Hurricane NORBERT

ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM
HURRICANE NORBERT DISCUSSION NUMBER  30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP152008
200 AM PDT SAT OCT 11 2008
 
SATELLITE IMAGERY INDICATES NORBERT HAS BECOME BETTER ORGANIZED
DURING THE PAST 6 HOURS AND HAS RE-STRENGTHENED INTO A MAJOR
HURRICANE. A 23-NMI DIAMETER ROUND EYE HAS BECOME EVEN MORE DISTINCT
AND IS EMBEDDED IN THE CENTER OF THE CONVECTIVE CLOUD MASS. DVORAK
SATELLITE INTENSITY ESTIMATES ARE A CONSENSUS T5.5/102 KT FROM TAFB
AND SAB...BUT SATELLITE ESTIMATES ARE NOT FAR FROM BEING CLASSIFIED
AS T6.0/115 KT. THE INITIAL INTENSITY IS SET AT 100 KT. OUTFLOW IS
GOOD IN ALL QUADRANTS AND IS BECOMING MORE SYMMETRICAL.

THE INITIAL MOTION ESTIMATE IS 020/13. NORBERT REMAINS ON TRACK...
AND GRADUAL RECURVATURE TOWARD THE NORTHEAST WITH AN INCREASE IN
FORWARD SPEED IS EXPECTED NOW THAT THE HURRICANE HAS PASSED NORTH
OF THE SUBTROPICAL RIDGE AXIS. IN ABOUT 24 HOURS...NORBERT SHOULD
BEGIN TO FEEL THE EFFECTS OF INCREASING SOUTHWESTERLY FLOW AHEAD OF
AN APPROACHING MID- TO UPPER-LEVEL TROUGH CURRENTLY DROPPING
SOUTHWARD OVER THE SOUTHWESTERN UNITED STATES. THE OFFICIAL TRACK
FORECAST IS SIMILAR TO THE PREVIOUS TRACK...AND IS CLOSE TO THE NHC
MODEL CONSENSUS....WHICH CALLS FOR LANDFALL ALONG THE SOUTHWESTERN
COAST OF BAJA CALIFORNIA BETWEEN BAHIA MAGDALENA AND SANTA FE.

THE BETTER DEFINED EYE...COLD-TOPPED CONVECTION ENCIRCLING THE
EYE...IMPROVING OUTFLOW...AND SSTS NEAR 28C SUGGEST THAT NORBERT
COULD STRENGTHEN A LITTLE BIT MORE BEFORE MAKING LANDFALL ALONG THE
SOUTHWESTERN COAST OF BAJA CALIFORNIA LATER THIS MORNING. AFTER
LANDFALL...THE MOUNTAINOUS TERRAIN SHOULD INDUCE RAPID WEAKENING...
BUT NORBERT IS STILL EXPECTED TO BE NEAR HURRICANE STRENGTH WHEN IT
MAKES ITS SECOND LANDFALL ALONG THE NORTHWESTERN COAST OF MAINLAND
MEXICO TONIGHT. JUST HOW STRONG NORBERT WILL BE AT THE SECOND
LANDFALL WILL BE DETERMINED BY HOW STRONG IT IS WHEN IT MAKES
LANDFALL ALONG THE BAJA COAST THIS MORNING. 
 
AFTER NORBERT MAKES ITS SECOND LANDFALL...THE HIGH TERRAIN OF THE
SIERRA NEVADA MOUNTAIN RANGE SHOULD QUICKLY DECOUPLE THE LOW-LEVEL
CIRCULATION FROM THE MID- AND UPPER-LEVEL CIRCULATIONS. ALTHOUGH
MOST OF THE MODELS INDICATE THAT THE REMNANT MID-LEVEL VORTICITY
WILL BECOME STRETCHED OUT TO THE NORTHEAST AND WEAKENS...THIS MAY BE
OVERDONE GIVEN THAT NORBERT IS A STRONGER CYCLONE. AS NORBERT
CROSSES NORTHERN MEXICO AND THE SOUTHERN AND CENTRAL U.S. PLAINS...
ITS DEEP MOISTURE PLUME SHOULD BE ADVECTED WELL AHEAD OF THE
DISSIPATING CYCLONE CIRCULATION...AND INTERACTION WITH A FRONTAL
SYSTEM IN THE REGION COULD POSSIBLY CREATE A HEAVY RAINFALL
SCENARIO NOT UNLIKE THAT OF HURRICANE TICO OF 1983.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/0900Z 23.5N 112.5W   100 KT
 12HR VT     11/1800Z 25.5N 111.4W    80 KT...INLAND BAJA
 24HR VT     12/0600Z 28.3N 109.2W    35 KT...INLAND MEXICO
 36HR VT     12/1800Z 31.5N 106.6W    20 KT...REMNANT LOW INLAND
 48HR VT     13/0600Z...DISSIPATED INLAND
 
$$
FORECASTER STEWART
 
NNNN