000
AXPZ20 KNHC 162218
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON APR 16 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...

ITCZ AXIS IS CENTERED ALONG 6N77W 9N93W 5N110W 6N120W 4N140W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120NM N 
OF THE AXIS BETWEEN 94W-100W. SCATTERED MODERATE IS S OF THE 
AXIS FROM 4N-6N BETWEEN 94W-99W...AND WITHIN 300NM N OF AXIS 
BETWEEN 102W-111W AND BETWEEN 117W-127W. 

...DISCUSSION...
AT THE SURFACE...A 1034 MB HIGH IS CENTERED N OF THE REGION NEAR 
34N134W. THIS IS PRODUCING MODERATE TO FRESH TRADEWINDS OVER 
MUCH OF THE AREA ESPECIALLY W OF 115W. ONLY SUBTLE CHANGES 
ANTICIPATED IN THIS PATTERN THROUGH MIDWEEK. HOWEVER...A BIT 
STRONGER SURGE OF NLY WINDS EXPECTED N OF 25N E OF 125W...OFF OF 
CALIFORNIA AND NRN BAJA...BY WED INTO THU. THE LATE SEASON GULF 
OF TEHUANTEPEC GALE HAS BEEN ALLOWED TO EXPIRE AT 16/1800 UTC. 
HAVE KEPT 20-25 KT WINDS THROUGH TUE AFTERNOON THOUGH WHICH 
LEANS MORE TOWARDS THE NAM SOLUTION. SIMILAR WINDS IN THE GULF 
OF PAPAGAYO ALSO EXPECTED TO RELAX BY TOMORROW EVENING. 

ALOFT...SIGNS OF A REX BLOCK NOTED IN THE WRN PORTION OF THE 
DISCUSSION AREA WITH AN UPPER HIGH NEAR 28N134W N OF AN UPPER 
LOW NEAR 18N135W. NW FLOW AROUND A PRONOUNCED UPPER LOW OVER 
ARIZONA HAS ADVECTING VERY DRY/STABLE AIR INTO THE PAC WATERS 
OFF OF BAJA/E OF 130W. SWLY JET IS ADVECTING TROPICAL MOISTURE 
OVER THE ITCZ CONVECTION THROUGH THE NE PAC AND CENTRAL MEXICO. 
PRONOUNCED UPPER RIDGE AXIS FROM THE CARIBBEAN LIES OVER THE FAR 
NE PAC...WITH AXIS GENERALLY EXTENDING W ALONG 13N. UPPER 
DIFFLUENCE AROUND THIS RIDGE IS HELPING SUPPORT CONVECTION OVER 
THE ITCZ.

$$
WILLIS