SPC AC 150559
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT TUE JUN 15 2010
VALID 151200Z - 161200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID-MS
VALLEY AND OH VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN HIGH
PLAINS...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN
ROCKIES...
...OH VALLEY...
AN UPPER-LEVEL TROUGH OVER THE CNTRL PLAINS TODAY WILL MOVE ENEWD
INTO THE MID TO UPPER MS VALLEY. AN MCS ASSOCIATED WITH THE
LOW-LEVEL JET SHOULD BE ONGOING ACROSS ERN MO AND IL THIS MORNING.
AHEAD OF AND TO THE SOUTH OF THE MCS...A MODERATELY UNSTABLE AIRMASS
SHOULD BE IN PLACE FROM THE MID-MS VALLEY ENEWD ACROSS IND AND OH.
THE NAM AND GFS SOLUTIONS INCREASE MLCAPE VALUES INTO THE 2000 TO
3000 J/KG RANGE BY EARLY AFTERNOON. THE CURRENT THINKING IS THAT
THUNDERSTORMS WILL INITIATE ON THE SRN SIDE OF THE DECAYING MCS
ALONG THE WRN EDGE OF STRONG INSTABILITY WITH A SECOND MCS
ORGANIZING AND MOVING ENEWD ACROSS THE OH VALLEY. HAVE TAKEN A
COMPROMISE BETWEEN THE GFS AND NAM SOLUTIONS WHICH WOULD TAKE THE
CONVECTION ACROSS CNTRL IL...CNTRL IND AND WRN OH LATE THIS
AFTERNOON INTO EARLY THIS EVENING.
ETA-KF FORECAST SOUNDINGS FROM CNTRL IL AND CNTRL IND LATE THIS
AFTERNOON SHOW 30 TO 40 KT OF 0-6 KM SHEAR WITH UNIDIRECTIONAL WIND
PROFILES AND STEEP LOW-LEVEL LAPSE RATES. THIS ENVIRONMENT SHOULD BE
FAVORABLE FOR A BOWING LINE-SEGMENT WITH AN ENHANCED WIND DAMAGE
THREAT. THE GFS AND NAM SOLUTIONS BOTH APPEAR TO DEVELOP A LINEAR
MCS WHICH SUPPORTS THIS IDEA. AN ISOLATED TORNADO THREAT MAY ALSO
DEVELOP WITH THE STRONGER ROTATING CELLS EMBEDDED IN THE LINE.
...SRN HIGH PLAINS...
HEIGHTS WILL RISE ACROSS THE GREAT PLAINS TODAY AS AN UPPER-LEVEL
RIDGE BUILDS NWD INTO THE CNTRL AND NRN PLAINS. SLY FLOW WILL REMAIN
ENHANCED ON THE WRN SIDE OF THE RIDGE IN THE SRN HIGH PLAINS
ALLOWING A MOIST AIRMASS TO REMAIN IN PLACE ACROSS WEST TX...THE OK
PANHANDLE AND SW KS. THIS SHOULD RESULT IN MODERATE DESTABILIZATION
ACROSS THE REGION WITH THUNDERSTORMS INITIATING ACROSS THE SLIGHT
RISK AREA IN THE LATE AFTERNOON. DUE TO THE LACK OF LARGE-SCALE
ASCENT...ANY THUNDERSTORMS THAT INITIATE SHOULD REMAIN RATHER
ISOLATED LATE THIS AFTERNOON AND EARLY THIS EVENING.
ETA-KF FORECAST SOUNDINGS ACROSS THE TX PANHANDLE AT 00Z SHOW 35 TO
40 KT OF 0-6 KM SHEAR WITH SUBSTANTIAL DIRECTIONAL SHEAR BELOW 700
MB. THIS SHEAR ENVIRONMENT ALONG WITH MODERATE INSTABILITY SHOULD BE
FAVORABLE FOR SUPERCELL DEVELOPMENT WITH LARGE HAIL THE PRIMARY
THREAT. A POTENTIAL FOR DAMAGING WIND GUSTS COULD ALSO DEVELOP
ESPECIALLY IF A CLUSTER OF STORMS CAN ORGANIZE ACROSS THE REGION
EARLY THIS EVENING.
...ERN SEABOARD...
A VERY MOIST AIRMASS WILL REMAIN IN PLACE ACROSS THE CAROLINAS AND
GA TODAY WHERE SFC DEWPOINTS SHOULD BE IN THE LOWER 70S F. THIS
SHOULD AGAIN RESULT IN MODERATE TO STRONG INSTABILITY BY EARLY
AFTERNOON WITH SCATTERED TO NUMEROUS THUNDERSTORMS DEVELOPING FROM
THE SRN APPALACHIAN MTNS IN NC SWD ACROSS THE COASTAL PLAINS OF ERN
GA. ETA-KF FORECAST SOUNDINGS ACROSS SC AND ERN GA AT 21Z SHOW
MLCAPE VALUES IN THE 2000 TO 3000 J/KG WITH WEAK DEEP LAYER SHEAR
AND VERY STEEP LOW-LEVEL LAPSE RATES. THIS ENVIRONMENT COULD BE
FAVORABLE FOR PULSE STORMS WITH STRONG WIND GUSTS.
...NRN ROCKIES...
AN UPPER-LEVEL LOW WILL MOVE SLOWLY SSEWD ACROSS THE PACIFIC
NORTHWEST TODAY AS SOUTHWEST FLOW REMAINS IN PLACE ACROSS THE NRN
ROCKIES. SCATTERED THUNDERSTORMS SHOULD INITIATE EAST OF THE
UPPER-LEVEL LOW IN THE NRN ROCKIES AS SFC TEMPS WARM TODAY. THE
GREATEST POTENTIAL FOR STRONG UPDRAFTS SHOULD EXIST ACROSS ERN ID
AND SRN MT NEAR THE EXIT REGION OF THE MID-LEVEL JET. ETA-KF
FORECAST SOUNDINGS IN ERN ID AND SRN MT DEVELOP MLCAPE OF 1000-1200
J/KG WITH 0-6KM SHEAR IN THE 45 TO 55 KT RANGE. THIS COMBINED WITH
VERY STEEP LAPSE RATES SHOULD BE FAVORABLE FOR A SUPERCELL THREAT
WITH A POTENTIAL FOR LARGE HAIL. AN ISOLATED DAMAGING WIND GUST
POTENTIAL SHOULD ALSO EXIST ESPECIALLY DURING THE LATE AFTERNOON
WHEN LOW-LEVEL LAPSE RATES SHOULD BE STEEPEST.
..BROYLES/GARNER.. 06/15/2010
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