000
WTPZ45 KNHC 101500
TCDEP5
HURRICANE NORBERT DISCUSSION NUMBER  27
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP152008
800 AM PDT FRI OCT 10 2008
 
A HEALTHY RING OF DEEP CONVECTION HAS BEEN WRAPPING AROUND THE EYE
OF NORBERT...WHICH HAS SHRUNK TO 10-15 NM IN DIAMETER.  SATELLITE
IMAGERY STILL SUGGESTS THAT THERE ARE TWO EYEWALLS APPROXIMATELY 15
AND 50 NM AWAY FROM THE CENTER...ALTHOUGH THIS NEW CONVECTIVE
ACTIVITY MIGHT FINALLY ALLOW THE OUTER EYEWALL TO BECOME THE MORE
DOMINANT FEATURE.  DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB
HAVE RISEN TO T5.0...OR 90 KT...BUT THE INITIAL INTENSITY IS RAISED
CONSERVATIVELY TO 85 KT JUST IN CASE THE STRONGEST WINDS ARE STILL
NOT REACHING THE SURFACE.  A BETTER JUDGMENT ON THE INTENSITY CAN
BE MADE ONCE THE AIR FORCE HURRICANE HUNTER AIRCRAFT REACHES
NORBERT AROUND MIDDAY.

MODEL GUIDANCE IS TIGHTLY-CLUSTERED THROUGH 36 HOURS...AND EVEN THE
GFS NOW AGREES WITH THE OTHER DYNAMICAL MODELS ON LANDFALL ALONG
THE SOUTHERN BAJA CALIFORNIA COAST IN ABOUT 24 HOURS.  AS
SUCH...THERE HAS BEEN LITTLE CHANGE IN THE FORECAST TRACK FROM THE
PREVIOUS FORECAST.  FORECAST POINTS ARE ONLY GIVEN THROUGH 48 HOURS
SINCE THE LOW-LEVEL CENTER OF NORBERT WILL PROBABLY NOT SURVIVE A
CROSSING OF THE SIERRA MADRES.  HOWEVER...THE MID-LEVEL REMNANTS
AND ASSOCIATED RAINFALL WILL STILL SPREAD NORTHEASTWARD ACROSS
NORTHERN MEXICO AND PORTIONS OF THE SOUTHWESTERN AND SOUTH-CENTRAL
UNITED STATES OVER THE NEXT 24-48 HOURS.

THE INTENSITY FORECAST LIES VERY CLOSE TO THE SHIPS AND LGEM MODELS
UP TO LANDFALL SINCE THESE MODELS APPEAR TO BE ACCOUNTING FOR THE
EXPECTED INCREASE OF VERTICAL SHEAR OVER THE NEXT 24 HOURS. THE NEW
FORECAST IS ONLY 5 KT HIGHER THAN THE PREVIOUS FORECAST...DUE TO
THE RECENT APPARENT STRENGTHENING. THE INTENSITY AT 36 HOURS...
AFTER NORBERT HAS CROSSED THE BAJA PENINSULA AND IS OVER THE GULF
OF CALIFORNIA...IS STILL AT HURRICANE STRENGTH ALTHOUGH IS NOT AS
HIGH AS THE INTENSITY CONSENSUS AT THAT TIME. THE TROPICAL STORM
WARNING ON THE EAST SIDE OF THE BAJA PENINSULA WAS NOT DESIGNATED
AS A HURRICANE WARNING SINCE HURRICANE FORCE WINDS ARE ONLY
EXPECTED ON THE EAST SIDE OF THE SYSTEM...AND THESE WINDS WILL BE
BLOWING OFFSHORE. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/1500Z 20.6N 113.4W    85 KT
 12HR VT     11/0000Z 21.9N 113.4W    80 KT
 24HR VT     11/1200Z 23.9N 112.5W    75 KT
 36HR VT     12/0000Z 26.1N 110.8W    65 KT
 48HR VT     12/1200Z 28.3N 109.0W    35 KT...INLAND
 72HR VT     13/1200Z...DISSIPATED INLAND
 
$$
FORECASTER BERG