626 
 WTPZ43 KNHC 250843
 TCDEP3
  
 HURRICANE MIRIAM DISCUSSION NUMBER  14
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132012
 200 AM PDT TUE SEP 25 2012
  
 MICROWAVE AND INFRARED SATELLITE IMAGERY INDICATE MIRIAM HAS
 COMPLETED ITS EYEWALL REPLACEMENT CYCLE AND A 30 N MI DIAMETER EYE
 APPEARS TO HAVE STABILIZED. CLOUD TOPS HAVE COOLED SIGNIFICANTLY
 AROUND THE EYE OVER THE PAST 4 HOURS...AND UW-CIMSS ADT AND NHC
 AODT SATELLITE INTENSITY ESTIMATES HAVE INCREASED TO T5.3/97 KT AND
 T5.6/105 KT...RESPECTIVELY. AS A RESULT...THE INITIAL INTENSITY IS
 BEING MAINTAINED AT 90 KT...WHICH COULD BE CONSERVATIVE.
  
 THE INITIAL MOTION ESTIMATE IS 310/05 KT. MIRIAM IS ON TRACK AND...
 AS A RESULT...THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS
 FORECAST TRACK OR REASONING. MIRIAM IS EXPECTED TO GRADUALLY TURN
 TOWARD THE NORTHWEST LATER TODAY AND TURN NORTHWARD IN 24-36 HOURS
 AS THE CYCLONE BECOMES EMBEDDED IN WEAK SOUTHERLY STEERING FLOW
 BETWEEN A SUBTROPICAL RIDGE SITUATED TO THE EAST AND A MID- TO
 UPPER-LEVEL LOW LOCATED TO ITS WEST AND NORTHWEST. THE UKMET MODEL
 REMAINS A SIGNIFICANT OUTLIER WITH A STRONG WEST BIAS AND HAS...
 THEREFORE...BEEN DISCOUNTED FOR THIS FORECAST CYCLE. AS A RESULT...
 THE OFFICIAL FORECAST TRACK REMAINS TO THE EAST OF THE CONSENSUS
 MODELS TV15 AND TVCE...AND IS FAIRLY CLOSE TO A BLEND OF THE GFS
 AND ECMWF MODELS...WHICH BETTER DEPICT A STRONGER AND MORE
 VERTICALLY DEEP CYCLONE AS CURRENTLY ANALYZED.
  
 GRADUAL WEAKENING IS FORECAST DURING THE NEXT 24 TO 36 HOURS AS
 SOUTHWESTERLY SHEAR INCREASES AHEAD OF A SLOWLY ADVANCING
 MID-/UPPER-LEVEL TROUGH NOTED TO THE WEST AND NORTHWEST OF MIRIAM
 IN WATER VAPOR IMAGERY. BY DAYS 3-5...THE GLOBAL MODELS ARE
 FORECASTING A LARGE MID-/UPPER-LEVEL LOW DEVELOPING NEAR 30N 130W.
 THIS LOW IS EXPECTED TO INCREASE THE VERTICAL SHEAR ABOVE 30 KT...
 WHICH SHOULD INDUCE MORE RAPID WEAKENING AND POSSIBLE DISSIPATION
 BEFORE MIRIAM REACHES BAJA CALIFORNIA. THE OFFICIAL FORECAST IS
 SIMILAR TO THE PREVIOUS ADVISORY AND FOLLOWS A BLEND OF THE SHIPS
 AND LGEM MODELS.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  25/0900Z 18.7N 114.3W   90 KT 105 MPH
  12H  25/1800Z 19.3N 114.7W   85 KT 100 MPH
  24H  26/0600Z 20.1N 115.0W   80 KT  90 MPH
  36H  26/1800Z 21.1N 115.2W   70 KT  80 MPH
  48H  27/0600Z 22.1N 115.3W   65 KT  75 MPH
  72H  28/0600Z 24.0N 115.3W   50 KT  60 MPH
  96H  29/0600Z 25.7N 114.9W   40 KT  45 MPH
 120H  30/0600Z 27.2N 114.4W   30 KT  35 MPH...POST-TROP/REMNT LOW
  
 $$
 FORECASTER STEWART