And in fact, followed by 5% severe tomorrow. The main concern today will be this evening mainly after 5pm. A front will move south into the area very slowly. Thunderstorms out ahead could produce small hail and high winds. There is potential for damaging winds in some storms. Tornadic development is not a concern at this time. Heavy rain which could produce flooding is possible in some of the storms this evening. Heavy rains will be more of a threat tomorrow as the front slows almost to a stall. A train of slow moving showers and thunderstorms could produce 2 to 3 inches of rain, although, in areas hit hard multiple times, rainfall could locally exceed 5 inches.
SPC PRODUCTS FOR TODAY:




DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT TUE MAY 15 2007
...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF NEW ENGLAND AND
THE LOWER GREAT LAKES SWWD INTO THE OZARKS...
...SYNOPSIS...
UPPER TROUGH OVER THE N CENTRAL CONUS AT THE START OF THE PERIOD
SHOULD DIG/STRENGTHEN WITH TIME AS IT MOVES ACROSS THE MS
VALLEY/UPPER GREAT LAKES AND EVENTUALLY INTO THE OH VALLEY.
ELSEWHERE...A RIDGE WILL PREVAIL ACROSS THE ROCKIES...WHILE A
WEAKER/FLAT RIDGE MOVES EWD ACROSS THE ERN CONUS INTO THE WRN
ATLANTIC AHEAD OF THE DIGGING CENTRAL U.S. TROUGH.
AT THE SURFACE...MAIN FEATURE WILL BE A COLD FRONT WHICH WILL MOVE
SLOWLY EWD AHEAD OF UPPER TROUGH. BY LATE AFTERNOON...THIS BOUNDARY
AND ITS ASSOCIATED LINE OF THUNDERSTORMS SHOULD EXTEND FROM NEW
ENGLAND/NY WSWWD ACROSS THE LOWER GREAT LAKES/MIDWEST AND INTO THE
SRN PLAINS.
...THE OZARKS NEWD INTO THE LOWER GREAT LAKES/NEW ENGLAND...
STORMS SHOULD BE ONGOING INVOF FRONT DURING THE START OF THE
PERIOD...THOUGH CONVECTION SHOULD REMAIN GENERALLY SUB-SEVERE
THROUGH EARLY AFTERNOON.
MODERATE DESTABILIZATION WILL OCCUR THROUGH THE AFTERNOON...AS
COMBINATION OF DAYTIME HEATING AND DEWPOINTS IN THE 60S AHEAD OF THE
FRONT SHOULD RESULT IN 1000 TO 2000 J/KG MEAN-LAYER CAPE.
AS STORMS REDEVELOP ALONG/AHEAD OF FRONT...LINEAR STORM MODE SHOULD
QUICKLY EVOLVE. MODERATE DEEP-LAYER WIND FIELD -- PARTICULARLY FROM
THE LOWER OH VALLEY ENEWD -- WILL SUPPORT SMALL-SCALE BOWS WITHIN
THE LINE. THEREFORE...LOCALLY-DAMAGING WINDS WILL BE POSSIBLE IN
ADDITION TO THE THREAT FOR HAIL. GREATEST SEVERE THREAT APPEARS TO
EXIST ACROSS PARTS OF IL/IN/OH...WHERE 40 KT FLOW AT LOW- TO
MID-LEVELS IS EXPECTED.
OTHER STORMS MAY DEVELOP DURING THE AFTERNOON IN A W-E ZONE FROM NEW
YORK EWD ACROSS PARTS OF VT/NH/MA...AHEAD OF WEAK SURFACE LOW.
COMBINATION OF MEAN-LAYER CAPE NEAR 500 J/KG AND 50 TO 60 KT
DEEP-LAYER FLOW SUGGESTS DAMAGING WIND POTENTIAL ACROSS THIS
CORRIDOR.
THOUGH CONVECTION SHOULD PERSIST FROM PARTS OF NEW ENGLAND/NY SWWD
ACROSS THE OH/MID MS VALLEY REGION INTO THE OVERNIGHT HOURS...SEVERE
THREAT SHOULD SLOWLY WANE AS BOUNDARY LAYER STABILIZES WITH TIME.
|posted by Sam Lillo @ 5/15/2007 06:37:00 AM