000 AXPZ20 KNHC 020941 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE JUN 02 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0915 UTC. ...ITCZ... AXIS FROM 09N83W TO 11N103W TO 08N118W TO 06N130W TO 07N140W. SCATTERED MODERATE CONVECTION IS FROM 05N TO 10N BETWEEN 85W AND 88W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 08N TO 13N BETWEEN 93W AND 106W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 05N TO 11N BETWEEN 108W AND 119W. SCATTERED MODERATE CONVECTION IS FROM 03N TO 13N BETWEEN 120W AND 133W. ...DISCUSSION... N OF 20N... A DEEP CLOSED LOW N OF THE AREA IS ASSOCIATED WITH A 1010 MB SURFACE LOW NEAR 36N130W...AND A SURFACE TROUGH ENTERING THE NW WATERS NEAR 30N131W AND EXTENDING TO 28N137W. THE SURFACE LOW AND TROUGH CONTINUE TO LOSE UPPER SUPPORT AS THE ATTENDANT UPPER LOW IS SEPARATED FROM ANY LARGE-SCALE JET STREAM. THUS...THE PRESSURE GRADIENT AROUND THE SURFACE LOW CONTINUES TO WEAKEN...AND THE QUIKSCAT PASS AROUND 02/0300 UTC CONFIRMS THAT NW WINDS W OF THE TROUGH HAVE FALLEN TO AROUND 10 KT. DURING THE NEXT FEW DAYS...SEVERAL UPPER TROUGHS ARE FORECAST TO PIVOT CYCLONICALLY AROUND THE PARENT DEEP LOW N OF THE AREA. DIFFLUENT SOUTHWESTERLY FLOW ALOFT E OF THE UPPER TROUGHS WILL DRIVE SURFACE PRESSURE FALLS AND SURFACE TROUGHING OVER N MEXICO AND THE N GULF OF CALIFORNIA. THE CORRESPONDING PRESSURE GRADIENT IS ALREADY INCREASING SW WINDS ACROSS THE N GULF OF CALIFORNIA TONIGHT...WHICH ARE INTERACTING WITH DOWNSLOPE FLOW OFF THE BAJA CALIFORNIA COAST TO SUPPORT SW WINDS OF 20 KT. AROUND 02/0000 UTC...A SURFACE OBSERVATION ALONG NEAR THE GULF OF CALIFORNIA ALONG THE W COAST OF MEXICO NEAR 28N111W INDICATED SW WINDS NEAR 20 KT. A SIMILAR PATTERN IS EXPECTED OVER THE N GULF OF CALIFORNIA DURING THE NEXT FEW NIGHTS...WITH SW FLOW ALOFT CONTINUING OVER THE N GULF OF CALIFORNIA AS THE AFOREMENTIONED UPPER LOW DRIFTS SOUTHEASTWARD TOWARD THE WESTERN UNITED STATES COAST. THE STRONGEST WINDS OVER THE NORTHERN GULF OF CALIFORNIA ARE FORECAST TO OCCUR WED NIGHT AND THU NIGHT...WHEN THE UPPER LEVEL HEIGHT GRADIENT AT THE SOUTHERN PERIPHERY OF THE UPPER LEVEL CYCLONE TIGHTENS...YIELDING A 90-100-KT UPPER LEVEL JET MAX S OF THE UPPER LOW...ENHANCING THE DOWNSLOPE FLOW INTO THE N GULF OF CALIFORNIA. THE STRONGEST DOWNSLOPE WINDS ARE EXPECTED AT NIGHT WHEN NOCTURNAL DRAINING FLOW IS MAXIMIZED. THE SURFACE PRESSURE GRADIENT BETWEEN PERSISTENT SURFACE TROUGHING OVER MEXICO AND WEAK SURFACE RIDGING OVER THE E PACIFIC WILL CONTINUE DRIVING NW WINDS AROUND 20 KT NEAR THE S AND W COASTS OF BAJA CALIFORNIA. THESE CONDITIONS WERE EVIDENT IN THE QUIKSCAT PASS AROUND 01/0130 UTC AND THE ASCAT PASS AROUND 01/0445 UTC. THE PROLONGED DURATION OF THESE WINDS ARE LIKELY INCREASING SEAS TO 8 FT LOCALLY. S OF 20N... A SURFACE TROUGH EMBEDDED WITHIN THE ITCZ EXTENDS FROM 16N102W TO 07N109W. WINDS TO 20 KT WILL IMPACT LOCATIONS WITHIN 60 NM EITHER SIDE OF THIS TROUGH AS IT PROGRESSES WESTWARD DURING THE NEXT TWO DAYS AROUND 10 KT. LOW LEVEL CONVERGENCE NEAR THIS TROUGH IS ALSO ENHANCING CONVECTION ASSOCIATED WITH THE ITCZ. HOWEVER...NORTHWESTERLY FLOW ALOFT APPEARS TO BE ADVECTING DRY AIR TOWARD THIS SYSTEM...WITH THE CONVECTION RATHER DISORGANIZED. FARTHER TO THE W...AN UPPER LEVEL LOW IS CENTERED NEAR 16N138W. UPPER LEVEL DIFFLUENCE IN MOIST SOUTHWESTERLY FLOW ALOFT E OF THE LOW IS ENHANCING SEVERAL AREAS OF CONVECTION OVER WESTERN PORTIONS OF THE DISCUSSION AREA...WITH THE GREATEST CONCENTRATION OF THE STRONGEST CONVECTION NEAR A SURFACE TROUGH EXTENDING FROM 11N118W TO 08N122W TO 05N124W. ALSO...THE PRESSURE GRADIENT NW OF THE TROUGH IS ENHANCING AN AREA OF NE TO E TRADE WINDS AROUND 20 KT FROM 11N TO 19N W OF 130W BASED ON THE ASCAT PASS AROUND 02/0615 UTC. THESE TRADES ARE FORECAST TO PERSIST IN THE SAME GENERAL AREA WITH NEARLY THE SAME INTENSITY WITH SURFACE RIDGING FARTHER TO THE N. ENHANCED EASTERLY TRADE WINDS IN THE CARIBBEAN ARE FORECAST TO BLEED INTO THE GULF OF PAPAGAYO DURING THE NEXT TWO DAYS...WHEN NE TO E WINDS OF 20 KT ARE EXPECTED NEAR AND DOWNWIND OF THE GULF OF PAPAGAYO. THE ASCAT PASS AROUND 02/0300 UTC CONFIRMED NE TO E WINDS OF 20 TO 25 KT FROM 10N TO 12N E OF 89W INCLUDING GULF OF PAPAGAYO. $$ COHEN