000
AXPZ20 KNHC 200404
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE FEB 20 2007

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0345 UTC.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE IS ALONG LINE 2N79W 2N100W 6N120W 
2N140W. SCATTERED MODERATE FROM 2N TO 6N BETWEEN 88W AND 100W. 

...DISCUSSION...
UPPER LEVELS...
SHEARED POSITIVELY TILTED MID-UPPER LEVEL TROUGH EXTENDS FROM A 
CYCLONIC CIRCULATION OVER CENTRAL ARIZONA SWWD THROUGH 30N118W 
23N130W 20N140W. STRONG UPPER LEVEL SUBSIDENCE WAS OCCURRING 
WITHIN 120 NM SE OF THE TROUGH AXIS W OF 125W. THIS TROUGH WAS 
PART OF A LONGWAVE TROUGH WHICH COVERED THE AREA N OF 15N W OF 
115W. ANTICYCLONE NEAR 30N138W PREVAILED OVER THE AREA N AND W 
OF AFOREMENTIONED TROUGH. ANOTHER LARGE ANTICYCLONE WAS LOCATED 
OVER THE TROPICAL E PACIFIC NEAR 15N95W DOMINATED THE AREA E OF 
115W. AXIS OF SUBTROPICAL JTST EXTENDED FROM 17N140W ENEWD 
THROUGH 23N125W CENTRAL BAJA CALIFORNIA/NW MEXICO TO THE SRN 
PLAINS/TEXAS. SATELLITE DERIVED WINDS INDICATED CORE SPEEDS OF 
120-145 KT. JET WAS ADVECTING SOME MID-UPPER LEVEL MOISTURE NEWD 
OVER THE TROPICAL PACIFIC AND NRN MEXICO.    

SURFACE...
RIDGE AXIS EXTENDED FROM A 1033 MB HIGH NEAR 32N148W SEWD 
AND DOMINATED THE AREA N OF 10N W OF 110W. WEAKENING COLD FRONT 
WAS OVER THE SEA OF CORTEZ AND BAJA CALIFORNIA N OF 29N. 

MODERATE 20-25 KT TRADES ARE IN THE AREA NORTH OF THE ITCZ AND 
SOUTH OF 25N W OF ABOUT 125W.

GAP WINDS...
THE EDGE OF A HIGH RESOLUTION QUIKSCAT PASS SUGGESTS WINDS HAVE
DECREASED MARKEDLY OVER THE GULF OF TEHUANTEPEC WITH WINDS 
BARELY 20 KT. LATEST NWP MODELS ARE FORECASTING THE WINDS TO 
DECREASE TO LESS THAN 20 KT WITHIN THE NEXT 12 HOURS. 

THE SAME QUIKSCAT PASS ALSO INDICATED THAT WINDS HAVE DECREASED 
BELOW GALE FORCE IN THE GULF OF PAPAGAYO AND FONSECA 6-12 HOURS 
AHEAD OF SCHEDULE WITH 20-25 KT NE WINDS NOTED. THESE WINDS ARE 
EXPECTED TO DROP TO 20 KT OR SO THROUGH 48 HOURS. 

20 KT WINDS WERE NOTED IN THE GULF OF PANAMA...HOWEVER THESE 
WINDS WILL DECREASE TO LESS THAN 20 KT IN ABOUT 18-24 HOURS.

$$
COBB