000
AXPZ20 KNHC 220356
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE FEB 22 2011

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0330 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED FROM 06N77W 
TO 00N88W THEN CONTINUES FROM 03N112W TO 04N130W TO 02N140W. NO 
SIGNIFICANT CONVECTION.

...DISCUSSION...

THE LONGWAVE UPPER PATTERN IS EXPECTED TO CHANGE LITTLE OVER 
THE NEXT TWO DAYS AND FEATURES AN UPPER TROUGH WITH MEAN AXIS 
ALONG 125W BOOKENDED BY RIDGING WITH THE EASTERN RIDGE LYING 
OVER THE FORECAST AREA ALONG 94W/95W...AND THE WESTERN RIDGE W 
OF THE AREA ALONG 150W. A SHORTWAVE TROUGH WAS NOTED IN THE 
TROPICS EXTENDING FROM 15N122W TO 05N117W WITH AN AREA OF MAINLY 
MID LEVEL MOISTURE BEING ADVECTED TO THE N AHEAD OF THE UPPER 
TROUGH AXIS BY SOUTHERLY WINDS OF 30-40 KT AT THE UPPER LEVELS. 

FARTHER NW AND N...HIGH PRES DOMINATES AT THE SURFACE. RIDGING 
EXTENDS INTO THE AREA THROUGH 30N137W TO 26N125W TO 17N105W.
NW WINDS HAVE BEGUN TO DECREASE ALONG THE W COAST OF THE BAJA 
CALIFORNIA PENINSULA ON THE E EDGE OF THIS RIDGING WHICH 
APPEARS TO BE SLOWLY WEAKENING. A VIGOROUS UPPER LEVEL LOW AND 
ASSOCIATED SHORTWAVE TROUGH NOW LOCATED OFF THE CALIFORNIA COAST 
NEAR 36N127W IS DROPPING SWD AT 25 KT AND IS EXPECTED TO PROVIDE 
SUPPORT FOR A COLD FRONT WHICH WILL SWEEP INTO THE FAR N 
PORTIONS OF THE DISCUSSION AREA ALONG 30N125W TO 28N130W TO 
30N138W JUST BEFORE SUNRISE TUE AND EXTEND FROM 28N120W TO TO 
26N135W BY LATE TUE. THIS FRONT WILL USHER IN NORTHERLY WINDS OF 
20 TO 30 KT WITH SEAS BUILDING 8 TO 16 FT. THE LATEST GFS 
ENSEMBLE FORECASTS DEPICT A SLIM PROBABILITY...10 PERCENT... OF 
GALE FORCE WINDS BEHIND THE FRONT WELL N OF 30N.

THE PRES GRADIENT BETWEEN THE ANOMALOUSLY SOUTHERN ITCZ AND THE 
RIDGING N OF IT IS MAINTAINING FRESH TRADE WINDS AS FAR S AS 
06N. THE SURFACE TROUGH WHICH WAS EMBEDDED IN THE ITCZ EARLIER 
HAS DEGENERATED WITHIN THE LARGER ITCZ. THE AREA OF TRADES IS 
EXPECTED TO GRADUALLY RETREAT WESTWARD THROUGH WED MORNING AS 
THE SURFACE RIDGING IS COMPROMISED BY THE APPROACHING DEEP 
LAYERED LOW AND COLD FRONT. 

GAP WINDS...
GULF OF PAPAGAYO...FRESH NE TRADE WINDS WILL CONTINUE TO SPILL 
FROM THE WESTERN CARIBBEAN INTO THE GULF OF PAPAGAYO WITH 20 KT 
WINDS MOST PREVALENT DURING THE EARLY MORNING HOURS WHEN THE 
NIGHTTIME MOUNTAIN DRAINAGE FLOW IS AT A MAXIMUM.

GULF OF PANAMA...THE PRES GRADIENT OVER NW COLOMBIA WILL 
CONTINUE TO BE TIGHT ENOUGH TO SUPPORT FRESH NORTHERLY WINDS 
UNTIL TUE AFTERNOON. 

$$
COBB