000 WTPZ45 KNHC 111449 TCDEP5 HURRICANE NORBERT DISCUSSION NUMBER 31 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152008 800 AM PDT SAT OCT 11 2008 THE SATELLITE APPEARANCE OF NORBERT HAS GRADUALLY DEGRADED THIS MORNING...AS THE EYE HAS FILLED IN. THIS HAS RESULTED IN A DECREASE OF THE DVORAK DATA T-NUMBERS FROM BOTH AGENCIES. A BLEND OF THE DVORAK DATA T AND CURRENT INTENSITY NUMBERS...HOWEVER...YIELDS AN INITIAL INTENSITY ESTIMATE OF 90 KT...OR CATEGORY TWO STRENGTH. NORBERT IS MOVING ON A MOTION BETWEEN NORTH-NORTHEAST AND NORTHEAST AT ABOUT 13 KT...AHEAD OF A TROUGH MOVING INTO THE SOUTHWEST UNITED STATES. THE HURRICANE IS ABOUT TO MAKE LANDFALL ALONG THE SOUTHWEST COAST OF THE BAJA PENINSULA AND IS EXPECTED TO EMERGE OVER THE GULF OF CALIFORNIA THIS AFTERNOON...THEN MAKE A FINAL LANDFALL ALONG THE COAST OF MAINLAND MEXICO THIS EVENING. THE TRACK GUIDANCE AGREES ON THIS SOLUTION...BUT THERE ARE SOME DIFFERENCES IN HOW FAST NORBERT ACCELERATES NORTHEASTWARD. THE OFFICIAL FORECAST REMAINS SIMILAR TO THE PREVIOUS ADVISORY AND USES A BLEND OF THE DIFFERING SPEEDS OF THE DYNAMICAL GUIDANCE. SOUTHWESTERLY SHEAR AND LAND INTERACTION SHOULD GRADUALLY WEAKEN THE THE CYCLONE...BUT NORBERT IS EXPECTED TO REMAIN A HURRICANE AS IT MOVES INTO MAINLAND MEXICO. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO FLY INTO NORBERT THIS AFTERNOON...WHICH SHOULD PROVIDE A BETTER ASSESSMENT OF NORBERT'S INTENSITY. AFTER LANDFALL IN NORTHWEST MEXICO...THE LOW-LEVEL CIRCULATION IS EXPECTED TO QUICKLY WEAKEN AND DISSIPATE OVER THE MOUNTAINOUS TERRAIN. HOWEVER...MOISTURE FROM THIS SYSTEM IS FORECAST TO SPREAD OVER THE SOUTHERN AND CENTRAL U.S. PLAINS OVER THE NEXT COUPLE OF DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 11/1500Z 24.3N 111.9W 90 KT 12HR VT 12/0000Z 26.5N 110.4W 70 KT 24HR VT 12/1200Z 30.0N 107.8W 30 KT...INLAND 36HR VT 13/0000Z...DISSIPATED $$ FORECASTER BROWN/AVILA