SWODY1
SPC AC 010526
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1226 AM CDT TUE JUL 01 2008
VALID 011200Z - 021200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN ROCKIES...
...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE NRN PLAINS
INTO UPPER MS VALLEY...
...SYNOPSIS...
LARGE-SCALE RIDGE IN PLACE OVER THE ROCKIES WILL DEAMPLIFY THIS
PERIOD AS WELL-DEFINED SHORT WAVE TROUGH CURRENTLY OVER NRN CA/WRN
NV LIFTS NEWD INTO THE NRN ROCKIES. MEANWHILE...A SIGNIFICANT SHORT
WAVE TROUGH WILL TRANSLATES SEWD THROUGH SASKATCHEWAN AND MANITOBA
AND EVENTUALLY INTO WRN ONTARIO AND THE UPPER GREAT LAKES TONIGHT.
IN THE E...UPPER TROUGH WILL CONTINUE EWD TO ALONG THE ATLANTIC
COAST.
AT THE SURFACE...COLD FRONT ATTENDANT TO CNTRL CANADA SHORT WAVE
TROUGH WILL PUSH SWD/SEWD THROUGH THE NRN PLAINS AND UPPER MS
VALLEY. IN THE E...A SLOW-MOVING FRONTAL BOUNDARY WILL PUSH THROUGH
NEW ENGLAND AND THE MID ATLANTIC COAST TODAY INTO TONIGHT.
...NRN ROCKIES...
RELATIVELY STEEP MIDLEVEL LAPSE RATES OF 7-7.5 C/KM COUPLED WITH
MODEST BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE 40S TO LOCALLY
LOWER TO MID 50S/ WILL CONTRIBUTE TO THE DEVELOPMENT OF A MODERATELY
UNSTABLE AIR MASS TODAY WITH MLCAPES APPROACHING 1000-1500 J/KG.
INCREASED LARGE-SCALE FORCING FOR ASCENT ASSOCIATED WITH APPROACHING
SHORT WAVE TROUGH IN CONCERT WITH TERRAIN INFLUENCES SHOULD SUPPORT
THE DEVELOPMENT OF SCATTERED TSTMS THIS AFTERNOON INTO EVENING.
WHILE VERTICAL SHEAR IS NOT FORECAST TO BE PARTICULARLY STRONG...THE
PRESENCE OF THE STEEP LAPSE RATES...RELATIVELY COOL THERMODYNAMIC
PROFILES AND DEEPLY-MIXED BOUNDARY LAYER CONDITIONS SUGGEST THE
POTENTIAL FOR LOCALLY DAMAGING WIND GUSTS AND HAIL WITH THE MOST
INTENSE STORMS. AN INCREASED WIND THREAT WILL EXIST IF STORMS CAN
GROW UPSCALE INTO A LARGER-SCALE SYSTEM WHICH COULD ORGANIZE A COLD
POOL.
...NRN PLAINS INTO UPPER GREAT LAKES...
LATEST MODEL GUIDANCE SUGGESTS THAT AIR MASS WILL REMAIN CAPPED MUCH
OF TODAY WITH BOUNDARY LAYER DEWPOINTS IN THE 50S TO LOWER 60S AND
STEEP LAPSE RATES CONTRIBUTING TO MLCAPES OF 1000-2000 J/KG.
MESOSCALE ASCENT ALONG COLD FRONT IN CONJUNCTION WITH THE INCREASING
INFLUENCE OF STRONG SHORT WAVE TROUGH DIGGING SEWD THROUGH THE
CANADIAN PRAIRIES SHOULD EVENTUALLY SUPPORT TSTM DEVELOPMENT BY LATE
AFTERNOON OR EVENING ALONG OR IN THE IMMEDIATE WAKE OF BOUNDARY.
THE PRESENCE OF THE MODERATE INSTABILITY AND 30-40 KT OF WNWLY DEEP
LAYER SPEED SHEAR SHOULD BE SUPPORTIVE OF ORGANIZED STORMS INCLUDING
BOWING AND/OR SUPERCELL STRUCTURES WITH THE POTENTIAL FOR DAMAGING
WIND GUSTS AND LARGE HAIL.
...FL...
A VERY MOIST AIR MASS WILL RESULT IN THE DEVELOPMENT OF MODERATE
INSTABILITY TODAY WITH MLCAPES OF 1000-2000 J/KG. EXCEPT FOR THE
UPPER TROPOSPHERIC FLOW ACROSS THE NRN PART OF THE STATE...WIND
FIELDS WILL REMAIN RATHER WEAK. DIURNAL TSTMS WILL BECOME FOCUSED
ALONG STRENGTHENING SEA BREEZE CIRCULATIONS WITH THE MORE INTENSE
STORMS CAPABLE OF STRONG WET MICROBURSTS.
...DE RIVER VALLEY INTO NEW ENGLAND...
THE EWD PROGRESSION OF MIDLEVEL THERMAL TROUGH COUPLED WITH BOUNDARY
LAYER DEWPOINTS IN THE 60S WILL CONTRIBUTE TO POCKETS OF MODERATE
INSTABILITY THIS AFTERNOON WITH MLCAPES APPROACHING 1000 J/KG.
HIGH-LEVEL WIND FIELDS WILL REMAIN QUITE STRONG OWING TO PROXIMITY
OF UPPER JET STREAK PROPAGATING NEWD ALONG THE ATLANTIC COAST.
BUT...LOWER TO MID-TROPOSPHERIC FLOW WILL REMAIN SOMEWHAT MARGINAL
FOR STORM ORGANIZATION. NONETHELESS...THE POTENTIAL WILL EXIST FOR
ISOLATED STRONG TO MARGINALLY SEVERE STORMS THIS AFTERNOON ALONG
SURFACE BOUNDARY WITH THE PRIMARY HAZARDS BEING STRONG WIND GUSTS
AND PERHAPS SOME HAIL.
..MEAD/GRAMS.. 07/01/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment