000
AXPZ20 KNHC 200329
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE JUL 20 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0300 UTC.

...ITCZ...
AXIS FROM 14N90W TO 08N105W TO 15N123W TO 07N140W.  SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM S OF AXIS 
THROUGHOUT.

...DISCUSSION...
VERY COMPLEX TRANSITIONING UPPER LEVEL PATTERN WITH AN ARRAY OF 
DOUBLE BARREL ANTICYCLONIC GYRES NEAR 142W...TRIPLE CYCLONIC 
VORTICES DOWNSTREAM AND A COMBINED DOUBLE BARREL OF ONE OF EACH 
FURTHER EAST SPANNING ACROSS E PAC N OF 13N.  A MORE FAMILIAR  
E-NE WIND FLOW ALOFT S OF 13N WITH ABUNDANT MOISTURE ADVECTING 
FROM CARIBBEAN SEA UNTO E PAC FEEDING SCATTERED MODERATE 
ISOLATED STRONG DEEP CONVECTION ALONG ENTIRE LENGTH OF ITCZ.  

MODERATELY STRONG EASTERLY SHEAR CURTAILS CONVECTION AND NO 
SURFACE SYSTEMS ACTIVE TO PROMPT TROPICAL ORGANIZATION.  AIR 
MASS REMAINS FAIRLY DRY AND STABLE N OF 15N W OF 110W.  MODEL 
GUIDANCE CHANGES OVERALL UPPER PATTERN VERY LITTLE WITH CUT OFF 
CYCLONIC VORTEX OVER MANZANILLO MEXICO EMBEDDED IN BROAD 
ANTICYCLONE WHICH COVERS FLOW N OF 10N E OF 120W.  SHARP TROUGH 
ALONG 130W WITH ANOTHER BROAD ANTICYCLONIC GYRE W OF 135W.

AT THE SURFACE...
HIGH PRES CENTER 1037 MB WELL NW OF BASIN HAS RIDGE EXTEND TO 
19N117W WITH VERY DRY AIR MASS UNDER IT.  WEAK OPEN TROUGH... 
REMNANTS OF OLD AND TIRED T.D. SIX-E...STILL LINGER ALONG 128W 
FROM 15N-20N...WITH THE ONLY MOISTURE AVAILABLE UNDER RIDGE.   
NO CHANCES OF REGENERATION SEEN FOR SYSTEM.  

STRONG GALE FORCE WINDS ALONG NORTHERN CALIFORNIA COAST FORCE 
8-10 FT N SWELL INTO E PAC N OF 25N FROM 118W TO 135W WITHIN 6 
HRS AND EXTENDING BEYOND FORECAST PERIOD. 

LONG PERIOD SWELLS UP TO 11 FT ENCROACH INTO BASIN ACROSS 
EQUATOR SPREADING AS FAR AS 25N THROUGH FORECAST PERIOD. 

$$
WALLY BARNES