Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 221949
SWOMCD
SPC MCD 221948
TXZ000-222145-

MESOSCALE DISCUSSION 0717
NWS STORM PREDICTION CENTER NORMAN OK
0248 PM CDT FRI MAY 22 2015

AREAS AFFECTED...SWRN TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 221948Z - 222145Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED STORMS ARE EXPECTED TO DEVELOP OVER SWRN TX BY
21Z. STORMS MAY DEVELOP SUPERCELL STRUCTURES WITH LARGE HAIL AND
DAMAGING WIND AND A TORNADO OR TWO POSSIBLE. A WW WILL PROBABLY NOT
BE NEEDED UNLESS IT BEGINS TO APPEAR STORM COVERAGE WILL BE GREATER
THAN CURRENTLY ANTICIPATED.

DISCUSSION...STRONG DIABATIC WARMING HAS BOOSTED SFC TEMPERATURES
INTO THE 80S WITHIN THE MOIST BOUNDARY LAYER WHERE DEWPOINTS ARE IN
THE 50S TO LOW 60S. CUMULUS HAS BEEN INCREASING OVER THE HIGHER
TERRAIN...AND A FEW THUNDERSTORMS WILL PROBABLY DEVELOP OVER THE
DAVIS MOUNTAINS BEFORE 21Z. WV IMAGERY...RAP PFCS AND 12Z OBSERVED
SOUNDINGS INDICATE AN AREA OF SUBSTANTIAL DRY AIR ALOFT OVER THIS
REGION THAT WILL LIKELY PERSIST THROUGH EARLY EVENING. THIS SUGGESTS
CONVECTION WILL EXPERIENCE CONSIDERABLE ENTRAINMENT AS UPDRAFTS
DEVELOP...POSSIBLY LIMITING STORM COVERAGE THIS AFTERNOON.
NEVERTHELESS AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT IS EXPECTED
WITHIN THE MODERATELY TO STRONGLY UNSTABLE ENVIRONMENT WITH MLCAPE
BETWEEN 2000-3000 J/KG BASED ON LATEST OBJECTIVE ANALYSIS. VEERING
LOW-LEVEL WINDS BENEATH 30-40 KT FLOW ALOFT IS PROMOTING EFFECTIVE
BULK SHEAR FROM 40-50 KT OVER MUCH OF THIS REGION...SUPPORTIVE OF
SUPERCELLS.

WHILE INITIAL DEVELOPMENT WILL PROBABLY REMAIN ISOLATED...THERE IS
SOME CHANCE FOR GREATER COVERAGE DURING THE EVENING AS THE LLJ
STRENGTHENS AND MID-LEVELS MOISTEN IN ASSOCIATION WITH AN
APPROACHING SRN STREAM IMPULSE MOVING ENEWD ACROSS NRN MEXICO.

..DIAL/GOSS.. 05/22/2015

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

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

LAT...LON   30800401 31190312 31120228 30520190 30000195 29820267
            29070313 29370391 30180425 30800401




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