Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 061846
SWOMCD
SPC MCD 061846
TXZ000-062045-

MESOSCALE DISCUSSION 0517
NWS STORM PREDICTION CENTER NORMAN OK
0146 PM CDT WED MAY 06 2015

AREAS AFFECTED...PORTIONS OF SOUTHWEST TEXAS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 061846Z - 062045Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THUNDERSTORMS ARE DEVELOPING AND WILL BE EXPANDING IN
COVERAGE THROUGH THE AFTERNOON.  A WEATHER WATCH IS POSSIBLE.

DISCUSSION...STRONG HEATING CONTINUES TO ERODE CONVECTIVE INHIBITION
WITH BOUNDARY-LAYER DEWPOINTS HOLDING IN THE MID-60S.  SHOWERS AND A
FEW THUNDERSTORMS HAVE DEVELOPED ON THE NORTHERN EDGE OF A
PERSISTENT STRATUS FIELD OVER THE BIG BEND REGION. ADDITIONAL
THUNDERSTORMS ARE LIKELY...BOTH ALONG THE DRYLINE STRETCHING FROM
FORT STOCKTON TO MIDLAND AND POINTS NORTHEAST...AND WITHIN A
THICKENING FIELD OF CUMULUS WHERE MIXED-LAYER CAPE VALUES HAVE
INCREASED TO 1500-2000 J/KG. EFFECTIVE SHEAR VALUES OF 30-40 KT WILL
SUPPORT MULTICELL STRUCTURES WITH SOME SUPERCELL STRUCTURES LIKELY
WITH PERSISTENT UPDRAFTS. A NEGATIVE FACTOR FOR THUNDERSTORM
POTENTIAL IS A SIGNAL FOR MID-LEVEL SUBSIDENCE TO SPREAD IN FROM THE
WEST...POSSIBLY ASSOCIATED WITH THE EQUATOR-WARD SIDE OF THE
ENHANCED 400-250 MB FLOW. THE RESULTANT LOWERING OF MID-LEVEL LAPSE
RATES COULD INITIALLY LIMIT THE SEVERE POTENTIAL TO MARGINALLY
SEVERE HAIL...AND PERHAPS A FEW SEVERE WIND GUSTS GIVEN THE DRY
MID-LEVEL AIR SPREADING IN. THE TORNADO THREAT IS EXPECTED TO REMAIN
LOW INITIALLY BECAUSE OF WEAK LOW-LEVEL WINDS...AND IS EXPECTED TO
REMAIN WEAK UNTIL EARLY EVENING. THEREFORE THE INITIAL THOUGHT IS TO
ISSUE A SEVERE THUNDERSTORM WATCH IF ONE IS ISSUED...BUT THE WIND
FIELDS AND RADAR TRENDS OF THE DEVELOPING THUNDERSTORMS WILL
CONTINUE TO BE MONITORED FOR ANY UPTICK IN TORNADO POTENTIAL.

..CONIGLIO/HART.. 05/06/2015

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

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

LAT...LON   31420219 32020182 32510137 32760042 32619904 32079867
            31129878 30369930 29999975 29770089 29750161 29840204
            30210249 30920232 31420219



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