000
AXPZ20 KNHC 221605
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI JUL 22 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURE...
HURRICANE DORA CENTERED NEAR 19.3N 109.4W AT 1500 UTC MOVING NW 
OR 310 DEGREES AT 8 KT. MAXIMUM SUSTAINED WINDS ARE 75 KT WITH 
GUSTS TO 90 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 981 MB.
INCREASED NORTHERLY SHEAR HAS CAUSED CONVECTION TO GREATLY WEAKEN
N AND NW OF THE CENTER WHILE MODERATE TO STRONG DEEP CONVECTION 
CONTINUES FROM 17N TO 20N BETWEEN 106W AND 111W. DORA IS MOVING 
UNDER A MID TO UPPER LEVEL RIDGE AND WILL CONTINUE TO TRACK OVER 
INCREASINGLY COOLER OCEAN WATERS. ASSOCIATED SWELLS WILL LIKELY 
CAUSE LARGE SURF AND RIP CURRENT CONDITIONS AS THEY REACH THE 
COAST OF CENTRAL MEXICO AND THE SOUTHERN PORTIONS OF THE BAJA 
CALIFORNIA PENINSULA. PLEASE SEE LATEST NHC FORECAST/ ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 10N84W TO 08N93W...AND FROM 15N110W 
TO 12N120W...THEN AS ITCZ FROM 12N120W TO 13N127W TO 09N140W. 
SCATTERED MODERATE CONVECTION N OF 04N E OF 86W. 

...DISCUSSION...
A WEAK PRES GRADIENT EXISTS OVER NW PORTION OF THE DISCUSSION 
AREA N OF 15N W OF 120W...WITH NE TRADE WINDS 10-15 KT AND SEAS 
GENERALLY 6-7 FT IN MIXED N AND SE SWELL. FURTHER SOUTH...THE 
ITCZ HAS RE-ESTABLISHED ITSELF W OF AROUND 120-125W AS LARGE 
SCALE MONSOON FLOW WEAKENS E OF 120W. MULTIPLE WEAK VORTICES ARE 
EVIDENT ALONG THE ITCZ AXIS NEAR 11N119W...11N124W...13N128W... 
11N134W AND 10N138W. LITTLE CHANGE IS EXPECTED IN THIS REGION 
THE NEXT DAY OR SO...AND NONE OF THE WEAK VORTICES ALONG THE 
ITCZ ARE EXPECTED TO DEVELOP INTO DISTINCT AREAS OF LOW PRES.

SATELLITE AND SURFACE DATA INDICATE A WEAK MONSOON TROUGH EXISTS 
E OF 95W ALONG 07-08N. CONVECTION ASSOCIATED WITH THE MONSOON 
TROUGH REMAINS SPOTTY E OF 100W. DEEP LAYER E WINDS HAVE RETURNED
TO CENTRAL AMERICA. A WEAK TO MODERATE PAPAGAYO GAP WIND EVENT 
WILL PULSE THE NEXT SEVERAL DAYS WITH WINDS REACHING 20 KT IN 
THE EARLY MORNING...AND FADING BY LATE AFTERNOON.

CROSS-EQUATORIAL SE SWELLS ARE PROPAGATING NW ACROSS THE EQUATOR 
SW OF A LINE FROM 10N140W TO EQ110W...MIXING WITH NE TRADE SWELL 
ALONG 10N BETWEEN 130W AND 140W. SOUTHERLY SWELL PREVAILS OVER 
THE TROPICAL WATERS E OF 125W. N TO NW SWELL WILL REACH N WATERS 
IN ABOUT 24 HOURS RAISING SEAS TO 8-9 FT N OF 26N BETWEEN 118N 
AND 126W. THESE SWELLS WILL BE ASSOCIATED WITH STRONG NWLY WINDS 
EXPECTED TO DEVELOP OFF THE CALIFORNIA COAST...AND WILL MIX WITH 
SE SWELL GENERATED BY HURRICANE DORA.

$$
MUNDELL