000
AXPZ20 KNHC 150910
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU AUG 15 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
                                      
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           

THE MONSOON TROUGH EXTENDS FROM 10N85W TO 11N100W TO 10N108W TO 
12N115W TO 06N131W WHERE LOW LEVEL WINDS SUGGEST A TRANSITION TO 
ITCZ WHICH EXTENDS TO BEYOND 08N140W. SCATTERED MODERATE 
CONVECTION WAS NOTED WITHIN 90 NM N OF TROUGH BETWEEN 96W AND 
100W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS 
NOTED WITHIN 90 NM OF TROUGH BETWEEN 105W AND 130W. 

...DISCUSSION...                                                 

A WEAK SURFACE RIDGE EXTENDS ACROSS THE NORTHERN PART OF THE 
AREA. THE MONSOON TROUGH EXTENDS ROUGHLY ALONG 10N EXTENDING 
FROM CENTRAL AMERICA TO NEAR 130W WHERE IT TRANSITIONS TO ITCZ 
AS MENTIONED ABOVE. THE PRESSURE GRADIENT BETWEEN THE RIDGE AND 
LOWER PRESSURE ASSOCIATED WITH THE MONSOON TROUGH AND IN THE 
VICINITY OF THE ITCZ IS MAINTAINING MODERATE TO FRESH 
TRADEWINDS. LINGERING SEAS TO 8 FT REMAIN OVER A SMALL AREA FROM 
16N TO 20N W OF 136W. THESE SEAS ARE EXPECTED TO DECREASE BELOW 
8 FT BY THIS EVENING. 

EARLIER ASCAT SCATTEROMETER DATA DEPICTED STRONG GAP WINDS IN 
THE GULF OF TEHUANTEPEC. THIS IS THE RESULT OF WIND FLOW AROUND 
A TROPICAL DISTURBANCE IN THE WESTERN CARIBBEAN INDUCING 
NORTHERLY FLOW THROUGH THE CHIVELA PASS INTO THE GULF OF 
TEHUANTEPEC. WINDS WILL CONTINUE TO PULSE TO NEAR 25 KT OVER THE 
NEXT 24-48 HOURS AS THE TROPICAL DISTURBANCE MOVES INTO THE GULF 
OF MEXICO. 

OTHER THAN THESE TWO AREAS...THE PRESSURE GRADIENT IS GENERALLY 
WEAK AND WINDS ARE BELOW ADVISORY CRITERIA. IN ADDITION...THERE 
ARE NO SIGNIFICANT LONG-PERIOD SWELL EVENTS EXPECTED OVER THE 
FORECAST AREA DURING THE NEXT SEVERAL DAYS. OVERALL...THE NE 
PACIFIC REMAINS RELATIVELY QUIET NEAR THE PEAK OF HURRICANE 
SEASON.

$$ 
AL