000
AXPZ20 KNHC 301528
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURE...                                            
SATELLITE IMAGES INDICATE THAT THE SHOWER AND TSTM ACTIVITY 
ASSOCIATED WITH A LOW PRESSURE EMBEDDED IN THE MONSOON TROUGH 
AND LOCATED ABOUT 680 NM SOUTH-SOUTHWEST OF THE SOUTHERN TIP OF 
THE BAJA CALIFORNIA PENINSULA HAS BECOME BETTER ORGANIZED AND A 
TROPICAL DEPRESSION HAS FORMED. THE DEPRESSION NAMED SEVEN-E IS 
CENTERED NEAR 12.3N 114.9W AT 30/1500 UTC MOVING WEST-NORTHWEST 
OR 285 DEGREES AT 14 KT. A WEST-NORTHWESTWARD MOTION WITH A 
SLIGHT DECREASE IN FORWARD SPEED IS EXPECTED THROUGH EARLY 
THURSDAY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM 
SUSTAINED WIND SPEED IS 25 KT G TO 35 KT. CURRENTLY...SCATTERED 
MODERATE TO STRONG CONVECTION IS NOTED WITHIN 75 NM OF CENTER 
WITH A BAND OF MODERATE TO ISOLATED STRONG CONVECTION COVERING 
THE AREA FROM 13N TO 16N BETWEEN 113W AND 117W. ENVIRONMENTAL 
CONDITIONS APPEAR CONDUCIVE FOR INTENSIFICATION AND THE OFFICIAL 
FORECAST CALLS FOR THE DEPRESSION TO BECOME A TROPICAL STORM 
LATER TODAY AND LIKELY A HURRICANE IN ABOUT 72 HOURS. SEE LATEST 
NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTNT24 
KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 12N100W TO 1011 MB 
LOW PRES NEAR 11N107W TO 1008 MB LOW PRES 11N114W TO 11N120W. 
ITCZ AXIS CONTINUES FROM 11N120W TO 12N130W TO 11N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 04N 
TO 08N E OF 81W TO THE COAST OF COLOMBIA. ISOLATED MODERATE TO 
STRONG CONVECTION IS FROM 07N TO 10N BETWEEN 86W AND 90W...AND 
FROM 11N TO 15N BETWEEN 120W AND 125W.       

...DISCUSSION...  
             
NEARLY STATIONARY HIGH PRES LOCATED JUST NW OF THE DISCUSSION 
AREA EXTENDS A RIDGE ACROSS THE N WATERS MAINLY N OF 17N W OF 
114W. GENTLE TO MODERATE WINDS ARE NOTED PER SCATTEROMETER DATA 
UNDER THE INFLUENCE OF THIS RIDGE...MAINLY E OF 120W. NE WINDS 
OF 10-15 KT ARE NOTED W OF 130W. AN EARLIER ASCAT PASS ALSO 
SHOWED TRADE WINDS OF 15-20 KT ON THE SOUTHERN PERIPHERY OF THE 
RIDGE AND N OF THE ITCZ. THE TRADE WINDS ARE EXPECTED TO 
INCREASE TO 20-25 KT WITH BUILDING SEAS TO AROUND 9 FT FROM 13N 
TO 18N W OF 133W IN ABOUT 24 HOURS AS THE PRES GRADIENT TIGHTENS 
OVER THIS AREA BETWEEN THE HIGH PRES TO THE N AND APPROACHING 
TROPICAL CYCLONE. 

CROSS EQUATORIAL SOUTHERLY SWELLS WITH PERIODS IN THE 18-19 
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. 

$$
GR