SWODY2
SPC AC 011724
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1224 PM CDT TUE JUL 01 2008
VALID 021200Z - 031200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH
PLAINS...CNTRL PLAINS...UPPER MIDWEST AND GREAT LAKES...
...UPPER MIDWEST/GREAT LAKES...
AN UPPER-LEVEL TROUGH OVER SRN CANADA TONIGHT WILL MOVE ESEWD ACROSS
THE GREAT LAKES WEDNESDAY. AT THE SFC...A SHARPLY DEFINED COLD FRONT
IS FORECAST TO ADVANCE SEWD INTO THE REGION WEDNESDAY AND SHOULD BE
POSITIONED FROM LOWER MI SWWD ACROSS NRN IL INTO NRN MO BY
AFTERNOON. LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY AND LARGE-SCALE
ASCENT AHEAD OF THE APPROACHING UPPER-LEVEL TROUGH SHOULD ALLOW
SCATTERED TO NUMEROUS THUNDERSTORMS TO DEVELOP. BY EARLY
EVENING...SOME MODELS FORECAST A LINEAR MCS TO BE ONGOING ALONG THE
BOUNDARY.
CONCERNING THE SEVERE POTENTIAL...A 50 TO 60 KT MID-LEVEL JET ON THE
SRN SIDE OF THE UPPER-LEVEL TROUGH WILL HELP TO CREATE MODERATE
VERTICAL SHEAR PROFILES ALONG THE BOUNDARY. FORECAST SOUNDINGS IN
LOWER MI...NRN IND AND NRN IL WEDNESDAY AFTERNOON INCREASE 0-6 KM
SHEAR VALUES INTO THE 35 TO 45 KT RANGE SUGGESTING SHEAR WILL BE
SUFFICIENT FOR SEVERE STORMS. HOWEVER...STORM MODE REMAINS
QUESTIONABLE ATTM. THE MOST LIKELY SCENARIO WOULD BE THE DEVELOPMENT
OF A SQUALL-LINE WITH WIND DAMAGE POTENTIAL DUE TO UNDIRECTIONAL
WIND PROFILES. EARLY IN THE DEVELOPMENT OF THE LINE...A FEW
SUPERCELLS WITH LARGE HAIL WILL ALSO BE POSSIBLE. THE WIND DAMAGE
THREAT COULD BECOME ENHANCED AS A WELL-FOCUSED LOW-LEVEL JET
STRENGTHENS AHEAD OF THE BOUNDARY DURING THE EARLY EVENING.
...HIGH PLAINS/CNTRL PLAINS...
AN UPPER-LEVEL RIDGE WILL BE IN PLACE ACROSS THE FOUR CORNERS REGION
WEDNESDAY WITH NORTHWEST FLOW REMAINING ACROSS THE HIGH PLAINS AND
CNTRL PLAINS. AT THE SFC...A COLD FRONT IS FORECAST TO MOVE SWD
ACROSS SRN NEB INTO CNTRL KS EXTENDING WWD INTO ERN CO. SFC HEATING
SHOULD ALLOW SCATTERED THUNDERSTORMS TO DEVELOP ALONG THE BOUNDARY
AND IN THE HIGHER TERRAIN OF ERN CO AND WY. SEVERAL STORM CLUSTERS
SHOULD PERSIST INTO THE EVENING.
CONCERNING THE SEVERE POTENTIAL...FORECAST SOUNDINGS ACROSS THE
REGION WEDNESDAY SHOW SUBSTANTIAL DIRECTIONAL SHEAR DUE TO BACKED
SFC WINDS BEHIND THE FRONT AND NWLY FLOW ALOFT. THIS IS ESPECIALLY
TRUE OVER THE CNTRL PLAINS SUGGESTING A FEW SUPERCELLS WITH LARGE
HAIL WILL BE POSSIBLE. HOWEVER...MULTICELL LINE SEGMENTS WITH WIND
DAMAGE POTENTIAL WILL ALSO BE POSSIBLE. FURTHER NORTHWEST ACROSS
NERN CO AND SERN WY...LARGER TEMP-DEWPOINT SPREADS AND SLIGHTLY
STRONGER MID-LEVEL FLOW MAY RESULT IN PREDOMINANTLY HIGH-BASED
SUPERCELLS WITH LARGE HAIL. THE SEVERE THREAT SHOULD CONTINUE INTO
THE EVENING WITH ANY STORM CLUSTER THAT CAN ORGANIZE AND PERSIST.
...NM...
AN UPPER-LEVEL RIDGE OVER THE FOUR CORNERS REGION WILL REMAIN IN
PLACE THROUGH WEDNESDAY. ON THE ERN SIDE OF THE RIDGE...SCATTERED TO
NUMEROUS THUNDERSTORMS WILL DEVELOP AS SFC TEMPS WARM BY WEDNESDAY
AFTERNOON. ALTHOUGH MID-LEVEL FLOW IS FORECAST TO BE RELATIVELY
WEAK...DIRECTIONAL SHEAR MAY BE ENOUGH FOR A FEW MARGINALLY SEVERE
STORMS. INSTABILITY SHOULD BE GREAT ENOUGH COMBINED WITH STEEP LAPSE
RATES ON FORECAST SOUNDINGS FOR HAIL AND OR STRONG WIND GUSTS WITH
THE MORE INTENSE MULTICELLS.
...FLORIDA...
A MOIST BOUNDARY LAYER WILL REMAIN IN PLACE ACROSS FLORIDA WEDNESDAY
AS MODERATE INSTABILITY DEVELOPS BY AFTERNOON. THUNDERSTORMS SHOULD
INITIATE ALONG OUTFLOW BOUNDARIES AND MOVE SLOWLY ACROSS THE
PENINSULA. FORECAST SOUNDINGS ACROSS FLORIDA WEDNESDAY AFTERNOON
SHOW ENOUGH INSTABILITY AND STEEP ENOUGH LOW-LEVEL LAPSE RATES FOR A
MARGINAL WIND DAMAGE THREAT NEAR PEAK HEATING.
...ORE/WA...
AN UPPER-LEVEL LOW AND ASSOCIATED TROUGH WILL APPROACH THE PACIFIC
NORTHWEST WITH SLY TO SSWLY FLOW ALOFT IN PLACE. AT THE
SFC...ONSHORE FLOW SHOULD EXIST ACROSS THE PACIFIC NORTHWEST WITH AN
AXIS OF MOISTURE LOCATED ACROSS WRN ORE AND WRN WA. MODERATE
INSTABILITY IS FORECAST ALONG THE MOIST AXIS BY EARLY AFTERNOON WITH
THE MODELS DEVELOPING SCATTERED THUNDERSTORMS. FORECAST SOUNDINGS
ALONG THE MOIST AXIS SUGGEST 0-6 KM SHEAR VALUES WILL RANGE FROM 30
TO 40 KT WHICH MAY RESULT IN AN ISOLATED SUPERCELL THREAT. STEEP
LAPSE RATES SHOULD SUPPORT A THREAT FOR HAIL AND STRONG WIND GUSTS.
..BROYLES.. 07/01/2008
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