SPC AC 130548
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1248 AM CDT SUN JUN 13 2010
VALID 131200Z - 141200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN AND
CNTRL PLAINS...MID-MO VALLEY AND LOWER OH VALLEY...
...SRN PLAINS/CNTRL PLAINS/MID-MS VALLEY...
AN UPPER-LEVEL LOW OVER THE CNTRL ROCKIES WILL MOVE NEWD TOWARD THE
NRN HIGH PLAINS TODAY AS A MID-LEVEL JET MOVES ACROSS THE SRN AND
CNTRL HIGH PLAINS. AT THE SFC...A LOW PRESSURE CENTER IS FORECAST TO
REMAIN ACROSS WEST TX WITH A STATIONARY FRONT EXTENDING NEWD INTO
SCNTRL AND NE KS. AN MCS WILL LIKELY BE ONGOING THIS MORNING ON THE
NOSE OF A 30 TO 40 KT LOW-LEVEL JET ACROSS THE CNTRL PLAINS WITH
THIS ACTIVITY MOVING NEWD INTO ERN KS...NRN MO AND SRN IA BY
AFTERNOON. SFC-BASED THUNDERSTORMS SHOULD INITIATE DURING THE LATE
AFTERNOON ALONG THE BOUNDARY FROM THE ERN TX PANHANDLE NEWD INTO
CNTRL KS WITH THIS CONVECTION RAPIDLY EXPANDING IN COVERAGE DURING
THE EARLY EVENING. ISOLATED THUNDERSTORMS SHOULD ALSO DEVELOP SSWWD
INTO FAR WEST TX ALONG AN AXIS OF MODERATE INSTABILITY.
THE GREATEST POTENTIAL FOR SEVERE SHOULD BE ACROSS THE ERN TX
PANHANDLE AND SCNTRL KS IN THE WAKE OF THE EXITING MCS WHERE THE
MODELS DEVELOP A CORRIDOR OF STRONG INSTABILITY. NAMKF FORECAST
SOUNDINGS BY LATE AFTERNOON ACROSS THE SLIGHT RISK AREA SHOW SFC
DEWPOINTS NEAR 70 F WITH MLCAPE IN THE 2500 TO 3500 J/KG RANGE. IN
ADDITION...THE MID-LEVEL JET ASSOCIATED WITH THE CNTRL ROCKIES
UPPER-LEVEL LOW WILL CREATE MODERATE TO STRONG DEEP LAYER SHEAR IN
THE CNTRL AND SRN HIGH PLAINS WHICH WILL BE FAVORABLE FOR SEVERE
STORMS. THE GREATEST THREAT FOR SUPERCELLS AND LARGE HAIL SHOULD
EXIST WITH DISCRETE STORMS THAT INITIATE IN THE SWRN PART OF THE
SLIGHT RISK AREA WHERE A 30 % HAIL PROBABILITY IS MAINTAINED AND A
FEW TORNADOES WILL ALSO BE POSSIBLE. HOWEVER...A TRANSITION TO A
LINEAR MCS MAY OCCUR AS STORMS CONGEAL ALONG THE FRONTAL BOUNDARY
DURING THE EVENING. THE WIND DAMAGE THREAT COULD BECOME ENHANCED IF
A BOWING LINE-SEGMENT CAN ORGANIZE. UNCERTAINTY STILL REMAINS AS TO
WHERE THE GREATEST WIND DAMAGE THREAT MAY DEVELOP.
FURTHER EAST NORTHEAST ACROSS THE MID-MO VALLEY EWD INTO THE LOWER
OH VALLEY...THE MORNING REMNANT MCS ON THE NOSE OF THE LOW-LEVEL JET
SHOULD MOVE INTO THE REGION FROM THE WEST SOUTHWEST BY MIDDAY. A
MARGINAL THREAT SHOULD INITIALLY EXIST WITH THE STRONGER CELLS IN
THE MCS. HOWEVER...THE GREATER SEVERE THREAT SHOULD DEVELOP AS SFC
TEMPS WARM AND MODERATE INSTABILITY DEVELOPS IN THE MID TO LATE
AFTERNOON. AS NEW STORMS INITIATE...A FEW SUPERCELLS WITH LARGE HAIL
WILL BE POSSIBLE IN NRN MO WHERE ETA-KF FORECAST SOUNDINGS SHOW 50
KT OF 0-6 KM SHEAR AND ABOUT 2000 J/KG OF MLCAPE. MULTICELL STORMS
WITH WIND DAMAGE POTENTIAL MAY ALSO DEVELOP SWD ACROSS THE WARM
SECTOR IN CNTRL MO AND CNTRL IL AS LOW-LEVEL LAPSE RATES BECOME
STEEP IN THE LATE AFTERNOON.
...UPPER OH VALLEY/CNTRL APPALACHIAN MTNS/MID-ATLANTIC...
AN UPPER-LEVEL RIDGE IS FORECAST ACROSS THE OH VALLEY AND GREAT
LAKES REGION TODAY AS A QUASI-STATIONARY FRONT REMAINS IN PLACE
EXTENDING FROM CNTRL KY ENEWD INTO THE MID-ATLANTIC. ALTHOUGH
LARGE-SCALE ASCENT SHOULD BE RELATIVELY WEAK...SFC BASED
THUNDERSTORMS SHOULD INITIATE ALONG THE FRONTAL BOUNDARY BY EARLY TO
MID-AFTERNOON WHERE MODEL FORECASTS DEVELOP MODERATE INSTABILITY.
ETA-KF FORECAST SOUNDINGS GENERALLY SHOW 15 TO 25 KT OF DEEP LAYER
SHEAR ACROSS THE UPPER OH VALLEY AND MID-ATLANTIC REGION SUGGESTING
MOST OF THE CONVECTION WILL BE PULSE OR MULTICELLULAR. THE EXCEPTION
COULD BE IN ERN PA AND NJ WHERE MODERATE DEEP LAYER SHEAR IS
FORECAST. THIS AREA MAY HAVE A POTENTIAL FOR ROTATING STORMS BUT
WEAK INSTABILITY IS THE MAIN CONCERN THIS FAR NORTHEAST AND WILL NOT
INTRODUCE A SLIGHT ATTM.
..BROYLES/GARNER.. 06/13/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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