000
WTNT41 KNHC 120840
TCDAT1
HURRICANE IGOR DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112010
500 AM AST SUN SEP 12 2010
 
SATELLITE IMAGES SUGGEST THAT IGOR HAS STRENGTHENED A LITTLE MORE
THIS MORNING. ALTHOUGH DVORAK CLASSIFICATIONS WERE 65 KT FROM BOTH
TAFB AND SAB AT 0600 UTC...THE CURVED BAND OVER THE EASTERN
SEMICIRCLE HAS BECOME BETTER DEFINED AND THE OVERALL CLOUD PATTERN
IS NOW MORE SYMMETRIC. THEREFORE...THE INITIAL INTENSITY IS RAISED
TO 70 KT FOR THIS ADVISORY...WHICH IS IN AGREEMENT WITH THE ADT
ESTIMATES.
 
CONDITIONS APPEAR FAVORABLE FOR ADDITIONAL STRENGTHENING DURING THE
NEXT FEW DAYS AS IGOR MOVES OVER STEADILY INCREASING SEA SURFACE
TEMPERATURES AND REMAINS IN A LOW WIND SHEAR ENVIRONMENT. MOST OF
THE INTENSITY MODELS BRING IGOR TO MAJOR HURRICANE STATUS WITHIN A
COUPLE OF DAYS...AND THE OFFICIAL FORECAST FOLLOWS THIS GUIDANCE.
BEYOND A FEW DAYS...THE MODELS ARE MIXED WITH SOME SHOWING LITTLE
CHANGE IN STRENGTH AND OTHERS GRADUAL WEAKENING. THE OFFICIAL
FORECAST IS SIMILAR TO THE PREVIOUS ONE...AND CLOSER TO THE LGEM
AND SHIPS MODELS...PREDICTING IGOR TO MAINTAIN MAJOR HURRICANE
STATUS.
 
IGOR CONTINUES TO MOVE WESTWARD ABOUT THE SAME SPEED AS ESTIMATED
EARLIER...275/16. A SUBTROPICAL RIDGE LOCATED TO THE NORTH OF THE
HURRICANE IS EXPECTED TO KEEP IGOR ON A WESTWARD TRACK FOR THE NEXT
2 TO 3 DAYS. THEREAFTER...THE GLOBAL MODELS ARE IN AGREEMENT IN
SHOWING THE RIDGE ERODE DUE TO PERSISTENT BROAD TROUGHING OVER THE
WESTERN ATLANTIC. THIS FLOW PATTERN SHOULD ALLOW IGOR TO TURN
WEST-NORTHWESTWARD TO NORTHWESTWARD DURING THAT TIME PERIOD. THE
MODEL GUIDANCE HAS NOT CHANGED MUCH FROM THE LAST CYCLE...AND
THE OFFICIAL FORECAST IS GENERALLY AN UPDATE OF THE PREVIOUS ONE.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/0900Z 17.7N  44.4W    70 KT
 12HR VT     12/1800Z 17.9N  46.5W    75 KT
 24HR VT     13/0600Z 18.1N  49.1W    80 KT
 36HR VT     13/1800Z 18.3N  51.3W    90 KT
 48HR VT     14/0600Z 18.7N  53.2W   100 KT
 72HR VT     15/0600Z 20.2N  56.3W   115 KT
 96HR VT     16/0600Z 22.5N  59.0W   115 KT
120HR VT     17/0600Z 24.5N  62.0W   115 KT
 
$$
FORECASTER CANGIALOSI