SPC AC 010528
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 AM CDT TUE JUN 01 2010
VALID 011200Z - 021200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MIDWEST
INTO THE N-CNTRL HIGH PLAINS...
...SYNOPSIS...
A PROGRESSIVE...LOW-AMPLITUDE REGIME WILL PERSIST THROUGH THE DAY
ONE PERIOD WITH THE MOST CONCENTRATED ZONES OF HEIGHT FALLS/DYNAMIC
FORCING FOR ASCENT ASSOCIATED WITH MIDLEVEL IMPULSES MOVING THROUGH
NEW ENGLAND AND ONTARIO INTO QUEBEC. FARTHER UPSTREAM...00Z MODEL
GUIDANCE SUGGESTS THAT A SHORT WAVE TROUGH CURRENTLY MOVING THROUGH
NRN CA INTO NWRN NV WILL CONTINUE EWD...REACHING THE CNTRL HIGH
PLAINS BY THIS EVENING.
IN THE LOW LEVELS...A SURFACE CYCLONE AND ASSOCIATED COLD FRONT WILL
ATTEND MIDLEVEL SYSTEM EWD THROUGH THE HUDSON VALLEY AND NEW ENGLAND
TODAY WITH THE TRAILING EXTENSION OF THE FRONT PUSHING SEWD THROUGH
THE MID ATLANTIC STATES THIS AFTERNOON INTO TONIGHT. ELSEWHERE...A
COLD FRONT WILL PUSH SEWD THROUGH THE N-CNTRL STATES...LIKELY
EXTENDING FROM CNTRL WI/SRN MN SWWD TO A LEE CYCLONE NEAR THE CO/KS
BORDER.
...CNTRL/WRN CORN BELT INTO THE N-CNTRL HIGH PLAINS...
A NW-SE ORIENTED BAND OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING
AT 12Z FROM PORTIONS OF CNTRL/SRN NEB INTO NRN KS WITHIN EXIT REGION
OF NOCTURNAL LLJ. THE PRESENCE OF STEEP LAPSE RATES/MODERATE
CONVECTIVE INSTABILITY INDICATE A THREAT OF SEVERE HAIL WITH THESE
STORMS THROUGH THE MORNING HOURS. IN THE WAKE OF THIS INITIAL
ACTIVITY AND AHEAD OF COLD FRONT...DEW POINTS IN THE 60S COUPLED
WITH STEEP LAPSE RATES AND DAYTIME HEATING ARE EXPECTED TO YIELD A
MODERATE TO STRONGLY UNSTABLE AIR MASS OVER THE MID MO VALLEY WITH
AFTERNOON MLCAPE OF 2500-3500 J/KG.
LATEST MESOSCALE AND TSTM-RESOLVING MODEL GUIDANCE IS SUGGESTIVE
THAT SOME REMNANT OF THE MORNING ELEVATED TSTMS WILL PERSIST THROUGH
THE DAY...PERHAPS EVEN REINTENSIFY BY AFTERNOON WITHIN THE
DESTABILIZING WARM SECTOR OVER ERN NEB/WRN IA INTO NERN KS/NRN MO.
ADDITIONAL TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
BY AFTERNOON ALONG THE COLD FRONT FROM PARTS OF SERN SD INTO SRN MN
AND SWWD INTO CNTRL NEB. OTHER MORE ISOLATED STORMS WILL ALSO BE
POSSIBLE ALONG WARM FRONT/OUTFLOW COMPOSITE BOUNDARY PRESENT ACROSS
SRN NEB/NRN KS...AS WELL AS IN THE UPSLOPE REGIME OF NERN CO.
THE STRONGEST DEEP-LAYER SHEAR /I.E. 40-50 KT/ IS EXPECTED TO RESIDE
GENERALLY TO THE N OF NEB/KS AND IA/MO BORDERS. AND WHILE THE
DISTRIBUTION OF WARM SECTOR MOISTURE/LAPSE RATES MAY TEND TO BE
MODULATED BY THE EARLY DAY STORMS...SUPERCELLS CAPABLE OF VERY LARGE
HAIL AND A FEW TORNADOES WILL BE POSSIBLE IN AREAS WHERE THE
STRONGER INSTABILITY COINCIDES WITH THE MODERATELY STRONG VERTICAL
SHEAR. UPSCALE GROWTH INTO ONE OR MORE MCS/S WILL LIKELY OCCUR BY
LATE EVENING WITH AN ASSOCIATED INCREASE IN DAMAGING WIND POTENTIAL.
...ERN NEW ENGLAND INTO THE MID ATLANTIC STATES...
SCATTERED TSTMS ARE EXPECTED TO DEVELOP TODAY ALONG THE COLD FRONT
PUSHING EWD THROUGH THE REGION. LINGERING CLOUDINESS FROM CURRENT
TSTM ACTIVITY OVER THE LOWER GREAT LAKES MAY LIMIT DIABATIC HEATING
AND RESULTANT INSTABILITY ACROSS NEW ENGLAND WHERE THE
STRONGEST...DEEP WLY SHEAR IS FORECAST. FARTHER S...COMPARABLY
STRONGER HEATING MAY YIELD A MODERATELY UNSTABLE AIR MASS BY
AFTERNOON WITH MLCAPE OF 1000-1500 J/KG...BUT WITHIN A WEAKER
SHEARED ENVIRONMENT.
ISOLATED SEVERE STORMS CAPABLE OF SOME HAIL AND GUSTY WINDS WILL BE
POSSIBLE INTO THIS EVENING. HOWEVER...THE DISPLACEMENT OF THE
STRONGER SHEAR FROM THE BETTER INSTABILITY WILL LIKELY LIMIT THE
POTENTIAL FOR A MORE ROBUST SEVERE WEATHER THREAT.
..MEAD/STOPPKOTTE.. 06/01/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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