000 AXPZ20 KNHC 011603 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED AUG 01 2012 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 1500 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS NOTED FROM 15N96W TO 10N97W MOVING W AT 10 TO 15 KT. THE WAVE IS IN AN AREA OF FAIRLY SUBSIDENT MID TO UPPER FLOW ON THE EAST SIDE OF AN UPPER ANTICYCLONE CENTERED NEAR 15N101W. WHILE THIS IS SUPPRESSING WIDESPREAD CONVECTION LIGHTNING DATA IS SHOWING A DEVELOPING LINE FROM 15N98W TO 14N101W...AND A SMALL AREA OF CONVECTION FROM 05N TO 08N BETWEEN 96W AND 99W NEAR WHERE THE WAVE IS CLOSE PROXIMITY TO THE MONSOON TROUGH. AN ASCAT PASS FROM 0412 UTC INDICATED SUBTLE CYCLONIC TURNING ALONG 95W N OF 09N LIKELY ATTRIBUTABLE TO THE TROPICAL WAVE. HOWEVER RECENT SATELLITE DERIVED HIGH DENSITY WIND DATA SHOWED ONLY MODEST CYCLONIC TURNING NEAR THE WAVE INDICATING IT MAY BE WEAKENING. LOOKING AHEAD...GFS MODEL DEPICTS MORE STABLE CONDITIONS AND WEAKENING EASTERLY FLOW THROUGH THE WAVE...ALLOWING THE WAVE TO DAMPEN FURTHER. A BETTER DEFINED TROPICAL WAVE IS NOTED FROM 18N110W TO 10N112W MOVING W 10 TO 15 KT. RECENT LOWER TO MID LEVEL SATELLITE DERIVED HIGH DENSITY WINDS INDICATE CLEAR CYCLONIC FLOW NEAR THIS FEATURE. AN EARLIER 0418 UTC ASCAT PASS SHOWED BROAD CYCLONIC TURNING AT THE SURFACE IN THE SAME AREA...WITH A SMALL AREA OF WINDS REACHING 20 KT NEAR THE NORTHERN EXTENT OF THE WAVE. SCATTERED CONVECTION IS NOTED 11N TO 14N BETWEEN 109W AND 112W NEAR THE WAVE. THE WAVE IS EXPECTED HOLD TOGETHER AS IT SHIFTS W REACHING NEAR 115W BY EARLY THU...AND NEAR 120W FRI. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH FROM 08N85W TO 10N110W TO 08N140W. ITCZ FROM 10N115W TO 08N140W. NUMEROUS MODERATE ISOLATED STRONG CONVECTION FROM 04N TO 06N E OF 78W...AND 05N TO 07N BETWEEN 88W AND 91W. SCATTERED MODERATE CONVECTION FROM 05N TO 08N BETWEEN 96W AND 99W. SCATTERED MODERATE CONVECTION 08N TO 110N BETWEEN 104W AND 107W...AND FROM 11N TO 14N BETWEEN 109W AND 112W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM S OF ITCZ AXIS BETWEEN 125W AND 135W. ...DISCUSSION... AN UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 29N128W WITH TROUGH SW TO 12N140W. GLOBAL MODELS CONSENSUS INDICATES THE UPPER CYCLONE WILL DRIFT SLOWLY W THROUGH 72 HOURS TO 120 W AND SLOWLY DIMINISH AS THE TRAILING TROUGH DEAMPLIFIES...FOLLOWED BY A MID TO UPPER LEVEL RIDGE THAT WILL BE CENTERED NEAR 22N135W BY FRI. THIS WILL REINFORCE THE BOUNDARY LAYER RIDGE ALREADY IN PLACE AND MAINTAIN FRESH TRADE FLOW FROM ROUGHLY 10N TO 17N W OF 125W...AND ALLOW THEM TO STRENGTHEN BY FRI. DIVERGENCE ALOFT ON THE SE SIDE OF THE UPPER TROUGH ALONG WITH MARKED CONFLUENCE OF NE AND SE SURFACE FLOW IS ALLOWING LARGE CLUSTERS OF MODERATE TO OCCASIONALLY STRONG CONVECTION TO PERSIST ALONG THE ITCZ AXIS W OF 120W. WW3...ECWAVE...AND UKWAVE MODELS ARE INDICATING SOUTHERLY CROSS EQUATORIAL SWELL MOVING AS FAR N AS 04N THROUGH THE NEXT 48 TO 72 HOURS. E OF 110W...MODEL CONSENSUS SHOWS SW FLOW S OF THE MONSOON TROUGH INCREASING SLIGHTLY THROUGH THE WEEKEND. GIVEN THE VERY MOIST PROFILE IN THIS AREA...INCREASED CONVECTION IS LIKELY. THE ECMWF AND GFS INDICATE WEAK LOW SPINNING UP ALONG THE MONSOON TROUGH...BUT SW FLOW REMAINS LESS THAN 15 KT AND NO SIGNIFICANT CYCLOGENESIS IS ANTICIPATED. MEANWHILE THE GULF OF CALIFORNIA WILL LIKELY SEE PERIODS OF WINDS TO 20 KT...BUT ONLY FOR SHORT DURATIONS OVER THE NEXT COUPLE OF DAYS. SIMILARLY...THE BUILDING SURFACE RIDGE OVER THE E PACIFIC NEAR 37N137W MAY ALLOW NW TO N FLOW ALONG THE BAJA COAST TO INCREASE SLIGHTLY. GFS SHOWS ISOLATED AREAS OF 20 KT...ALTHOUGH THESE APPEAR TO BE TRANSIENT INCIDENTS. $$ CHRISTENSEN