000
WTNT43 KNHC 222049
TCDAT3
TROPICAL STORM CRISTOBAL DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL032008
500 PM EDT TUE JUL 22 2008
 
VISIBLE SATELLITE IMAGES INDICATE THAT THE MID-LEVEL CENTER OF
CRISTOBAL IS RAPIDLY BECOMING DECOUPLED FROM THE LOW-LEVEL CENTER.
WINDS ARE DECREASED TO 45 KT ON THIS ADVISORY AND SHOULD DIMINISH
AS THE SYSTEM BECOMES EXTRATROPICAL OVERNIGHT. A STEADY DECREASE IN
STRENGTH IS SHOWN BY ALL GUIDANCE AND THE OFFICIAL FORECAST IS
ADJUSTED DOWNWARD. STEADY WEAKENING AS AN EXTRATROPICAL CYCLONE IS
ALSO FORECAST DUE TO A STRONG SHEARING ENVIRONMENT AND NO
BAROCLINIC FORCING.
 
CRISTOBAL HAS CONTINUED TO ACCELERATE AND IS MOVING NORTHEAST AT
ABOUT 24 KT.  MOST OF THE MODELS SHOW A DECREASE IN FORWARD SPEED
AS THE SYSTEM TRANSITIONS INTO AN EXTRATROPICAL CYCLONE. THE
REMNANT OF CRISTOBAL ARE EXPECTED TO TURN TOWARD THE EAST TOMORROW
AS IT MOVES ACROSS THE NORTHERN PERIPHERY OF A SUBTROPICAL RIDGE IN
THE CENTRAL ATLANTIC. GLOBAL MODELS TURN THE CYCLONE TOWARD THE
SOUTHEAST DUE TO AN APPROACHING MIDDLE-LATITUDE TROUGH.  THIS
SYSTEM SHOULD EITHER OPEN UP INTO A TROUGH OR BE ABSORBED BY A COLD
FRONT IN ABOUT 3 DAYS. TRACK GUIDANCE IS IN EXCELLENT AGREEMENT AND
THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ONE.

CANADIAN BUOY 44137 WAS VERY HELPFUL IN DETERMINING THE WIND RADII.  
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/2100Z 42.2N  62.9W    45 KT
 12HR VT     23/0600Z 44.0N  58.5W    40 KT...EXTRATROPICAL
 24HR VT     23/1800Z 45.0N  53.5W    35 KT...EXTRATROPICAL
 36HR VT     24/0600Z 44.0N  48.0W    30 KT...EXTRATROPICAL
 48HR VT     24/1800Z 42.0N  43.0W    25 KT...EXTRATROPICAL
 72HR VT     25/1800Z...DISSIPATED
 
$$
FORECASTER BLAKE