000
WTPZ43 KNHC 190834
TCDEP3
 
HURRICANE MANUEL DISCUSSION NUMBER  20
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132013
200 AM PDT THU SEP 19 2013
 
THE LOW-LEVEL CENTER OF MANUEL HAS BEEN DIFFICULT TO LOCATE IN
GEOSTATIONARY IMAGERY OVERNIGHT...HOWEVER A SERIES OF MICROWAVE
PASSES AND RADAR DATA FROM GUASAVE MEXICO SUGGEST THAT THE CENTER
HAS REMAINED OFFSHORE THUS FAR...ALTHOUGH THE NORTHERN EYEWALL HAS
BEEN OVER LAND FOR SEVERAL HOURS. MICROWAVE IMAGERY ALSO SUGGESTED
SOME TILT TO THE CIRCULATION...WITH THE LOW-LEVEL CENTER DISPLACED
A BIT TO THE SOUTHWEST OF THE MID-LEVEL CENTER. GIVEN THAT THE
CENTER STILL APPEARS TO BE OFFSHORE...THE INITIAL INTENSITY IS HELD
AT 65 KT BASED ON THE LATEST DVORAK CURRENT INTENSITY ESTIMATE FROM
TAFB.
 
THE INITIAL MOTION ESTIMATE IS 355/03. THE AFOREMENTIONED
MICROWAVE FIXES SHOWED THAT THE CENTER IS A LITTLE FARTHER WEST AND
SOUTH THAN PREVIOUS ESTIMATES. WITH WEAK SYNOPTIC-SCALE STEERING...
THE TRACK MODEL GUIDANCE CONTINUES TO SHOW LARGE SPREAD. THE NHC
FORECAST WILL MAINTAIN CONTINUITY AND SHOW THE CENTER OF MANUEL
MOVING SLOWLY INLAND NEAR THE COAST OVER THE NEXT COUPLE OF DAYS.
THIS GENERAL IDEA IS SUPPORTED BY THE GFS...ECMWF...FIM...AND HWRF
MODELS. AN ALTERNATE SCENARIO IS THAT THE LOW-LEVEL CIRCULATION OF
MANUEL COULD DECOUPLE FROM THE MID/UPPER-LEVEL CIRCULATION AND
LINGER OVER THE GULF OF CALIFORNIA FOR THE NEXT 2 OR 3 DAYS...AS
SHOWN BY THE UKMET. NEEDLESS TO SAY...CONFIDENCE REMAINS QUITE LOW
IN THE TRACK FORECAST.
 
AS MORE OF THE CIRCULATION MOVES OVER LAND IN THE NEXT FEW HOURS...
WEAKENING SHOULD BEGIN. WITH THE NHC TRACK FORECAST SHOWING THE
CYCLONE REMAINING INLAND...THE OFFICIAL INTENSITY FORECAST CALLS FOR
STEADY WEAKENING WITH DISSIPATION EXPECTED BY 72 HOURS. IF THE
CENTER REMAINS OVER WATER LONGER...THE CIRCULATION COULD PERSIST
LONGER AND WEAKEN SLOWER THAN SHOWN HERE.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  19/0900Z 24.8N 108.2W   65 KT  75 MPH
 12H  19/1800Z 25.3N 108.2W   55 KT  65 MPH...INLAND
 24H  20/0600Z 25.5N 108.3W   45 KT  50 MPH...INLAND
 36H  20/1800Z 25.6N 108.4W   35 KT  40 MPH...INLAND
 48H  21/0600Z 25.7N 108.6W   25 KT  30 MPH...INLAND
 72H  22/0600Z...DISSIPATED
 
$$
FORECASTER BRENNAN