000
AXPZ20 KNHC 220258
TWDEP 

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

...SPECIAL FEATURE...
HURRICANE DORA CONTINUES TO WEAKEN AND NOW IS A CATEGORY THREE 
HURRICANE ON THE SAFFIR-SIMPSON SCALE. IT IS CENTERED NEAR 18.3N 
108.1W AT 0300 UTC MOVING NW OR 315 DEGREES AT 8 KT. MAXIMUM 
SUSTAINED WINDS ARE 110 KT WITH GUSTS TO 140 KT. ESTIMATED 
MINIMUM CENTRAL PRESSURE IS 950 MB. SEE LATEST NHC FORECAST/ 
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE 
DETAILS. NUMEROUS MODERATE TO STRONG CONVECTION IS NOTED WITHIN 
120 NM OF CENTER. LARGE SWELLS GENERATED BY DORA WILL AFFECT THE 
COAST OF SOUTHWESTERN MEXICO DURING THE NEXT COUPLE OF DAYS. 
SWELLS WILL BEGIN AFFECTING THE COAST OF THE SOUTHERN PORTION OF 
BAJA CALIFORNIA LATER TONIGHT. THESE SWELLS WILL LIKELY CAUSE 
LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS.

...ITCZ/MONSOON TROUGH...
WEAK MONSOON TROUGH EXTENDS FROM 08N78W TO 08N86W TO 14N97W THEN 
RESUMES AT 14N112W TO 12N119W THEN 10N130W TO 08N140W. ISOLATED 
TO SCATTERED MODERATE CONVECTION IS FROM 04N TO 06N BETWEEN 80W 
AND 91W. SIMILAR CONVECTION IS ALSO NOTED NEAR 07N91WW AND NEAR 
08N92W.

...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 134W. NE WINDS TO 20 KT ARE FOUND ACROSS FAR NW PORTIONS OF 
THE AREA MAINLY N OF 22N W OF 132W. THE MOST RECENT ASCAT PASS 
PROVIDED OBSERVATIONS OF THESE WIND SPEEDS. WINDS ARE FORECAST 
TO DIMINISH BELOW 20 KT IN ABOUT 24 HOURS.

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 INVADE THE N WATERS IN ABOUT 
36 HOURS RAISING SEAS TO AROUND 9 FT PARTICULARLY N OF 26N 
BETWEEN 118N AND 126W. THESE SWELLS WILL BE ASSOCIATED WITH 
STRONG NWLY WINDS EXPECTED TO DEVELOP OFF THE CALIFORNIA COAST. 

$$
GR