000 AXPZ20 KNHC 032149 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED AUG 03 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...SPECIAL FEATURES... HURRICANE EUGENE WAS LOCATED AT 16.0N 115.4W AT 03/2100Z UTC MOVING W-NW OR 290 DEGREES AT 12 KT WITH CENTRAL PRES 942 MB. MAXIMUM SUSTAINED WINDS ARE NOW 120 KT WITH GUSTS TO 145 KT. THE EYE FEATURE SEEN IN SATELLITE IMAGERY THIS AFTERNOON HAS CLEARED SOMEWHAT...WHILE CONVECTION HAS BECOME MORE UNIFORM SURROUNDING THE EYE. THIS SUGGESTS THAT EUGENE HAS STRENGTHENED IN INTENSITY AND IS NOW A CATEGORY FOUR HURRICANE. NUMEROUS STRONG CONVECTION WAS OCCURRING WITHIN 90-120 NM OF THE CENTER OF EUGENE. EUGENE REMAINS UNDER FAVORABLE UPPER LEVEL CONDITIONS BUT HAS BEGUN TO MOVE OVER SLIGHTLY COOLER WATER TEMPERATES. THUS EUGENE IS NEAR OR HAS LIKELY REACHED ITS PEAK INTENSITY. EUGENE IS FORECAST TO CONTINUE TO MOVE W-NW OVER THE NEXT TWO DAYS...AND OVER GRADUALLY COOLER WATER...LEADING TO A WEAKENING TREND...BUT IS EXPECTED TO REMAIN A HURRICANE THROUGH AT LEAST EARLY FRI MORNING. 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. A 1006 MB LOW PRES SYSTEM SW OF THE GULF OF TEHAUNTEPEC NEAR 14N98.5W REMAINS EMBEDDED WITHIN A BROAD AREA OF VERY HIGH MOISTURE ALONG COASTAL MEXICO BETWEEN 95W AND 104W. SCATTERED MODERATE TO STRONG CONVECTION WAS OCCURRING N OF 13N TO THE MEXICAN COAST BETWEEN 99W AND 106W. THIS ACTIVE WEATHER AND ASSOCIATED MOISTURE WILL SHIFT W-NW OVER THE NEXT FEW DAYS AND CONTINUE TO AFFECT COASTAL MEXICO AND THE ADJACENT COASTAL WATERS...AND BEGIN TO SPREAD TO S OF THE MOUTH OF THE GULF OF CALIFORNIA BY FRIDAY. ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR THE DEVELOPMENT OF THIS SYSTEM INTO A TROPICAL CYCLONE OVER THE NEXT DAY OR TWO AS THE SYSTEM TRACKS W-NW. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO 1006 MB LOW NEAR 14N98W. IT RESUMES AT 13N119W TO 10N130W WHERE IT THEN BECOMES THE ITCZ AXIS TO 08N136W TO 07N140W. SCATTERED MODERATE WITHIN 180 NM S OF THE TROUGH BETWEEN 79W AND 84W...AND BETWEEN 86W AND 90W. ...DISCUSSION... THE EPAC SUBTROPICAL HIGH CONTINUES TO BE WEAKENED AND DISPLACED WESTWARD BY MEAN DEEP LAYERED TROUGHING JUST OFF THE W COAST OF THE UNITED STATES. AS A RESULT...TYPICAL FRESH TRADE WINDS ACROSS THE AREA ARE LIMITED TO THE TROPICAL WATERS W OF 130W. AFTERNOON SCATTEROMETER PASSES SHOWED WINDS TO 20 KT FROM THE ITCZ TO 25N. THE RIDGE HAS SHIFTED SLIGHTLY SE IN THE PAST 24 HOURS AND HAS TIGHTENED THE PRES GRADIENT OFF OF CALIFORNIA S TO OFFSHORE OF NRN BAJA CALIFORNIA...WHERE A 1716 UTC AST PASS SHOWED NW WINDS 15 TO 20 KT SPREADING S OF 30N ACROSS THE WATERS BETWEEN THE BAJA PENINSULA AND 122W. GLOBAL MODELS SUGGEST THIS WIND FLOW WILL CONTINUE THROUGH SUNDAY. A WEAK MIDDLE TO UPPER LEVEL TROUGH ENTERS THE AREA NEAR 30N130W AND MEANDERS SW TO NEAR 17149W. E OF THIS TROUGH...A MEAN UPPER RIDGE PERSISTS ACROSS THE S CENTRAL U.S. AND THE NRN GULF OF MEXICO...EXTENDING SW TO AN ANTICYCLONE OVER CENTRAL BAJA CALIFORNIA NEAR 26N113W...WITH RIDGING CONTINUING SW TO NEAR 16N125W. A WEAK INVERTED MID TO UPPER TROUGHING FROM 22N125W TO THE ITCZ ALONG 135W IS DRIFTING NW AND SEPARATES THIS RIDGE FROM A COLLAPSING UPPER ANTICYCLONE NEAR 22N133W. THE LARGE RIDGE AXIS PENETRATES DOWNWARD INTO THE MID LEVELS AND WILL REMAIN RELATIVELY STATIONARY OVER THE NEXT FEW DAYS...AND MAINTAIN A GENERAL W TO W-NW STEERING FLOW ACROSS MUCH OF THE TROPICAL EPAC E OF 120W...AND GUIDE BOTH HURRICANE EUGENE...AND THE LOW PRES SYSTEM TO ITS E...TOWARD THE W-NW. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION LIES N OF 04N E OF 89W AND ACROSS THE GULF OF PANAMA AND PORTIONS OF PANAMA AND INTO NW COLOMBIAN. THIS CONVECTION IS OCCURRING IN THE MOISTURE RICH AIR JUST S OF THE MONSOON TROUGH AND UNDER A REGION OF WEAK ELY WINDS ALOFT. CONVECTION IS EXPECTED TO REMAIN ACTIVE THERE FOR THE NEXT 24-48 HOURS AS ADDITIONAL LOW LEVEL MOISTURE MOVES FROM E PORTIONS OF COLOMBIA AND THE ADJACENT CARIBBEAN...AND CONVERGES S OF THE MONSOON TROUGH. RECENT SCATTEROMETER PASSES SHOWED FRESH TO STRONG S TO SW WINDS FEEDING INTO EUGENE FROM NEAR THE EQUATOR NORTHWEST BETWEEN 108W AND 125W. LATE MORNING SCATTEROMETER PASSES ALSO CONTINUE TO SHOW LIGHT TO MODERATE SW TO WLY FLOW OCCURRING S OF THE MONSOON TROUGH FROM 100W E TO 80W. SWELL GENERATED FROM EUGENE WILL CONTINUE TO PROPAGATE NORTHWARD THROUGH FRI...BOTH INTO THE GULF OF CALIFORNIA...AND ACROSS THE PACIFIC WATERS W OF THE BAJA PENINSULA. LONG PERIOD CROSS-EQUATORIAL SW SWELL HAS BROUGHT SEAS ABOVE 8 FT TO S CENTRAL WATERS S OF 05N AND W OF 96W. A NEW PULSE OF 16-18 SECOND PERIOD SW SWELL WILL MOVE INTO THE AREA TONIGHT AND KEEP COMBINED SEAS IN THE 8-10 FT RANGE THERE THROUGH THE FORECAST PERIOD. $$ STRIPLING