000
AXPZ20 KNHC 211000
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JUL 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...
MAJOR HURRICANE DORA IS CENTERED NEAR 16.6N 106.1W 942 MB AT 
0900 OR ABOUT 265 MI S OF CABO CORRIENTES MEXICO MOVING NW AT 
11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 948 MB. MAXIMUM 
SUSTAINED WINDS ARE 120 KT WITH GUSTS TO 145 KT. NUMEROUS 
MODERATE TO STRONG CONVECTION IS WITHIN 120 NM OF THE CENTER. 
SATELLITE IMAGERY THIS MORNING INDICATES A BEAUTIFUL SYMMETRICAL 
HURRICANE WITH AN EYE 25 NM IN DIAMETER. DORA IS IN AN 
ENVIRONMENT CONDUCIVE FOR INTENSIFICATION AND SHOULD BE EXPECTED 
TO FLUCTUATE IN INTENSIFY DURING THE NEXT DAY AS IT MOVES NW. 
SEAS OF 12 TO 15 FT ARE CURRENTLY BATTERING THE MEXICAN 
COASTLINE AND NEARSHORE WATERS FROM NEAR ACAPULCO TO CABO 
CORRIENTES. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
WEAK MONSOON TROUGH EXTENDS FROM NW COLOMBIA TO 05N90W TO 05N94W 
THEN TRANSITIONS TO ITCZ AND CONTINUES TO 09N107W TO 11N126W TO 
11N130W TO 08N136W TO BEYOND 08N140W. NUMEROUS MODERATE TO 
STRONG N OF 05.5N AND E OF 80WW. SCATTERED MODERATE WITHIN 60 NM 
OF AXIS BETWEEN 126W AND 135W.

...DISCUSSION...
A 1039 MB HIGH CENTERED WELL NW OF THE AREA NEAR 42N150W IS
INDUCING ONLY A MODEST PRESSURE GRADIENT ACROSS W AND NW 
PORTIONS OF THE DISCUSSION AREA...YIELDING WEAK NE TRADE WINDS 
KT N OF THE ITCZ W OF 120W EXCEPT FOR A NARROW ZONE OF 20 KT NE 
WINDS W OF 132W N OF THE ITCZ TO 12N. NE WINDS TO 20 KT HAVE 
SPREAD ACROSS FAR NW PORTIONS OF THE AREA OVERNIGHT...W OF 135W 
AND WILL PERSIST THROUGH FRI MORNING BEFORE FADING WWD.

THE MONSOON TROUGH HAS WEAKENED CONSIDERABLY E AND SE OF DORA 
OVER THE PAST FEW DAYS...WITH WEAK S TO SW WINDS E OF125W. DEEP 
LAYER E WINDS ARE BEGINNING TO RETURN TO CENTRAL AMERICA... 
BRINGING ABOUT A MORE TYPICAL MID-SUMMER WEATHER PATTERN...AND A 
RETURN TO MORE USUAL DIURNAL-NOCTURNAL CYCLES. A WEAK PAPAGAYO 
GAP WIND EVENT WILL OCCUR DURING THE NEXT FEW DAYS WITH PULSING 
WINDS REACHING 15-20 KT IN THE EARLY MORNING...AND FADING BY 
LATE AFTERNOON. WITH THE PULSING WEAK NATURE OF THIS 
EVENT...THESE PAPAGAYO WINDS ARE NOT INCLUDED INTO THE HIGH SEAS 
FORECAST.

MODERATE PERIOD N TO NW SWELL WILL REACH 30N THIS EVENING WITH 
SEAS BUILDING TO 8 FT...PRODUCED BY STRONG NWLY WINDS EXPECTED 
TO DEVELOP OFF THE CALIFORNIA COAST. SEAS ACROSS NE PORTIONS OF 
THE AREA WILL PEAK AROUND 9 FT SATURDAY MORNING BEFORE FADING 
THROUGH SUNDAY.

$$
STRIPLING