913 
 WTNT41 KNHC 142055
 TCDAT1
 
 Tropical Storm Florence Discussion Number  62
 NWS National Hurricane Center Miami FL       AL062018
 500 PM EDT Fri Sep 14 2018
 
 Florence's satellite appearance continues to be quite impressive
 with well-established outflow and a nearly symmetrical cloud
 pattern. In radar imagery, however, the inner-core convection has
 continued to weaken and the echoes are now more stratiform in
 nature, while outer banding remains rather vigorous, especially
 south of Cape Lookout and Morehead City, North Carolina. An eye is
 no longer evident, and the pressure has continued to rise to a
 now estimated to be 972 mb based on nearby surface observations. Air
 Force Reserve aircraft data, NOAA Doppler weather radar velocity
 data from Wilmington, and nearby surface observations indicate that
 Florence's intensity has decreased to 60 kt, tropical storm status.
 
 Florence has turned westward and the motion estimate is now 270/03
 kt. The new 1200Z global and regional model guidance is in good
 agreement on Florence moving slowly in a general westward direction
 for the next 48 hours or so, followed by a northward motion on day 3
 as the system moves around the western periphery of a narrow
 subtropical ridge. On days 4 and 5, the cyclone is forecast to turn
 northeastward and accelerate ahead of an approaching shortwave
 trough and frontal system, and emerge off the northeast U.S. coast
 as an extratropical low. The new official forecast track is very
 similar to the previous advisory, and is lies near the northern
 and eastern edge of model guidance envelope, is closer to the
 TVCA/TVCN consensus models.
 
 Florence is expected to only slowly weaken overnight due to its
 proximity to the warm Atlantic where convective bands are expected
 to continue to develop and propagate inland in the eastern and
 southern portion of the circulation, which will act to bring down
 some of the stronger winds aloft. It is worth noting that the last
 reconnaissance pass indicated 700-mb flight-level winds of 77 kt
 just east of Charleston, South Carolina, so it won't take much
 convection to bring down some of those stronger winds to the
 surface as gusts. More rapid weakening is forecast over the weekend
 as Florence moves westward across the higher terrain of central
 and northwestern South Carolina. The official intensity forecast
 follows the weakening trend of the previous advisory, and is similar
 to an average of the GFS- and ECMWF-based Decay SHIPS models.
 
 Although coastal storm surge flooding will gradually subside
 tonight and Saturday, it cannot be emphasized enough that another
 serious hazard associated with slow-moving Florence will continue
 to be extremely heavy rainfall. More than 16 inches of rain has
 already fallen in many areas across southeastern North Carolina, and
 more rain is still to come, which will cause disastrous flooding
 that will spread inland through the weekend.
 
 Key Messages:
 
 1. Life-threatening storm surge will continue along portions of
 the North Carolina coast through tonight, and also along the Neuse
 and Pamlico Rivers in western Pamlico Sound, where rainfall and
 freshwater flooding will also contribute to high water levels.
 Dangerous storm surge could also affect portions of the northeast
 coast of South Carolina coast tonight.
 
 2: Life-threatening, catastrophic flash floods and prolonged
 significant river flooding are likely over portions of the
 Carolinas and the southern to central Appalachians from western
 North Carolina into southwest Virginia through early next week, as
 Florence moves slowly inland.  In addition to the flash flood and
 flooding threat, mudslides are also possible in the higher terrain
 of the southern and central Appalachians across western North
 Carolina into southwest Virginia.
 
 3. Tropical storm conditions will continue along the coast within
 the tropical storm warning area and also well inland across portions
 of South Carolina and North Carolina.
 
 4. Large swells affecting Bermuda, portions of the U.S. East Coast,
 and the northwestern and central Bahamas will continue this week,
 resulting in life-threatening surf and rip currents.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  14/2100Z 34.0N  78.6W   60 KT  70 MPH...INLAND
  12H  15/0600Z 33.9N  79.3W   50 KT  60 MPH...INLAND
  24H  15/1800Z 33.9N  80.3W   40 KT  45 MPH...INLAND
  36H  16/0600Z 34.4N  81.4W   25 KT  30 MPH...INLAND
  48H  16/1800Z 35.5N  82.6W   25 KT  30 MPH...INLAND
  72H  17/1800Z 38.5N  82.6W   20 KT  25 MPH...POST-TROP/INLAND
  96H  18/1800Z 41.5N  76.0W   20 KT  25 MPH...POST-TROP/INLAND
 120H  19/1800Z 44.0N  64.5W   30 KT  35 MPH...POST-TROP/EXTRATROP
 
 $$
 Forecaster Stewart