000
AXPZ20 KNHC 091554
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN MAY 09 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...

THE ITCZ AXIS EXTENDS ALONG 05N77W TO 03N85W TO 07N115W TO 
04N140W. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 03N TO 
06N BETWEEN 78W AND 86W AND ALSO WITHIN 15 NM OF 03N98W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 
240 NM EITHER SIDE OF A LINE FROM 09N111W TO 04N127W TO 
05N140W.  

...DISCUSSION...

AN UPPER TROUGH EXTENDS S INTO THE DISCUSSION AREA ALONG 32N128W 
TO 20N135W TO 10N135W. A UPPER LEVEL BAND OF MOISTURE CONTINUES 
JUST E OF THIS TROUGH...ROUGHLY WITHIN 150 NM EITHER SIDE OF A 
LINE FROM 20N125W TO OVER THE BAJA PENINSULA AT 27N112W...AND 
CONTINUING NE OVER NORTHWESTERN OLD MEXICO AND WESTERN TEXAS.  
THIS MOISTURE MERGES WITH ABUNDANT CONVECTIVE DEBRIS MOISTURE 
OVER CENTRAL TEXAS...AND BECOMES PART OF A LARGE PLUME NOW 
SPILLING SE OVER THE NORTHERN GULF OF MEXICO AND ALSO EXTENDING 
E ACROSS THE ENTIRE SE CONUS. A SECOND NARROW PLUME OF MOISTURE 
IS ROTATING THROUGH THE UPPER TROUGH...ROUGHLY WITH 60 NM LINE 
28N140W TO 32N123W CONTINUING NE OVER SW CALIFORNIA. DRY UPPER 
AIR IS NOTED N OF 12N W OF 128W. 

A MID TO UPPER LEVEL TROPICAL ANTICYCLONE IS ESTIMATED NEAR 
08N118W WITH A RIDGE EXTENDING E AND W ALONG 08N BETWEEN 110W 
AND 135W. A RIDGE AXIS IS ALSO EXTENDING NE TO A CREST AT 19N115W
AND APPEARS TO BE MERGING WITH A LONGWAVE RIDGE DOMINATING 
CENTRAL N AMERICA WITH ITS AXIS ROUGHLY ALONG 07W TO THE S OF 
32N. THE ASSOCIATED UPPER DIFFLUENCE IS ENHANCING ITCZ 
CONVECTION BETWEEN 120W AND 141W. THE ASSOCIATED UPPER DEBRIS 
MOISTURE HAS BEEN FANNING OUT OVER THE DISCUSSION AREA S OF 10N 
W OF 120W...WITH SOME OF THE MOISTURE NOW ADVECTED N TO 18N116W 
UNDER THE PREVIOUSLY DESCRIBED UPPER RIDGE.  

AN UPPER TROUGH HAS SWUNG OFF THE E COAST OF THE CONUS BUT STILL 
TRAILS ITS SOUTHERN SEGMENT OVER THE NW CARIBBEAN AND OVER 
CENTRAL AMERICA TO 15N93W WHERE A SMALL UPPER CYCLONE IS 
OBSERVED. THIS UPPER TROUGH CONTINUES S OVER THE TROPICAL 
PACIFIC TO THE EQUATOR AT 94W. AN UPPER RIDGE EXTENDS W FROM S 
AMERICA TO A GENTLE CREST OVER THE TROPICS NEAR 06N88W...AND IS 
ENHANCING THE MODERATE CONVECTION S OF 06N E OF 86W. A SMALL 
CLUSTER OF CONVECTION IS CURRENTLY DISSIPATING OVER THE SW GULF 
OF TEHUANTEPEC WITH ITS DEBRIS MOISTURE QUICKLY EVAPORATING IN  
THE DRY UPPER AIR THAT DOMINATES THE REMAINDER OF THE UPPER 
LEVELS S OF 23N E OF 105W.  

AT THE SURFACE...A BROAD RIDGE AXIS DOMINATES MOST OF THE 
DISCUSSION AREA WITH ITS AXIS MEANDERING FROM 32N135W TO 
15N105W. NE TRADES IN THE 15 TO 20 KT RANGE ARE SW OF THE RIDGE 
AXIS FROM 05N TO 27N W OF 125W. NORTHERLY WINDS IN THE 20 KT 
RANGE ARE OCCURRING N OF 27N E OF THE RIDGE TO THE BAJA 
PENINSULA AND EXPECTED TO SPREAD S TO ALONG 20N AND INCREASE TO 
20 TO 25 KT BY LATE TUE. THE ASSOCIATED N AND NE SWELLS ARE THE 
PRIMARY SWELL OVER THE WATERS W OF 110W. A NEAR SERIES OF LONG 
PERIOD SOUTHERLY SWELL WILL REACH THE EQUATOR BETWEEN 105W AND 
135W BEGINNING TONIGHT WITH ASSOCIATED SEAS BUILDING TO ABOUT 11 
FT ALONG THE EQUATOR WED.  

GAP WINDS...NE TO E WINDS AT 20 TO 25 KT ARE SURGING OVER THE 
GULF OF PAPAGAYO AND EXPECTED TO CONTINUE FOR AT LEAST 48 
HOURS...BUILDING COMBINED SEAS TO 10 FT IN ENE SWELL ALONG 10N 
TO NEAR 93W OVER THE NEXT FEW DAYS.

$$
NELSON