000
AXPZ20 KNHC 290938
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU DEC 29 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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

MONSOON TROUGH AXIS 09N85W TO 07N90W. ITCZ AXIS FROM 07N90W TO 
04N98W TO 08N120W TO BEYOND 06N140W. SCATTERED MODERATE 
CONVECTION FROM 12N TO 16N BETWEEN 130W AND 135W.

...DISCUSSION...

W OF 110W...A CUT OFF MID TO UPPER LEVEL CYCLONE REMAINS 
ANCHORED NEAR 17N142...WITH TROUGH EXTENDING NE TO 30N128W. GOES 
DERIVED HIGH DENSITY WINDS SHOW STRONGLY DIVERGENT UPPER 
FLOW...SUPPORTING AND AMPLIFYING A SURFACE TROUGH FROM 16N135W 
TO 11N135W. A SECOND LOWER AMPLITUDE SURFACE TROUGH IS NOTED 
FURTHER TO THE SE ALONG THE ITCZ NEAR 125W...MIGRATING W. 20 TO 
25 KT TRADEWIND FLOW COVERS MUCH OF THE AREA FROM 12N TO 25N W 
OF 120W...BETWEEN THE TROUGHING TO THE SOUTH AND A 1030 MB 
SURFACE CENTERED N OF THE AREA NEAR 35N130W. TRADEWIND 
CONVERGENCE IS WORKING IN CONCERT WITH THE UPPER DIVERGENT FLOW 
TO ENHANCE CONVECTION E OF THE FIRST SURFACE TROUGH FROM 12N TO 
16N BETWEEN 130W AND 135W. THE FORECAST THROUGH 48 HOURS 
MAINTAINS 20 TO 25 KT TRADEWINDS WITH THE STRONGEST WINDS NEAR 
135W. THE MORE AGGRESSIVE GFS MODELS AND RELATED WAVEWATCH WAVE 
MODEL ARE LIKELY SHOWING SOME CONVECTIVE FEEDBACK ISSUES...AND 
FORECAST FAVORS MORE CONSERVATIVE ECMWF. NW SWELL

E OF 110W...OVERNIGHT DRAINAGE EFFECTS AND FRESH E FLOW WILL 
MAINTAIN 20 TO 25 KT GAP FLOW THROUGH THE GULF OF PAPAGAYO OVER 
THE NEXT COUPLE OF DAYS WITH PEAK WINDS IN THE EARLY MORNING 
HOURS. A 0342 UTC ASCAT PASS SHOWED GAP WIND FLOW THROUGH THE 
GULF OF PAPAGAYO PERSISTING WITH WINDS TO 20 KT REACHING AS FAR 
W AS 89W. FURTHER N...GAP FLOW THROUGH THE GULF OF TEHUANTEPEC 
CONTINUES TO DIMINISH...ALTHOUGH ASSOCIATED SEAS TO 9 FT IN NE 
SWELL PERSIST SW OF THE TEHUANTEPEC AREA...MIXING WITH E SWELL 
OUT OF THE PAPAGAYO AREA...GENERALLY FROM 05N TO 11N BETWEEN 90W 
AND 110W. LIMITED DEEP LAYER MOISTURE UNDER AN UPPER RIDGE ALONG 
WITH NO LOW LEVEL FORCING IS SUPPRESSING CONVECTIVE DEVELOPMENT 
E OF 110W.

GULF OF CALIFORNIA...A 0040 UTC WINDSAT PASS SHOWED NW WINDS TO 
20 KT OVER THE SOUTHERN HALF OF THE GULF OF CALIFORNIA. HIGH 
PRES NW OF THE AREA WILL WEAKEN AND SHIFT FURTHER W...ALLOWING 
THESE WINDS TO DIMINISH TODAY.

$$
CHRISTENSEN