465 
 WTPZ43 KNHC 262035
 TCDEP3
  
 TROPICAL STORM MIRIAM DISCUSSION NUMBER  20
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132012
 200 PM PDT WED SEP 26 2012
  
 SATELLITE IMAGES INDICATE THAT MIRIAM CONTINUES TO WEAKEN...AS THE
 20-25 KT OF SOUTHWESTERLY SHEAR DIAGNOSED OVER THE CYCLONE IS
 GRADUALLY TAKING A TOLL.  INNER CORE CONVECTION IS MINIMAL...AND
 DEEP CONVECTION IN A BAND WRAPPING AROUND THE PERIPHERY OF THE
 CIRCULATION HAS WARMED CONSIDERABLY DURING THE PAST SEVERAL HOURS.   
 DVORAK T-NUMBERS ARE SLOWLY DECREASING...AND A BLEND OF T-
 AND CI-NUMBERS IS USED TO ARRIVE AT THE INITIAL INTENSITY ESTIMATE
 OF 50 KT.
  
 NO DECREASE IN THE SOUTHWESTERLY TO WEST-SOUTHWESTERLY SHEAR IS
 PREDICTED DURING THE NEXT COUPLE OF DAYS.  THE COMBINATION OF THE
 SHEAR...PROGRESSIVELY COOLER WATERS...AND THE ENTRAINMENT OF A
 SUBSTANTIALLY DRIER AND MORE STABLE AIR MASS SHOULD PROMOTE
 ADDITIONAL WEAKENING.  THE NHC INTENSITY FORECAST IS JUST ABOUT THE
 SAME AS THE PREVIOUS ONE...AND IS LINE WITH THE SHIPS...LGEM...
 AND INTENSITY CONSENSUS AIDS.  REMNANT LOW STATUS IS INDICATED IN 48
 HOURS...THOUGH IT COULD OCCUR SOONER.
  
 MICROWAVE DATA AND VISIBLE SATELLITE IMAGERY WERE USED TO MAKE AN
 EASTWARD RELOCATION OF THE CENTER....AND HAVE BEEN HELPFUL IN
 ESTABLISHING A MORE CONFIDENT INITIAL MOTION OF 350/06. SO LONG AS 
 AS THE CIRCULATION OF MIRIAM MAINTAINS VERTICAL INTEGRITY...THE
 CYCLONE SHOULD MOVE CYCLONICALLY AROUND A PIECE OF AN UPPER-LEVEL
 TROUGH CURRENTLY ROTATING AROUND THE STORM. AS THE CYCLONE BECOMES
 MORE SHALLOW IN NATURE AND RESPONDS TO THE LOW- LEVEL FLOW...A
 WESTWARD BEND IS ANTICIPATED. THIS BEND COULD EVEN BE TOWARD THE
 SOUTHWEST OR SOUTH-SOUTHWEST...AS DEPICTED IN SEVERAL MODEL
 SOLUTIONS. THE NHC TRACK IS ADJUSTED SLIGHTLY TO THE LEFT AFTER 24
 HOURS...NEAR BUT TO THE NORTH OF THE MULTI-MODEL CONSENSUS.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  26/2100Z 20.8N 115.4W   50 KT  60 MPH
  12H  27/0600Z 21.6N 115.6W   45 KT  50 MPH
  24H  27/1800Z 22.4N 116.1W   35 KT  40 MPH
  36H  28/0600Z 22.8N 116.5W   30 KT  35 MPH
  48H  28/1800Z 22.9N 116.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
  72H  29/1800Z 22.9N 117.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
  96H  30/1800Z 22.9N 117.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 120H  01/1800Z...DISSIPATED
  
 $$
 FORECASTER KIMBERLAIN