000
AXPZ20 KNHC 250930
TWDEP 

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

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 10N85W TO 10N96W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 10N96W TO 12N105W TO 11N117W 
THEN RESUMES FROM LOW PRES NEAR 12N124W TO 07N140W. ISOLATED TO 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF A 
LINE FROM 10N121W TO 07N135W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM CENTRAL CALIFORNIA NEAR 
39N120W TO 32N127W TO 18N140W. VERY DRY AIR IS NOTED IN THE WAKE 
OF THIS TROUGH OVER THE NW PORTION OF THE AREA. AN UPPER LEVEL 
RIDGE DOMINATES THE REMAINDER OF THE AREA E OF THE TROUGH 
ANCHORED BY AN ANTICYCLONE OVER 20N110W. THE UPPER TROUGH IS 
FORECAST TO DIG SOUTHWARD TO 10N136W BY THU AS THE RIDGE ALONG 
110W EXPANDS TO THE W. THIS PATTERN WILL HELP TO MAINTAIN A 
SURFACE RIDGE ACROSS THE N AND NW PORTIONS THROUGH WED.

A TIGHT SURFACE PRES GRADIENT IS OVER THE FAR NW CORNER BETWEEN 
1034 MB HIGH PRES WELL N OF THE AREA NEAR 44N134W AND 1015 MB 
LOW PRES NEAR 30N126W WITH FRESH NE WINDS N OF 29N W OF 130W 
ALONG WITH AN AREA OF 8-11 FT SEAS IN NW SWELL W OF A LINE FROM 
30N127W TO 23N140W. THE FRESH WINDS WILL EXPAND S TO 27N IN 24 
HOURS AND CONTINUING S TO 24N IN 48 HOURS WHILE THE SWELL WILL 
CONTINUE TO PROPAGATE S-SE THROUGH 48 HOURS WITH A NEW SET OF NE 
SWELL MOVING INTO THE NORTHERN WATERS MIXING WITH THE PRESENT NW 
SWELL. THIS TIGHTENED PRES GRADIENT IS ALSO PRODUCING FRESH 
TRADES FROM 08N TO 15N W OF 132W AS CAPTURED BY RECENT 0610 UTC 
ASCAT AND 0310 UTC WINDSAT SCATTEROMETER PASSES. THESE WINDS 
WILL PERSIST THROUGH 24 HOURS WHILE A SURFACE TROUGH APPROACHES 
THE W CENTRAL PORTION. FRESH WINDS WILL ACCOMPANY THE TROUGH AS 
IT MOVES WESTWARD FROM 24-48 HOURS.

A TIGHT GRADIENT WILL ALSO BECOME ESTABLISHED OVER THE BAJA 
CALIFORNIA REGION WITH FRESH NORTHERLY WINDS COMMENCING IN THE 
NORTHERN GULF OF CALIFORNIA IN 48 HOURS ALONG WITH FRESH WINDS 
WITHIN 180 NM W OF THE PENINSULA AT THE SAME TIME.

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. GALE FORCE WINDS ARE 
FORECAST TO CONTINUE THROUGH THE NEXT 12 HOURS IN THE GULF OF 
TEHUANTEPEC WHEN THEY WILL DIMINISH BELOW GALE FORCE. SEAS UP TO 
12 FT WILL ACCOMPANY THESE WINDS. FRESH TO STRONG WINDS WILL 
THEN PERSIST THROUGH WED DIMINISHING TO LESS THAN 20 KT BY WED 
NIGHT.
 
$$
LEWITSKY