000
AXPZ20 KNHC 182203
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED APR 18 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 
2145 UTC.

...ITCZ...

AXIS 5N77W 6N90W 10N104W 3N120W 2N140W. SCATTERED MODERATE 
ISOLATED STRONG WITHIN 180 NM OF AXIS BETWEEN 82W TO 107W AND 
WITHIN 60 NM OF 8N120W AND 4N130W.

...DISCUSSION...

AN UPPER SHORTWAVE TROUGH EXTENDS ALONG 32N112W 28N129W TO 
BEYOND 26N140W WITH DRY AIR NOTED WITHIN 60 NM N OF THE TROUGH. 
AN UPPER CYCLONE IS FILLING NEAR 24N123W WITH A TROUGH EXTENDING 
S TO A BASE AT 15N121W. AN UPPER RIDGE EXTENDS NE ACROSS THE 
EQUATOR CRESTING ALONG POINTS 20N140W 12N130W 1N118W...WITH ITS 
UPPER DIFFLUENCE ENHANCING CONVECTION ALONG THE ITCZ W OF 114W.
SOME OF THE RESULTANT DEBRIS MOISTURE IS ADVECTED S OF THE 
EQUATOR. 

AN UPPER ANTICYCLONE IS ESTIMATED NEAR 9N75W WITH A RIDGE 
EXTENDING NW CRESTING ALONG POINTS 17N120W 27N116W 33N105W 
30N90W. ASSOCIATED UPPER DIFFLUENCE ENHANCED ITCZ CONVECTION 
NEAR 10N100W. THE RESULTANT DEBRIS MOISTURE FROM THIS CONVECTION 
MERGES WITH MOISTURE FROM CONVECTION W OF 120W...AND TOGETHER 
THE MOISTURE IS ADVECTED NE UNDER THE RIDGE INTO A MOISTURE 
PLUME THAT TURNS EASTWARD ACROSS MOST OF OLD MEXICO AND THE 
SW GULF OF MEXICO. OTHERWISE DRY UPPER AIR IS NOTED OVER THE W 
PORTION OF THE DISCUSSION AREA...ROUGHLY N OF 16N W OF 120W AND 
N OF THE ITCZ TO THE E OF 98W.

AT THE BROAD HIGH PRES DOMINATES THE DISCUSSION AREA N OF THE 
ITCZ W OF 105W. THE ITCZ IS STRETCHED N TO NEAR 10N AT 105W. THE 
LATEST GUIDANCE SUGGESTS NW WINDS WILL REMAIN BELOW 20 KT 
THROUGH 48 HOURS IN THE SEA OF CORTEZ.

$$
NELSON