SWODY1
SPC AC 311250
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0750 AM CDT FRI AUG 31 2007
VALID 311300Z - 011200Z
..THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY
TONIGHT FROM CENTRAL/NE ORE INTO SE WA AND THE ID PANHANDLE...
..INTERIOR NW/NRN ROCKIES AREA THROUGH TONIGHT...
A SERIES OF LOW AMPLITUDE TROUGHS AND THE ACCOMPANYING MONSOONAL
MOISTURE PLUME WILL EJECT NEWD OVER THE NRN GREAT BASIN AND NRN
ROCKIES...IN ADVANCE OF A STRONGER MID LEVEL TROUGH NEAR 130 W THAT
WILL MOVE INLAND OVER WA/ORE/ID BY LATE EVENING. ASCENT DOWNSTREAM
FROM THE MID LEVEL TROUGH AND IN CONJUNCTION WITH THE LOW-LEVEL
BAROCLINIC ZONE WILL CONTRIBUTE TO A FAVORABLE ENVIRONMENT FOR
THUNDERSTORM DEVELOPMENT...ESPECIALLY THIS AFTERNOON INTO EARLY
TONIGHT.
RESIDUAL LOW-MID LEVEL MOISTURE ALONG THE W EDGE OF THE MONSOONAL
PLUME...AND LOW-LEVEL MOISTENING FROM RAINFALL THROUGH THIS
MORNING...WILL COMBINE WITH DAYTIME HEATING/STEEP LOW-LEVEL LAPSE
RATES TO SUPPORT MLCAPE VALUES OF 500-750 J/KG. POTENTIAL LIMITING
FACTORS FOR THE DEGREE OF INSTABILITY WILL BE RATHER MODEST MID
LEVEL LAPSE RATES AND LINGERING CLOUD COVER. STILL...SURFACE
HEATING SHOULD BE SUFFICIENT TO GENERATE INVERTED-V PROFILES IN THE
LOW LEVELS AND PROMOTE STRONG DOWNDRAFT POTENTIAL...WHILE INCREASING
DEEP LAYER VERTICAL SHEAR WILL SUPPORT ORGANIZED STORM STRUCTURES.
THEREFORE...WILL MAINTAIN A LOW END SLIGHT RISK FOR THE DAMAGING
WIND POTENTIAL LATER THIS AFTERNOON INTO EARLY THIS EVENING.
..ELSEWHERE...
A WEAK NELY MID LEVEL FLOW REGIME OVER SE AZ MAY ALLOW DIURNAL
CONVECTION OVER THE SE MOUNTAINS AND RIM TO PROPAGATE SWWD INTO THE
LOWER DESERTS THIS EVENING. OTHER THUNDERSTORMS CAN BE EXPECTED
THIS AFTERNOON/EVENING OVER THE INTERIOR MOUNTAINS OF SRN CA NWD
ALONG THE SIERRA NEVADA. THE STRONGEST STORMS MAY PRODUCE ISOLATED
STRONG DOWNBURST WINDS DURING THE AFTERNOON.
FARTHER E...A DIFFUSE LOW-LEVEL FRONTAL ZONE AND ASSOCIATED WEAK MID
LEVEL TROUGHING WILL FOCUS SCATTERED THUNDERSTORM DEVELOPMENT FROM
TX EWD TO THE SE ATLANTIC STATES TODAY INTO TONIGHT. THE STRONGER
INSTABILITY AND MORE WIDESPREAD THUNDERSTORM COVERAGE WILL OCCUR
DURING THE AFTERNOON/EVENING HOURS...THOUGH MOIST PROFILES WILL
SUPPORT SOME CONVECTION THROUGH TONIGHT.
.THOMPSON/CROSBIE.. 08/31/2007
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.
No comments:
Post a Comment