000
AXPZ20 KNHC 041518
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JUN 04 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 AXIS WAS ANALYZED FROM 08N78W TO 08N82W TO 
10N95W. ITCZ AXIS WAS ANALYZED FROM 10N95W TO LOW PRES NEAR 
09N119W TO 05N127W TO 05N135W TO 02N140W. SCATTERED MODERATE 
CONVECTION LIES WITHIN 270 NM S OF THE AXIS BETWEEN 78W AND 82W. 
SCATTERED MODERATE CONVECTION ALSO LIES BETWEEN 75 NM AND 210 NM 
N OF THE AXIS BETWEEN 87W AND 103W EXCEPT WITHIN 120 NM N OF THE 
AXIS BETWEEN 92W AND 95W. THE LOW PRES SYSTEM NEAR 09N119W HAS 
SCATTERED MODERATE CONVECTION BETWEEN 60 NM AND 240 NM OF ITS 
CENTER.

...DISCUSSION...

THE AMPLIFIED UPPER PATTERN IN THE PACIFIC WILL CONTINUE TO 
DAMPEN OVER THE NEXT FEW DAYS. THIS PATTERN IS CURRENTLY MARKED 
BY AN ANTICYCLONE CENTERED OVER HONDURAS...AN UPPER TROUGH ALONG 
104W N OF 09N...A RIDGE ALONG 117W N OF 10N...AND A CUT OFF LOW 
JUST E OF THE HAWAIIAN ISLANDS CENTERED NEAR 20N151W. THE UPPER 
RIDGING OVER CENTRAL WATERS IS BEING WEAKENED BY A PROGRESSIVE 
NORTHERN STREAM TROUGH ENCROACHING ON ITS NORTHERN SIDE ON ITS 
WAY INTO THE U.S. WEST COAST TONIGHT. ENERGY IN THE SOUTHERN 
EDGE OF THIS TROUGH WILL SLOWLY SLIP SOUTH OF 30N ON TUE AND 
DISSIPATE THE RIDGE. FARTHER E...A 30-40 KT SOUTHWESTERLY UPPER 
JET OVER SOUTHERN MEXICO IS SHEARING CONVECTION N OF THE ITCZ 
BETWEEN 92W AND 110W. THIS CONVECTION IS DESCRIBED IN THE 
SECTION ABOVE.  

AT THE SURFACE...A COLD FRONT ASSOCIATED WITH THE AFOREMENTIONED 
NORTHERN STREAM TROUGH ALOFT HAS MOVED INTO NW WATERS FROM 
30N130W TO 27N140W. THE COLD FRONT IS USHERING FRESH N TO NE 
WINDS INTO THE FORECAST AREA ACCORDING TO THE 0602 UTC ASCAT 
PASS. THE SUBTROPICAL HIGH CURRENTLY RESIDES WELL NW OF THIS 
FRONT NEAR 36N150W. THE HIGH WILL SHIFT SOUTHEASTWARD BEHIND THE 
COLD FRONT. THE PRES GRADIENT WILL BUILD OVER N WATERS BETWEEN 
THE SUBTROPICAL RIDGE AND TROUGHING OVER THE WESTERN U.S. AND NW 
MEXICO...WITH FRESH TO STRONG NW TO N WINDS EXPECTED OFF BAJA 
CALIFORNIA BY TUE AND SEAS BUILDING TO 12 FT BY WED MORNING IN 
NW SWELL. THE PRES GRADIENT WILL ALSO INCREASE N OF THE ITCZ 
OVER W WATERS AND ALLOW FRESH NE TRADE WINDS TO RETURN BY TUE. 

A 1009 MB LOW PRES SYSTEM IS EMBEDDED IN THE ITCZ NEAR 09N119W. 
THE 0556 UTC ASCAT PASS SHOWS 20 KT WINDS RESIDE WITHIN 150 NM 
NW OF THE LOW CENTER AND THE 0106 UTC JASON2 AND 0154 JASON1 
PASSES SHOW SEAS TO 8 FT NEAR THE LOW. THIS LOW IS FORECAST TO 
CONTINUE WESTWARD AROUND 10 KT OVER THE NEXT FEW DAYS. AS THE 
SUBTROPICAL RIDGE BUILDS TO ITS N...THE AREA OF FRESH WINDS IN 
THE N SEMICIRCLE OF THE LOW IS EXPECTED TO EXPAND.

$$
SCHAUER