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 426 
 WTNT43 KNHC 130235
 TCDAT3
 
 TROPICAL STORM GONZALO DISCUSSION NUMBER   3
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082014
 1100 PM AST SUN OCT 12 2014
 
 The circulation of Gonzalo, which has shown some signs of inner-core
 features, is apparent in radar imagery from Guadeloupe, but the
 cyclone's overall convective pattern is somewhat disorganized in
 satellite imagery. A small area of central convection is noted near
 the center, along with a rather linear convective band in the
 eastern semicircle. Little deep convection is noted west of the
 center, perhaps due to westerly shear of around 10 kt and some dry
 air in the mid and upper levels seen in radiosonde data from St.
 Maarten. The initial intensity remains 40 kt based on the earlier
 aircraft data and a blend of the latest Dvorak data-T numbers from
 TAFB and SAB. The SHIPS model shows the shear weakening in 12 to 18
 hours, and most of the intensity guidance shows Gonzalo reaching
 hurricane status in about 36 hours. Additional intensification is
 forecast after that time in a low-shear environment over warm
 waters. The new NHC intensity forecast is largely an update of the
 previous one and is close to the IVCN consensus through the period.
 
 The initial motion estimate is 275/10, as Gonzalo is being steered
 by a mid-level ridge to its northeast. During the next 36 to 48
 hours, the cyclone will gradually turn northwestward as it moves
 around the western periphery of this ridge. Overall, the guidance
 envelope has shifted a little to the right through the first 2 days,
 and the NHC forecast has been adjusted in that direction but lies
 south of the multi-model consensus and close to the ECMWF. After
 that time, most of the guidance shows the cyclone turning northward
 into a weakness in the ridge and then accelerating northeastward
 ahead of a mid-latitude trough by day 5. There is still a large
 amount of along-track spread at these time ranges, with the GFS,
 HWRF, GFDL, and GEFS ensemble mean showing a faster northeastward
 acceleration, and the slower ECMWF showing the trough missing
 Gonzalo and leaving the cyclone moving slowly northeastward
 by the end of the period. At days 3 through 5, the NHC forecast is
 faster and shows more of a northeastward motion compared to the
 previous one, but is much slower than the GFS and south of the
 consensus out of respect for the ECMWF model.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  13/0300Z 16.6N  60.2W   40 KT  45 MPH
  12H  13/1200Z 16.9N  61.9W   50 KT  60 MPH
  24H  14/0000Z 17.7N  63.8W   55 KT  65 MPH
  36H  14/1200Z 18.8N  65.3W   65 KT  75 MPH
  48H  15/0000Z 20.0N  66.5W   70 KT  80 MPH
  72H  16/0000Z 22.5N  68.0W   85 KT 100 MPH
  96H  17/0000Z 24.5N  68.0W   95 KT 110 MPH
 120H  18/0000Z 27.0N  66.0W   90 KT 105 MPH
 
 $$
 Forecaster Brennan
 
 
 
 428 
 WTNT42 KNHC 130235
 TCDAT2
 
 TROPICAL STORM FAY DISCUSSION NUMBER  12
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072014
 1100 PM AST SUN OCT 12 2014
 
 Fay's cloud pattern has rapidly deteriorated in organization since
 this afternoon due to strong southwesterly vertical wind shear.
 Microwave and last-light visible satellite imagery indicate that the
 low-level center has become exposed to the southwest of a large mass
 of very cold-topped convection. The same satellite data also
 indicate that the center has become increasingly deformed, making
 the initial position more uncertain than normal.  This uncertainty
 has resulted in a large scatter in Dvorak intensity estimates. The
 initial intensity is lowered to 55 kt, in agreement with the latest
 Dvorak estimate from SAB, which was closest to the estimated center
 position.
 
 Even stronger west-southwesterly shear should affect Fay during the
 next couple of days.  Meanwhile, much drier and more stable air
 behind a cold front impinging on the storm from the northwest should
 become entrained within Fay's circulation.  The combination of these
 factors should lead to additional steady weakening, with global
 models showing extratropical transition occurring in about 24 hours
 (or perhaps sooner). The NHC intensity forecast is similar to the
 previous one and in excellent agreement with the latest statistical-
 dynamical model consensus.
 
 The exposed center in the last few visible images was south of
 previous estimates, and as a result the initial motion estimate is
 now more sharply toward the east, or 080/21. Fay is expected to
 continue racing eastward or east-southeastward at the base of a
 potent shortwave trough moving through eastern Atlantic Canada and
 the north Atlantic.  The NHC track forecast has been adjusted toward
 the right of the previous one, based primarily on the new center
 position and motion.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  13/0300Z 34.1N  58.2W   55 KT  65 MPH
  12H  13/1200Z 34.4N  53.6W   50 KT  60 MPH
  24H  14/0000Z 33.9N  48.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
  36H  14/1200Z 33.4N  42.6W   35 KT  40 MPH...POST-TROP/EXTRATROP
  48H  15/0000Z 33.0N  37.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
  72H  16/0000Z...DISSIPATED
 
 $$
 Forecaster Kimberlain
 
 
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