000
AXPZ20 KNHC 292120
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC MON JUL 29 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 09N80W TO LOW PRES NEAR 
10.5N109W TO 11N129W. THE ITCZ AXIS EXTENDS FROM 11N129W TO 
08N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS  
WITHIN 300 NM S OF THE TROUGH E OF 86W...WITHIN 120 NM N OF THE 
TROUGH BETWEEN 94W AND 97W...FROM 07N TO 13N BETWEEN 102W AND 
106W...AND WITHIN 120 NM IN THE SW SEMICIRCLE OF THE LOW. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE TROUGH 
BETWEEN 118W AND 122W.

...DISCUSSION...                                               

HIGH PRES LOCATED WELL N OF THE AREA NEAR 34N143W EXTENDS A 
RIDGE ACROSS THE N WATERS MAINLY N OF 19NW OF 110W. GENTLE TO 
MODERATE WINDS ARE NOTED PER SCATTEROMETER DATA UNDER THE 
INFLUENCE OF THIS RIDGE. THE TRADE WINDS ARE EXPECTED TO 
INCREASE TO 20 KT WITH BUILDING SEAS TO 8 FT FROM 14N TO 18N W 
OF W OF 134W IN ABOUT 48 HOURS AS A NEW HIGH PRES CENTER 
DEVELOPS FARTHER SOUTH NEAR 39N138W.

STRONG WINDS ALONG THE COAST OF NORTHERN CALIFORNIA BETWEEN 
TROUGHING OVER INTERIOR CALIFORNIA AND THE SUBTROPICAL RIDGE 
CONTINUES TO GENERATE SEAS UP TO 8 FT REACHING S TO 31N/30N. 
THESE SEAS WILL SUBSIDE TO LESS THAN 8 FT TONIGHT. 

COMPUTER MODELS CONTINUE TO SUGGEST THE DEVELOPMENT OF A SERIES 
OF CYCLONIC SWIRLS ALONG THE MONSOON TROUGH OVER THE NEXT FEW 
DAYS WITH THE GFS THE MOST AGGRESSIVE. CURRENTLY...AN EMBEDDED 
1009 MB SURFACE LOW IS NEAR 10.5N109W. THIS LOW IS PRODUCING 
DISORGANIZED SHOWER AND THUNDERSTORM ACTIVITY AS IS DESCRIBED IN 
THE SECTION ABOVE. ENVIRONMENTAL CONDITIONS COULD FAVOR SLOW 
DEVELOPMENT OF THIS SYSTEM OVER THE NEXT SEVERAL DAYS AS IT 
MOVES TO THE WEST OR W-NW AT ABOUT 10 KT. CURRENTLY...THIS LOW 
HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 
48 HOURS. FOR NOW...EXPECT WINDS OF 20-25 KT AND SEAS OF 8-10 FT 
IN ASSOCIATION WITH THE LOW...INCREASING TO 20-30 KT AND 8-11 FT 
BY 48 HOURS.

CROSS EQUATORIAL SOUTHERLY SWELLS WITH PERIODS IN THE 19-21 
SECOND RANGE ARE AFFECTING MOST THE COASTS OF MEXICO AND CENTRAL 
AMERICA LIKELY PRODUCING ROUGH SURF CONDITIONS AND DANGEROUS RIP 
CURRENTS TO THOSE COASTS. ADDITIONAL PULSES OF LONG PERIOD CROSS 
EQUATORIAL SWELL WILL PROPAGATE ACROSS THE S WATERS MAINLY 
BETWEEN 105W AND 135W WED AND THU...REACHING PARTS OF THE COASTS 
OF MEXICO AND CENTRAL AMERICA BY FRI. 

$$ 
LEWITSKY