Hurricane MANUEL
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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
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