Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 260518
SWODY2
SPC AC 260518

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1218 AM CDT TUE MAY 26 2015

VALID 271200Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SOUTHERN
HIGH PLAINS...

...THERE IS A MRGL RISK OF SVR TSTMS FROM THE HIGH PLAINS TO NRN NEW
ENGLAND...

...SUMMARY...
STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE PARTICULARLY ACROSS
PARTS OF THE HIGH PLAINS AND NORTHEAST UNITED STATES ON WEDNESDAY.

...CENTRAL/SOUTHERN HIGH PLAINS...

NEUTRAL-WEAK HEIGHT RISES ARE EXPECTED ACROSS MUCH OF THE MIDDLE OF
THE U.S...INCLUDING THE HIGH PLAINS DURING THE DAY2 PERIOD.  HEIGHTS
WILL NOT BEGIN TO FALL ACROSS THE SRN HIGH PLAINS UNTIL AFTER
MIDNIGHT ON THE 28TH.  WEAK UPPER RIDGING SHOULD DOMINATE THE PLAINS
DURING THE DAY...THOUGH LATEST NAM GUIDANCE HINTS AT SOME FLATTENING
ACROSS WRN KS INTO THE TX PANHANDLE.  IN THE ABSENCE OF LARGE SCALE
ASCENT...IT APPEARS DIABATIC HEATING WILL PROVE THE PRIMARY
INSTIGATOR IN GENERATING CONVECTION ACROSS SLGT RISK REGION
WEDNESDAY.  BOTH THE NAM AND GFS SUGGEST EARLY-DAY CONVECTION MAY BE
ONGOING ACROSS ERN KS/OK/NCNTRL TX.  STRONG HEATING ALONG WRN FRINGE
OF THIS CONVECTION SHOULD FOCUS FROM WRN KS INTO THE TX SOUTH PLAINS
WHERE DRY LINE IS EXPECTED TO GENERATE ISOLATED ROBUST CONVECTION BY
LATE AFTERNOON.  WHILE DEEP LAYER FLOW IS NOT FORECAST TO BE
PARTICULARLY STRONG...VEERING WIND PROFILES WITH HEIGHT...ABUNDANT
LOW-LEVEL MOISTURE AND STRONG INSTABILITY FAVOR WEAK SUPERCELLS OR
SEVERE MULTI-CELLS CAPABLE OF PRODUCING LARGE HAIL AND GUSTY WINDS.

...NORTHEASTERN U.S...

PROGRESSIVE SHORT-WAVE TROUGH WILL EJECT ACROSS THE GREAT LAKES INTO
ON/QB EARLY IN THE PERIOD WITH PRIMARY CORRIDOR OF HEIGHT FALLS
FORECAST TO SPREAD ACROSS SERN CANADA.  WHILE LARGE SCALE FORCING
SHOULD FOCUS NORTH OF THE INTERNATIONAL BORDER LATEST GUIDANCE
SUGGESTS A ZONE OF PRE-FRONTAL CONVECTION MAY DEVELOP ACROSS THE
WARM SECTOR WITHIN A ZONE OF MODEST SWLY DEEP-LAYER SHEAR.  FORECAST
SOUNDINGS FAVOR LINE SEGMENTS WITH STORM MOTIONS OF
20-30KT...SEEMINGLY SUPPORTIVE OF AT LEAST MARGINALLY SEVERE WIND
GUSTS.  IF BUOYANCY IS GREATER THAN EXPECTED ACROSS NY/VT/NH/ME THEN
A SLGT RISK MAY BE WARRANTED FOR LOCALLY SEVERE WIND GUSTS.

...ELSEWHERE...

SCT CONVECTION IS EXPECTED TO DEVELOP ACROSS MUCH OF THE CONUS FROM
THE NRN ROCKIES INTO THE LOWER OH VALLEY...SWD TO THE GULF COAST.
WHILE INDIVIDUAL TSTMS MAY AT TIMES INTENSIFY TO SEVERE LEVELS
LATEST GUIDANCE DOES NOT PROVIDE CONFIDENCE FOR MORE THAN 5 PERCENT
SEVERE PROBS WITH MOST OF THIS CONVECTION.  ONE EXCEPTION COULD BE
ACROSS THE ARKLATEX OR LOWER MS VALLEY IF AN MCS-TYPE COMPLEX
EVOLVES OVER THIS REGION.  HOWEVER...PREDICTABILITY WILL REMAIN LOW
ON THIS EVOLUTION UNTIL EARLY IN THE DAY1 PERIOD.

..DARROW.. 05/26/2015



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