000
WTPZ43 KNHC 270852
TCDEP3
 
TROPICAL STORM MIRIAM DISCUSSION NUMBER  22
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132012
200 AM PDT THU SEP 27 2012
 
MIRIAM IS BARELY HOLDING ON AS A TROPICAL CYCLONE...WITH ANY DEEP
CONVECTION LOCATED BETWEEN 75 AND 105 N MI N OF THE CENTER.
ALTHOUGH THE LATEST SUBJECTIVE DVORAK ESTIMATES ARE LOWER THAN
EARLIER...AN ASCAT PASS AT 0440 UTC HAD WINDS STILL HAD WINDS OF
ABOUT 40 KT.  IN CONSIDERATION OF THE LOW BIAS OF THAT SATELLITE...
THE INITIAL WIND SPEED IS KEPT AT 40 KT.  WEAKENING IS FORECAST BY
ALL GUIDANCE DUE TO MODERATE OR STRONG SHEAR AND COOL SSTS.  THE
OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ONE...BUT IT SHOWS
MIRIAM BECOMING A REMNANT LOW WITHIN 24 HOURS.  IF CURRENT
CONVECTIVE TRENDS CONTINUE...IT COULD BE SOONER THAN THAT TIME.
 
RECENT INFRARED IMAGES SHOW THAT MIRIAM IS MOVING AT ABOUT 330/5.
THE STORM SHOULD SLOW DOWN AND TURN WESTWARD AND SOUTHWARD WITH
TIME AS BECOMES STEERED BY THE EASTERN PACIFIC SUBTROPICAL HIGH.
THE OFFICIAL FORECAST IS A BIT SOUTH OF THE PREVIOUS ONE...BUT NOT
AS FAR SOUTH AS THE LATEST GFS/ECMWF GUIDANCE.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  27/0900Z 21.8N 116.0W   40 KT  45 MPH
 12H  27/1800Z 22.3N 116.5W   35 KT  40 MPH
 24H  28/0600Z 22.5N 116.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  28/1800Z 22.5N 117.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  29/0600Z 22.4N 117.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  30/0600Z 22.0N 118.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  01/0600Z...DISSIPATED
 
$$
FORECASTER BLAKE