SPC AC 310050
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0750 PM CDT SUN JUL 30 2006
VALID 310100Z - 311200Z
...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FROM ND INTO THE UPPER
OH VALLEY...
...ND INTO THE UPPER GREAT LAKES...
EVENING WATER VAPOR IMAGERY SHOWS SHORT WAVE TROUGH LIFTING NEWD
THROUGH ERN MT WITH AN ASSOCIATED BELT OF 40-45 KT MID-LEVEL FLOW
SPREADING EWD ACROSS ND INTO THE RED RIVER VALLEY. AIR MASS ALONG
AND S OF SURFACE LOW /NEAR BIS/ AND ATTENDANT SURFACE FRONT
EXTENDING ENEWD INTO NWRN MN HAS ONCE AGAIN BECOME QUITE HOT WITH
TEMPERATURES WARMING TO WELL OVER 100 F OVER CNTRL SD INTO S-CNTRL
ND. STRONG CAPPING APPEARS TO HAVE INHIBITED SURFACE-BASED STORM
DEVELOPMENT THUS FAR EXCEPT OVER FAR NERN MT IN CLOSER PROXIMITY TO
SHORT WAVE TROUGH /REF. MCD 1680 FOR ADDITIONAL SHORT TERM
GUIDANCE/.
FARTHER TO THE E...REMNANT OUTFLOW BOUNDARY FROM SATURDAY
NIGHT-EARLY SUNDAY MCS EXTENDS FROM INTERSECTION WITH SYNOPTIC FRONT
OVER N-CNTRL MN SEWD THROUGH WRN WI INTO N-CNTRL IL. AGAIN
TONIGHT...00Z MPX SOUNDINGS INDICATES THAT THE STRONGEST INSTABILITY
RESIDES ALONG AND JUST TO THE S OF THIS OUTFLOW BOUNDARY OVER
CNTRL/SRN MN WHERE MLCAPES REMAIN AROUND 3000-4000 J/KG.
LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THAT TSTMS /MAINLY
ELEVATED/ WILL INCREASE IN COVERAGE OVERNIGHT N OF FRONTAL ZONE
ACROSS NRN PARTS OF ND/MN...EVENTUALLY EWD INTO LAKE SUPERIOR AND
THE UP OF MI AS LOW-LEVEL WAA/ISENTROPIC UPGLIDE INCREASE N OF FRONT
AND OUTFLOW BOUNDARY. REGIONAL VWPS INDICATE THAT SUFFICIENT
VERTICAL SHEAR WILL EXIST FOR SUPERCELLS CAPABLE OF LARGE HAIL AND
DAMAGING WINDS. GREATEST POTENTIAL FOR A TORNADO WOULD EXIST WITH
ANY NEAR SURFACE BASED SUPERCELLS THAT CAN MATURE NEAR SYNOPTIC
FRONT/OUTFLOW BOUNDARY INTERSECTION OVER NWRN/N-CNTRL MN WHERE
LOW-LEVEL SHEAR IS MAXIMIZED.
POTENTIAL FOR UPSCALE GROWTH INTO AN MCS WILL EXIST LATE TONIGHT
OVER THE ARROWHEAD/LAKE SUPERIOR/UP OF MI WITH ANY ASSOCIATED WIND
THREAT DEVELOPING SEWD INTO NRN WI AND PERHAPS LOWER MI.
...UPPER OH VALLEY...
CLUSTERS OF TSTMS ARE IN PROGRESS OVER E-CNTRL OH/W-CNTRL PA WITHIN
MOIST AND MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF AROUND 2000
J/KG /PER 00Z PIT SOUNDING/. SHORT WAVE TROUGH OVER LOWER MI INTO
LAKE ERIE IS FORECAST TO CONTINUE SEWD TONIGHT...PROVIDING
BACKGROUND FORCING TO SUSTAIN ACTIVITY CONVECTION INTO THE OVERNIGHT
HOURS. IT APPEARS THE GREATEST POTENTIAL FOR ADDITIONAL STRONG TO
SEVERE TSTMS WILL EXIST ALONG THE WRN FLANK OF ONGOING TSTM COMPLEX
WHICH WILL BE MAINTAINED BY LOW-LEVEL WAA ALONG MODEST WLY LLJ.
VERTICAL SHEAR IS NOT PARTICULARLY STRONG...THOUGH THE POTENTIAL
WILL EXIST FOR LOCALLY DAMAGING WINDS...ESPECIALLY IF A COLD POOL
CAN ORGANIZE.
...CNTRL GULF COAST...
LARGE TSTM COMPLEX HAS EVOLVED OVER SERN MS/SWRN AL WITHIN A MOIST
AND MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF 1000-2000 J/KG.
THIS SYSTEM APPEARS TO HAVE ORGANIZED A COLD POOL AND SOME THREAT OF
LOCALLY DAMAGING WINDS WILL CONTINUE FOR THE NEXT COUPLE OF HOURS AS
STORMS MOVE/DEVELOP SWD TOWARD THE COAST.
...AZ...
TSTM CLUSTERS OVER SRN COCONINO AND NAVAJO COUNTIES IN NRN AZ APPEAR
TO HAVE SOME ORGANIZATION AS THEY MOVE GENERALLY SWD AT 10-15 KT.
ENVIRONMENT REMAINS RELATIVELY MOIST AND MODERATELY UNSTABLE...WHICH
SHOULD MAINTAIN STORMS SWD TOWARD THE LOWER DESERTS LATER THIS
EVENING. ARE VWPS AND 00Z SOUNDINGS INDICATE THAT VERTICAL SHEAR IS
QUITE WEAK WHICH SHOULD LIMIT THE OVERALL SEVERE THREAT.
STILL...LOCALLY DAMAGING WINDS WILL REMAIN POSSIBLE WITH MOST
INTENSE STORMS.
..MEAD.. 07/31/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
|
