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HURRICANE SIMON DISCUSSION NUMBER  14
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP192014
800 PM PDT SAT OCT 04 2014

After the NOAA Hurricane Hunter aircraft left Simon earlier today,
satellite images revealed that the eye became quite distinct and
surrounded by very deep convection.  Dvorak subjective and
objective numbers from TAFB, SAB and UW-CIMSS jumped to T6.0 on
the Dvorak scale. Based on this data, the initial intensity was
adjusted upward to 115 kt. This makes Simon the 6th Category Four
Hurricane on the Saffir-Simpson Hurricane Scale this season.

Simon reached 115 kt just before entering a region of cool waters,
and as we speak, a portion of the circulation is already doing so.
Most of the global models increase the shear as the cyclone moves
northward toward the mid-latitude westerlies.  Based on these two
factors, the NHC forecast calls for significant weakening during the
next few days.  In fact, if Simon reaches Baja California, it is
likely to be a weak tropical storm or a tropical depression.

Simon is already turning and is now moving toward the northwest or
315 degrees at 9 kt. The ridge that has been steering Simon is
forecast to weaken and shift southward. This pattern will move Simon
northward until the cyclone encounters the mid-latitude westerlies,
and a recurvature toward Baja California will then begin in 48
hours.  One large uncertainty is how fast Simon will move after
recurvature. The GFS and the ECMWF are now in better agreement in
accelerating the cyclone, but many of the other models are not quite
so fast. The NHC forecast is not as fast as the GFS/ECMWF pair at
this time, but I would not be surprised if a faster motion has to be
indicated in the next forecast.

The trend of models suggests that moisture from Simon could bring
another heavy rain event to the southwestern United States in a
few days.


FORECAST POSITIONS AND MAX WINDS

INIT  05/0300Z 21.4N 115.9W  115 KT 130 MPH
 12H  05/1200Z 22.4N 117.0W  100 KT 115 MPH
 24H  06/0000Z 23.5N 117.6W   90 KT 105 MPH
 36H  06/1200Z 24.4N 117.8W   75 KT  85 MPH
 48H  07/0000Z 25.2N 117.5W   60 KT  70 MPH
 72H  08/0000Z 27.0N 116.2W   40 KT  45 MPH
 96H  09/0000Z 28.5N 114.5W   30 KT  35 MPH
120H  10/0000Z 30.0N 113.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Avila

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