000
AXPZ20 KNHC 061523
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...SPECIAL FEATURES...

TROPICAL STORM EUGENE HAS BEEN DOWNGRADED TO A REMNANT LOW AND 
IS CENTERED NEAR 19.3N 128.2W AT 06/1500 UTC MOVING W-NW OR 285 
DEGREES AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. 
DESPITE THE DOWNGRADE...MAXIMUM SUSTAINED WINDS REMAIN NEAR 35 
KT WITH GUSTS TO 45 KT. INFRARED SATELLITE IMAGERY INDICATES THAT
EUGENE IS VOID OF ANY DEEP CONVECTION ALTHOUGH THE CIRCULATION 
ITSELF REMAINS VIGOROUS. ADDITIONAL WEAKENING IS FORECAST AS THE 
REMNANT LOW CONTINUES TO MOVE WESTWARD OVER COLDER WATER. THIS 
IS THE LAST ADVISORY ON EUGENE. FOR ADDITIONAL INFORMATION SEE 
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 10N86W TO 09N102W TO 18N108W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 14N127W TO 
10N140W. SCATTERED MODERATE FROM 08N TO 11N BETWEEN 91W AND 107W.

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS CENTERED OFF THE NORTHERN BAJA 
CALIFORNIA PENINSULA NEAR 29N117W WITH AN UPPER RIDGE REACHING 
FROM THE ANTICYCLONE TO 25N130W TO A COL NEAR 14N138W. THE NOW 
REMNANT LOW OF FORMER TROPICAL STORM EUGENE CONTINUES TO MOVE 
W-NW AROUND THE SOUTHERN PERIPHERY OF THIS UPPER RIDGE. AN UPPER 
LEVEL TROUGH IS CLIPPING THE FAR NW CORNER OF THE AREA FROM 
32N140W TO JUST NE OF THE BIG ISLAND OF HAWAII. THIS TROUGH 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 12N W OF 130W AND N OF 24N W 
OF THE BAJA CALIFORNIA PENINSULA. OTHERWISE...PRIMARILY EASTERLY 
UPPER LEVEL WINDS DOMINATE THE REMAINDER OF THE DISCUSSION AREA 
ALOFT WITH MID TO UPPER LEVEL TROPICAL MOISTURE BEING ADVECTED
WESTWARD S OF 24N TO ALONG 130W. 

AT THE SURFACE...1034 MB HIGH PRES CENTERED NW OF THE FORECAST 
REGION NEAR 41N149W WITH AN ASSOCIATED RIDGE EXTENDING SE TO 
25N118W. THE PRES GRADIENT BETWEEN THE RIDGE AND EUGENE IS 
RESULTING IN FRESH NE WINDS FROM 20N TO 25N W OF 127W. A 0704 
UTC ASCAT PASS CAPTURED A SMALL AREA OF SE 20 KT WINDS FROM 03N 
TO 06N W OF 135W. EXPECT THESE WINDS TO DIMINISH TO LESS THAN 20 
KT WITHIN THE NEXT 12-24 HOURS.

A TIGHT PRES GRADIENT IS RESULTING IN 20 KT NORTHERLY WINDS N OF 
28N WITHIN 120 NM W OF THE BAJA CALIFORNIA PENINSULA AS CAPTURED 
BY 0715 UTC EXPERIMENTAL HI-RES COASTAL ASCAT WINDS. THESE WINDS 
ARE FORECAST TO DIMINISH TO LESS THAN 20 KT IN 24 HOURS AS THE 
PRES GRADIENT WEAKENS.

A WEAK AREA OF LOW PRES IS CENTERED NEAR 19N110W. ALL CONVECTION 
HAS DISSIPATED IN ASSOCIATION WITH THE LOW AND ENVIRONMENTAL 
CONDITIONS ARE NOT CONDUCIVE FOR DEVELOPMENT. THE LOW IS 
EXPECTED TO DISSIPATE WITHIN THE NEXT 24 HOURS.

CROSS-EQUATORIAL SOUTHERLY SWELL CONTINUES TO PROPAGATE ACROSS 
THE REGIONAL WATERS MAINLY S OF 10N AND W OF 95W BUILDING SEAS 
TO 10 FT. THIS SWELL WILL GRADUALLY DECAY AND BECOME CONFINED TO 
W OF 100W IN 24 HOURS...THEN TO W OF 105W IN 48 HOURS.

$$
COBB