000
AXPZ20 KNHC 240307
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JUL 24 2011

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 
0300 UTC.

...SPECIAL FEATURE...

TROPICAL STORM DORA CENTERED NEAR 22.5N 113.4W AT 24/0300 UTC 
MOVING NW OR 315 DEGREES AT 10 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH 
GUSTS TO 50 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. DORA IS 
EXPERIENCING LIGHT TO MODERATE NORTHEASTERLY VERTICAL WIND SHEAR 
WHICH WILL CONTINUE AS DORA PARALLELS THE COAST OF THE BAJA 
CALIFORNIA PENINSULA. ISOLATED MODERATE CONVECTION IS OCCURRING 
WITHIN 30-60 NM OF THE CENTER. DORA IS FORECAST TO WEAKEN TO A 
POST TROPICAL REMNANT LOW IN ABOUT 24 HOURS AS IT CONTINUES TO 
MOVE OVER COLDER SEA SURFACE TEMPERATURES. MEANWHILE LARGE 
SWELLS GENERATED BY DORA WILL AFFECT THE COAST OF SOUTHWESTERN 
MEXICO AND BAJA CALIFORNIA DURING THE NEXT COUPLE OF DAYS. THESE 
SWELLS WILL LIKELY CAUSE LIFE-THREATENING SURF AND RIP CURRENT 
CONDITIONS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 09N84W TO 08N97W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 08N97W TO 09N109W THEN 
RESUMES NEAR 06N114W TO 10N128W TO 09N140W. SCATTERED MODERATE 
AND ISOLATED STRONG CONVECTION IS WITHIN 90 NM N OF THE ITCZ 
BETWEEN 128W AND 130W. ALSO...SCATTERED MODERATE TO STRONG 
CONVECTION IS FROM 19N TO 23N WITHIN 60 NM OF THE COAST OF 
MEXICO.

...DISCUSSION...

AN UPPER LEVEL TROUGH IS INTRUDING ON THE FAR W PORTION OF THE 
AREA ALONG 140W/141W PRODUCING LIGHT TO MODERATE S TO SW WINDS 
EAST OF THIS UPPER FEATURE AT THE SURFACE. AN UPPER LEVEL 
ANTICYCLONE IS CENTERED NEAR 23N121W. UPPER LEVEL NE WINDS IN 
ASSOCIATION WITH THE CIRCULATION OF THIS ANTICYCLONE ARE 
IMPACTING TROPICAL STORM DORA AS DESCRIBED IN THE SPECIAL 
FEATURE SECTION ABOVE. AN UPPER LEVEL CYCLONE IS OVER THE DEEP 
TROPICAL PACIFIC NEAR 04N125W. AN ASSOCIATED UPPER LEVEL TROUGH 
EXTENDS WESTWARD FROM THE CYCLONE ALONG 04N...AND EASTWARD FROM 
THE CYCLONE TO 07N110W TO 05N100W. OTHERWISE UPPER LEVEL 
ANTICYCLONIC FLOW DOMINATES THE MAJORITY OF THE REMAINDER OF THE 
TROPICAL NE PACIFIC. UPPER LEVEL DIFFLUENCE IS HELPING TO INDUCE 
MINIMAL CONVECTION AS DESCRIBED ABOVE.

ELSEWHERE AT THE SURFACE...A BROAD RIDGE EXTENDS FROM 32N140W TO 
20N120W. A RECENT ASCAT PASS CAPTURED 20 KT E-SE WINDS IN AN 
AREA GENERALLY S OF 04N W OF 132W. THESE WINDS ARE EXPECTED TO 
DIMINISH TO LESS THAN 20 KT ON SUN. 

CROSS-EQUATORIAL SE SWELLS OF 8-9 FT ARE PROPAGATING ACROSS THE 
SW CORNER OF THE AREA SW OF A LINE FROM 10N140W TO 00N120W. 
THESE HIGHER SWELLS WILL PROPAGATE TO SW OF A LINE FROM 05N140W 
TO 00N115W IN 24 HOURS...THEN BECOME CONFINED TO S OF 05N W OF 
100W IN 48 HOURS AS A NEW SET OF CROSS-EQUATORIAL SW SWELL 
BEGINS TO COMMINGLE WITH THE DECAYING SE SWELL.

A WEAK TO MODERATE GULF OF PAPAGAYO GAP WIND EVENT WILL OCCUR 
LATE TONIGHT THROUGH EARLY MON AS FRESH TRADE WIND FLOW IN THE 
SW CARIBBEAN FUNNELS THROUGH THE GAP. ALSO...A SURGE OF 20-25 KT 
NORTHERLY WINDS IS FORECAST IN THE GULF OF TEHUANTEPEC BEGINNING 
LATE SUN NIGHT/EARLY MON MORNING THROUGH MON AFTERNOON.

$$
LEWITSKY