000
AXPZ20 KNHC 050303
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN AUG 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0115 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE LIES FROM 17N101W TO 07N103W AND IS MOVING W AT 
10 KT. THE 1548 UTC ASCAT PASS SUGGESTS THAT WINDS ARE ONLY AS 
STRONG AS A MODERATE BREEZE WITH THIS WAVE. SCATTERED MODERATE 
CONVECTION WAS WITHIN 450 NM W AND 180 NM E OF THE WAVE FROM 07N 
TO 12N...PRIMARILY WHERE THE WAVE IS CLOSEST TO THE MONSOON 
TROUGH AXIS. THIS WAVE IS FORECAST TO CONTINUE WESTWARD AROUND 
10 KT OVER THE NEXT FEW DAYS. 

A TROPICAL WAVE STRETCHES ALONG 125W FROM 10N TO 18W WITH LOW 
PRES 1009 MB ANALYZED NEAR 13N125W. THE WAVE IS MOVING W AROUND 
5 KT. THE 1726 UTC ASCAT PASS SHOWED FRESH NE TO E WINDS WITHIN 
150 NM N QUADRANT OF THE LOW PRES CENTER. THIS LOW IS EXPECTED 
TO GRADUALLY WEAKEN ALONG THE WAVE OVER THE NEXT DAY OR SO. 
HOWEVER...WINDS SHOULD STAY FRESH TO STRONG NEAR THE WAVE AS THE 
PRES GRADIENT REMAINS STRONG BETWEEN THE RIDGING THE WAVE IS 
MOVING INTO AND THE LOWER PRES ASSOCIATED WITH THE WAVE. 
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FROM 07N 
TO 10N BETWEEN 123W AND 128W. THE AVAILABLE MOISTURE EXPECTED TO 
DIMINISH NEAR THE WAVE OVER THE NEXT FEW DAYS AND THE UPPER 
RIDGE AXIS OVER THE WAVE IS FORECAST TO BREAK DOWN. CONVECTION 
SHOULD BEGIN TO WANE IN RESPONSE.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 08N78W TO 09N84W TO 
09N95W THEN CONTINUES FROM 11N106W TO 12N120W. THE ITCZ AXIS WAS 
ANALYZED FROM 10N127W TO 09N140W. SCATTERED MODERATE CONVECTION 
WAS WITHIN 150 NM S OF THE AXIS BETWEEN 91W AND 95W AS WELL AS 
WITHIN 120 NM N AND 210 NM S OF THE AXIS BETWEEN 114W AND 121W.

...DISCUSSION...
THE 1029 MB SUBTROPICAL HIGH NEAR 42N146W IS FORECAST TO WEAKEN 
AS IT CONTINUES MOVING W OVER THE NEXT TWO DAYS...WEAKENING THE 
RIDGING OVER THE FORECAST AREA. TRADE WINDS HAVE DIMINISHED TO 
20 KT OR LESS ACCORDING TO THE 1908 UTC ASCAT PASS AND SWELL HAS 
SUBSIDED BELOW 8 FT.

THE LEADING EDGE OF A CROSS-EQUATORIAL SOUTHERLY SWELL TRAIN HAS 
REACHED AS FAR N AS THE SE GULF OF CALIFORNIA AND THE PACIFIC 
COAST OF BAJA CALIFORNIA NORTE. THE LEADING EDGE OF THIS SWELL 
HAS PERIODS IN EXCESS OF 20 SECONDS. THIS SWELL CONTINUES TO 
IMPACT THE THE COASTLINE OVER THE ENTIRE FORECAST AREA BUT IS 
BEGINNING TO DIMINISH. STILL...INTERESTS ALONG THE COAST SHOULD 
BE AWARE OF THE POTENTIAL FOR HIGH SURF AND POSSIBLY SOME 
COMPLICATIONS ENTERING HARBORS AND INLETS. SWELL HEIGHTS TO 10 
FT CAN BE EXPECTED AS FAR N AS 11N W OF THE GALAPAGOS ISLANDS 
INTO SUN...WITH SEAS OFFSHORE OF THE COASTLINE EXPECTED TO BE 
PRIMARILY IN THE 5-8 FT RANGE SOUTH OF THE GULF OF TEHUANTEPEC. 
SEAS WILL SUBSIDE CONSIDERABLY BY MON. 

ALOFT...A VAST RIDGE AXIS SPANS FROM AN ANTICYCLONE OVER THE MID 
MISSISSIPPI VALLEY SOUTHWESTWARD TO A TROUGH SNAKING OFF THE 
COAST OF MEXICO FROM 32N120W TO 26N117W TO 15N103W. THE RIDGE 
AXIS THEN CONTINUES FROM 26N121W TO ANOTHER ANTICYCLONE NEAR 
17N140W. A THIRD ANTICYCLONE LIES NEAR 14N109W AND EXTENDS A 
RIDGE AXIS OVER THE NORTH HALF OF THE TROPICAL WAVE ALONG 125W. 
THIS ANTICYCLONE AND RIDGE WILL WEAKEN OVER THE NEXT DAY OR SO.

GAP WINDS...NORTHERLY WINDS ARE EXPECTED TO BRIEFLY INCREASE TO 
20 TO 25 KT IN THE GULF OF TEHUANTEPEC BY EARLY MON MORNING. 
WINDS AND SEAS SHOULD DIMINISH BY THE END OF THE PERIOD MON 
EVENING...BUT MAY PULSE TO A FRESH TO STRONG BREEZE IN THE 
OVERNIGHT AND EARLY MORNING HOURS THROUGH TUE.

$$
SCHAUER