TROPICAL STORM BERTHA DISCUSSION NUMBER  68
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL022008
1100 PM EDT SAT JUL 19 2008

THE SATELLITE PRESENTATION OF BERTHA HAS DEGRADED OVER THE PAST FEW
HOURS...WITH THE CONVECTION BECOMING LESS SYMMETRIC AND BEGINNING
TO WARM. THE EYE THAT WAS VISIBLE SIX HOURS AGO IS GONE. DVORAK T
NUMBERS ARE DECREASING...AND THE INITIAL INTENSITY IS LOWERED TO 60
KT. FORECAST TO BE OVER 11C WATERS IN ABOUT 18 HOURS...BERTHA
SHOULD NOT BE ABLE TO MAINTAIN TROPICAL CHARACTERISTICS BEYOND
MIDDAY TOMORROW. DESPITE THE TRANSITION...THE WINDS WILL PROBABLY
NOT FALL OFF VERY FAST...AND BERTHA WILL BE A LARGE AND POWERFUL
EXTRATROPICAL CYCLONE FOR TWO TO THREE DAYS UNTIL IT IS ABSORBED BY
OR MERGES WITH ANOTHER SYSTEM CROSSING CANADA.

THE INITIAL MOTION IS 040/21...ABOUT THE SAME AS BEFORE.  AN
INCREASE IN FORWARD SPEED IS FORECAST...IN CLOSE AGREEMENT WITH A
TIGHTLY-PACKED MODEL CONSENSUS AND THE PREVIOUS ADVISORY. 

FORECAST POSITIONS AND MAX WINDS

INITIAL      20/0300Z 45.7N  41.8W    60 KT
12HR VT     20/1200Z 49.8N  37.4W    55 KT
24HR VT     21/0000Z 55.0N  31.4W    55 KT...EXTRATROPICAL
36HR VT     21/1200Z 60.1N  24.8W    50 KT...EXTRATROPICAL
48HR VT     22/0000Z 64.0N  18.0W    50 KT...EXTRATROPICAL
72HR VT     23/0000Z...ABSORBED

$$
FORECASTER FRANKLIN