Tropical Depression ONE-E

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TROPICAL DEPRESSION ONE-E DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP012007
800 AM PDT SUN MAY 27 2007
 
MICROWAVE PASSES AT 0847 AND 1004 UTC PROVIDED GOOD CENTER
FIXES...AND SHOWED THAT THE CENTER OF THE DEPRESSION IS WELL TO THE
NORTH AND EAST OF THE MAIN...AND POORLY ORGANIZED...CONVECTIVE
AREAS.  SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 35 AND
30 KT...RESPECTIVELY...AND GIVEN RECENT CONVECTIVE TRENDS THE
ADVISORY INTENSITY WILL REMAIN 30 KT.  ALTHOUGH THE WATERS BELOW
ARE WARM AND THE SHEAR IS NOT PROHIBITIVE...THE THERMODYNAMICS OF
THE ENVIRONMENT APPEAR TO BE INHIBITING DEVELOPMENT...WITH MUCH OF
THE LOW-LEVEL FLOW INTO THE DEPRESSION FROM THE NORTHWEST.  BOTH
SHIPS AND THE LGE-SHIPS MODELS HAVE TRENDED DOWNWARD WITH THEIR
EXPECTATIONS FOR THIS SYSTEM.  IT SHOULD BE NOTED THAT THE GFS
GRADUALLY DISSIPATES THE CYCLONE INTO THE ITCZ AS IT DEVELOPS A NEW
CYCLONE TO ITS EAST.  ALTHOUGH THE NEW CYCLOGENESIS SEEMS 
OVERDONE...THE MODEL MAY WELL BE CORRECT ABOUT THE DEVELOPMENT
PROSPECTS OF THE DEPRESSION.  THE OFFICIAL FORECAST...FOR
NOW...REMAINS CLOSE TO SHIPS GUIDANCE. 

THE INITIAL MOTION ESTIMATE IS 280/3.  THE DEPRESSION IS IN A WEAK
STEERING ENVIRONMENT...WITH A MID-LEVEL TROUGH CURRENTLY PASSING TO
ITS NORTH.  A LARGE MID-LEVEL RIDGE NORTHWEST OF THE DEPRESSION IS
FORECAST TO MOVE NORTHEASTWARD...WHICH IS EXPECTED TO RESULT IN A
SLOW WESTWARD TRACK OF THE CYCLONE THROUGH THE FORECAST PERIOD. 
THIS IS THE SOLUTION OFFERED BY THE ECMWF AND THE ONE FOLLOWED BY
THE OFFICIAL FORECAST.  THE BAM MODELS ARE SIMILAR BUT SOMEWHAT
FASTER.  ON THE OTHER HAND...THE UKMET KEEPS THE RIDGE MORE IN
PLACE...BLOCKING THE DEPRESSION AND KEEPING THE MOTION VERY SLOW. 
EVEN MORE EXTREME ARE THE SOLUTIONS OF THE GFS/NOGAPS/GFDL...WHICH
SHOW AN INTERACTION WITH THE AFOREMENTIONED MODEL CYCLOGENESIS TO
THE EAST THAT RESULTS IN A SOUTHWARD AND THEN EASTWARD MOTION FOR
THE DEPRESSION.  THERE DOES NOT APPEAR TO BE ANY EVIDENCE OF SUCH
CYCLOGENESIS AT THIS TIME...AND THIS LATTER SCENARIO IS CONSIDERED
UNLIKELY. 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/1500Z 13.0N 111.2W    30 KT
 12HR VT     28/0000Z 13.1N 111.7W    30 KT
 24HR VT     28/1200Z 13.1N 112.4W    35 KT
 36HR VT     29/0000Z 13.1N 113.2W    40 KT
 48HR VT     29/1200Z 13.0N 114.2W    45 KT
 72HR VT     30/1200Z 13.0N 116.0W    50 KT
 96HR VT     31/1200Z 13.0N 118.5W    50 KT
120HR VT     01/1200Z 12.5N 120.5W    50 KT
 
$$
FORECASTER FRANKLIN
 
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