Hurricane NADINE Forecast Discussion

000
WTNT44 KNHC 150852
TCDAT4

HURRICANE NADINE DISCUSSION NUMBER  16
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST SAT SEP 15 2012

NADINE HAS CHANGED LITTLE IN ORGANIZATION OVER THE PAST SEVERAL
HOURS. THE HURRICANE IS MAINTAINING CENTRAL CONVECTIVE BANDING...
ALTHOUGH A RECENT AMSU OVERPASS SUGGESTS THAT THE MID-LEVEL CENTER
IS DISPLACED TO THE NORTHEAST OR EAST OF THE LOW-LEVEL CENTER.
SATELLITE INTENSITY ESTIMATES ARE 77 KT FROM SAB AND 65 KT FROM
TAFB...AND RECENT AMSU INTENSITY ESTIMATES FROM CIMSS AND CIRA ARE
76 AND 73 KT RESPECTIVELY. DUE TO THE UNCERTAINTY ABOUT THE
ORGANIZATION...THE INITIAL INTENSITY REMAINS 65 KT. HOWEVER...THIS
INTENSITY COULD BE A LITTLE CONSERVATIVE.

NADINE CONTINUES ITS RECURVATURE INTO THE WESTERLIES WITH AN INITIAL
MOTION OF 050/13.  THE CYCLONE SHOULD MOVE GENERALLY EASTWARD IN
THE WESTERLIES FOR THE NEXT 2-3 DAYS...AND THERE IS A CHANCE IT
COULD MOVE A LITTLE SOUTH OF EAST AS SHOWN BY THE ECMWF.  AFTER
THREE DAYS...NADINE IS LIKELY TO TURN NORTHEASTWARD AS A DEEP-LAYER
LOW PRESSURE SYSTEM FORMS TO THE WEST OVER THE CENTRAL ATLANTIC. 
THE GFS...GFS ENSEMBLE MEAN...ECMWF...UKMET...AND FLORIDA STATE
SUPERENSEMBLE ARE NEAR THE CENTER OF THE TRACK GUIDANCE ENVELOPE...
AND THE NEW TRACK FORECAST LIES NEAR THESE MODELS. THE NEW FORECAST
IS SIMILAR TO THE OLD FORECAST THROUGH 48 HR...AND THEN IS SHIFTED
TO THE EAST OF THE PREVIOUS FORECAST DUE TO AN OVERALL SHIFT IN THE
TRACK GUIDANCE.

NADINE CONTINUES TO EXPERIENCE 25-35 KT OF SOUTHWESTERLY VERTICAL
WIND SHEAR...AND IT IS UNCLEAR HOW THE CYCLONE HAS BEEN ABLE TO
MAINTAIN ITSELF SO WELL IN THIS ENVIRONMENT. ALL GLOBAL MODEL
GUIDANCE FORECASTS AT LEAST 25-35 KT OF SHEAR TO CONTINUE THROUGH
THE FORECAST PERIOD...WHICH SHOULD PRECLUDE ANY SIGNIFICANT
STRENGTHENING. THE GFS...ECMWF...AND UKMET FORECAST A SHORTWAVE
TROUGH IN THE WESTERLIES TO INTERACT WITH NADINE IN 72-96 HR...
WHICH COULD CHANGE THE INTENSITY AND STRUCTURE. HOWEVER...THE
RESULTS OF THIS INTERACTION ARE NOT CURRENTLY REFLECTED IN ANY OF
THE INTENSITY GUIDANCE. THE NEW INTENSITY FORECAST IS THE SAME AS
THE PREVIOUS FORECAST AND IS SIMILAR TO THE SHIPS...LGEM...AND THE
INTENSITY CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INIT  15/0900Z 30.7N  51.4W   65 KT  75 MPH
 12H  15/1800Z 31.1N  49.6W   70 KT  80 MPH
 24H  16/0600Z 31.1N  46.8W   70 KT  80 MPH
 36H  16/1800Z 31.0N  43.6W   70 KT  80 MPH
 48H  17/0600Z 31.4N  40.5W   70 KT  80 MPH
 72H  18/0600Z 33.0N  35.0W   65 KT  75 MPH
 96H  19/0600Z 35.5N  31.5W   60 KT  70 MPH
120H  20/0600Z 37.5N  29.5W   50 KT  60 MPH

$$
FORECASTER BEVEN