954 
 WTPZ45 KNHC 252044
 TCDEP5
 HURRICANE DARBY DISCUSSION NUMBER  12
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP052010
 200 PM PDT FRI JUN 25 2010
  
 DARBY REMAINS A WELL-ORGANIZED HURRICANE WITH VISIBLE IMAGERY
 SHOWING A DISTINCT EYE AND AN IMPRESSIVE OUTFLOW PATTERN. DVORAK
 SATELLITE CLASSIFICATIONS FROM TAFB AND SAB AT 1800 UTC WERE
 T5.5...102 KT.  SINCE THAT TIME...THE SYSTEM HAS BECOME BETTER
 ORGANIZED WITH DEEPER CONVECTION IN THE EYEWALL. THUS...THE INITIAL
 INTENSITY IS NUDGED UPWARD TO 105 KT.  EASTERLY SHEAR IS FORECAST
 BY ALL OF THE GLOBAL MODELS TO INCREASE OVERNIGHT WHICH SHOULD
 LIMIT FUTURE STRENGTHENING.  THIS SHEAR WILL LIKELY PERSIST FOR
 SEVERAL DAYS AND CAUSE DARBY TO GRADUALLY WEAKEN.  MOST OF THE
 INTENSITY GUIDANCE IS IN REASONABLE AGREEMENT ON THIS SCENARIO...
 AND THE NHC FORECAST IS BASICALLY AN UPDATE OF THE PREVIOUS
 ADVISORY.
  
 THE INITIAL MOTION OF THE TROPICAL CYCLONE IS TOWARD THE
 WEST-NORTHWEST OR 285/5.  A MID-TROPOSPHERIC RIDGE OVER MEXICO IS
 FORECAST BY ALL OF THE GLOBAL MODELS TO WEAKEN DURING THE NEXT 24
 HOURS...WHICH SHOULD CAUSE DARBY TO SLOW DOWN AND BECOME NEARLY
 STATIONARY.  THEREAFTER...THE MODELS HAVE WILDLY DIVERGENT
 SOLUTIONS...WITH THE HWRF CONTINUING A WESTWARD MOTION OF DARBY AND
 THE ECMWF/UKMET SHOWING AN EASTWARD MOTION.  MOST OF THIS
 DISAGREEMENT IS CAUSED BY THE HANDLING OF THE SYSTEM OVER THE
 NORTHWESTERN CARIBBEAN...AND WHETHER THE MUCH-SMALLER DARBY GETS
 CAUGHT UP IN WESTERLY FLOW SOUTH OF MEXICO.  IT IS BEST TO STAY
 CLOSE TO THE MODEL CONSENSUS FOR NOW...AND THE NHC FORECAST IS
 CLOSE TO THE PREVIOUS ONE...A LITTLE WEST OF THE DYNAMICAL MODEL
 CONSENSUS.
  
 DARBY IS THE EARLIEST SECOND MAJOR HURRICANE FORMATION IN THE
 EASTERN PACIFIC SINCE RELIABLE RECORDS BEGAN IN 1971...ECLIPSING OF
 THE PREVIOUS RECORD OF HURRICANE DANIEL ON JUNE 30 1978.
   
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      25/2100Z 13.6N 101.5W   105 KT
  12HR VT     26/0600Z 13.7N 102.3W   105 KT
  24HR VT     26/1800Z 13.5N 103.3W   100 KT
  36HR VT     27/0600Z 13.4N 103.8W    90 KT
  48HR VT     27/1800Z 13.5N 104.2W    80 KT
  72HR VT     28/1800Z 14.0N 103.5W    65 KT
  96HR VT     29/1800Z 14.3N 102.7W    55 KT
 120HR VT     30/1800Z 14.6N 102.0W    45 KT
  
 $$
 FORECASTER BLAKE