Post-Tropical Cyclone GONZALO Forecast Discussion

000
WTNT43 KNHC 192039
TCDAT3

POST-TROPICAL CYCLONE GONZALO DISCUSSION NUMBER  30
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082014
500 PM AST SUN OCT 19 2014

The combined effect of sea-surface temperatures around 10C and
southwesterly vertical wind shear of more than 40 kt has finally
taken its toll on Gonzalo. The upper-level circulation is tilted
more than 100 nmi to the northeast of the low-level circulation
center, and an abundance of cold-air stratocumulus clouds has
wrapped all the way around the entire low-level circulation. Gonzalo
looks like a frontal low in satellite imagery, suggesting that the
system has completed its transformation into an extratropical
cyclone. The initial intensity has been decreased to 70 kt, which is
consistent with various decay models. Only gradual weakening is
expected during the next 48 hours.

The initial motion estimate is 060/45 kt. Gonzalo has turned toward
the east-northeast, and that general motion is expected for the next
24-36 hours, after which the cyclone is forecast to slow down
considerably and turn northward and be absorbed by a larger low
pressure system north of the British Isles by 72 hours. The NHC
track forecast is close to a blend of the GFS and ECMWF models, and
is near the latest forecast guidance provided by the NOAA Ocean
Prediction Center.

This is the last NHC advisory on Gonzalo.  Additional information on
this system can be found in High Seas Forecasts issued by the
National Weather Service...under AWIPS header NFDHSFAT1 and WMO
header FZNT01 KWBC.

FORECAST POSITIONS AND MAX WINDS

INIT  19/2100Z 51.6N  41.8W   70 KT  80 MPH...POST-TROP/EXTRATROP
 12H  20/0600Z 53.6N  31.5W   65 KT  75 MPH...POST-TROP/EXTRATROP
 24H  20/1800Z 56.5N  15.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 36H  21/0600Z 58.5N   1.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 48H  21/1800Z 64.5N   1.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 72H  22/1800Z...ABSORBED

$$
Forecaster Stewart