000
AXPZ20 KNHC 251531
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 25 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 
1415 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH IS FROM 10N85W TO 10N95W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 10N95W TO 12N105W TO 11N122W 
THEN RESUMES FROM 1010 MB LOW PRES NEAR 11N125W TO 06N140W.  
SCATTERED MODERATE CONVECTION WITHIN 60 NM EITHER SIDE OF ITCZ 
AXIS BETWEEN 126W AND 132W...AND W OF 137W. 

...DISCUSSION...

AN UPPER-LEVEL TROUGH ENTERS THE FORECAST AREA NEAR 30N128W THEN 
CONTINUES SW TO 20N136W THEN S-SE TO 10N134W. VERY DRY AIR IS 
NOTED IN THE WAKE OF THIS TROUGH OVER THE NW PORTION OF THE 
AREA. E OF THE TROUGH...AN UPPER-LEVEL RIDGE DOMINATES THE 
REMAINDER OF THE REGION ANCHORED BY AN ANTICYCLONE OVER 23N108W. 
ELY UPPER-LEVEL FLOW IS NOTED E OF 100W. 

A SURFACE RIDGE DOMINATES THE N WATERS N OF 20N W OF 115W. PRES 
GRADIENT BETWEEN A WEAK 1016 MB LOW PRES LOCATED NEAR 30N125W 
AND THE RIDGE IS RESULTING IN AN AREA OF NE WINDS 20 KT N OF 28N 
W OF 130W WITH SEAS IN THE 10-12 FT RANGE IN NW SWELL. A SURFACE 
TROUGH EXTENDS FROM 19N121W TO 11N125W. N OF THE ITCZ AXIS AND W 
OF THE TROUGH THERE IS AN AREA OF TRADE WINDS OF 20 KT WITH SEAS 
TO 9 FT IN MIXED NE AND NW SWELL. SCATTEROMETER DATA PROVIDED 
OBSERVATIONS OF THESE WIND SPEEDS. ACCORDING TO THE MARINE 
GUIDANCE...FRESH WINDS WILL ACCOMPANY THE TROUGH AS IT MOVES 
WESTWARD DURING THE NEXT COUPLE OF DAYS REACHING A POSITION FROM 
19N133W TO 11N134W BY THU MORNING. 

A TIGHT GRADIENT WILL ALSO BECOME ESTABLISHED OVER THE BAJA 
CALIFORNIA REGION WITH FRESH NORTHERLY WINDS COMMENCING IN THE 
NORTHERN GULF OF CALIFORNIA IN ABOUT 42 HOURS ALONG WITH FRESH 
WINDS WITHIN AROUND 180 NM W OF THE BAJA PENINSULA AT THE SAME 
TIME.

LONG PERIOD NW SWELL WILL CONTINUE TO PROPAGATE SE ACROSS THE 
EAST PACIFIC THROUGH 48 HOURS WITH A NEW SET OF NE SWELL MOVING 
INTO THE NORTHERN WATERS LATER TODAY. CROSS EQUATORIAL SW SWELL 
DOMINATES MOST OF THE REGIONAL WATERS E OF 120W. THESE SWELLS 
ARE MIXING WITH THE WIND WAVES GENERATING BY THE GAP WIND EVENT 
IN THE GULF OF TEHUANTEPEC. 

GAP WINDS...
N-NE MEAN FLOW AROUND THE OUTER CIRCULATION OF SLOW MOVING 
HURRICANE RINA IN THE NW CARIBBEAN WILL CONTINUE TO FUNNEL 
NORTHERLY WINDS THROUGH THE CHIVELA PASS INTO THE GULF OF 
TEHUANTEPEC. GALE FORCE WINDS ARE FORECAST TO CONTINUE IN THAT 
REGION THROUGH THIS EVENING WHEN WINDS ARE FORECAST TO DIMINISH 
BELOW GALE FORCE. SEAS UP TO 13 FT WILL ACCOMPANY THESE WINDS. 
FRESH TO STRONG WINDS WILL THEN PERSIST THROUGH WED DIMINISHING 
TO LESS THAN 20 KT BY WED NIGHT.
 
$$
GR