Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 190446
SWODY2
SPC AC 190445

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1145 PM CDT FRI APR 18 2014

VALID 201200Z - 211200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS WEST TX...

...SUMMARY...
ISOLATED SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A
DRYLINE ACROSS THE SOUTHERN HIGH PLAINS OF WEST TEXAS.  A FEW STRONG
STORMS MAY ALSO DEVELOP ACROSS PORTIONS OF WESTERN OKLAHOMA INTO
CENTRAL KANSAS.

...SOUTHERN/CENTRAL PLAINS...

SLOW-MOVING UPPER LOW IS DRIFTING EWD ACROSS THE LOWER CO RIVER
VALLEY.  THIS FEATURE IS EXPECTED TO GRADUALLY DEAMPLIFY AND EJECT
INTO THE SRN ROCKIES EARLY SUNDAY MORNING WITH THE TROUGH AXIS
LIKELY EXTENDING ACROSS THE SRN HIGH PLAINS OF WEST TX BY 21/00Z.
STRONGEST BELT OF MID-HIGH LEVEL FLOW WILL TRANSLATE OVER NRN MEXICO
WITH 30-40KT AT 500MB FORECAST TO EXTEND OVER WEST TX DRYLINE BY
PEAK HEATING.  DEEP-LAYER SHEAR SHOULD INCREASE ENOUGH TO SUPPORT
SUSTAINED ROTATING UPDRAFTS...ESPECIALLY SOUTH OF I-20 WHERE SFC-6KM
VALUES SHOULD EXCEED 40KT.

LATEST MODEL GUIDANCE CONTINUES TO SUGGEST 50S SFC DEW POINTS WILL
ADVANCE NWWD INTO CONVERGENT LEE TROUGH/DRYLINE SUCH THAT AMPLE
INSTABILITY SHOULD EXIST BY EARLY-MID AFTERNOON FOR ROBUST UPDRAFTS.
IN FACT...COOLING PROFILES ALOFT MAY ALLOW INHIBITION TO WEAKEN
ENOUGH FOR TSTM INITIATION FAIRLY EARLY...POSSIBLY BY 18Z.
HOWEVER...CONTINUED BOUNDARY LAYER HEATING COULD RESULT IN SBCAPE
VALUES APPROACHING 1500 J/KG WITHIN STRONGLY SHEARED ENVIRONMENT.
FORECAST SOUNDING AT MAF AT 21/00Z STRONGLY SUPPORTS SUPERCELL
DEVELOPMENT.  CONVECTION THAT EVOLVES ACROSS THE SRN HIGH PLAINS
SHOULD MOVE ESEWD THOUGH NEWD DEVELOPMENT ALONG THE DRYLINE IS
EXPECTED ACROSS OK INTO KS.  TSTMS THAT DEVELOP ACROSS THE CNTRL
PLAINS WILL DO SO WITHIN CONSIDERABLY WEAKER SHEAR AND FORECAST
INSTABILITY DOES NOT APPEARS STRONG ENOUGH TO WARRANT MORE THAN 5
PERCENT SEVERE PROBS DESPITE SCT COVERAGE EXPECTED.

LARGE HAIL IS THE PRIMARY SEVERE THREAT WITH SUPERCELLS ALONG WITH
GUSTY WINDS.  WHILE A BRIEF TORNADO CAN NOT BE RULED OUT OVER WEST
TX LOW LEVEL SHEAR MAY BE INADEQUATE TO SUPPORT MORE SIGNIFICANT
TORNADO THREAT.

..DARROW.. 04/19/2014



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