000
AXPZ20 KNHC 210931
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT NOV 21 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 
0915 UTC.

...ITCZ...
THE ITCZ AXIS EXTENDS FROM 05N76W TO 04N82W TO 07N95W TO 06N108W 
TO 08N123W TO 07N140W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION WITHIN 200 NM N OF AXIS AND 120 NM S OF AXIS W OF 
118W. 

...DISCUSSION...

W OF 115W...
DEEP LAYER TROUGH IS NOW OVER THE WESTERN US. COLD FRONT EXTENDS 
FROM LOW PRESSURE OVER S NEVADA ACROSS S CALIFORNIA TOWARD THE 
CENTRAL PORTION OF THE FORECAST AREA N OF 28N. HIGH PRESSURE 
1028 MB CENTERED NEAR 34N150W AS DEPICTED IN 05Z QUIKSCAT PASS. 
THIS FEATURE WILL SHIFT TO A POSITION N OF THE FORECAST AREA 
TODAY THROUGH TONIGHT...WHERE IT WILL REMAIN THROUGH AT LEAST 
THE BEGINNING OF NEXT WEEK. THE LOCATION OF THIS HIGH PRESSURE 
CENTER WILL MAINTAIN FRESH TO STRONG TRADES FROM 08N TO 24N W OF 
117W. WHILE THE PRIMARY SWELL DIRECTION WILL CONTINUE FROM THE 
NW...NE WINDS WILL GENERATE WIND WAVES THAT MIX WITH THE NW 
SWELL. THE STRONGEST TRADES WILL BE FROM 14N TO 18N W OF 135W 
WHICH WILL PRODUCE COMBINED SEAS OF 12 FT. THE STRONGEST REGION 
OF LOW LEVEL CONFLUENCE IN THE ITCZ IS W OF 118W WHERE MODERATE 
TO FRESH SE WINDS S OF THE ITCZ CONVERGE WITH FRESH TO LOCALLY 
STRONG NE TRADES N OF THE ITCZ...WHICH HAS RESULTED IN MORE 
ACTIVE CONVECTION.   

E OF 115W...GAP WINDS WILL CONTINUE THROUGH THE WEEKEND AND 
PRODUCE 20 KT TO OCCASIONAL 25 KT WINDS IN THE GULF OF FONSECA 
AND PAPAGAYO...WITH THE STRONGER WINDS IN THE OVERNIGHT AND 
MORNING HOURS DUE TO DRAINAGE FLOW ENHANCING THE WINDS. AS 
INDICATED IN THE LATEST SCATTEROMETER PASSES...WINDS HAVE 
DIMINISHED OVER THE GULF OF TEHUANTEPEC. WINDS WILL PICK UP 
AGAIN TODAY AS WINDS BEHIND THE COLD FRONT IN THE GULF OF MEXICO 
FLOW THROUGH THE PASS. FRESH TRADEWINDS WILL CONTINUE TO FLOW 
THROUGH THE GULF OF PANAMA FOR THE NEXT 24 HOURS...THEN WILL 
DIMINISH.   

$$

AL