000
WTNT42 KNHC 182029
TCDAT2
HURRICANE BERTHA DISCUSSION NUMBER  63
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL022008
500 PM EDT FRI JUL 18 2008

SATELLITE IMAGES INDICATE THAT BERTHA IS NOW A HURRICANE AGAIN.  THE
EYE HAS BECOME BETTER-DEFINED WITH DEEP CONVECTION INCREASING AROUND
A CONSOLIDATING EYEWALL.  THE INITIAL INTENSITY IS RAISED TO 65 KT
IN AGREEMENT WITH THE SATELLITE CLASSIFICATION FROM SAB.  BERTHA
SHOULDN'T BE A HURRICANE FOR TOO LONG AS IT IS FORECAST TO BE OVER
WATERS LESS THAN 70F BY THIS TIME TOMORROW.  A SLOW WEAKENING IS
INDICATED...WHICH IS IN GOOD AGREEMENT WITH MOST GUIDANCE.  PHASE
DIAGRAMS FROM FLORIDA STATE INDICATE THAT THE HURRICANE SHOULD
BEGIN ITS EXTRATROPICAL TRANSITION IN A DAY OR SO...WITH THE
PROCESS COMPLETE IN ABOUT 48 HR.  
 
BERTHA CONTINUES MOVING TO THE NORTHEAST...NOW AT ABOUT 19 KT. THERE
IS NO CHANGE TO THE SYNOPTIC REASONING. THE HURRICANE SHOULD
ACCELERATE OUT TO SEA IN A WELL-DEFINED STEERING CURRENT BETWEEN A
HIGH TO THE SOUTHEAST AND THE MIDDLE-LATITUDE WESTERLIES. MODEL
GUIDANCE IS GENERALLY SHOWING GREATER INTERACTION THAN EARLIER WITH
BERTHA AND AN APPROACHING TROUGH FROM NORTH AMERICA... RESULTING IN
A SLIGHTLY MORE POLEWARD TRACK OF THE CYCLONE. THE OFFICIAL
FORECAST IS SHIFTED WESTWARD TO ACCOUNT FOR THIS TREND AND LIES ON
THE EASTERN SIDE OF THE GUIDANCE ENVELOPE. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/2100Z 37.6N  50.6W    65 KT
 12HR VT     19/0600Z 39.8N  48.2W    65 KT
 24HR VT     19/1800Z 42.9N  44.8W    60 KT
 36HR VT     20/0600Z 46.7N  40.6W    55 KT...BECOMING EXTRATROPICAL
 48HR VT     20/1800Z 51.5N  36.0W    50 KT...EXTRATROPICAL
 72HR VT     21/1800Z 61.0N  23.0W    50 KT...EXTRATROPICAL
 96HR VT     22/1800Z...ABSORBED
 
$$
FORECASTER BLAKE