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000
WTNT41 KNHC 152032
TCDAT1

POST-TROPICAL CYCLONE ALEX DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012016
500 PM AST FRI JAN 15 2016

Geostationary and low-level microwave satellite images show the cloud pattern becoming elongated and taking on a comma, i.e. frontal, shape. Short-term model forecasts show significant thermal advection in the circulation, and this is also suggested by surface data. An earlier scatterometer pass showed that the system was losing its inner-core wind maximum, with the strongest winds well-removed to the northeast of the center. Therefore Alex has made the transition to an extratropical cyclone, and this will be the last advisory.

Maximum winds are estimated to be just below hurricane strength, and the post-tropical cyclone could re-intensify slightly in the short term due to baroclinic energy sources. Within 48 hours, the global models generally agree on the system merging with another extratropical low over the north Atlantic.

The cyclone has accelerated greatly during the day and is now moving slightly west of due north, or 350/35. The dynamical guidance shows the system rotating counterclockwise around a large gyre over the north Atlantic during the next day or so. This is also shown in the official forecast, which is based mainly on input from the NOAA Ocean Prediction Center.

Additional information on this system can be found in High Seas Forecasts issued by the National Weather Service under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and available on the Web at http://www.opc.ncep.noaa.gov/shtml/NFDHSFAT1.shtml, and in high seas forecasts issued by Meteo France under WMO header FQNT50 LFPW and available on the web at http://www.meteofrance.com/previsions-meteo-marine/bulletin.

FORECAST POSITIONS AND MAX WINDS

INIT 15/2100Z 43.0N 27.8W 60 KT 70 MPH...POST-TROP/EXTRATROP 12H 16/0600Z 49.2N 29.4W 65 KT 75 MPH...POST-TROP/EXTRATROP 24H 16/1800Z 56.3N 36.1W 65 KT 75 MPH...POST-TROP/EXTRATROP 36H 17/0600Z 56.5N 47.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 17/1800Z...ABSORBED BY ANOTHER EXTRATROPICAL LOW

$$ Forecaster Pasch

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