000
AXPZ20 KNHC 040940
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT AUG 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...TROPICAL WAVES...
THE SOUTHERN END OF A TROPICAL WAVE OVER GUATEMALA CURRENTLY 
LIES ALONG 92W N OF 10N AND IS MOVING W AROUND 5-10 KT. MOST OF 
THE CONVECTIVE ACTIVITY ASSOCIATED WITH THIS WAVE IS INLAND OVER 
PARTS OF GUATEMALA AND EL SALVADOR. WINDS ARE LIGHT ON EITHER 
SIDE OF THE WAVE AXIS PER THE MOST RECENT ASCAT PASS. THE WAVE 
WILL MOVE ACROSS THE GULF OF TEHUANTEPEC IN ABOUT 36-48 HOURS.

A TROPICAL WAVE LIES ALONG 105W FROM 11N TO 18N. THE WAVE IS 
MOVING W AROUND 5-10 KT. SCATTERED SHOWERS AND ISOLATED TSTMS 
ARE NOTED WITHIN 180 NM ON EITHER SIDE OF AXIS. THE GFS MODEL 
MAINTAINS THIS WAVE MOVING WWD WITH A WELL DEFINED WIND SHIFT 
ASSOCIATED WITH IT. WINDS ARE MAINLY LIGHT NEAR THE WAVE AXIS. 

A TROPICAL WAVE STRETCHES FROM 17N122W TO 11N123W AND IS MOVING 
W AROUND 10 KT. SCATTERED MODERATE CONVECTION IS NOTED FROM 12N 
TO 17N BETWEEN 120W AND 124W. LATEST SCATTEROMETER DATA SHOWED 
WINDS OF 15 KT IN ASSOCIATION WITH THIS WAVE. EXPECT INCREASING 
WINDS TO 20 KT AND SEAS TO 8 FT NEAR THE NORTHERN END OF THE 
WAVE AS IT CONTINUES TO MOVE WWD OVER THE NEXT COUPLE OF DAYS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO 11N100W TO 11N110W TO 
14N122W TO 08N135W. ITCZ AXIS CONTINUES FROM 08N135W TO 07N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION CAN BE FOUND FROM 
07N TO 11N BETWEEN 100W AND 115W...AND FROM 06N TO 11N BETWEEN 
118W AND 121W. 

...DISCUSSION...
1030 MB SUBTROPICAL HIGH LOCATED NEAR 42N144W EXTENDS A RIDGE 
OVER THE N WATERS TO NEAR 20N120W. THIS HIGH IS FORECAST TO 
WEAKEN AS IT MOVES SW OVER THE NEXT TWO DAYS...WEAKENING THE 
RIDGING OVER THE FORECAST AREA. THE BELT OF TRADE WINDS N OF THE 
ITCZ AND W OF 135W HAS DIMINISHED TO 20 KT ACCORDING TO THE 0636 
UTC ASCAT PASS. NE SWELL WILL KEEP SEAS AT AROUND 8 FT IN THIS 
REGION TODAY. THE 0452 UTC ASCAT PASS REVEALS AN AREA OF SE 
WINDS 20 KT S OF THE MONSOON TROUGH COVERING ROUGHLY FROM 03N TO 
08N BETWEEN 115W AND 120W. WINDS INCREASE TO 25 KT NEAR THE 
CONVECTIVE ACTIVITY LOCATED BETWEEN 118 AND 121W.  

CROSS-EQUATORIAL LONG PERIOD SOUTHERLY SWELLS ARE NOW IMPACTING  
THE COAST OF CENTRAL AMERICA AND THE COAST OF MEXICO S OF CABO 
CORRIENTES. THE LEADING EDGE OF THIS SWELL EVENT HAS PERIODS IN 
EXCESS OF 20 SECONDS. IT WILL MOVE NORTHWARD INTO THE SOUTHERN 
GULF OF CALIFORNIA AND THE PACIFIC COAST OF BAJA CALIFORNIA 
TODAY BEFORE MAKING ITS WAY N ONTO THE CALIFORNIA COAST TONIGHT. 
INTERESTS ALONG THE COAST SHOULD BE AWARE OF THE POTENTIAL FOR 
HIGH SURF AND POSSIBLY SOME COMPLICATIONS ENTERING HARBORS AND 
INLETS. SWELL HEIGHTS TO 9 FT CAN BE EXPECTED AS FAR N AS 10N 
THROUGH TONIGHT. 

EXPECT WINDS OF 15 TO 20 KT IN THE EVENING HOURS ALONG THE 
PACIFIC COAST OF BAJA CALIFORNIA OVER THE NEXT FEW DAYS AS PRES 
GRADIENT INCREASES BETWEEN THE AFOREMENTIONED RIDGE AND LOWER 
PRESSURE OVER MAINLAND MEXICO.  

$$
GR