000 AXPZ20 KNHC 082130 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED OCT 08 2008 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 2115 UTC. ...SPECIAL FEATURES... AT 08/2100 UTC HURRICANE NORBERT IS CENTERED NEAR 16.6N 111.2W OR ABOUT 385 NM...715 KM...SOUTH OF THE SOUTHERN TIP OF BAJA CALIFORNIA...MOVING WNW OR 290 DEG AT 8 KT. A NORTHWESTWARD MOTION IS EXPECTED TO BEGIN LATER TODAY OR TONIGHT...FOLLOWED BY A TURN TOWARD THE NORTH ON THURSDAY NIGHT OR FRIDAY. ESTIMATED MINIMUM CENTRAL PRES IS 948 MB. MAXIMUM SUSTAINED WIND SPEED IS 115 KT WITH GUSTS TO 140 KT. NORBERT IS A CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON SCALE. REFER TO LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC AND INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP5/ WTPZ35 KNHC FOR MORE DETAILS. NORBERT IS A VERY IMPRESSIVE-LOOKING HURRICANE WITH VERY COLD CLOUD TOPS SURROUNDING A RATHER SYMMETRIC 30-35 NM WIDE EYE. ENVIRONMENTAL CONDITIONS ARE FORECAST TO REMAIN FAVORABLE FOR ANOTHER DAY OR SO...AND THE INTENSITY FORECAST ALLOWS FOR SOME SLIGHT ADDITIONAL INTENSIFICATION IN THE NEAR TERM. THEREAFTER NORBERT WILL BE MOVING OVER SLIGHTLY COOLER WATERS...WHICH IS EXPECTED TO INITIATE GRADUAL WEAKENING. IT IS MUCH TOO EARLY TO DETERMINE HOW STRONG NORBERT WILL BE WHEN IT APPROACHES THE BAJA PENINSULA. SO...INTERESTS IN THE SOUTHERN BAJA CALIFORNIA PENINSULA SHOULD MONITOR THE PROGRESS OF THIS MAJOR HURRICANE. THE BROAD AREA OF LOW PRES LOCATED ABOUT 125 MILES SOUTH OF THE GUATEMALA-EL SALVADOR BORDER IS UPGRADED TO TROPICAL DEPRESSION 16E AT 08/2100 UTC. AT THIS TIME...ITS CENTER IS NEAR 12.1N 90.9W MOVING WNW OR 285 DEG AT 8 KT. ESTIMATED MINIMUM CENTRAL PRES IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC AND INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP1/WTPZ31 KNHC FOR MORE DETAILS. ALTHOUGH THERE IS NOT MUCH DEEP CONVECTION OVER THE CENTER OF CIRCULATION...BANDING FEATURES ARE BECOMING EVIDENT. VERTICAL SHEAR HAS RELAXED OVER THE SYSTEM AND SEA SURFACE TEMPERATURES ARE QUITE WARM. AS A RESULT...THE INTENSITY FORECAST CALLS FOR THIS SYSTEM TO BECOME A TROPICAL STORM IN ABOUT 12 TO 24 HOURS. THE OUTER FRINGES OF THE DEPRESSION ARE BRINGING SOME LOCALLY HEAVY RAINS TO PORTIONS OF THE PACIFIC COAST OF CENTRAL AMERICA. SCATTERED MODERATE CONVECTION COVERS THE AREA FROM 8N TO 13N BETWEEN 90W AND 97W. ...ITCZ... ITCZ AXIS ALONG 11N95W TO 08N110W TO 09N120W TO 11N130W TO 11N140W. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM S OF AXIS BETWEEN 103W AND 106W. SIMILAR CONVECTION IS WITHIN 50 NM EITHER SIDE OF AXIS WEST OF 132W. ...DISCUSSION... THE REMNANTS OF MARIE...NOW A SWIRL OF LOW CLOUDS...ARE DRIFTING WSW ABOUT 7 KT IN THE TRADE WIND FLOW NEAR 17N127W. EVEN THOUGH WHAT IS LEFT OF MARIE CONTINUES TO WIND DOWN...AN AREA OF 20 TO 25 KT WINDS IS WITHIN 300 NM OF NW SEMICIRCLE. THESE WINDS ARE THE RESULT OF THE PRESSURE GRADIENT BETWEEN THE REMNANTS OF MARIE AND STRONG HIGH PRESSURE CENTERED WELL TO THE N OF THE FORECAST AREA. THIS SYSTEM IS EXPECTED TO DISSIPATE WITHIN 24-36 HOURS. A STRONG TROUGH IS FORECAST TO DEVELOP OVER THE WESTERN UNITED STATES AND ADJACENT PACIFIC...WHICH SHOULD USHER IN AN EQUALLY STRONG COLD FRONT INTO THE SOUTHWESTERN U.S. STRONG SURFACE HIGH PRESSURE BUILDING IN ITS WAKE WILL CAUSE STRONG NORTHERLY WINDS TO BLOW OFF THE U.S. WEST COAST...WITH N TO NE WINDS OF 20 TO 30 KT FORECAST TO COVER MOST OF THE NW WATERS NW OF A LINE FROM 30N120W TO 18N140W BY FRI MORNING. SEAS OF 11 TO 19 FT IN N TO NE SWELL SHOULD REACH INTO THE WATERS GENERALLY N OF 24N W OF 120W. $$ GR