SWODY1
SPC AC 080059
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0759 PM CDT TUE AUG 07 2007
VALID 080100Z - 081200Z
..THERE IS A SLGT RISK OF SVR TSTMS FROM NY/PA WWD TO MID MS/LOWER
MO VALLEYS TO THE CENTRAL PLAINS...
..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN
PLAINS...
..NY/PA WWD TO LOWER MI/OH...
SATELLITE IMAGERY INDICATED AN MCV OVER LM MOVING EWD INTO SRN LOWER
MI AT THIS TIME. ASCENT WITH THIS FEATURE IS EXPECTED TO ALLOW FOR
ADDITIONAL TSTM DEVELOPMENT OVER SERN LOWER MI THROUGH NRN OH...AND
EVENTUALLY DEVELOP/MOVE INTO PARTS OF PA/NY TONIGHT AS THIS IMPULSE
MOVES TO THE EAST. ALTHOUGH EXTENSIVE CLOUDINESS HAS INHIBITED
DESTABILIZATION OVER MUCH OF NY/CENTRAL-ERN PA TODAY...SURFACE
HEATING/MOISTURE ADVECTION IN THE WAKE OF THIS EARLIER ACTIVITY HAS
RESULTED IN A MODERATELY UNSTABLE AIR MASS AS FAR E AS WRN PA.
INCREASING WSWLY LOW LEVEL WINDS ARE EXPECTED TO ADVECT HIGHER
THETAE AIR MASS INTO NY/PA OVERNIGHT WITH POTENTIAL FOR TSTMS TO
REMAIN SURFACE BASED AS WARM FRONT MOVES ENEWD ACROSS NY/PA TOWARD
WRN NEW ENGLAND. THIS COMBINED WITH INCREASING ASCENT AND WIND
FIELDS ACROSS NY/PA AS ONTARIO MID LEVEL TROUGH AMPLIFIES SEWD TO
SRN ONTARIO/QUEBEC SUGGESTS POTENTIAL FOR AN INCREASING DAMAGING
WIND THREAT AS TSTMS SPREAD EWD.
..IA/NRN MO EWD TO IL/IND...
ONGOING TSTM COMPLEX LOCATED OVER SRN IA/FAR NRN MO IS BEING AIDED
BY ASCENT AHEAD OF A SHORT WAVE TROUGH TRACKING NEWD INTO SRN IA AT
THIS TIME AND AN MCV MOVING EWD INTO IA. THIS ACTIVITY FORMED IN
THE VICINITY OF A SURFACE BOUNDARY THAT EXTENDED EWD THROUGH NRN IL
TO NRN OH. DOWNSTREAM AIR MASS FROM THIS ONGOING COMPLEX IS VERY
UNSTABLE WITH EFFECTIVE BULK SHEAR VALUES SUPPORTIVE OF ORGANIZED
STORMS. GIVEN THESE PARAMETERS...THE POTENTIAL EXISTS FOR
ADDITIONAL UPSCALE GROWTH INTO A FORWARD PROPAGATING MCS TOWARD NRN
IL/IND OVERNIGHT. IF AN MCS IS MAINTAINED OVERNIGHT... DAMAGING
WINDS SHOULD BE THE PRIMARY THREAT.
..ERN CO INTO CENTRAL PLAINS...
SATELLITE IMAGERY SHOWED A SHORT WAVE TROUGH TRACKING TO THE ENE
THROUGH CENTRAL CO...WITH MODELS SUGGESTING THIS FEATURE MOVES INTO
WRN KS/NEB BY 12Z WEDNESDAY. ASCENT WITH THIS FEATURE WILL SUPPORT
ADDITIONAL STRONG TO SEVERE TSTMS THIS EVENING ACROSS ERN CO WHERE
THE AIR MASS REMAINS MODERATELY UNSTABLE. WEAK DEEP LAYER SHEAR AND
INVERTED-V THERMODYNAMIC PROFILES SUGGEST TSTMS SHOULD BE OUTFLOW
DOMINATED WITH STRONG WIND GUSTS BEING THE PRIMARY THREAT.
HOWEVER...ISOLATED HAIL MAY BE A THREAT AS WELL. FARTHER EAST...
STRONG SURFACE HEATING ALONG SURFACE BOUNDARY OVER CENTRAL TO NE KS
HAS AIDED IN A FEW STRONG-SEVERE TSTMS. WEAK DEEP LAYER SHEAR ALSO
ACROSS THIS AREA SUGGESTS DAMAGING WINDS AND ISOLATED HAIL WILL THE
MAIN THREATS THROUGH THE EVENING.
..ERN MT/WY TO WRN DAKOTAS...
ASCENT ATTENDANT WITH WEAK MID LEVEL IMPULSES EMBEDDED WITHIN PLUME
OF MOISTURE EXTENDING FROM THE SWRN STATES TO THE NRN PLAINS REGION
WILL CONTINUE TO SUPPORT TSTM DEVELOPMENT FROM ERN MT INTO THE WRN
DAKOTAS THIS EVENING. DESPITE MODEST INSTABILITY /MLCAPE VALUES
500-1000 J/KG/...INCREASING WSWLY MID LEVEL WINDS...SLY LLJ...AND
HEIGHT FALLS WITH APPROACH OF WRN MT SHORT WAVE TROUGH ARE EXPECTED
TO ALSO AID TSTM DEVELOPMENT OVERNIGHT. DEEP BOUNDARY LAYER PER 00Z
GGW SOUNDING SUGGESTS DAMAGING WIND GUSTS WILL BE POSSIBLE THROUGH
THE EVENING...WHILE STEEP LAPSE RATES ALSO SUPPORT A HAIL THREAT.
OVERALL SEVERE THREAT SHOULD WANE BY MID-LATE EVENING AS INSTABILITY
DECREASES...BUT A FEW SEVERE STORMS MAY OCCUR OVERNIGHT FROM ERN MT
INTO WRN DAKOTAS.
.PETERS.. 08/08/2007
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