000
AXPZ20 KNHC 110908
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED APR 11 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N81W 7N95W 3N110W 4N125W 1N140W. 
SCATTERED MODERATE WITHIN 90-120 NM OF THE AXIS BETWEEN 90W AND 
102W. 

...DISCUSSION...

PROGRESSIVE PATTERN CONTINUES OVER THE DISCUSSION AREA WITH 
A SERIES OF SHORTWAVE TROUGHS AND RIDGES SWEEPING EWD IN
W TO NW FLOW OVER THE AREA N OF 18N. THE FIRST TROUGH EXTENDS 
FROM 27N127W SWWD THROUGH 20N137 AND W OF THE AREA NEAR 14N144W. 
RIDGE TO THE E OF THE TROUGH EXTENDS FROM AN ANTICYCLONIC 
CIRCULATION NEAR 12N120W NWD ALONG 120W/122W TO 30N. BROAD FLAT 
DOWNSTREAM TROUGH COVERED MOST OF MEXICO BUT WAS AMPLIFYING 
ALONG THE SRN END NEAR 16N114W. CONFLUENT FLOW IN THE WAKE OF 
THIS TROUGH RESULTED IN A LARGE AREA OF STRONG UPPER LEVEL 
SUBSIDENCE GENERALLY OVER THE AREA FROM 17N TO 28N E OF 115W.    
AXIS OF SUBTROPICAL JET STREAM ENTERS THE AREA NEAR 16N140W 
AND TURNS NE OVER THE RIDGE AXIS NOTED ABOVE THEN DIVES SEWD
INTO THE BASE OF THE TROUGH NEAR 16N114W  THEN TURNS ENEWD 
ACROSS THE ISTHMUS OF TEHUANTEPEC INTO THE WRN CARIBBEAN. 
SATELLITE DERIVED WINDS REVEALED CORE SPEEDS OF 75-95 KT. 

THE FLOW OVER THE TROPICAL E PACIFIC E OF 95W REMAINS BROADLY 
ANTICYCLONIC IN NATURE AND WAS INCREASINGLY DIFLUENT OVER THE 
TROPICAL PACIFIC E OF 90W. STRONG UPPER LEVEL SWLY FLOW JUST S 
OF THE JETSTREAM NOTED ABOVE WAS IMPINGING UPON THE TROPICAL 
PACIFIC W OF 95W. THIS FLOW WAS ADVECTING SOME UPPER LEVEL 
CONVECTIVE DEBRIS NEWD OVER THE ISTHMUS OF TEHUANTEPEC. UPPER 
LEVEL FLOW IS FORECAST TO BE GENERALLY SW TO W BY THE END OF THE 
WEEK...WITH VERY STRONG NW FLOW OVER THE FAR SW PORTION DUE TO 
THE NRN PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC CENTER WELL SW 
OF THE AREA.

AT THE SURFACE...HIGH PRESSURE RIDGE EXTENDS INTO THE DISCUSSION 
AREA THROUGH 30N133W TO 18N110W AND COVERED THE AREA N OF 12N W 
OF 110W.

ON THE MARINE FRONT...SEAS IN THE 8-9 FT RANGE WITH LONG PERIOD 
SWELLS ON THE ORDER OF 15-16 SECONDS ARE STILL IMPACTING THE  
COASTAL AREAS OF CENTRAL AMERICA AND MEXICO AS WELL AS BAJA 
CALIFORNIA. HIGH RESOLUTION WAVE WATCH MODEL GUIDANCE SUGGESTS 
THAT THESE SWELLS SHOULD SLOWLY SUBSIDE TODAY AND THURSDAY. 
HOWEVER...THE POTENTIAL FOR LARGE AND DANGEROUS BREAKING SURF 
ALONG THE SOUTHWARD FACING COASTAL RESORT AREAS REMAINS A 
POSSIBILITY FOR TODAY.  

$$
COBB