522 
 WTPZ45 KNHC 260850
 TCDEP5
 HURRICANE DARBY DISCUSSION NUMBER  14
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP052010
 200 AM PDT SAT JUN 26 2010
  
 DARBY IS AN INCREDIBLY SMALL HURRICANE.  AN ASCAT PASS AROUND 0345
 UTC INDICATED THAT TROPICAL STORM FORCE WINDS DO NOT EXTEND ANY
 FARTHER THAN ABOUT 35 N MI FROM THE CENTER.  THE HURRICANE HAD BEEN
 MAINTAINING A SMALL 10-N MI WIDE EYE SURROUNDED BY DEEP
 CONVECTION...WHICH SUPPORTED 0600 UTC DVORAK ESTIMATES OF T5.5 FROM
 BOTH TAFB AND SAB.  HOWEVER...THE EYE HAS RECENTLY BECOME
 OBSCURED...AND THE MOST RECENT ADT ESTIMATE FROM UW-CIMSS IS T5.1.
 THE INITIAL INTENSITY IS THEREFORE LOWERED TO 95 KT.  VERTICAL
 SHEAR IS EXPECTED TO INCREASE OVER DARBY OVER THE NEXT SEVERAL
 DAYS...WHICH IS EXPECTED TO INDUCE GRADUAL WEAKENING.  THE
 WEAKENING IS EXPECTED TO BE MORE RAPID FROM 72-120 HOURS AS A
 STRONG UPPER RIDGE BUILDS OVER MEXICO...CREATING FAIRLY STRONG
 UPPER-LEVEL EASTERLY WINDS NEAR THE CYCLONE.  THE NEW OFFICIAL
 FORECAST CLOSELY FOLLOWS THE SHIPS AND LGEM INTENSITY
 GUIDANCE...AND IS NOT TOO DIFFERENT FROM THE PREVIOUS ADVISORY.
  
 DARBY HAS BEEN MOVING ALMOST WEST-SOUTHWESTWARD OVER THE PAST FEW
 HOURS...AND THE INITIAL MOTION IS 260/5.  THE STEERING CURRENTS
 AROUND THE HURRICANE ARE STILL EXPECTED TO COLLAPSE THROUGH THE
 FORECAST PERIOD...AND DARBY SHOULD BEGIN TO MOVE VERY SLOWLY
 WESTWARD OVER THE NEXT 24-36 HOURS.  THEREAFTER...THE CYCLONE IS
 EXPECTED TO BEGIN FEELING THE INFLUENCE OF NEWLY-NAMED TROPICAL
 STORM ALEX IN THE WESTERN CARIBBEAN.  THE OFFICIAL FORECAST
 INDICATES A SLOW NORTHEASTWARD MOTION BETWEEN DAYS 3 AND 5...BUT IT
 SHOULD BE NOTED THAT THE GUIDANCE ENVELOPE IS STILL RATHER
 DIVERGENT AND DARBY COULD DRIFT OR MEANDER IN PLACE FOR SEVERAL
 DAYS.  THE ECMWF SHOWS A QUICK NORTHEASTWARD MOTION AND BRINGS
 DARBY TO THE MEXICAN COAST IN 3 DAYS...BUT THIS SOLUTION IS
 DISCOUNTED AT THIS TIME.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      26/0900Z 13.5N 102.7W    95 KT
  12HR VT     26/1800Z 13.4N 103.4W    90 KT
  24HR VT     27/0600Z 13.4N 104.1W    85 KT
  36HR VT     27/1800Z 13.6N 104.4W    75 KT
  48HR VT     28/0600Z 13.9N 104.1W    70 KT
  72HR VT     29/0600Z 14.3N 103.3W    55 KT
  96HR VT     30/0600Z 14.7N 102.8W    45 KT
 120HR VT     01/0600Z 15.0N 102.5W    35 KT
  
 $$
 FORECASTER BERG