000 AXPZ20 KNHC 092154 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON MAY 09 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...ITCZ... THE AXIS IS ANALYZED FROM 09N85W TO 05N131W. SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED IN GULF OF PANAMA TO THE N OF 08N...AND ALSO WITHIN 45 NM EITHER SIDE OF A LINE FROM 07.5N87.5W TO 08N94W. AN EMBEDDED SURFACE LOW NEAR 09N85W AND IS ESTIMATED AT 1006 MB. ISOLATED MODERATE AND STRONG CONVECTION... ORGANIZED IN 15 NM DIAMETER CLUSTERS...IS ALSO NOTED ELSEWHERE FROM 06N TO 12N E OF 100W. A SECOND 1009 MB SURFACE LOW NEAR 08N100W SEEMS TO BE FILLING AND MAY BE DROPPED FROM THE 00Z ANALYSIS IN A FEW HOURS. SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED FROM 06N TO 10N BETWEEN 111W AND 120W...WITH AN EMBEDDED SURFACE LOW AT 08N116W ESTIMATED AT 1010 MB. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 150 NM OF 06N125W. ...DISCUSSION... AN UPPER LEVEL CYCLONE HAS CUT OFF NEAR 24N141W AND IS SURROUNDED BY UPPER MOISTURE EXTENDING ABOUT 600 NM OVER THE E SEMICIRCLE. AN UPPER LEVEL LONG WAVE TROUGH EXTENDS S ALONG THE WESTERN CONUS CONTINUING S OVER THE PACIFIC TO BASE AT 26N115W. A SHORTWAVE TROUGH IS ROTATING SE INTO THE LONGWAVE...WITH ITS MEAN AXIS CURRENTLY FROM 32N120W TO 22N122W. A LARGE ANTICYCLONE IS N OF THE AREA NEAR 35N142W. THE COMBINED UPPER LEVEL NORTHERLY FLOW W OF THE TROUGHS AND E OF THE ANTICYCLONE...IS PUSHING UPPER MOISTURE SOUTHWARD TO ALONG 28N WHERE A 60 NM WIDE BAND OF DRY UPPER AIR IS NOTED ALONG POINTS 0N110W TO 27N124W TO 26N140W. OF SIGNIFICANCE IS THAT SOME OF THE MOISTURE CONCENTRATES INTO A PLUME NEAR 31N120W...AND CONTINUES NE THROUGH THE LONGWAVE TROUGH AND ACROSS SE ARIZONA AND WESTERN NEW MEXICO FUELING INTO A CONVECTIVE LINE OVER THE CENTRAL CONUS. AN UPPER LEVEL ANTICYCLONE IS OVER THE DEEP TROPICAL PACIFIC AT 07N132W AND ANOTHER IS CENTERED AT 07N119W. THE ASSOCIATED UPPER ANTICYCLONIC FLOW DOMINATES THE UPPER LEVELS S OF 18N BETWEEN 105W AND 138W...WITH THE ASSOCIATED DIFFLUENCE ENHANCING CONVECTION ALONG THE ITCZ AS PREVIOUSLY DESCRIBED. THE RESULTANT DEBRIS MOISTURE SPREADS N AND MERGES WITH A 600 NM WIDE TROPICAL MOISTURE PLUME...ORIGINATING IN THE CENTRAL PACIFIC...WITH THE MOISTURE CONTINUING NE OVER THE BAJA CALIFORNIA PENINSULA S OF 28N...AND ACROSS OLD MEXICO N OF 20N...AND ACROSS MOST OF TEXAS...WITH SOME OF THE MOISTURE TURNING E ACROSS THE WESTERN GULF OF MEXICO. AN AREA OF UPPER DRY AIR IS NOTED OVER THE TROPICS S OF 18N BETWEEN 106W AND 98W AND IS SUPPRESSING CONVECTION TO A FEW SMALL CLUSTERS ALONG THE ITCZ BETWEEN 98W AND 106W. AN UPPER LEVEL ANTICYCLONE IS ESTIMATED NEAR 07N90W WITH A RIDGE EXTENDING N TO WELL BEYOND 32N94W. THE ASSOCIATED UPPER DIFFLUENCE IS ENHANCING THE ITCZ CONVECTION PREVIOUSLY DESCRIBED TO THE E OF 100W. THE DEBRIS MOISTURE IS SPREADING N ACROSS THE CENTRAL AMERICA...THEN TURNING E ACROSS THE CENTRAL CARIBBEAN S OF 16N. AT THE LOW LEVELS A SURFACE RIDGE EXTENDS ROUGHLY ALONG 30N140W TO 15N105W WITH THE RIDGE EXPECTED TO SHIFT EASTWARD AND EXTEND FROM 32N133W TO 13N105W ON WED. THE GRADIENT NE OF THE RIDGE IS CURRENTLY SUPPORTING 15-20 KT NORTHERLY WINDS OVER THE PACIFIC WATERS WITHIN 150 NM W OF THE BAJA CALIFORNIA PENINSULA. EXPECT THESE CONDITIONS TO CONTINUE THROUGH TUE...THEN DIMINISH AS THE RIDGE SHIFTS EASTWARD ON WED. NE TRADES SW OF THE RIDGE ARE AT 15-20 KT FROM 10N TO 15N W OF 135W...WITH THESE CONDITIONS SHRINKING S AND SPREADING A LITTLE FURTHER E ON WED. CROSS EQUATORIAL SOUTHERLY SWELL RESULTING IN SEAS TO 8 FT WILL CONTINUE OVER THE DEEP TROPICS S OF 08N BETWEEN 105W AND 128W THROUGH TUE THEN SUBSIDE TO LESS THAN 8 FT. $$ NELSON