SPC AC 070600
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT SAT JUL 07 2007
VALID 081200Z - 091200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN GREAT LAKES INTO
PARTS OF THE UPPER MS VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS UPSTATE NY INTO PARTS OF
NEW ENGLAND...
...PART OF UPPER MS VALLEY INTO WRN GREAT LAKES...
SHORT WAVE TROUGH...CURRENTLY LOCATED OVER NERN CA PER WATER VAPOR
IMAGERY...IS EXPECTED TO REACH THE NRN HIGH PLAINS BY THE START OF
DAY 2. THIS FEATURE WILL THEN TRACK TOWARD THE UPPER MS VALLEY/WRN
GREAT LAKES REGION ON SUNDAY...AND SHOULD PHASE WITH A SHORT WAVE
TROUGH...NOW LOCATED OVER AB...AMPLIFYING SEWD INTO ONTARIO/NRN
GREAT LAKES. ALTHOUGH 00Z GFS REMAINS FASTER WITH THE AB IMPULSE
THAN THE NAM...EACH MODEL INDICATED WEAK HEIGHT FALLS ACROSS THE WRN
GREAT LAKES REGION. TSTMS SHOULD BE ONGOING AT THE START OF DAY 2
ACROSS PARTS OF THE U.P. OF MI WITHIN LOW LEVEL WAA REGIME ATTENDANT
WITH ASCENT AHEAD OF AB IMPULSE.
A COLD FRONT IS EXPECTED TO MOVE SWD THROUGH THE UPPER MS VALLEY AND
MUCH OF THE GREAT LAKES REGION ON SUNDAY. SWLY LOW LEVEL WINDS
AHEAD OF THE COLD FRONT WILL MAINTAIN MOISTURE RETURN INTO THE GREAT
LAKES REGION WITH SURFACE DEWPOINTS EXPECTED TO BE IN THE 60S.
PLUME OF STEEP LAPSE RATES EXTENDING EWD ATOP THE MOIST AXIS WILL
RESULT IN MODERATE INSTABILITY WITHIN THE WARM SECTOR AND ASCENT
WITHIN ENTRANCE REGION OF MID LEVEL JET WILL SUPPORT TSTM
DEVELOPMENT SUNDAY AFTERNOON AS THE COLD FRONT ADVANCES SWD. STRONG
DEEP LAYER SHEAR WILL FAVOR ORGANIZED STRONG TO SEVERE TSTMS...WITH
THE GREATEST SEVERE POTENTIAL EXPECTED FROM ERN U.P. OF MI/NRN LOWER
MI SWWD THROUGH WI TO SERN MN/NERN IA.
...NY INTO NEW ENGLAND...
ALTHOUGH HEIGHTS RISE ON SUNDAY ACROSS THE NERN STATES AS AN UPPER
TROUGH MOVES NEWD ACROSS THE CANADIAN MARITIMES...WNWLY MID LEVEL
WINDS/DEEP LAYER SHEAR WILL REMAIN STRONG ENOUGH TO SUPPORT
ORGANIZED TSTMS. WATER VAPOR IMAGERY INDICATED A MID LEVEL IMPULSE
OVER SERN ID/SWRN MT AT THIS TIME. THIS FEATURE IS EXPECTED TO
BECOME EMBEDDED WITHIN STRONGER BAND OF WESTERLIES LOCATED ALONG THE
NRN TIER OF STATES DURING DAY 1 AND SHOULD REACH NRN GREAT LAKES BY
START OF DAY 2. THIS IMPULSE WILL THEN MOVE EWD INTO NEW ENGLAND BY
SUNDAY EVENING.
A WARM FRONT EXTENDING ESEWD FROM A SURFACE LOW...WHICH IS FORECAST
TO TRACK FROM LS TO SWRN QUEBEC ON DAY 2...IS PROGGED TO SHIFT NEWD
ACROSS NEW ENGLAND. LOW LEVEL MOISTURE AND PLUME OF STEEP LAPSE
RATES WILL ADVECT EWD ACROSS SRN ONTARIO INTO UPSTATE NY AND NRN NEW
ENGLAND ALONG WARM FRONT. AIR MASS SHOULD BECOME MODERATELY
UNSTABLE INTO UPSTATE NY SUNDAY AFTERNOON...AND POTENTIALLY PARTS OF
VT/NH. ALTHOUGH ERN EXTENT OF INSTABILITY MAY ONLY EXTEND INTO
NH...STRONG DEEP WLY WINDS WITH 40-50 KT IN THE 850-700 MB LAYER
SUGGEST A THREAT FOR DAMAGING WINDS AS STRONG/SEVERE TSTMS DEVELOP/
SPREAD ESEWD FROM ONTARIO/SWRN QUEBEC INTO UPSTATE NY AND NRN NEW
ENGLAND.
...HIGH PLAINS FROM SERN MT TO NERN CO/WRN NEB...
MOIST...POST-FRONTAL UPSLOPE FLOW INTO THE HIGHER TERRAIN OF
SRN-SERN MT TO NRN CO AND THE BLACK HILLS COMBINED WITH A WEAK MID
LEVEL IMPULSE MOVING SEWD ACROSS THIS REGION ARE EXPECTED TO SUPPORT
TSTM DEVELOPMENT SUNDAY AFTERNOON. MODEL SOLUTIONS REMAIN UNCERTAIN
WITH THE AMOUNT OF INSTABILITY AND DEEP LAYER SHEAR THAT DEVELOPS
ACROSS THE HIGH PLAINS DURING THIS PERIOD. THUS WILL ONLY FORECAST
LOW SEVERE PROBABILITIES AT THIS TIME.
..PETERS.. 07/07/2007
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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