ACUS01 KWNS 220550
SWODY1
SPC AC 220548
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1248 AM CDT WED MAY 22 2013
VALID 221200Z - 231200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER GREAT
LAKES...OH VALLEY AND TN VALLEY...
...LOWER GREAT LAKES/OH VALLEY/TN VALLEY...
A POSITIVELY-TILTED UPPER-LEVEL TROUGH WILL MOVE EWD ACROSS THE MID
TO UPPER MS VALLEY TODAY WITH SOUTHWEST FLOW LOCATED AHEAD OF THE
SYSTEM FROM THE TN VALLEY NWD INTO THE LOWER GREAT LAKES. AT THE
SFC...A LOW IS FORECAST TO MOVE ENEWD ACROSS LOWER MI WITH A
CORRIDOR OF MOISTURE WITH SFC DEWPOINTS IN THE LOWER TO MID 60S F
EXTENDING NWD FROM THE TN VALLEY INTO THE UPPER OH VALLEY AND LOWER
GREAT LAKES REGION. MODEL FORECASTS SUGGEST SEVERAL THUNDERSTORM
CLUSTERS WILL BE ONGOING THIS MORNING WITH CONVECTIVE COVERAGE
RAPIDLY INCREASING ACROSS THE WRN EDGE OF MODERATE INSTABILITY THIS
AFTERNOON. MCS DEVELOPMENT WILL BE POSSIBLE ACROSS PARTS OF THE
SLIGHT RISK AREA LATE THIS AFTERNOON WITH SEVERAL CONVECTIVE
CLUSTERS PERSISTING INTO THE EVENING AHEAD OF THE APPROACHING
UPPER-LEVEL TROUGH.
FORECAST SOUNDINGS AT 21Z AT ROCHESTER NY...COLUMBUS OH AND
LEXINGTON KY SHOW SBCAPE VALUES FROM 750 TO 1250 J/KG WITH STEEP
LOW-LEVEL LAPSE RATES AND 35 TO 40 KT OF 0-6 KM SHEAR. THIS
ENVIRONMENT SHOULD BE FAVORABLE FOR DAMAGING WIND GUSTS AS CELLS
INCREASE IN COVERAGE AND INTENSITY LATE THIS AFTERNOON. THE GREATEST
POTENTIAL FOR WIND DAMAGE SHOULD EXIST FROM LAKE ERIE SWD ACROSS
MUCH OF OH ALONG THE AXIS OF A 30 TO 40 KT LOW-LEVEL JET. THE WIND
DAMAGE THREAT COULD BECOME ENHANCED IF A LINEAR MCS CAN ORGANIZE
ACROSS THE UPPER OH VALLEY. A FEW TORNADOES MAY OCCUR WITH ROTATING
CELL ELEMENTS EMBEDDED IN THE MCS. LARGE HAIL COULD ALSO ACCOMPANY
THE MORE INTENSE CELLS BUT THE HAIL THREAT SHOULD REMAIN ISOLATED
MAINLY DUE TO THE RELATIVELY WEAK INSTABILITY.
...CNTRL GULF COAST/LOWER MS VALLEY...
THE SRN EXTENSION OF AN UPPER-LEVEL TROUGH WILL MOVE ACROSS THE
LOWER MS VALLEY TODAY WITH A SFC TROUGH LOCATED ACROSS ERN AR AND
LA. TO THE EAST OF THE SFC TROUGH...DEWPOINTS SHOULD BE IN THE MID
TO UPPER 60S F WITH MODERATE INSTABILITY DEVELOPING BY AFTERNOON.
THE MODELS INITIATE SCATTERED THUNDERSTORMS AHEAD OF THE SFC TROUGH
WHERE FORECAST SOUNDINGS SHOW STEEP LOW-LEVEL LAPSE RATES. THIS
ALONG WITH THE ABUNDANT LOW-LEVEL MOISTURE COULD BE ENOUGH FOR
MARGINALLY SEVERE WET DOWNBURSTS ASSOCIATED WITH THE BETTER
ORGANIZED MULTICELLS.
..BROYLES/MEAD.. 05/22/2013