000
AXPZ20 KNHC 140915
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT NOV 14 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 09N83W TO 
06N96W TO 09N111W TO 09N125W TO 11N136W. ISOLATED MODERATE 
CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS FROM 89W TO 
103W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 150 NM EITHER SIDE OF THE AXIS FROM 103W TO 116W...AND 
WITHIN 210 NM EITHER SIDE OF THE AXIS FROM 116W TO 140W. 

...DISCUSSION...

AN ASCAT PASS FROM 0602 UTC AND A QUIKSCAT PASS FROM 0308 UTC 
SHOWED EVIDENCE OF A WELL DEFINED SURFACE TROUGH EXTENDING FROM 
13N135W TO 09N140W. THE SCATTEROMETER DATA ALSO CONTINUED TO 
SHOW A BROAD AREA OF 20 TO 25 KT TRADE WINDS GENERALLY W OF 126W 
N OF 10N ASSOCIATED WITH A TIGHT PRES GRADIENT BETWEEN A 1030 MB 
SURFACE HIGH PRES CENTERED NEAR 35N148W AND THE SURFACE TROUGH. 
THE TRADE WINDS ARE PRODUCING LOCALLY GENERATED WIND WAVES AND 
THIS COUPLED WITH PERSISTENT NORTHERLY SWELL IS RESULTING IN 
COMBINED SEAS IN THE 8 TO 13 FT RANGE. THE PRES GRADIENT WILL 
REMAIN TIGHT AS THE HIGH PRES SYSTEM MOVES TO NEAR 32N127W BY 
MON. THE HIGH WILL WEAKEN BY MID WEEK AS A STRONG COLD FRONT 
APPROACHES 30N140W.

OTHERWISE...FARTHER EAST EARLY MORNING SCATTEROMETER DATA ALSO 
CAPTURED A SURFACE TROUGH EXTENDING FROM 15N113W TO 10N115W. A 
DEVELOPING 1008 MB SURFACE LOW PRES SYSTEM WAS ALSO INDICATED 
NEAR 07N89W. MODEL GUIDANCE SLOWLY MOVES THIS SYSTEM TO THE W 
WHILE HOLDING THE LOW AT 1008 MB IF NOT SLIGHTLY WEAKENING AND 
BRINGING IT TO NEAR 06N94W BY 06 UTC MON. INFRARED SATELLITE 
IMAGERY OVER THE PAST SEVERAL HOURS SHOWS THAT ANY ASSOCIATED 
CONVECTION WITH THIS SYSTEM HAS SIGNIFICANTLY WEAKENED WITH ONLY 
SCATTERED SHOWERS NOW OCCURRING. 

TO THE SOUTH...AN EARLY MORNING JASON ALTIMETER PASS SHOWED 8 FT 
SEAS ASSOCIATED WITH SOUTHERLY SWELL GENERALLY S OF 12N BETWEEN 
93W AND 118W. THIS SWELL WILL GRADUALLY SUBSIDE TO BELOW 8 FT IN
THE NEXT 36 HOURS. 

ANOTHER AREA OF CONCERN WILL BE THE GULF OF CALIFORNIA WHERE IN 
36 HOURS OR LESS NW WINDS WILL INCREASE TO 20 TO 25 KT AS AN 
INVERTED TROUGH DEVELOPS OVER THE GULF BETWEEN A HIGH PRES RIDGE 
TO THE WEST OF BAJA AND A STRENGTHENING RIDGE OVER THE U.S. 
GREAT BASIN STATES. MODEL GUIDANCE (INCLUDING GFS...NAM...AND 
ECMWF) KEEP FORECAST WINDS BELOW GALE ALTHOUGH GUSTS TO 30 KT 
WILL BE POSSIBLE. THESE WINDS WILL THEN GRADUALLY DIMINISH BY 
MID WEEK AS THE HIGH PRES RIDGE TO THE WEST WEAKENS. 

$$
LEWITSKY