000
AXPZ20 KNHC 071554
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAY 07 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...

ITCZ AXIS EXTENDS ALONG 08N78W TO 06N110W TO 06N123W TO 04N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 
NM OF 07N104W AND ALSO WITHIN 90 NM EITHER SIDE OF A LINE FROM  
11N110W TO 08N120W. ISOLATED MODERATE AND STRONG NOTED ELSEWHERE 
FROM 05N TO 10N BETWEEN 92W AND 112W.
 
...DISCUSSION...

AN UPPER TROUGH EXTENDS WSW ALONG 32N110W TO 30N130W AND INTO AN 
UPPER CYCLONE CUTTING OFF NEAR 22N136W. DEBRIS MOISTURE IS 
SPREADING NE OVER THE AREA FROM 15N TO 28N BETWEEN 130W AND 
120W. MOISTURE IS ALSO NOTED NW OF LINE 28N140W TO 32N130W. 
IMMEDIATELY TO THE S...AN UPPER SHORTWAVE RIDGE EXTENDS E INTO 
THE AREA ALONG 03N140W TO A SHARP CREST AT 00N124W. UPPER DEBRIS 
MOISTURE FROM ITCZ CONVECTION W OF 140W IS SPREADING E OVER THE 
AREA UNDER THE RIDGE...ROUGHLY WITHIN 180 NM EITHER SIDE OF LINE 
07N140W TO 00N124W. OTHERWISE THE UPPER LEVELS ARE DRY W OF 130W 
AND N OF 28N E OF 125W. 

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 16N104W. A BROAD 
RIDGE COVERS THE UPPER LEVELS N OF THE ITCZ BETWEEN 115W AND 
92W. ITCZ CONVECTION IS ENHANCED BETWEEN 108W AND 120W WITH THE 
DEBRIS MOISTURE SPREADING N TO NEAR 15N 114W WHERE IT EVAPORATES 
IN THE DRY AIR ACCOMPANYING THE RIDGE ELSEWHERE BETWEEN 120W AND 
85W.

AN UPPER SHORTWAVE TROUGH EXTENDS S OVER THE NW CARIBBEAN AND 
CENTRAL AMERICA TO A BASE OVER THE E PACIFIC NEAR 05N89W. ONLY A 
SMALL CLUSTER OF CONVECTION IS NOTED NEAR 05N93W...BUT 
CONVECTION IS ALSO ENHANCED N OF AREA OVER THE SW CARIBBEAN NEAR 
11N80W.

AT THE SURFACE...A BROAD RIDGE AXIS DOMINATES MOST OF THE 
DISCUSSION AREA WITH ITS AXIS MEANDERING FROM 32N133W TO 
14N100W. NE TRADES IN THE 15 TO 20 KT RANGE ARE SW OF THE RIDGE 
AXIS FROM 05N TO 26N W OF 130W. TO THE NE OF THE RIDGE... 
NORTHERLY WINDS IN THE 20 KT RANGE ARE OCCURRING ELSEWHERE N OF 
20N BETWEEN 130W AND 115W. THE ASSOCIATED NE SWELLS ARE 
MIXING WITH CROSS EQUATORIAL SW SWELL OVER MOST OF THE WATERS E 
130W. 

A LOW LEVEL TROUGH IS ANALYZED THIS MORNING FROM 08N117W TO 
12N115W.  

GAP WINDS...NE-E WINDS OF 20 KT ARE SURGING OVER THE GULF OF 
PAPAGAYO AND EXPECTED TO INCREASE TO 20 TO 25 KT ON SAT AND SUN.

$$
NELSON