000
AXPZ20 KNHC 300954
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JAN 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 
0945 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 07N78W TO 03N106W TO 03N140W. 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 NM OF 04N78W AND 
05N86W.

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS N OF THE AREA NEAR 40N130W. 
ANOTHER UPPER ANTICYCLONE IS CENTERED OVER THE TROPICS AT 
12N106W WITH A RIDGE EXTENDING NW TO NEAR 28N140W. AN UPPER 
CYCLONE IS NEAR 31N124W...MOVING W WITH TIME...WITH A TROUGH 
EXTENDING W TO NEAR 29N133W...EFFECTIVELY SEPARATING THE TWO 
UPPER RIDGES. A MOISTURE PLUME ORIGINATING FROM FORMER ITCZ 
CONVECTION THAT FLARED W OF AREA NEAR 157W...IS NOW STREAMING NE 
UNDER THE UPPER RIDGE...ROUGHLY FROM 17N TO 27N BETWEEN 128W AND 
143W. THE UPPER FLOW IS VERY DIFFLUENT IN THIS AREA AND 
CONVECTION COULD BE ENHANCED. OTHERWISE...UPPER LEVEL DRY AIR IS 
NOTED N OF 28N BETWEEN 95W AND 127W AND OVER THE TROPICS...S OF 
23N E OF 110W AND S OF S OF 15N BETWEEN 110W AND 135W.   

AT THE LOW LEVELS A RIDGE EXTENDS FROM 32N135W TO 12N104W. 
SURFACE WINDS TO THE SW OF THIS RIDGE AT 20 TO 25 KT WITH SEAS 
TO 11 FT NEAR 11N140W. WINDS NW OF THE RIDGE HAVE DIMINISHED 
OVER THE PACIFIC WATERS...BUT CONTINUE AT NW AT 20 KT 
THROUGHOUT MOST OF THE GULF OF CALIFORNIA. THESE WINDS ARE 
EXPECTED TO PERSIST TONIGHT AND SAT DIMINISHING TO LESS THAN 20 
KT SAT NIGHT. 

GAPS...N WINDS HAVE BEEN SURGING TO 20 KT IN GULF OF TEHUANTEPEC 
AS A COLD FRONT MOVES INTO THE CENTRAL BAY OF CAMPECHE. HIGH
PRESSURE IN WAKE OF FRONT IS EXPECTED TO TRACK OVER THE NW GULF 
OF MEXICO AND THIS WILL INCREASE THE NORTHERLY WINDS TO MINIMAL 
GALE FORCE THIS AFTERNOON...AND FURTHER INCREASE TO MINIMAL 
STORM FORCE TONIGHT CONTINUING WELL INTO MID DAY SAT...THEN 
DIMINISH TO GALE SAT NIGHT INTO SUN MORNING...THEN QUICKLY 
DIMINISH TO LESS THAN 20 KT BY SUNSET SUN. NE WINDS IN AND 
DOWNSTREAM OF THE GULF OF PAPAGAYO HAVE ALSO BEEN SURGING TO 20 
KT. EXPECT LITTLE CHANGE SAT...THEN WINDS SHOULD SURGE THROUGH 
ALL THE PACIFIC GAPS FROM COSTA RICA TO GUATEMALA SUN. BY THEN 
THE ASSOCIATED FRONT SHOULD BE DISSIPATING OVER THE SW CARIBBEAN 
WITH N WINDS INCREASING TO 20 KT IN AND DOWNSTREAM OF THE PANAMA 
COASTAL WATERS BY SUNSET SUN.             

$$
NELSON