000
AXPZ20 KNHC 101551
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON MAY 10 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 13N85W TO 05N95W TO 
05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED FROM 03N TO 07N E OF 86W...WITHIN 30 NM EITHER SIDE OF 
A LINE FROM 06N87W TO 07N95W...AND FROM 03N TO 12N BETWEEN 106W 
AND 123W...AND ALSO WITHIN 120 NM EITHER SIDE OF A LINE FROM 
04N123W TO 06N138W. 

...DISCUSSION...

AN UPPER TROUGH EXTENDS S INTO THE DISCUSSION AREA ALONG 32N112W 
TO 08N133W. THIN UPPER MOISTURE IS NOTED ALONG 26N BETWEEN 120W 
AND 140W. UPPER DRY AIR ACCOMPANIES THE TROUGH FROM 28N TO 33N 
FROM SOUTHERN ARIZONA TO BEYOND 140W. UPPER DRY AIR IS ALSO 
INDICATED FROM 11N TO 22N W OF 125W.  

A MID TO UPPER LEVEL TROPICAL ANTICYCLONE IS ESTIMATED NEAR 
11N114W WITH A RIDGE EXTENDING E AND W ALONG 08N BETWEEN 105W 
AND 127W. A RIDGE AXIS IS ALSO EXTENDING NE TO BEYOND 32N92W 
MERGING WITH A LONGWAVE RIDGE DOMINATING CENTRAL N AMERICA.
CYCLONIC LOW LEVEL TURNING IDENTIFIES A LOW LEVEL TROUGH 
EXTENDING FROM 10N117W TO 04N121W. UPPER DIFFLUENCE IS ENHANCING 
CONVECTION ALONG THIS TROUGH...AND ALONG THE ITCZ BETWEEN 110W 
AND 135W. THE ASSOCIATED DENSE UPPER DEBRIS MOISTURE IS ADVECTED 
NE UNDER THE UPPER RIDGE NARROWING INTO A TROPICAL MOISTURE 
PLUME CONTINUING NE OVER OLD MEXICO...ROUGHLY WITHIN 150 NM OF 
LINE FROM 20N115W TO BEYOND 32N102W. THIS PLUME MERGES WITH A 
LARGE PLUME OF UPPER MOISTURE NOW SPILLING E ACROSS THE SE 
CONUS. 

AN UPPER TROUGH HAS SWUNG OFF THE E COAST OF THE CONUS BUT STILL 
TRAILS ITS SOUTHERN SEGMENT OVER THE NW CARIBBEAN AND CENTRAL 
AMERICA TO 14N92W WITH THE UPPER TROUGH CONTINUING S OVER THE 
TROPICAL PACIFIC TO THE EQUATOR AT 100W. AN UPPER RIDGE EXTENDS 
W FROM S AMERICA TO A GENTLE CREST OVER THE TROPICS NEAR 06N90W. 
THE ASSOCIATED UPPER DIFFLUENCE IS ENHANCING CONVECTION FROM 03N 
TO 07N E OF 85W. SMALL CLUSTERS OF CONVECTION ARE DISSIPATING 
07N93W AND 11N101W. OTHERWISE...DRY UPPER AIR DOMINATES THE 
REMAINDER OF THE UPPER LEVELS S OF 20N E OF 103W.  

AT THE SURFACE...A BROAD RIDGE AXIS DOMINATES MOST OF THE 
DISCUSSION AREA WITH ITS AXIS MEANDERING FROM 32N130W TO 
15N105W. NE TRADES IN THE 15 TO 20 KT RANGE ARE SW OF THE RIDGE 
AXIS FROM 06N TO 27N W OF 120W. NORTHERLY WINDS IN THE 20 KT 
RANGE ARE OCCURRING N OF 22N E OF THE RIDGE TO THE BAJA 
PENINSULA. THE ASSOCIATED N AND NE SWELLS ARE THE PRIMARY SWELL 
OVER THE WATERS N OF THE ITCZ W OF 110W. A NEAR SERIES OF LONG 
PERIOD SOUTHERLY SWELLS ARE CROSSING THE EQUATOR BETWEEN 105W 
AND 135W AND EXPECTED TO BUILD THE COMBINED SEAS TO ABOUT 11 FT 
OVER THE WATERS S OF 07N W OF 95W 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.

$$
NELSON