000
AXPZ20 KNHC 161516
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAY 16 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...06N77W TO 
09N105W TO 09N120W TO 06N140W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION IS WITHIN 60 NM OF A LINE FROM 06N81W TO 
12.5N90W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION 
WITHIN 60 NM OF A LINE FROM 11.5N107.5W TO 13N115W. SCATTERED 
MODERATE TO STRONG CONVECTION IS WITHIN 120 NM OF THE POINT 
08N117W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IS 
WITHIN 60 NM OF THE POINT 09N121.5W. SCATTERED MODERATE TO 
STRONG CONVECTION IS WITHIN 75 NM OF THE POINT 09N127.5W. 
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IS WITHIN 60 
NM OF THE POINT 08N130W. SCATTERED MODERATE CONVECTION IS WITHIN 
60 NM OF THE POINT 07N136W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION WITHIN 60 NM OF THE POINT 05.5N139.5W.

...DISCUSSION...

WEAK RIDGE IS NORTHWEST OF A LINE THROUGH 32N135W TO 28N140W. 
THIS FEATURE IS FORECAST TO PERSIST FOR THE NEXT SEVERAL DAYS. 
MIDDLE AND UPPER LEVELS ARE MOIST BUT CLOUD FREE.

ELSEWHERE NW OF A LINE FROM SOUTH TEXAS TO THE SOUTHERN GULF OF 
CALIFORNIA NEAR 25N110W TO THE ITCZ NEAR 125W A LARGE TROUGH IS 
OBSERVED. THIS AREA IS DRY AND CLOUD FREE IN THE MIDDLE AND 
UPPER LEVELS INDICATING MODERATE MIDDLE AND UPPER LEVEL 
SUBSIDENCE IN THIS REGION. THIS FEATURE IS ALSO FORECAST TO 
PERSIST THROUGH THE NEXT SEVERAL DAYS AND CHANGE LITTLE IN 
STRENGTH.

THE REMAINDER OF THE AREA...THAT IS...THE AREA SOUTHEAST OF THE 
TROUGH IS A BROAD SCALE ANTICYCLONIC CIRCULATION THAT IS MOIST 
IN THE MIDDLE AND UPPER LEVELS WITH AREAS OF MULTI LEVEL 
CLOUDINESS AND EMBEDDED AREAS OF CONVECTION. THIS FEATURE IS 
ALSO FORECAST TO PERSIST THROUGH THE NEXT SEVERAL DAYS.

WEAK SURFACE RIDGE IS NORTH OF 13N WEST OF 115W. WEAK TROUGH 
WITHIN THE ITCZ NEAR 114W AND ALSO NEAR 92W. OTHERWISE A BROAD 
TROUGH IS ANALYZED AT THE SURFACE.

GAP WINDS...A BROAD TROUGH IS FORECAST OVER THE EASTERN GULF OF 
MEXICO EARLY NEXT WEEK SETTING UP THE CONDITIONS FOR N WINDS AT 
20 KT TO BRIDGE THE ISTHMUS OF TEHUANTEPEC INTO THE GULF OF 
TEHUANTEPEC LATE SUN NIGHT.

$$
LL