Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 301935
SWODY1
SPC AC 301934

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0234 PM CDT FRI SEP 30 2016

VALID 302000Z - 011200Z

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PORTIONS OF ERN
INDIANA/OH/WRN WV...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF SRN VA AND INTO
NC/EXTREME NERN SC...

...SUMMARY...
A FEW STRONG TO LOCALLY SEVERE THUNDERSTORMS REMAIN POSSIBLE TODAY
ACROSS PORTIONS OF VIRGINIA AND NORTH CAROLINA AS WELL AS THE OHIO
RIVER VALLEY.

...DISCUSSION...
NO SUBSTANTIVE CHANGES ARE BEING MADE TO THE OUTLOOK ATTM...WITH
ONLY MINOR LINE ADJUSTMENTS APPEARING NECESSARY.  RISK FOR A SEVERE
STORM OR TWO WILL LINGER INTO EARLY EVENING ACROSS PORTIONS OF
WV/OH/INDIANA...AS WELL AS PORTIONS OF THE VA AND NC VICINITY.

..GOSS.. 09/30/2016

.PREV DISCUSSION... /ISSUED 1129 AM CDT FRI SEP 30 2016/

...NC THROUGH VA...

AS OF MID DAY A QUASI-STATIONARY FRONT /PORTIONS OF WHICH HAVE BEEN
CONVECTIVELY REINFORCED/ EXTENDS FROM NERN NC WSWWD TO A WEAK LOW
PRESSURE AREA IN WRN NC. A COLD FRONT EXTENDS FROM ERN SC NWWD INTO
CNTRL NC WHERE IT INTERSECTS THE STATIONARY FRONT. WIDESPREAD CLOUDS
AND SCATTERED ONGOING STORMS CONTINUE THROUGH MUCH OF WARM
SECTOR...BUT CLOUD BREAKS IN WAKE OF EARLY STORMS WILL RESULT IN AT
LEAST MODEST BOUNDARY LAYER DESTABILIZATION...ESPECIALLY FROM NRN NC
INTO A PORTION OF SRN VA. WEAK MID-LEVEL LAPSE RATES SHOULD LIMIT
MLCAPE TO AOB 1500 J/KG WITH THE STRONGER INSTABILITY OVER ERN NC.
STORMS DEVELOPING WITHIN AN ARC FROM ERN NC NWWD THROUGH WCNTRL VA
WILL CONTINUE NWD INTO THE AFTERNOON. STRONGEST STORM WITH SUPERCELL
STRUCTURES REMAINS OVER NCNTRL NC AND MAY CONTINUE TO POSE A
SHORT-TERM THREAT FOR MAINLY HAIL AND STRONG WIND GUSTS...BUT A
BRIEF TORNADO CANNOT BE RULED OUT.

IN WAKE OF ONGOING ARC OF STORMS...ADDITIONAL CONVECTION MAY DEVELOP
WHERE THE SFC-LAYER IS DESTABILIZING IN VICINITY OF A NW-SE ORIENTED
OUTFLOW BOUNDARY ACROSS NWRN THROUGH CNTRL NC AND NWD INTO SCNTRL
VA. HOWEVER...WV IMAGERY SHOWS A ZONE OF SIGNIFICANT DRYING ALOFT
SPREADING NWD...AND THIS WAS SAMPLED BY THE 12Z GSO RAOB. WEAK
MID-LEVEL LAPSE RATES AND SUBSTANTIAL DRY AIR ALOFT MAY TEND TO
REDUCE UPDRAFT STRENGTH THROUGH ENTRAINMENT...LIMITING OVERALL
SEVERE POTENTIAL. NEVERTHELESS...A CONDITIONAL RISK FOR FEW STRONG
TO SEVERE STORMS WILL REMAIN POSSIBLE INTO THE AFTERNOON GIVEN 40+
KT EFFECTIVE SHEAR AND VEERING LOW-LEVEL WIND PROFILES SUPPORTIVE OF
UPDRAFT ROTATION.

...OH VALLEY AREA...

THUNDERSTORMS CONTINUE DEVELOPING IN AN ARC WITHIN UPPER LOW
CIRCULATION ACROSS CNTRL OH. DIABATIC WARMING OF THE BOUNDARY LAYER
WITHIN ZONE OF CLEARING IN VICINITY OF THE STORMS MAY RESULT IN SOME
INTENSIFICATION DURING THE AFTERNOON. COOL TEMPERATURES ALOFT AND
DIABATIC WARMING WILL CONTRIBUTE TO WEAK BUOYANCY WHERE EFFECTIVE
SHEAR IS SUPPORTIVE OF A FEW STORMS TO DEVELOP UPDRAFT ROTATION
WHICH MAY PROMOTE A THREAT FOR SMALL TO MARGINALLY SEVERE HAIL AND
PERHAPS A BRIEF TORNADO.

$$


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