000
AXPZ20 KNHC 032155
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAR 03 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...ITCZ...
AXIS ALONG 02N77W TO 01N100W TO 03N130W TO 01N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 60 NM OF 04N92W.

...DISCUSSION...

A LONGWAVE TROUGH DOMINATES THE EASTERN N PACIFIC WITH ITS AXIS 
EXTENDING S INTO THE DISCUSSION AREA FROM 32N131W TO 20N140W. A 
BAND OF DRY UPPER AIR IS SWEEPING THROUGH THE PATTERN WITHIN 120 
NM EITHER SIDE OF LINE 32N122W TO 24N140W. AN UPPER ANTICYCLONE 
IS CENTERED AT 20N11W WITH A RIDGE EXTENDING N TO WELL BEYOND 
32N103W...AND DOMINATING THE UPPER LEVELS OF CENTRAL N AMERICA. 
A LONGWAVE TROUGH OVER THE EASTER SEABOARD OF THE CONUS EXTENDS 
SW ALONG 23N83W TO 13N90W TO BASE NEAR 02N100W. UPPER DEBRIS 
MOISTURE...ORIGINATING FROM CONVECTION IN THE TROPICAL CENTRAL 
PACIFIC...CONCENTRATES INTO A PLUME AROUND THE W PERIPHERY OF 
THE RIDGE...WITHIN 180 NM EITHER SIDE OF POINTS 17N133W TO 
BEYOND 32N113W THEN SPILLING EASTWARD ACROSS THE RIDGE OVER THE 
CENTRAL CONUS. SOME OF THIS DEBRIS MOISTURE IS NOW PLUNGING SE 
OVER CENTRAL GULF OF MEXICO. CONVECTION IS ENHANCED ALONG THE 
ITCZ NEAR 03N93W WITH THE DEBRIS MOISTURE ADVECTED E NE ACROSS 
COSTA RICA. OTHERWISE THE UPPER LEVELS ARE VERY DRY E OF 115W.

GAP WINDS...N WINDS IN AND DOWNSTREAM OF THE GULF OF TEHUANTEPEC 
HAVE DIMINISHED BELOW GALE AND WILL CONTINUE TO WEAKEN TO ABOUT 
20 KT ON THU. NE WINDS IN THE GULF OF FONSECA AND THE GULF OF 
PAPAGAYO CONTINUE AT 20 TO 30 KT...AND EXPECTED TO DIMINISH TO 
20 TO 25 KT WED AND THU...BUT MAY SEE A BRIEF 30 KT JUST AFTER 
SUNRISE WED. THESE GAP WINDS ARE GENERATING A BROAD SWATH OF 
EASTERLY SWELL THAT WILL PROPAGATE W TO AROUND 115W MIXING WITH 
ONGOING NW SWELL. CARIBBEAN TRADES ARE PUSHING THROUGH THE 
ISTHMUS OF PANAMA MAINTAINING 20 TO 25 NORTHERLY FLOW THROUGH 
THE GULF OF PANAMA THROUGH THU.  

$$
NELSON