Severe Storm Outlook Narrative (AC)
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ACUS48 KWNS 040842
SWOD48
SPC AC 040841

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0341 AM CDT WED MAY 04 2016

VALID 071200Z - 121200Z

...DISCUSSION...
ECMWF AND GFS ARE IN FAIRLY GOOD AGREEMENT REGARDING THE EVOLUTION
OF UPPER LOW AS IT MIGRATES ACROSS THE SWRN U.S. INTO THE PLAINS
EARLY NEXT WEEK.  AT THIS TIME IT APPEARS A STRONG BELT OF MID-LEVEL
FLOW WILL TRANSLATE THROUGH THE BASE OF THE TROUGH ACROSS NRN MEXICO
INTO SERN NM BY 08/00Z.  IN RESPONSE TO THIS FEATURE...LLJ SHOULD
GRADUALLY RESPOND ACROSS THE SRN HIGH PLAINS ALLOWING MODIFIED GULF
AIR MASS TO ADVANCE NWD.

ONE CONCERN FOR SIGNIFICANT SEVERE DURING THE DAYS4-5 TIME FRAME
WILL BE THE QUALITY OF BOUNDARY-LAYER MOISTURE AVAILABLE FOR
SFC-BASED TSTMS.  EARLY SATURDAY IT APPEARS 60F+ SFC DEW POINTS WILL
STILL BE CONFINED TO SOUTH TX.  THIS AIR MASS WILL STRUGGLE TO REACH
THE DRY LINE DAY4...BUT SHOULD ADVANCE NWD INTO THE CNTRL PLAINS
DAY5.  SCT HIGH-BASED SUPERCELLS SHOULD EVOLVE ACROSS THE HIGH
PLAINS DAY4 AND LARGE HAIL WILL LIKELY BE THE PRIMARY SEVERE THREAT
WITH THIS ACTIVITY.  LATER DAY5...DRY LINE SHOULD BE DISLODGED EWD
WHERE SOMEWHAT HIGHER MOISTURE/INSTABILITY ARE EXPECTED.  SUPERCELLS
ARE ONCE AGAIN EXPECTED TO DEVELOP ALONG A SHARPENING DRY LINE AIDED
BY 50-70KT 500MB SPEED MAX EJECTING INTO SWRN OK DURING THE EVENING
HOURS.  FOR NOW 15 PERCENT SEVERE PROBS SHOULD SUFFICE.

BEYOND DAY5...MODELS BEGIN TO DIVERGE IN THEIR PROGRESSION OF LONG
WAVE TROUGH.  DAY5 CONVECTION COULD ALSO PROVE PROBLEMATIC IN AIR
MASS DISRUPTION/BUOYANCY.  PREDICTABILITY IS TOO LOW FOR DAYS6-8.

..DARROW.. 05/04/2016



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