[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 191253
SWOMCD
SPC MCD 191253 
CAZ000-191500-

MESOSCALE DISCUSSION 0169
NWS STORM PREDICTION CENTER NORMAN OK
0653 AM CST SAT FEB 19 2005

AREAS AFFECTED...L.A. BASIN AREA OF SRN CA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 191253Z - 191500Z

ENVIRONMENT IS BECOMING MORE FAVORABLE FOR SEVERE FROM CONVECTION
THAT CONTINUES TO FORM INVOF ERN CHANNEL ISLANDS AND MOVE ASHORE
COASTAL LOS ANGELES COUNTY.  EXPECT THREAT TO SHIFT GRADUALLY EWD
ACROSS ORANGE...SERN L.A. AND EXTREME NWRN SAN DIEGO COUNTIES
THROUGH NEXT FEW HOURS.  OCCASIONAL DAMAGING WIND AND MARGINALLY
SEVERE HAIL REMAIN POSSIBLE IN ASSOCIATION WITH MINI-SUPERCELLS AND
BOWS...AND BRIEF TORNADO CANNOT BE RULED OUT.

MOISTURE CHANNEL IMAGERY INDICATES SMALL MID/UPPER LEVEL VORTICITY
CENTER LOCATED OVER PACIFIC APPROXIMATELY 100 SW LAX AS OF 1230Z. 
AS THIS FEATURE APCHS...LOW-MIDLEVEL GRADIENT FLOW IS STRENGTHENING
ACROSS REGION PER VWP TRENDS...INCREASING DEEP-LAYER SHEAR. 
BOUNDARY LAYER RESPONSE HAS ENLARGED 0-1 AND 0-3 KM HODOGRAPHS ALSO.
 EXPECT 75-125 J/KG SRH THROUGH 0-1 KM AGL LAYER TO BE MAINTAINED
UNTIL VORT LOBE MOVES ASHORE AT APPROXIMATELY 15Z.  LAPSE RATES
SHOULD STEEPEN SLIGHTLY IN MIDLEVELS AS WELL...YIELDING MUCAPES UP
TO 400 J/KG...BASED ON MODIFIED RUC SOUNDINGS. STORM SCALE ROTATION
ALREADY APPARENT WITH CELLS NEAR ERN CATALINA AND SAN CLEMENTE
ISLANDS MAY INTENSIFY BECAUSE OF FRICTIONAL/CONVERGENCE EFFECTS AS
THEY MOVE INLAND...AND ADDITIONAL CONVECTION DEVELOPING FARTHER S
MAY FOLLOW SIMILAR MORPHOLOGY AS WELL AS ENTIRE REGIME SHIFTS EWD.

..EDWARDS.. 02/19/2005

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...SGX...LOX...

32581871 33521841 34061812 34131779 34061746 33501739
33181747 

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