000
AXPZ20 KNHC 172234
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE APR 17 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 4N77W 7N97W 12N105W 5N115W 5N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 120 NM EITHER SIDE OF LINE 
7N97W 12N105W AND LINE 8N110W 6N116W 6N122W. 

...DISCUSSION...

AN UPPER SHORTWAVE TROUGH IS SWINGING SE INTO THE NW PORTION 
ALONG 32N124W 29N140W WITH DRY AIR NOTED WITHIN 120 NM NW OF THE 
TROUGH. A LONGWAVE UPPER TROUGH IS STILL EVIDENT EXTENDING 
THROUGH UPPER CYCLONES AT 35N102W AND 25N128W WITH THE TROUGH 
CONTINUING S TO A BASE AT 6N130W. AN UPPER ANTICYCLONE IS AT 
15N88W WITH A RIDGE W TO A CREST ALONG POINTS 13N125W 25N120W 
28N104W 37N93W. ASSOCIATED UPPER DIFFLUENCE ENHANCED ITCZ 
CONVECTION BETWEEN 100W AND 125W. THE RESULTANT DEBRIS MOISTURE 
IS ADVECTED NE UNDER THE RIDGE INTO A MOISTURE PLUME ACROSS OLD 
MEXICO AND THE NW GULF OF MEXICO. OTHERWISE DRY UPPER AIR IS 
NOTED OVER THE W PORTION OF THE DISCUSSION AREA AND E OF 98W. 

AT THE LOW LEVELS A RIDGE EXTENDS INTO THE AREA ALONG 32N140W 
12N105W. THE ITCZ IS QUITE ACTIVE NEAR 11N104W WITH INTERMITTENT 
CYCLONIC TURNING. 

GAP WINDS...A LAST NLY SURGE TO 20 KT IN THE GULF OF TEHUANTEPEC 
IS OCCURRING WITH WINDS EXPECTED TO DIMINISH EARLY TONIGHT. THE 
LAST QSCAT PASS INDICATED ENE 20-25 KT IN THE GULF OF 
PAPAGAYO...THIS IS ALSO EXPECTED TO DIMINISH TONIGHT. NW WINDS 
IN THE SEA OF CORTEZ THIS AFTERNOON IS ALSO EXPECTED TO DIMINISH 
TONIGHT.

$$
NELSON