000
AXPZ20 KNHC 080911
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE SEP 08 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURES...
AT 08/0900 UTC...TROPICAL STORM LINDA IS LOCATED NEAR 15.1N 
128.4W MOVING W OR 265 DEG AT 7 KT. MAXIMUM SUSTAINED WIND SPEED 
IS 50 KT WITH GUSTS TO 60 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 
IS 997 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. NUMEROUS 
MODERATE WITH SCATTERED STRONG CONVECTION IS NOTED WITHIN 70 NM 
OF CENTER. SOME ADDITIONAL STRENGTHENING IS POSSIBLE OVER THE 
NEXT DAY OR TWO...AND THE OFFICIAL INTENSITY FORECAST KEEPS 
LINDA AS A TROPICAL STORM DURING THE NEXT 48 HOURS. SATELLITE 
IMAGERY SHOWS A SHARP WESTERN EDGE TO THE DEEP CONVECTIVE CLOUDS 
ASSOCIATED WITH LINDA...INDICATING THAT THE CYCLONE IS 
EXPERIENCING WESTERLY SHEAR.

...THE ITCZ...
THE ITCZ AXIS IS ALONG 08N78W TO 09N100W TO 08N115W TO 13N124W 
THEN CONTINUES FROM 11N131W TO 08N140W. SCATTERED MODERATE TO 
STRONG FROM 05N TO 08N E OF 83W. SCATTERED MODERATE ISOLATED 
STRONG WITHIN 200 NM N OF AXIS BETWEEN 95W AND 105W.

...DISCUSSION...
A MID/UPPER LEVEL ANTICYCLONE LOCATED W OF 140W HAS A RIDGE 
EXTENDING EWD OVER THE WESTERN PORTION OF THE FORECAST REGION. 
THE RIDGE AND THE ASSOCIATED DRY STABLE AIR AT THE MIDDLE AND 
UPPER LEVELS OF THE ATMOSPHERE COVERS THE AREA N OF 10N AND W OF 
130W. A SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM SE ARIZONA 
ACROSS CENTRAL BAJA CALIFORNIA TO 18N129W. ANOTHER UPPER LEVEL 
ANTICYCLONIC CIRCULATION IS CENTERED NEAR 15N116W. TROPICAL 
STORM LINDA IS MOVING AROUND THE WESTERN PERIPHERY OF THIS 
SYSTEM. THE THIRD MID/UPPER LEVEL HIGH IS OVER SOUTHERN MEXICO 
ALONG THE COAST OF THE BAY OF CAMPECHE AND IS ENHANCING 
CONVECTION N OF THE ITCZ BETWEEN 95W-105W. AN INVERTED UPPER 
LEVEL TROUGH WITH AXIS ALONG 111W SEPARATES THE ABOVE MENTIONED 
ANTICYCLONES. 

A SURFACE RIDGE CONTINUES TO DOMINATE THE NORTHERN PORTION OF 
DISCUSSION AREA MAINLY N OF 20N W OF 115W. PRES GRADIENT BETWEEN 
LINDA AND THE RIDGE IS PRODUCING A LARGE AREA OF NE WINDS 20 KT 
AND SEAS TO 9 FT PARTICULARLY FROM 15N TO 25N AND W OF 130W. 
THESE CONDITIONS ARE EXPECTED TO PERSIST DURING THE NEXT 48 
HOURS. STRATOCUMULUS CLOUDS ARE OBSERVED N OF 20N W OF 120W.

SWELLS FROM THE NW ARE EXPECTED IN THE NE PORTION OF THE AREA 
THROUGH TUE NIGHT. LATE IN THE WEEK...LONG PERIOD SWELLS OF 16 
SEC WILL APPROACH THE NW PART OF THE AREA RAISING SEAS TO 11 FT.

$$
GR