000
AXPZ20 KNHC 060241
TWDEP 

TROPICAL WEATHER DISCUSSION                                   
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC FRI APR 05 2013

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0145 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 07N77W TO 07N83W TO 
04N91W TO 05N98W. THE ITCZ AXIS WAS ANALYZED FROM 05N98W TO 
01N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 45 NM N AND 
120 NM S OF THE AXIS BETWEEN 84W AND 92W AS WELL AS WITHIN 90 NM 
N AND 60 NM S OF THE AXIS BETWEEN 94W AND 101W. 
                                             
...DISCUSSION...                                                
GULF OF TEHUANTEPEC...THE 1806 UTC ASCAT PASS SHOWS A SIZABLE 
AREA OF 30-35 KT WINDS IN THE GULF OF TEHUANTEPEC. THE GALE 
WARNING WILL PERSIST UNTIL SAT MORNING WHEN WINDS IN THE SW GULF 
WILL SHIFT SOUTHEASTERLY AS THE RIDGE BEHIND THE COLD FRONT 
PROGRESSES EASTWARD. WINDS WILL QUICKLY DIMINISH BELOW A STRONG 
BREEZE SAT AFTERNOON. NE SWELL WILL CONTINUE TO KEEP SEAS OVER 8 
FT SW OF THE GULF OF TEHUANTEPEC INTO EARLY SUN.
                                                
THE UPPER PATTERN CURRENTLY FEATURES AN ANTICYCLONE OVER NW 
VENEZUELA THAT EXTENDS A RIDGE WESTWARD ALONG 06N TO 95W. UPPER 
DIFFLUENCE ASSOCIATED WITH THIS RIDGE IS ENHANCING THE SCATTERED 
MODERATE CONVECTION ALONG THE MONSOON TROUGH DESCRIBED IN THE 
SECTION ABOVE. THE LONG-WAVE UPPER TROUGH SUPPORTING THE COLD 
FRONT THAT BROUGHT GALE FORCE WINDS TO TEHUANTEPEC IS FOUND FROM 
THE NE GULF OF MEXICO THROUGH THE YUCATAN PENINSULA TO 10N93W. 
IT IS MOVING N OF THE UPPER RIDGE TO ITS SE. ANOTHER RIDGE AXIS 
LIES TO ITS W FROM THE U.S. GREAT PLAINS TO 10N110W. A BAND OF 
MID- TO UPPER-LEVEL MOISTURE MANIFESTED PRIMARILY BY PATCHY 
CIRRUS IS FOUND N OF 10N W OF THE RIDGE AXIS...EXTENDING THROUGH 
THE MOUTH OF THE GULF OF CALIFORNIA AND INTO N CENTRAL MEXICO. 
MOISTURE ASSOCIATED WITH THIS BAND HAS DISSIPATED CONSIDERABLY 
OVER THE PAST 24 HOURS. 

THE 1025 MB SUBTROPICAL SURFACE HIGH LIES NEAR 30N133W. THE HIGH 
HAS STRENGTHENED SINCE YESTERDAY AND THE 2124 UTC OSCAT AND 1820 
UTC ASCAT PASSES SHOW TRADE WINDS ARE A FRESH TO STRONG NE 
BREEZE OVER WESTERN WATERS BETWEEN THE ITCZ AND 16N. THE 0020 
UTC JASON1 PASS SHOWS SEAS TO AT LEAST 9 FT ALONG 130W IN THIS 
AREA. TRADES WILL REMAIN FRESH TO STRONG THROUGH THE WEEKEND AS 
THE SUBTROPICAL RIDGE CONTINUES TO BUILD. THE PRESSURE GRADIENT 
HAS ALSO STRENGTHENED ALONG THE E EDGE OF THE RIDGE AXIS 
ALLOWING FRESH TO STRONG NW WINDS TO BECOME ESTABLISHED ALONG 
THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA N OF 28N. 
THESE WINDS ARE EXPECTED TO EXPAND SOUTHWARD TO 27N AND OUT TO 
330 NM AWAY FROM THE COAST THROUGH LATE SUN.

NW SWELL WITH PERIODS EXCEEDING 20 SECONDS HAS MOVED INTO NW 
WATERS. SEAS THERE ARE EXPECTED TO BUILD TO 11 FT BY SAT 
MORNING. THE LEADING EDGE OF THE SWELL WILL PROGRESS 
SOUTHEASTWARD....SPREADING SOUTHWARD ALONG THE BAJA CALIFORNIA 
PACIFIC COAST ON SAT AND REACHING CABO CORRIENTES MEXICO BY LATE 
SUN.

$$
SCHAUER