000
AXPZ20 KNHC 242146
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JUL 24 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.

...TROPICAL WAVES...
A TROPICAL WAVE IS N OF 05N ALONG 88W AND HAS MOVED W AT ABOUT 
23 KT OVER THE PAST 24 HOURS. SLIGHT CYCLONIC TURING IS NOTED 
ALONG THE WAVE AXIS AT 10N WITH CONVECTION MOSTLY ENHANCED 
WITHIN 120 NM W OF THE AXIS TO THE S OF 10N.
 
A TROPICAL WAVE TO THE N OF 04N ALONG 102W HAS MOVED W AROUND 25 
KT OVER THE PAST FEW DAYS. THE WAVE IS MOVING UNDER THE W 
PERIPHERY OF AN UPPER RIDGE WITH THE ASSOCIATED DIFFLUENCE 
ENHANCING CONVECTION FROM 07N TO 17N WITHIN 120 NM OF THE WAVE 
WITH NUMEROUS LIGHTNING STRIKES CURRENTLY NEAR 13N104W.
   
A TROPICAL WAVE EXTENDS FROM 04N TO 14N ALONG 111W AND HAS MOVED 
W AT ABOUT 20 KT OVER THE PAST 48 HOURS. THE WAVE IS MOVING 
THROUGH AN AREA OF UNFAVORABLE UPPER SUPPORT AND CONVECTION IS S 
SUPPRESSED N OF 10N WITH ONLY A FEW CLUSTERS NOTED ALONG THE 
WAVE S OF 10N.

A TROPICAL WAVE IS ANALYZED FROM 08N TO 14N AROUND 135W BUT IS 
DIFFICULT TO LOCATE. THIS WAVE IS MOVING THROUGH AN AREA OF 
SOUTHWESTERLY UPPER SHEAR THAT IS STRETCHING CONVECTION WELL TO 
THE E OF THE SURFACE SIGNATURE.

...ITCZ...
THE AXIS IS NOTED ALONG POINTS FROM 08N77W TO 09N103W TO 06N120W 
TO 12N134W TO 10N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED WITHIN 180 NM EITHER SIDE OF LINE FROM 
04N78W TO 07N92W TO 14N101W TO 06N105W...AND ALSO WITHIN 60 NM 
OF A LINE FROM 11N126W TO 14N130W TO 09N138W. 

...DISCUSSION...
AN UPPER LEVEL TROPICAL ANTICYCLONE IS CENTERED NEAR 11N137W 
WITH AN UPPER RIDGE EXTENDING E TO W OVER THE ITCZ BETWEEN 126W 
AND 149W. THE DEBRIS MOISTURE SEEMS TO REMAIN WITHIN RIDGE 
ENVELOPE...ROUGHLY FROM 06N TO 16N. AN UPPER ANTICYCLONE IS 
CENTERED OVER THE NEW MEXICO AND ARIZONA BORDER NEAR 34N109W 
WITH A RIDGE EXTENDING SE TO RIDGE CREST OVER OLD MEXICO AT 
24N101W. ANOTHER UPPER ANTICYCLONE IS CENTERED OVER SOUTHERN OLD 
MEXICO NEAR 17N96W WITH ITS ASSOCIATED UPPER DIFFLUENCE 
ENHANCING CONVECTION OVER THE TROPICAL E PACIFIC BETWEEN 109W 
AND 78W...WITH THE RESULTANT DEBRIS MOISTURE BASICALLY REMAINING 
UNDER THE UPPER RIDGE.

A MID TO UPPER LEVEL CYCLONE IS CENTERED NEAR 33N142W WITH ITS 
CYCLONIC FLOW DOMINATING THE UPPER LEVELS N OF 21N W OF 128W 
WHERE UPPER DEBRIS MOISTURE IS ALSO NOTED. A BAND OF DRY UPPER 
AIR IS NOTED N OF 13N BETWEEN 120W AND 126W. ANOTHER UPPER 
TROUGH IS WEAKENING OVER THE TROPICS S OF 19N ALONG 111W.

GAP WINDS...NE TO E WINDS IN AND DOWNSTREAM OF THE GULF OF 
PAPAGAYO WILL PULSE TO 20 KT THROUGH SAT...THEN INCREASE TO 20 
TO 25 KT SUN. NE WINDS AT 15 TO 20 KT SURGED THROUGH THE GULF OF 
TEHUANTEPEC THIS MORNING AND ARE EXPECTED TO CONTINUE THROUGH 
SAT. SOUTHERLY SWELLS ARE MIXING WITH THESE GAPS WINDS. 

THE LONG PERIOD SOUTHERLY SWELLS RESULTING IN SEAS TO AT LEAST 8 
FT ARE OBSERVED S OF A LINE FROM 17N140W TO 22N110W EXTENDING E 
ALONG HE COAST OF CENTRAL AMERICA TO 85W. THESE SWELLS SHOULD 
BEGIN TO DIMINISH TONIGHT AND ONLY BE OF CONCERN S OF 12N 
BETWEEN 125W AND 90W BY LATE SUN.

$$
NELSON