000
AXPZ20 KNHC 292137
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON MAY 29 2006

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 
2115 UTC.

...SPECIAL FEATURE...

TROPICAL STORM ALETTA IS ESTIMATED NEAR 15.9N 102.1W AT 2100 
UTC. THIS POSITION IS ABOUT 120 MILES...195 KM...SOUTH OF 
ZIHUATANEJO MEXICO. ALETTA IS MOVING W AT 5 KT. ESTIMATED 
MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND 
SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 150 NM ONLY OVER SE QUADRANT. SHEAR IS 
EXPECTED TO BRIEFLY WEAKEN AND STRENGTHEN AGAIN IN ABOUT 36 
HOURS SO THE ADVISORY MENTIONS A SLIGHT INCREASE FOR A DAY OR 
SO...WITHIN A WEAKENING TREND THEREAFTER. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC 
FOR MORE DETAILS. 

...TROPICAL WAVES...

A TROPICAL WAVE ALONG 97W N OF 2N HAS MOVED W 10 KT THE PAST OF 
DAYS. SCATTERED MODERATE CONVECTION NOTED WITHIN 60 NM OF THE 
WAVE AXIS FROM 4N TO 11N.

..ITCZ...

ITCZ AXIS IS CENTERED ALONG...AXIS ALONG 9N83W 7N95W 14N112W 
7N126W 7N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 30 NM 
EITHER SIDE OF LINE 5N80W 5N90W AND WITHIN 60 NM EITHER SIDE OF 
LINE 13N112W 7N125W. SCATTERED MODERATE FROM 5N TO 11N BETWEEN 
90W AND 100W AND WITHIN 90 NM EITHER SIDE OF LINE 7N125W 7N140W.

...DISCUSSION...

A SLIGHTLY NEGATIVE TILT SHORTWAVE TROUGH EXTENDS SSE INTO THE 
DISCUSSION AREA ALONG 32N116W TO ANOTHER UPPER CYCLONE NEAR 
24N96W. AN UPPER ANTICYCLONE IS FORMING NEAR 27N135W. TWO 
TROPICAL UPPER ANTICYCLONES SEEM TO HAVE MERGED NEAR 13.5N110W 
WITH A RIDGE EXTENDING SW TO BEYOND 8N140W. A RIDGE ALSO EXTENDS 
NE ACROSS THE TROPICAL CYCLONE TO A CREST NEAR 21N95W. 

DRY UPPER AIR IS INDICATED WITHIN A 300 NM WIDE BAND DEFINED BY 
POINTS 16N148W 24N130W 27N103W. ANOTHER AREA OF DRY AIR IS
INDICATED WITHIN 180 NM EITHER SIDE OF LINE 11N125W 20N114W
AND YET ANOTHER IS WITHIN 120 NM EITHER SIDE OF LINE 20N106W 
11N107W. DEBRIS MOISTURE FROM ITCZ CONVECTION W OF 133W IS 
ADVECTED NE AND REMAINS UNDER THE RIDGE WITHIN 120 NM EITHER 
SIDE OF LINE 9N137W 18N123W. UPPER DIFFLUENCE UNDER THE RIDGE TO 
THE E OF 120W IS ENHANCING CONVECTION ALONG THE ITCZ BETWEEN 
120W AND 110W...BUT THE DEBRIS MOISTURE REMAINS UNDER THE UPPER 
RIDGE. 

AT THE LOW LEVELS A HIGH PRES IS AT 32N137W 1026 MB WITH A RIDGE 
EXTENDING SE TO 16N105W. SCATTERED TO BROKEN STRATOCUMULUS IS 
OBSERVED SW OF LINE 32N123W 16N109W. 

AN UPPER ANTICYCLONE IS CENTERED OVER S AMERICA AT 9S68W WITH A 
RIDGE EXTENDING NW ACROSS THE EQUATOR TO A SHARP CREST AT 
10N99W. UPPER DIFFLUENCE UNDER THIS RIDGE IS ENHANCING 
CONVECTION ALONG THE ITCZ E OF 100W WITH THE DEBRIS MOISTURE 
OBSERVED FROM 2N TO 12N BETWEEN 98W AND 70W. 

$$
NELSON