000
AXPZ20 KNHC 021456
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JUN 02 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1230 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 09N84W TO 08N93W TO 11N101W TO 
LOW PRES NEAR 08N117W 1011 MB TO 06N121W. THE ITCZ EXTENDS FROM 
06N121W TO BEYOND 04N140W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION LIES N OF 02N TO THE MONSOON TROUGH E OF 85W. 
SCATTERED MODERATE CONVECTION WITHIN 120 NM E SEMICIRCLE AND 60 
NM W SEMICIRCLE OF LOW PRES.

...DISCUSSION...

THE AMPLIFIED UPPER PATTERN IN THE PACIFIC WILL PERSIST FOR THE 
NEXT FEW DAYS. THIS PATTERN IS MARKED BY AN ANTICYCLONE CENTERED 
OVER EASTERN HONDURAS/NICARAGUA...AN UPPER TROUGH ALONG 104W N 
OF 05N TO THE RIO GRANDE VALLEY...AN ANTICYCLONE CENTERED NEAR 
14N123W...AND A CUT OFF LOW JUST E OF THE HAWAIIAN ISLANDS 
CENTERED NEAR 21N149W. UPPER DIFFLUENCE ON THE SOUTH SIDE OF THE 
ANTICYCLONE OVER CENTRAL AMERICA IS ENHANCING THE SCATTERED 
MODERATE WITH ISOLATED STRONG CONVECTION N OF 02N TO THE MONSOON 
TROUGH E OF 85W INCLUDING THE GULF OF PANAMA. OTHERWISE...DEEP 
CONVECTION IS LIMITED TO NEAR THE LOW PRES SYSTEM EMBEDDED IN 
THE MONSOON TROUGH NEAR 08N117W. THIS CONVECTION IS DESCRIBED IN 
THE SECTION ABOVE.

AT THE SURFACE...THE SUBTROPICAL HIGH HAS RETREATED WELL W OF 
THE AREA BUT EXTENDS A WEAK RIDGE ALONG 30N TO 130W AND THEN 
SOUTHEASTWARD TO 20N120W. FRESH N WINDS LIE E OF THE RIDGE AXIS 
OVER NE WATERS WHERE THE PRES GRADIENT IS TIGHTEST BETWEEN THE 
RIDGE AND TROUGHING OVER THE SOUTHWESTERN U.S. AND NW MEXICO. 
THIS SAME PRES GRADIENT IS ALSO ENHANCING THE WINDS IN THE 
NORTHERN GULF OF CALIFORNIA. FRESH S TO SW WINDS ARE NOTED THERE 
N OF 29N. WINDS ON EITHER SIDE OF BAJA CALIFORNIA NORTE WILL 
DIMINISH TO A MODERATE TO GENTLE BREEZE OVER THE NEXT 24 HOURS 
AS A COLD FRONT PUSHES INTO NW WATERS...WEAKENING THE 
SUBTROPICAL RIDGE. THIS WILL ALSO CAUSE THE SMALL AREA OF NE 
TRADE WINDS SEEN BY THE 0302 UTC WINDSAT AND 0642 UTC ASCAT 
PASSES FROM 18N TO 25N W OF 137W TO DIMINISH. THE COLD FRONT 
WILL USHER FRESH N TO NE WINDS SUN AFTERNOON INTO NW WATERS. 

CROSS-EQUATORIAL SW SWELL IS PASSING THROUGH S CENTRAL WATERS AT 
THE MOMENT. SEAS TO 8 FT ASSOCIATED WITH THIS SWELL ARE MOVING 
THROUGH THE AREA OCCUPIED BY THE 1011 MB LOW PRES SYSTEM 
EMBEDDED IN THE MONSOON TROUGH. THE 0456 UTC ASCAT PASS SHOWS 
WINDS TO 20 KT IN THE SE QUADRANT OF THE LOW. THESE WINDS ARE 
EXPECTED TO GRADUALLY DIMINISH OVER THE NEXT 24 HOURS WHILE THE 
SWELL CONTINUES TO PROPAGATE NORTHEASTWARD...EVENTUALLY MERGING 
WITH THE MIXED NW AND N SWELL FOUND OFF BAJA CALIFORNIA. THE 
LEADING EDGE OF THE SWELL HAS PERIODS AS LONG AS 18 SECONDS AND 
IS EXPECTED TO REACH THE CENTRAL AMERICAN AND MEXICAN COAST 
OVERNIGHT TONIGHT.

$$
SCHAUER