000
AXPZ20 KNHC 301002
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON NOV 30 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...
AXIS ALONG 06N77W TO 09N90W TO 06N101W TO 06N115W TO 10N126W TO 
10N140W.  ISOLATED MODERATE CONVECTION WITHIN 45 NM OF AXIS E OF 
97W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 75 NM 
OF AXIS FROM 104W-110W.  SCATTERED MODERATE CONVECTION WITHIN 60 
NM OF AXIS W OF 131W.

...DISCUSSION...
SHARP LARGE AMPLITUDE DEEP LAYER TROUGH DIPS INTO E PAC FROM 
WELL DEFINED CYCLONE OVER SW ARIZONA THROUGH 17N119W BRINGS 
LARGE PLUME OF TROPICAL MOISTURE WITH 125 KT JET CORE ACROSS 
NORTHERN MEXICO TO FEED FRONTAL BOUNDARY NOW OVER SE TEXAS.  
SURFACE LOW PRES 1011 MB PRESENTLY FUNNELING NW TO N WINDS INTO 
GULF OF CALIFORNIA WILL MOVE QUICKLY NE EFFECTIVELY DIMINISHING 
WINDS BELOW 20 KT TUE.  DOWNSTREAM MID TO UPPER LEVEL RIDGE 
MAINTAINS VERY DRY SUBSIDING AIR MASS SE OF TROUGH AXIS WITH 
ONLY ISOLATED CONVECTION ALONG ITCZ AXIS E OF 100W.  ONLY 
MECHANICAL UPLIFT CAUSED BY SURFACE TROUGH ALONG 108W CAUSE 
ISOLATED CONVECTION ALONG ITCZ.  OTHERWISE ONLY OTHER 
SIGNIFICANT CONVECTION NOTED ALONG ITCZ IS IN VICINITY OF BROAD 
COMPLEX LOW PRES AREA W OF 130W.  

MODEL GUIDANCE SPLIT IN SOLUTIONS TO COMPLEX SURFACE LOW PRES 
AREA WITH GFS BRINGING...APPARENTLY TROPICAL...VORTICITY MAXIMUM 
FROM WELL W OF AREA AND SPINNING GALE FORCE WINDS W OF 130W 
ABSORBING COMPLEX LOW PRES AREA.  EUROPEAN...NAM AND NOGAPS 
SOLUTION DIFFER SIGNIFICANTLY FROM GFS SOLUTION AND BAROCLINIC 
CONDITIONS N OF 25N W OF 130W TRUMP GFS GUIDANCE.  FORECAST 
FOLLOWS ECMWF WHICH HAS TAMED VORT MAX ENTER E PAC MUCH LATER... 
WELL BEYOND FORECAST PERIOD...AND IS ABSORBED BY BAROCLINIC 
BOUNDARY WITH LITTLE EFFECT OF WINDS AND SEAS.

ELSEWHERE AT THE SURFACE...
TROUGH...REMNANTS OF PREVIOUS LOW PRES...ALONG 108W CONTINUES TO 
WEAKEN AS IT ENCOUNTERS HOSTILE SW SHEAR AND VERY DRY AIR ALOFT.
SYSTEM EXPECTED TO DISSIPATE WITHIN 24 HRS WHILE SEAS CONTINUE 
UNDER LARGE NW SWELLS.  ELSEWHERE...1025 MB HIGH PRES CENTER AT 
38N133W WITH RIDGE EXTENDING SE INTO BASIN TO 15N110W.  RIDGE 
FORCES NE TRADE WINDS W OF 120W...BUT WEAKEN AS HIGH PRES CENTER 
SHIFT NE.  AREA OF STRONG TRADES DIMINISH STRENGTH AND COVERAGE 
NEXT 48 HOURS.

HIGH PRES CENTER FORCED OUT BY COLD FRONT APPROACHING NW CORNER 
OF BASIN TUE.  SW WINDS AND HIGHER SEAS ASSOCIATED WITH FRONT 
EXPECTED TUE AND WED AS FRONT WEAKENS AND STAYS N OF 25N.  
ANOTHER EPISODE OF LARGE LONG PERIOD NW SWELLS SPREADING SE 
FOLLOW COLD FRONT LATE IN FORECAST PERIOD. 

...GAP WINDS...
EASTERLY TRADE WINDS ACROSS W CARIBBEAN CONTINUE TO FUNNEL WINDS 
THROUGH GULF OF PAPAGAYO AND DOWNSTREAM WATERS TO 90W. 

$$
WALLY BARNES