000 AXPZ20 KNHC 100339 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED SEP 10 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...SPECIAL FEATURES... TROPICAL STORM LOWELL CENTERED NEAR 21.3N 113.2W OR ABOUT 235 MILES WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AND ABOUT 245 MILES SSW OF CABO SAN LAZARO MEXICO AT 10/0300 UTC MOVING NE OR 360 DEG AT 04 KT. ESTIMATED CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WINDS ARE 40 KT WITH GUSTS TO 50 KT. SCATTERED MODERATE/ISOLATED STRONG IS WITHIN 100 NM OF THE CENTER OVER THE NW QUADRANT. THE OVERALL CLOUD PATTERN IS BECOMING LESS SYMMETRICAL WITH TIME AS LOWELL REMAINS UNDER UPPER LEVEL EASTERLY SHEAR. LOWELL IS FORECAST TO REMAIN A MINIMAL TROPICAL STORM MOVING GENERALLY NORTHWARD TONIGHT...WEAKENING TO A TROPICAL DEPRESSION AND TURNING TO THE NE TOWARDS THE BAJA PENINSULA ON WED AND CROSSING THE SOUTHERN BAJA PENINSULA EARLY THU...AND INTO THE GULF OF CALIFORNIA AS A REMNANT LOW PRES FRI AND EVENTUALLY DISSIPATING OVER INTERIOR NW OLD MEXICO ON SAT. PLEASE REFER TO THE LATEST NHC PUBLIC ADVISORY UNDER AWIPS HEADER MIATCPEP3 OR WMO HEADER WTPZ33 KNHC AND THE FULL FORECAST ADVISORY UNDER AWIPS HEADER MIATCMEP3 OR WMO HEADER WTPZ23 KNHC FOR MORE DETAILS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 09N84W 06N95W 9N107W WHERE IT TEMPORARILY ENDS. IT RESUMES AT 13N118W AND EXTENDS TO 10N129W TO 8N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 30 NM OF THE AXIS BETWEEN 127W-129W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 89W-92W. ...DISCUSSION... A MID/UPPER LEVEL TROUGH QUICKLY ESE RATHER QUICKLY EXTENDS FROM CALIFORNIA INTO THE REGION AT 32N121W...AND EXTENDS S THROUGH 28N121W TO COL REGION NEAR 21N121.5W. AN UPPER LEVEL ANTICYCLONE IS ANCHORED NEAR 22N134W...AND IS THE MAIN DOMINATE FEATURE IN THE AREA. A RIDGE EXTENDS W OF THE ANTICYCLONE ALONG 20N...WHILE ANOTHER RIDGE EXTENDS TO N OF THE AREA AT 32N137W...AND E FROM THE ANTICYCLONE TO 21N122W. SW UPPER LEVEL WINDS AHEAD THE TROUGH ARE SPREADING UPPER LEVEL MOISTURE FROM SHEARED CONVECTION ASSOCIATED WITH LOWELL NE TOWARDS SOUTHERN BAJA CALIFORNIA. THE TROUGH IS FORECAST TO LIFT NE OVER THE SW UNITED STATES BY DAY 2. THE UPPER ANTICYCLONE ASSOCIATED WITH TROPICAL STORM LOWELL IS CENTERED NEAR 22N113W AND HAS BECOME THE DOMINATE ANTICYCLONE ...WITH ITS RIDGE EXTENDING NE ACROSS NORTHERN OLD MEXICO CRESTING AT OVER TEXAS NEAR 29N98W. A RIDGE ALSO EXTENDS SW TO A CREST AT 17N148W. THESE UPPER FEATURES ALL COMBINE DRYING OUT THE UPPER LEVELS OF THE DISCUSSION AREA TO THE W OF A WELL DEFINED LINE FROM 32N105W TO 22N120W TO 12N140W. ANOTHER UPPER LEVEL ANTICYCLONE IS CENTERED OVER CENTRAL MEXICO NEAR 25N104W. THIS ANTICYCLONE IS CREATING MODERATE TO STRONG NE-E UPPER FLOW S OF 22N AND E OF 115W. UPPER LEVEL DEBRIS MOISTURE FROM CONVECTION OVER MEXICO IS BEING ADVECTED WSW ACROSS THE FAR E PACIFIC WATERS AS FAR W AS 119W AND AS FAR S AS THE EQUATOR...EXCEPT N OF 19N THIS MOISTURE ALONG WITH THAT ASSOCIATED WITH TROPICAL LOWELL IS BEING CHANNELED NE TOWARDS NORTHERN AND CENTRAL MEXICO. WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE TO STRONG SUBSIDENCE COVERING THE REMAINDER OF THE AREA NW OF A LINE FROM ABOUT 27N114W TO 20N122W TO 13N140W...AND ALSO S OF 05N BETWEEN 94W-115W AND S OF 9N W OF 130W. AT THE SURFACE...A RIDGE EXTENDS FROM 32N136W TO 26N129W. HIGH PRES COVER THE AREA N OF 24N W OF 130W. A WEAK AND SMALL 1009 MB LOW NEAR 10N138W IS MOVING W ABOUT 10 KT...BUT SHOULD DISSIPATE OVER THE NEXT 48 HOURS WITH ONLY A SMALL AREA OF 20 KT WINDS WITHIN 45-60 NM IN THE SE AND S QUADRANTS. $$ AGUIRRE