SPC: Slight risk severe today

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.