Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 252349
SWOMCD
SPC MCD 252348
TXZ000-260045-

MESOSCALE DISCUSSION 0447
NWS STORM PREDICTION CENTER NORMAN OK
0648 PM CDT MON APR 25 2016

AREAS AFFECTED...S TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 252348Z - 260045Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A FEW STRONG/SEVERE STORMS WILL CONTINUE ACROSS PARTS OF S
TX FOR THE NEXT COUPLE OF HOURS.  LARGE HAIL WILL BE THE MAIN
THREAT.

DISCUSSION...LATEST RADAR IMAGERY SHOWS A SMALL CLUSTER OF ISOLATED
STORMS ONGOING OVER S TX.  THE STORMS HAVE INITIATED NEAR A N-S
TROUGH/DRYLINE...SEPARATING AN UPPER 50S/LOW 60S DEWPOINT BOUNDARY
LAYER NEAR AND E OF THE RIO GRANDE FROM MOIST/TROPICAL MID 70S
DEWPOINT AIR ADVECTING INLAND ACROSS THE TX COASTAL PLAIN.  THE
ENVIRONMENT SUPPORTING THE CONVECTION IS CHARACTERIZED BY A VERY
UNSTABLE AIRMASS /3000 TO 4000 J/KG MIXED-LAYER CAPE/ ALONG AND E OF
THE DRYLINE...ALONG WITH MODERATE FLOW ALOFT WHICH VEERS WITH HEIGHT
YIELDING A WIND PROFILE SUPPORTIVE OF MID-LEVEL ROTATION.

THE TWO STRONGEST STORMS ATTM -- ONE MOVING NWD ACROSS BEXAR COUNTY
AND THE OTHER DRIFTING SLOWLY EWD ACROSS MCMULLEN COUNTY -- MAY
PRODUCE HAIL TO AROUND 2" IN DIAMETER...AND SHOULD PERSIST FOR THE
NEXT 1-2 HOURS.  ATTM HOWEVER...IT APPEARS THAT THE ONSET OF
BOUNDARY-LAYER COOLING A BIT LATER THIS EVENING WILL SUPPORT A
GRADUAL DECREASE IN STORM INTENSITY/SEVERE RISK.

FINALLY...A FEW ATTEMPTS AT CONVECTION HAVE BEEN EVIDENT OVER THE
HIGHER TERRAIN OF NRN MEXICO W OF MFE /MCALLEN TX/...BUT SUSTAINED
STORMS HAVE NOT DEVELOPED TO THIS POINT.  THOUGH SOME GUIDANCE HAS
SUGGESTED POTENTIAL FOR A STORM OR TWO MOVING ACROSS THE RIO GRANDE
INTO DEEP S TX THIS EVENING...ATTM SUCH A SCENARIO APPEARS UNLIKELY.

..GOSS/DARROW.. 04/25/2016

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

ATTN...WFO...CRP...EWX...

LAT...LON   30329846 30329737 29259720 28249721 27609773 27529823
            28229868 29469885 30029874 30329846




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