000
AXPZ20 KNHC 210317
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURE...
MAJOR HURRICANE DORA IS CENTERED NEAR 16.0N 105.4W AT 0300 UTC 
OR ABOUT 220 MI SSW OF MANZANILLO MEXICO MOVING WNW AT 
13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 948 MB. MAXIMUM 
SUSTAINED WINDS ARE 115 KT WITH GUSTS TO 140 KT. NUMEROUS 
MODERATE TO STRONG CONVECTION IS WITHIN 150 NM OF THE CENTER. 
DORA IS IN AN ENVIRONMENT CONDUCIVE FOR INTENSIFICATION AND MAY 
FURTHER INTENSIFY DURING THE NEXT DAY AS IT MOVES NW. THE 12 FT 
SEAS EXTEND AS FAR AS 240 NM FROM THE CENTER.  SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC 
FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
A DISCONTINUOUS MONSOON TROUGH EXTENDS FROM 09N78W TO 04N89W TO 
05N99W AND RESUMES NEAR 13N110W TO 07N140W. SCATTERED MODERATE 
CONVECTION IS WITHIN 60 NM OF AXIS BETWEEN 127W AND 133W.

...DISCUSSION...
A 1038 MB HIGH CENTERED WELL NW OF THE AREA NEAR 43N149W 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 MONSOON TROUGH W OF 115W EXCEPT FOR A NARROW ZONE OF 
20 KT NE WINDS W OF 120W NEAR 10N. A GRADUALLY DISSIPATING 1011 
MB SURFACE LOW CENTERED NEAR 21N117W WILL CONTINUE TO DRIFT WNW 
AND OPEN UP INTO A TROUGH LATER TODAY WITH SURFACE WINDS LESS 
THAN 20 KT EXPECTED.

OVER THE NEXT COUPLE OF DAYS...THE MONSOON TROUGH E AND SE OF 
DORA WILL REMAIN WEAK.  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.

SHORTER PERIOD N TO NW SWELL WILL REACH 30N LATE FRI WITH 8 FT 
SEAS...PRODUCED BY STRONG NWLY WINDS EXPECTED TO DEVELOP OFF THE 
CALIFORNIA COAST.  THE SEAS IN OUR NORTHERN AREA OF 
RESPONSIBILITY SHOULD PEAK AROUND 10 FT SATURDAY MORNING.

$$
LANDSEA