000
WTNT42 KNHC 291440
TCDAT2
TROPICAL DEPRESSION KAREN DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 AM EDT SAT SEP 29 2007
 
STRONGER THAN AVERAGE SHEAR NEAR KAREN IS WINNING THE BATTLE. 
KAREN IS BECOMING DISORGANIZED AS THE CENTER IS LOSING
DEFINITION AND THE CONVECTION REMAINS WELL REMOVED FROM THE
AREA OF MINIMUM SURFACE PRESSURE. IT LOOKS LIKE KAREN IS
BECOMING A TROUGH OF LOW PRESSURE. I WAS TEMPTED TO MAKE THIS THE
LAST ADVISORY BUT INSTEAD...AND A BETTER OPTION...IS TO DOWNGRADE
KAREN TO A TROPICAL DEPRESSION AND FORECAST IT TO BE A REMNANT LOW
WITHIN THE NEXT 12 HOURS. THIS WILL GIVE SOME TIME TO MONITOR IF A
NEW CENTER REFORMS NEAR THE CONVECTION. THIS IS BASED ON THE FACT
THAT GLOBAL MODELS INSIST ON KEEPING THE CYCLONE. MOREOVER...THE
GFDL AND HWRF MAKE KAREN A HURRICANE BY 3 TO 4 DAYS. THESE MODELS
ASSUME THAT KAREN WILL SURVIVE THE BAND OF STRONG SHEAR FOR ANOTHER
24 HOURS. ALTHOUGH THIS SOLUTION SEEMS UNLIKELY...I HIGHLY
VALUE THE NUMERICAL MODELS...SO KAREN OR ITS REMNANTS WILL CONTINUE
TO BE CLOSELY MONITORED FOR SIGNS OF REGENERATION DURING THE NEXT
FEW DAYS. 

THE DEPRESSION...OR THE BROAD REMNANT CIRCULATION..IS EXPECTED TO
MOVE TOWARD THE NORTHWEST OR 315 DEGREES AT  8 KNOTS FOR THE NEXT
DAY OR SO UNTIL DISSIPATION.  THERE IS NO REASON TO DISCUSS TRACK
GUIDANCE AT THIS TIME WHICH IN FACT HAS NOT CHANGED.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/1500Z 16.8N  53.8W    30 KT
 12HR VT     30/0000Z 17.5N  55.0W    25 KT...DISSIPATING
 24HR VT     30/1200Z 19.0N  56.0W    20 KT...REMNANT LOW
 36HR VT     01/0000Z 20.5N  57.0W    20 KT...REMNANT LOW
 
$$
FORECASTER AVILA