000
AXPZ20 KNHC 211555
TWDEP 

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

...SPECIAL FEATURE...
HURRICANE DORA IS CENTERED NEAR 17.1N 106.9W AT 1500 UTC OR 
ABOUT 240 MI SSW OF CABO CORRIENTES MEXICO MOVING NW AT 11 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 929 MB. MAXIMUM SUSTAINED 
WINDS ARE 135 KT WITH GUSTS TO 165 KT. NUMEROUS MODERATE TO 
STRONG CONVECTION IS WITHIN 150 NM OF THE CENTER. SATELLITE 
IMAGERY INDICATES A CIRCULAR RING OF VERY COLD CLOUD TOPS AROUND 
A NEARLY CLOUD-FREE 30 NM EYE. IT APPEARS TO BE NEARING ITS PEAK 
INTENSITY AND IS EXPECTED TO WEAKEN SLIGHTLY OVER THE NEXT 12-24 
HOURS THEN MORE RAPIDLY AS IT ENCOUNTERS COOL WATER AND STRONGER 
VERTICAL SHEARING EFFECTS. 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 07N81W TO 05N94W 
THEN TRANSITIONS TO AN ITCZ TO 07N111W TO 11N128W TO 07N140W. 
SCATTERED MODERATE TO STRONG CONVECTION N OF 5N E OF 81W.

...DISCUSSION...
A MODEST PRESSURE GRADIENT EXISTS ACROSS W AND NW PORTIONS OF 
THE DISCUSSION AREA...YIELDING WEAK NE TRADE WINDS N OF THE ITCZ 
W OF 120W. NE WINDS TO 20 KT ARE FOUND ACROSS FAR NW PORTIONS OF 
THE AREA W OF 135W AND WILL PERSIST THROUGH FRI THEN FADE WWD.

THE MONSOON TROUGH HAS WEAKENED CONSIDERABLY E AND SE OF DORA 
OVER THE PAST TWO DAYS...WITH WEAK S TO SW WINDS E OF 125W. DEEP 
LAYER E WINDS ARE BEGINNING TO RETURN TO CENTRAL AMERICA... 
BRINGING ABOUT A MORE TYPICAL MID-SUMMER WEATHER PATTERN...AND A 
RETURN TO THE USUAL DIURNAL-NOCTURNAL CYCLES. A WEAK PAPAGAYO 
GAP WIND EVENT WILL PULSE DURING THE NEXT FEW DAYS WITH WINDS 
REACHING 15-20 KT IN THE EARLY MORNING...AND FADING BY LATE 
AFTERNOON. DUE TO THE WEAK PULSING NATURE OF THIS EVENT...THESE 
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 SAT MORNING THEN FADE THROUGH SUN.

$$
MUNDELL