485 
 WTNT41 KNHC 050848
 TCDAT1
 
 Hurricane Florence Discussion Number  24
 NWS National Hurricane Center Miami FL       AL062018
 500 AM AST Wed Sep 05 2018
 
 Conventional satellite enhanced BD-curve infrared imagery and a
 0511 UTC GMI color composite microwave pass reveal improved inner
 core structure with impressive outer banding over the eastern
 semicircle.  Dvorak intensity estimates have again increased, and
 the initial intensity is once more increased to 90 kt, which also
 agrees with the latest SATCON analysis.
 
 This intensity forecast is still a bit murky.  The deterministic
 models show increasing southwesterly vertical shear and a less than
 favorable mid-tropospheric thermodynamic environment affecting the
 tropical cyclone over the next 48 hours.  This less-than-conducive
 environment should induce weakening during this time frame.
 Thereafter, and through the remaining forecast, most of the
 models show a mid- to upper-level low developing to the south of
 Florence in the base of the mid- Atlantic deep-layer trough, which
 should promote a somewhat more favorable diffluent upper wind
 pattern.  This more conducive upper wind pattern, and increasing sea
 surface temperatures, is expected to cause Florence to restrengthen.
 The NHC forecast is a little bit higher than the previous one
 between the 48 and 96 hr periods to agree more with the IVCN and
 NOAA-HCCA consensus forecasts.
 
 Florence is estimated to be moving northwestward, or 305/11 kt,
 which appears to be a temporary trochoidal eyewall wobble.  A turn
 back toward the west-northwest is expected later today, and this
 general motion is expected to continue through day 4 while the
 hurricane is steered by the southwestern periphery of the
 subtropical ridge.  By the end of the forecast period, Florence is
 expected to turn northwestward and slow down as it enters a break in
 the ridge.  The ECMWF model track forecast has shifted significantly
 toward the left this evening, closer to the other global models and
 their ensemble means, indicating less steering influence from the
 predicted growing weakness in the subtropical ridge.  Subsequently,
 an adjustment to the left of of the previous advisory, beyond 48
 hours, was made in order to nudge closer to the guidance suite and
 the consensus models.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  05/0900Z 21.4N  44.8W   90 KT 105 MPH
  12H  05/1800Z 22.2N  46.3W   90 KT 105 MPH
  24H  06/0600Z 23.2N  48.2W   80 KT  90 MPH
  36H  06/1800Z 24.2N  50.0W   70 KT  80 MPH
  48H  07/0600Z 24.9N  51.5W   70 KT  80 MPH
  72H  08/0600Z 25.6N  54.1W   75 KT  85 MPH
  96H  09/0600Z 26.8N  56.3W   80 KT  90 MPH
 120H  10/0600Z 28.7N  58.2W   85 KT 100 MPH
 
 $$
 Forecaster Roberts