[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 201418
SWOMCD
SPC MCD 201418 
CAZ000-201615-

MESOSCALE DISCUSSION 2345
NWS STORM PREDICTION CENTER NORMAN OK
0918 AM CDT WED OCT 20 2004

AREAS AFFECTED...COASTAL SRN CA AND ADJACENT WINDWARD MOUNTAIN
SLOPES.

CONCERNING...HEAVY RAINFALL...SEVERE CONVECTIVE POTENTIAL 

VALID 201418Z - 201615Z

LINE OF STRONGLY FORCED CONVECTION -- WITH NO CG LIGHTNING EVIDENT
SO FAR -- IS EXPECTED TO CONTINUE MOVING EWD ACROSS COASTAL SECTIONS
ORANGE/SAN DIEGO COUNTIES THROUGH APPROXIMATELY 16Z.  PRIMARY HAZARD
WILL BE HEAVY RAINFALL WITH RATES IN INITIAL BAND OF 1-2
INCHES/HOUR.  IN WINDWARD SLOPES OF SANTA ANA...LAGUNA AND ERN SAN
BERNARDINO RANGES...RATES WILL LOCALLY EXCEED 2 INCHES/HOUR IN
INITIAL BAND.  INTERMITTENT BURSTS OF 1-2 INCH/HOUR RATES POSSIBLE
THEREAFTER...ASSOCIATED WITH CONVECTIVE ELEMENTS WITHIN TRAILING
PRECIP REGION. SOUNDINGS SHOW VERY RICH LOW LEVEL MOISTURE WITH
1-1.25 INCH PW AND NEAR SATURATION THROUGH LOWEST 1-2 KM MSL. 
STRONG UPSLOPE FLOW COMPONENT EXPECTED OVER NEAR-COASTAL MOUNTAINS
GIVEN SLY AMBIENT WINDS IN BOUNDARY LAYER...VEERING TO SWLY.

ALSO...PATTERN WITH STRONG SHEAR PROFILES AND MARGINAL INSTABILITY 
FAVORS ISOLATED DAMAGING GUSTS AND PERHAPS A BRIEF TORNADO. 
MODIFIED NKX RAOB AND RUC SOUNDINGS INDICATE UP TO 300 J/KG
SBCAPE...GIVEN OBSERVED DEW POINTS LOW-MID 60S F NEAR SHORE.  MOST
CAPE IS BELOW FREEZING LEVEL.  OBSERVED/RUC SOUNDINGS AND VWP ALSO
INDICATE SRH 100-150 J/KG IN 0-1 KM LAYER.  BRIEF/SMALL TORNADO
CANNOT BE RULED OUT BUT THREAT APPEARS TOO LOCALIZED/SHORT-LIVED FOR
WW.

..EDWARDS.. 10/20/2004

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

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

32581678 33131698 33431711 33501725 33431735 33491750
33681765 33911768 34161768 34341758 34321714 34201680
33361655 32611630 

32521711 32721726 33061735 33321757 33491779 33631769
33731764 33631745 33411708 33151687 32721681 32611691 

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