000
AXPZ20 KNHC 060316
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT AUG 06 2011

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0245 UTC.

...SPECIAL FEATURES...

TROPICAL STORM EUGENE IS CENTERED NEAR 18.6N 125.9W AT 06/0300 
UTC MOVING W-NW OR 285 DEGREES AT 11 KT. ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 1003 MB. MAXIMUM SUSTAINED WINDS HAVE 
DECREASED TO 40 KT WITH GUSTS TO 50 KT. ADDITIONAL WEAKENING IS 
FORECAST AS THE CYCLONE TRAVERSES COLDER WATER AND AN 
INCREASINGLY MORE STABLE ENVIRONMENT. EUGENE WILL LIKELY BECOME 
A REMNANT LOW BY SUNDAY. SEE LATEST NHC PUBLIC ADVISORY UNDER 
AWIPS/WMO HEADERS TCPEP5/WTPZ35 KNHC AND FULL FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS TCMEP5/WTPZ25 FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 07N78W TO 07N84W TO 10N90W TO 
09N100W TO 18N108W THEN RESUMES NEAR 16N125W TO 12N133W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 12N133W TO 
BEYOND 11N140W. SCATTERED MODERATE CONVECTION IS NOTED FROM 06N 
TO 10N BETWEEN 95W AND 102W...FROM 16N TO 20N BETWEEN 104W AND 
108W...AND FROM 07N TO 11N W OF 134W.   

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER BAJA CALIFORNIA NEAR 
27N113W. TROPICAL CYCLONE EUGENE CONTINUES TO MOVE WNW AROUND 
THE SOUTHERN PERIPHERY OF THIS RIDGE. AN UPPER LEVEL TROUGH IS 
CLIPPING THE FAR NW CORNER OF THE AREA AND WILL REMAIN BLOCKED 
BY THE ANTICYCLONE DURING THE NEXT 24-48 HOURS. VERY DRY AIR 
UNDER MODERATE TO STRONG SUBSIDENCE IS NOTED BY WATER VAPOR 
SATELLITE IMAGERY N OF 15N W OF 130W AN N OF 23N W OF THE BAJA 
CALIFORNIA PENINSULA. OTHERWISE...NE-E UPPER LEVEL WINDS 
DOMINATE THE REMAINDER OF THE DISCUSSION AREA.

AT THE SURFACE...1035 MB HIGH PRES CENTERED NW OF THE FORECAST 
REGION NEAR 41N148W EXTENDS A RIDGE AXIS SE TO 27N121W. THE PRES 
GRADIENT BETWEEN THE RIDGE AND EUGENE IS RESULTING IN FRESH NE 
WINDS N OF 20N W OF 122W. THE 1818 UTC WINDSAT PASS PROVIDED 
OBSERVATIONS OF THESE WIND SPEEDS. 

THE 1818 WINDSAT ALSO WENT OVER EUGENE SHOWING A MAXIMUM 
INTENSITY OF AROUND 40 TO 50 KT. THE FRESH TO STRONG WINDS 
EXTEND AS FAR AS 240 NM N SEMICIRCLE AND 180 NM S SEMICIRCLE. 
SATELLITE IMAGERY SHOWS CONVECTION HAS DECREASES SIGNIFICANTLY 
OVER THE LAST SIX HOURS.  

A WEAK AREA OF LOW PRESSURE CENTERED IS S OF BAJA CALIFORNIA 
NEAR 18.5N108W. IT CONTINUES TO PRODUCE DISORGANIZED SHOWER AND 
THUNDERSTORM ACTIVITY PARTICULARLY FROM 16N TO 20N BETWEEN 104W 
AND 108W. ENVIRONMENTAL CONDITIONS ARE NOT CONDUCIVE FOR 
DEVELOPMENT...AND THIS SYSTEM HAS A LOW CHANCE OF BECOMING A 
TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES 
WEST-NORTHWESTWARD NEAR 10 MPH.

CROSS-EQUATORIAL SOUTHERLY SWELL CONTINUES TO PROPAGATE ACROSS 
THE REGIONAL WATERS MAINLY S OF 10N AND W OF 100W BUILDING SEAS 
TO 10 FT. THIS SWELL EVENT WILL GRADUALLY DECAY AND BECOME 
CONFINED TO W OF 115W IN 24 HOURS...AND W OF 120W IN 48 HOURS.

NORTHERLY WINDS ARE 20 KT N OF 28N WITHIN 120 NM OF THE W COAST 
OF THE BAJA CALIFORNIA PENINSULA AS THE PRES GRADIENT IN THE 
AREA TIGHTENS FOR THE NEXT 24 HOURS.

$$
FORMOSA