000 AXPZ20 KNHC 011613 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON AUG 01 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 WAS CENTERED AT 12.3N 103.9W AT 01/1500 UTC MOVING W-NW OR 295 DEGREES AT 9 KT...WITH CENTRAL PRES 997 MB. MAXIMUM SUSTAINED WINDS 55 GUSTS TO 65 KT. NUMEROUS STRONG CONVECTION WAS WITHIN 120 NM OF CENTER WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION ELSEWHERE WITHIN 240 NM W SEMICIRCLE. THE CONVECTION ASSOCIATED WITH THE CORE CIRCULATION OF EUGENE HAS INCREASED SIGNIFICANTLY OVERNIGHT...AND EUGENE IS EXPECTED TO BECOME A HURRICANE BY THIS EVENING OR EARLY TONIGHT. GRADUAL STRENGTHENING IS FORECAST OVER THE NEXT TWO DAYS AS EUGENE CONTINUES MOVING TOWARDS THE W-NW. 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. ...TROPICAL WAVES... A TROPICAL WAVE IS MOVING ACROSS THE YUCATAN PENINSULA AND EXTENDS S INTO THE EPAC WATER N OF 10N. MOISTURE WAS CONVERGING AHEAD OF THE WAVE AXIS ACROSS THE SW GULF OF MEXICO AND INTO ERN MEXICO AND THE BAY OF CAMPECHE. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM THE SW CARIBBEAN NEAR 08N79W W-SW ACROSS WESTERN PANAMA AND COSTA RICA TO 14N93W THEN CONTINUES FROM 12N108W TO 1008 MB LOW NEAR 11N120W TO 1010 MB LOW NEAR 10N132W TO 10N133W. THE ITCZ BEGINS FROM 10N133W TO 09N140W. SCATTERED MODERATE CONVECTION NOTED WITHIN 90 NM S OF AXIS FROM 91W TO 93W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 180 NM S OF MONSOON AXIS FROM 114W TO 119W. SIMILAR CONVECTION IS NOTED WITHIN 90 NM NE SEMICIRCLE OF THE WESTERNMOST LOW EMBEDDED IN THE MONSOON TROUGH. ...DISCUSSION... THE DEEP LAYERED NORTHERN STREAM TROUGH ALONG 130W THAT HAS WEAKENED THE SUBTROPICAL RIDGE THE LAST FEW DAYS HAS BEGUN TO WEAKEN...WITH PORTIONS N OF 25N FORECAST TO BEGIN TO SHIFT N TODAY. AT THE SURFACE...THE SUBTROPICAL HIGH IS MOVING SLOWLY SOUTHEASTWARD TOWARD ITS CLIMATOLOGICAL POSITION AND FRESHENING NE TRADE WINDS ARE EXPECTED TO RETURN TO WESTERN PORTIONS BETWEEN 13N AND 28N LATER TUESDAY AND WEDNESDAY...AND FRESHEN BETWEEN THE ITCZ AND 20N W OF 130W LATER TODAY. AN UPPER LEVEL ANTICYCLONE LIES NEAR 23N123W AND EXTENDS A RIDGE NE THROUGH CENTRAL BAJA CALIFORNIA TO ANOTHER ANTICYCLONE OVER SOUTHERN NEW MEXICO. SE OF THIS RIDGE...AN INVERTED UPPER TROUGH EXTENDED FROM NEAR THE ITCZ ALONG 12N119W TO CENTRAL BAJA CALIFORNIA NEAR 27N114W. A MIDDLE TO UPPER LEVEL RIDGE ACROSS THE WESTERN GULF OF MEXICO AND ACROSS MUCH OF MEXICO WAS AIDING IN FORCING THIS INVERTED TROUGH WWD...AS WELL AS IN STEERING EUGENE TOWARDS THE W-NW. THE INVERTED TROUGH WILL SHIFT MORE NW DURING THE NEXT FEW DAYS...ALLOWING THE RIDGE ACROSS THE WESTERN GULF OF MEXICO TO SHIFT WEST AND CONTINUE TO GUIDE EUGENE W-NW. ELSEWHERE AT THE SURFACE...THE SURFACE HIGH NEAR 37N143W EXTENDS A RIDGE SE TO JUST OFFSHORE OF THE N HALF OF BAJA CALIFORNIA...YIELDING NLY WINDS AROUND 15 KT PER OVERNIGHT SCATTEROMETER PASSES. 20 KT S TO SW MONSOON FLOW IS FOUND S OF THE MONSOON TROUGH BETWEEN 114W AND 120W...AND IN A BROAD ZONE S OF EUGENE. GAP WINDS...MODERATE TO FRESH N TO NE WINDS CONTINUE TO FUNNEL THROUGH THE ISTHMUS OF TEHUANTEPEC AHEAD OF THE TROPICAL WAVE ACROSS THE YUCATAN AND BETWEEN THE HIGHER PRES OVER THE FAR WESTERN GULF OF MEXICO AND LOWER PRES ASSOCIATED WITH EUGENE. ONCE THE TROPICAL WAVE MAKES ITS WAY THROUGH TEHUANTEPEC THIS EVENING...WINDS SHOULD BEGIN TO DIMINISH AND TURN MORE NE TO E AND DIMINISH BELOW 20 KT BY LATE TUE MORNING. THE TROPICAL WAVE IS EXPECTED TO BECOME ABSORBED IN THE MONSOON TROUGH OVER SOUTHERN MEXICO LATE TONIGHT AND TUE. $$ STRIPLING