000
AXPZ20 KNHC 101611
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAR 10 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 1N79W 8N88W 3N124W 4N140W. SCATTERED 
MODERATE CONVECTION IS NOTED WITHIN 15 NM EITHER SIDE OF LINE 
1N85W 4N92W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED WITHIN 60 NM EITHER SIDE OF LINE 7N109W 3N120W 4N140W.

...DISCUSSION...

A MID TO UPPER SHORTWAVE RIDGE IS AMPLIFYING NE OVER THE NW 
PORTION OF THE DISCUSSION AREA WITH ITS AXIS ALONG 23N140W TO 
BEYOND 32N136W. UPPER MOISTURE IS TRAPPED UNDER THE RIDGE... 
ROUGHLY N OF 28N W OF 125W. IMMEDIATELY TO THE E...A SERIES OF 
SHORTWAVE TROUGHS OVER THE WESTERN CONUS HAVE A MEAN AXIS 
EXTENDING SW INTO THE AREA ALONG 32N112W TO A BASE AT 11N122W. A 
SMALL UPPER CYCLONE HAS SPUN OFF AND APPEARS TO BE CUTTING OFF 
NEAR 19N133W. A BAND OF UPPER MOISTURE IS NOTED WITHIN 120 NM 
EITHER SIDE OF LINE 21N119W 32N104W. OTHERWISE...DRY UPPER AIR 
IS INDICATED N OF THE ITCZ W OF 118W.

AN UPPER ANTICYCLONE IS ESTIMATED NEAR 11N86W WITH A RIDGE 
EXTENDING W TO A CREST AT 11N113W. A MOISTURE PLUME... 
ORIGINATING FROM ITCZ CONVECTION BETWEEN 107W AND 127W...IS 
NOTED WITHIN 360 NM EITHER SIDE OF LINE FROM 12N112W TO 
21N104W...THEN THE PLUME NARROWS SLIGHTLY AS IT TURNS E IN UPPER 
ZONAL FLOW ACROSS THE RIDGE...WITHIN 270 NM EITHER SIDE OF LINE 
22N99W 26N75W. THE UPPER FLOW IS DIFFLUENT S OF 8N E OF 104W 
WITH SLIGHT ENHANCEMENT OF THE NORTHERN HEMISPHERE ITCZ E OF 98W.

AT THE LOW LEVELS...SURFACE HIGH PRES IS CENTERED NEAR 32N130W 
RIDGING SE TO 15N110W AND RIDGING SW TO THE HAWAIIAN ISLANDS.

GAP WINDS...GULF OF TEHUANTEPEC...NW WINDS 10 KT WILL INCREASE 
TO N AT 20 KT THIS AFTERNOON AND 20 TO 25 KT TONIGHT THEN 
DIMINISH TO LESS THAN 20 KT SUN. NE WINDS 20 TO 25 KT CONTINUE 
IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO WITH LITTLE CHANGE 
EXPECTED FOR AT LEAST 48 HOURS.

$$
NELSON