000
AXPZ20 KNHC 300232
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC TUE JUL 30 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 
0230 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 10N85W TO LOW PRES NEAR 
11N111W TO 10N120W TO 12N129W. THE ITCZ AXIS EXTENDS FROM 
12N129W TO 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS 
FROM 05N TO 09N BETWEEN 82W AND 88W. SCATTERED MODERATE 
CONVECTION IS FROM 08N TO 14N BETWEEN 102W AND 107W...AND
FROM 08N TO 13N BETWEEN 110W AND 114W.

...DISCUSSION...                                               

NEARLY STATIONARY HIGH PRES LOCATED JUST NW OF THE DISCUSSION 
AREA NEAR 34N143W EXTENDS A RIDGE ACROSS THE N WATERS MAINLY N 
OF 17N W 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 13N TO 18N W OF 134W IN ABOUT 36-48 HOURS AS THE PRES 
GRADIENT TIGHTENS OVER THIS AREA BETWEEN THE HIGH PRES TO THE N 
AND APPROACHING LOW PRES ALONG THE MONSOON TROUGH TO THE E.

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 LATER TONIGHT. 

COMPUTER MODELS CONTINUE TO SUGGEST THE DEVELOPMENT OF SURFACE 
LOW PRES ALONG THE MONSOON TROUGH CURRENTLY NEAR 11N111W...WITH 
THE GFS MODEL REMAINING THE MOST AGGRESSIVE. 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