTIVE SHEAR FAVOR
EFFICIENT HAIL GROWTH ALOFT. ADDITIONALLY...SOME POTENTIAL EXISTS
FOR A CELL OR TWO TO REACH THE EASTERN EDGE OF THE WATCH...AND A
SMALL AREAL EXTENSION TO THE EAST COULD BE NECESSARY.

ACROSS SOUTHERN PORTIONS OF WATCH 180...GREATER CONVECTIVE
INHIBITION /EXHIBITED BY LOW-LEVEL BILLOW STRUCTURES ON VISIBLE
SATELLITE/ COULD KEEP CELLS MORE ISOLATED OVER THE NEXT FEW HOURS.
HOWEVER...AS A CONSOLIDATING COLD POOL ACROSS THE EDWARDS PLATEAU
CONTINUES TO SHIFT SOUTHWARD...INCREASING DEVELOPMENT/COVERAGE IS
POSSIBLE LATER THIS EVENING...WITH A PERSISTING POTENTIAL FOR LARGE
HAIL/STRONG WINDS.

..PICCA.. 05/17/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

LAT...LON   30960249 31230225 31550068 31189964 29929860 28739859
            28529909 28219960 28170011 29210080 29760149 29890203
            30960249

Mesoscale Discussions in Texas, 2016Every mesoscale discussion in 2016

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.