000 AXPZ20 KNHC 110335 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU SEP 11 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON TCMAT4 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...SPECIAL FEATURES... TROPICAL STORM LOWELL CENTERED NEAR 23.1N 111.3W OR ABOUT 105 MILES WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AND ABOUT 140 MILES SSE OF CABO SAN LAZARO MEXICO AT 11/0300 UTC MOVING NE OR 045 DEG AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. NUMEROUS STRONG CONVECTION IS WITHIN 45 NM OF 25N111W. SCATTERED STRONG CONVECTION IS ELSEWHERE WITHIN 250 NM OF CENTER IN THE N AND NE QUADRANTS...AND 180 NM OF THE CENTER IN THE NW QUADRANT. THIS SYSTEM REMAINS SHEARED WITH THE LOW LEVEL CLOUD CENTER DETACHED FROM THE CONVECTION WHICH HAS INCREASED DURING THE PAST FEW HOURS OVER SOUTHERN BAJA CALIFORNIA AND GULF OF CALIFORNIA FROM 23N-27N. A RATHER DRY AND STABLE AIR MASS IS OBSERVED TO THE W AND NW OF LOWELL AS NOTED IN THE STRATOCUMULUS CLOUD FIELD EXISTING N OF 19N W OF 117W. LOWELL IS FORECAST TO CONTINUE TO TRACK NE CROSSING SOUTHERN BAJA CALIFORNIA TONIGHT INTO THU MORNING...AND INTO THE GULF OF CALIFORNIA LATER ON THU AS A REMNANT LOW PRES. THE REMNANT LOW WILL THEN DISSIPATE OVER INTERIOR NW OLD MEXICO ON FRI. 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 6N92W 6N100W 7N111W WHERE IT TEMPORARILY ENDS. IT RESUMES AT 13N116W AND EXTENDS TO 11N129W TO 11N140W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE AXIS BETWEEN 88W-92W. ...DISCUSSION... A MID/UPPER LEVEL CYCLONIC CIRCULATION DROPPING SSE ABOUT 20 KT IS OVER SRN CALIFORNIA NEAR 35N120W. A TROUGH EXTENDS S FROM THE CIRCULATION THROUGH 32N119W TO 27N122W TO 23N125W. AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 21N135W...WHILE A SECOND ONE IS E OF THE DISCUSSION AREA OVER SRN TEXAS NEAR 27N99W. A RIDGE EXTENDS SW FROM THE SECOND ONE THROUGH 24N107W TO 20N116W WHERE A COL REGION EXISTS BETWEEN BOTH ANTICYCLONES. SW UPPER LEVEL WINDS AHEAD OF THE TROUGH CONTINUE TO SPREAD UPPER LEVEL MOISTURE FROM THE SHEARED CONVECTION ASSOCIATED WITH LOWELL NE ACROSS SRN BAJA CALIFORNIA...AND TO WELL INLAND NRN MEXICO AND THE SW UNITED STATES. THE TROUGH IS FORECAST TO LIFT NE AND DAMPEN SOME OVER THE SW UNITED STATES IN ABOUT 48 HOURS. MODERATE TO STRONG NE-E UPPER FLOW IS STILL EVIDENT TO S OF THE RIDGE THAT EXTENDS FROM MEXICO SW TO 20N116W. THESE WINDS ARE ADVECTING UPPER LEVEL DEBRIS MOISTURE FROM CONVECTION OVER MEXICO WSW ACROSS THE FAR E PACIFIC WATERS AS FAR W AS 116W AND AS FAR S AS THE EQUATOR. WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE TO STRONG SUBSIDENCE COVERING THE REMAINDER OF THE AREA NW OF A LINE FROM ABOUT 27N114W TO 20N124W TO 13N140W...AND ALSO S OF 10N W OF 95W. AT THE SURFACE...A RIDGE EXTENDS FROM 32N134W TO 26N126W. HIGH PRES COVERS THE AREA N OF 24N W OF 128W. A SMALL AND SHEARED 1010 MB LOW IS NEAR 10N129W MOVING W 8 KT...BUT SHOULD DISSIPATE WITHIN THE NEXT 24-36 HOURS. IN REFERENCE TO THE HIGH SEAS MARINE FORECAST...LONG PERIOD SOUTHWEST SWELLS ARRIVING FROM THE SOUTHERN HEMISPHERE CONTINUE TO OVERSPREAD MUCH OF THE TROPICAL E PACIFIC WATERS...EXCEPT OVER THE W OF 124W WHERE A SE SWELL PREVAILS UNDER SE WINDS TO 20 KT. WAVE GUIDANCE SUGGESTS THAT WAVE HEIGHTS ARE FORECAST TO SUBSIDE TO 7-8 FT THROUGHOUT THIS AREA. $$ AGUIRRE