000
AXPZ20 KNHC 031605
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JUL 03 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1430 UTC.

...ITCZ...
AXIS ALONG 0N85W TO 10N92W TO 07N98W TO 11N116W TO 07N129W TO 
08N140W.  SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 120 
NM OF AXIS E OF 95W...AND WITHIN 60 NM N AND 150 NM S OF AXIS W 
OF 95W.

...DISCUSSION...
COMPLEX BLOCKING UPPER PATTERN TO THE N AND NW OF FORECAST AREA 
WITH QUASI STATIONARY UPPER LEVEL ANTICYCLONE NEAR 23N125W AND 
RIDGE EXTENDING NE TO N PORTIONS OF MEXICO...AND SW TO 17N142W. 
MID TO UPPER LEVEL CONVERGENCE YIELDING SUBSIDENCE GENERALLY 
PREVAILS WITHIN AND TO THE NW OF THE RIDGE AXIS. THE NE 
EXTENSION OF THE RIDGE IS ANCHORED ON A SECOND UPPER HIGH OVER 
MEXICO NEAR 27.5N102.5W...WHICH IS MAINTAINING UPPER DIVERGENCE 
THAT IS HELPING TO SUSTAIN DEEP CONVECTION ACROSS THE NE STATES 
OF MEXICO...ASSOCIATED WITH THE REMNANTS OF ALEX. MID TO UPPER 
LEVEL TROUGHING EXTENDS FROM THE N CENTRAL GULF OF MEXICO S-SW 
TO THE YUCATAN PENINSULA...AND HAS BECOME INVOLVED WITH AN 
ELONGATED VORTEX EXTENDING FROM ALONG THE GUATEMALA-MEXICO 
BORDER S-SW TO JUST N OF THE ITCZ. NE TO ELY FLOW OCCURRING 
BETWEEN THIS TROUGHING AND THE UPPER RIDGE IS CREATING A BROAD 
ZONE OF UPPER DIFFLUENCE N OF THE ITCZ W OF 95W. ELY UPPER LEVEL 
WINDS UP TO 55 KT ARE DEPICTED IN STLT DRIFT WINDS...WITH THIS 
BROAD JET FORECAST TO SHIFT W OF 125 DURING THE NEXT 24 HOURS. 

AT THE SURFACE...BROAD 1034 MB HIGH PRES WELL NW OF BASIN HAS 
RIDGE EXTEND SE TO 19N121W. A BROAD MONSOONAL CIRCULATION 
PERSISTS SE OF THIS RIDGE...LOCATED S OF 20N AND BETWEEN 94W AND 
112W...AND CONTINUES OT ADVECT ABUNDANT TROPICAL MOISTURE NE 
INTO MEXICO. STRONG NELY FLOW ALOFT ACROSS MEXICO S OF 22N WILL 
LIMIT SUSTAINED DEEP CONVECTION THERE THROUGH THIS AFTERNOON 
BEFORE UPPER WINDS DIMINISH AND CONVECTIVE POTENTIAL IMPROVES 
OVERNIGHT INTO MONDAY. WITH THIS MONSOONAL REGIME IN 
PLACE...WEAK LLVL CYCLONIC CIRCULATIONS WERE NOTED ALONG THE 
ITCZ AT 102W AND 92W...WHERE ACTIVE CONVECTION WAS OCCURRING. 
LITTLE CHANGE IN THIS OVERALL LOLL PATTERN IS EXPECTED IN THE 
NEXT 24 HOURS.

A TIGHT GRADIENT BETWEEN THE BROAD SURFACE RIDGE AND 
CLIMATOLOGICAL TROUGHING ALONG THE SIERRA MADRES IS PRODUCING 
FRESH BREEZE NLY E OF 125W...AND SLY WINDS AROUND 20 KT WITHIN 
THE GULF OF CALIFORNIA N OF 25N. WINDS EXPECTED TO DIMINISH ON 
BOTH SIDES OF BAJA CALIFORNIA WITHIN 24 HRS ALTHOUGH NW SWELL 
8-10 FT SHOULD LINGER THROUGH LATE SUN.  A VERY LONG PERIOD S-SW 
SWELL TRAIN MOVING NORTHWARD FROM THE SRN HEMI IS EXPECTED TO 
MERGE WITH ESTABLISHED NLY SWELLS N OF 23N PRODUCING HIGH AND 
CONFUSED SEAS. THIS SRN HEMI SWELL AT 16 SECONDS AND GREATER HAS 
BEGUN TO REACH THE PACIFIC COASTS OF CENTRAL AMERICA THIS 
MORNING...AND WILL INCREASE OVER THE NEXT 24-36 HOURS... 
PRODUCING LARGE BREAKING WAVES AND DANGEROUS SURF CONDITIONS 
ALONG EXPOSED SHOALS...REEFS AND BEACHES. 

$$
STRIPLING