000
WTNT43 KNHC 160229
TCDAT3
TROPICAL DEPRESSION INGRID DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL082007
1100 PM EDT SAT SEP 15 2007
 
THE CENTER OF INGRID IS MOSTLY EXPOSED ON NIGHT VISIBLE SATELLITE
PICTURES DURING THE PAST FEW HOURS...BUT THERE ARE TWO AREAS OF
CONVECTION IN THE CIRCULATION.  A BAND OF THUNDERSTORMS IS IN THE
WESTERN SEMICIRCLE OF THE DEPRESSION...AND A MUCH LARGER AREA OF
THUNDERSTORMS IS TO THE EAST AND SOUTHEAST OF THE CENTER. 
OVERALL...STRONG WESTERLY SHEAR CONTINUES TO AFFECT INGRID AND
CAUSE A DISORGANIZED CLOUD PATTERN.  QUIKSCAT SHOWS MAXIMUM WINDS
IN THE 25-30 KT RANGE...SO THE INITIAL INTENSITY WILL STAY 30 KT. 
MOST GLOBAL MODELS ARE SHOWING A RATHER HOSTILE ENVIRONMENT FOR THE
NEXT FEW DAYS AND IT SEEMS LIKELY THAT THE SYSTEM WILL CONTINUE TO
SLOWLY WEAKEN.  THEREAFTER...THE SHEAR MAY LESSEN...BUT THERE
PROBABLY WON'T BE MUCH LEFT OF THE SYSTEM TO TAKE ADVANTAGE OF THE
IMPROVED ENVIRONMENTAL CONDITIONS.  IN FACT...THE GFDL DISSIPATES
THE SYSTEM AFTER 48 HOURS AND THE GFS DOES THE SAME BY 96 HOURS. 
FOR NOW...THE OFFICIAL FORECAST WILL GO WITH THE IDEA OF A WEAK
SYSTEM PERSISTING FOR SEVERAL DAYS BEFORE DISSIPATING...BUT THE
FORECAST MAY BE A LITTLE OPTIMISTIC ON THE SURVIVAL CHANCES OF
INGRID.
 
THE SYSTEM HAS BEEN MOVING TO THE WEST-NORTHWEST THIS EVENING...
ESTIMATED AT 285/9.  A GRADUAL TURN TO THE NORTHWEST AND A
DECREASE IN FORWARD SPEED IS EXPECTED OVER THE NEXT FEW DAYS AS THE
LOW- TO MIDDLE-LEVEL RIDGING TO THE NORTH OF INGRID IS SLOWLY
ERODED AWAY BY A TROUGH.  IN GENERAL...MODEL GUIDANCE HAS SHIFTED
WESTWARD THIS EVENING...PERHAPS DUE TO THE MODELS RECOGNIZING THE
SHALLOW DEPTH OF THE DEPRESSION.  THE OFFICIAL FORECAST IS SHIFTED
TO THE WEST FOR THIS ADVISORY BUT IS NOT TOO FAR AWAY FROM THE
MODEL CONSENSUS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      16/0300Z 16.9N  55.7W    30 KT
 12HR VT     16/1200Z 17.4N  57.1W    25 KT
 24HR VT     17/0000Z 18.2N  58.6W    25 KT
 36HR VT     17/1200Z 19.0N  59.9W    25 KT
 48HR VT     18/0000Z 19.8N  60.8W    25 KT
 72HR VT     19/0000Z 21.5N  62.0W    25 KT
 96HR VT     20/0000Z 23.0N  63.0W    20 KT...DISSIPATING
120HR VT     21/0000Z...DISSIPATED
 
$$
FORECASTER BLAKE