000
AXPZ20 KNHC 290319
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN APR 29 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N78W 9N105W 5N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 120 NM 
EITHER SIDE OF LINE 5N84W 8N98W AND ALSO WITHIN 90 NM EITHER 
SIDE OF LINE 8N115W 8N123W 5N130W.

...DISCUSSION...

AN UPPER SHORTWAVE RIDGE CONTINUES OVER THE CENTRAL PORTION OF 
THE DISCUSSION AREA CRESTING ALONG 20N140W 27N122W 25N113W. AN 
UPPER ANTICYCLONE IS ALSO NOTED NEAR 8N125W. UPPER MOISTURE IS 
OBSERVED MOSTLY UNDER THE RIDGE....ROUGHLY WITHIN 360 NM EITHER 
SIDE OF 12N140W 23N120W. 

AN UPPER SHORTWAVE TROUGH...ACCOMPANIED BY CONSIDERABLE UPPER 
MOISTURE...IS ORIENTED NW TO SE INTO THE AREA FROM 32N137W 
25N131W. A BAND OF DRY UPPER AIR IS INDICATED WITHIN 120 NM OF 
LINE 28N129W 23N140W. 

AN UPPER CYCLONE HAS STALLED OVER THE SEA OF CORTEZ NEAR 28N112W 
WITH AN UPPER TROUGH EXTENDING SW TO NEAR 12N117W. DRY UPPER AIR 
IS INDICATED OVER THE DISCUSSION AREA N OF 20N BETWEEN 116W AND 
99W...AND FROM 10N TO 20N BETWEEN 118W AND 97W. UPPER DIFFLUENCE 
N OF THE CYCLONE IS ENHANCING CONVECTION WITHIN 90 NM OF LINE 
32N111W 29N101W. THE DEBRIS MOISTURE IS FANNING N OVER OVER 
ARIZONA AND NEW MEXICO.      

UPPER ANTICYCLONES ARE NOTED NEAR 16N96W AND 11N104W. THE 
ASSOCIATED COMBINED FLOW CREATES A NE TO SW ORIENTATED UPPER 
RIDGE FROM 20N92W TO 9N110W...AND LIKELY CONTRIBUTING TO THE 
LARGE AREA OF SUBSIDENCE DESCRIBED ABOVE. 

AN UPPER ANTICYCLONE E OF THE AREA NEAR 6N61W RIDGES W ALONG 
11N83W TO A SHARP CREST OVER THE ITCZ AT 9N93W. THERE IS A 
SLIGHT ENHANCEMENT OF CONVECTION ALONG THE E PAC ITCZ E OF 97W. 
THE DEBRIS MOISTURE SPREADS NE ACROSS CENTRAL AMERICA BUT SEEMS 
TO EVAPORATE OVER THE CARIBBEAN TO THE S OF 17N AND W OF 73W.

AT THE LOW LEVELS A RIDGE EXTENDS ALONG 32N137W 12N107W. LOCALLY 
BROKEN STRATA CUMULUS IS NOTED N OF 12N W OF 112W.  

GAP WINDS...BRISK ELY TRADES OVER THE W CARIBBEAN CONTINUE TO  
SURGE INTERMITTENTLY INTO THE GULF OF PAPAGAYO AT 20 TO 25 KT... 
AND EXPECTED TO CONTINUE FOR AT LEAST A COUPLE MORE DAYS.

$$
NELSON