[Tropical] Tropical Cyclone Discussion

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WTNT45 KNHC 111447
TCDAT5

TROPICAL STORM NICOLE DISCUSSION NUMBER  30
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL152016
1100 AM AST TUE OCT 11 2016

Nicole's cloud pattern has improved this morning, with several
bands of convection wrapping around the center.  Recent microwave
imagery has revealed a well-defined low-level eye feature and there
are hints of a ragged banding eye forming in last few visible
satellite pictures. Based on the increase in organization the
initial intensity is increased to 55 kt, which is in agreement with
a Dvorak estimate from SAB.  An Air Force Reserve Hurricane Hunter
aircraft is currently en route to investigate Nicole, and the data
they collect should provide a better estimate of the cyclone
intensity and size this afternoon.

The shear that has been plaguing Nicole during the past several
days has weakened, and is expected to remain low during the next
day or so.  This, along with warm waters along the forecast track,
should allow for strengthening during the 36 to 48 hours, and Nicole
is predicted to become a hurricane later today or tonight. Later in
the forecast period, some weakening is predicted due to cooler
waters and increasing shear, but Nicole is expected to become a
powerful extratropical cyclone over the North Atlantic. The new NHC
intensity forecast is a little higher than the previous advisory,
and is closest to the SHIPS and GFDL model guidance.

The tropical storm is moving north-northwestward at about 4 kt.
Nicole is forecast to turn northward into a break in the subtropical
ridge that is being caused by a mid-latitude trough that is
currently passing to the north of Bermuda.  As Nicole approaches
Bermuda, it will reach the mid-latitude westerly flow, which should
cause a turn toward the northeast and some increase in forward
speed.  The track guidance has come into much better agreement on
this scenario since yesterday, and the updated NHC track forecast
is near the middle of the now tightly clustered guidance.

A Hurricane Warning will likely be required for Bermuda this
afternoon.


FORECAST POSITIONS AND MAX WINDS

INIT  11/1500Z 27.3N  65.9W   55 KT  65 MPH
 12H  12/0000Z 27.7N  66.4W   65 KT  75 MPH
 24H  12/1200Z 28.6N  66.9W   75 KT  85 MPH
 36H  13/0000Z 30.2N  66.6W   80 KT  90 MPH
 48H  13/1200Z 32.2N  65.4W   85 KT 100 MPH
 72H  14/1200Z 36.8N  60.5W   80 KT  90 MPH
 96H  15/1200Z 40.5N  55.0W   75 KT  85 MPH...POST-TROP/EXTRATROP
120H  16/1200Z 41.8N  53.0W   65 KT  75 MPH...POST-TROP/EXTRATROP

$$
Forecaster Brown
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