559 
 WTNT44 KNHC 150841
 TCDAT4
 
 Remnants Of Isaac Discussion Number  31
 NWS National Hurricane Center Miami FL       AL092018
 500 AM EDT Sat Sep 15 2018
 
 A NOAA Hurricane Hunter aircraft investigated Isaac over the past
 few hours and was unable to identify a well-defined center. The
 plane found multiple small and poorly-defined circulations embedded
 within a larger area of weak and variable winds, well to the south
 of the previous estimated center location. The plane also found that
 the minimum pressure has risen to around 1006 mb. All of this data
 confirmed what two late-arriving ASCAT overpasses from earlier this
 evening indicated, that Isaac has opened up into a southwest to
 northeast oriented trough. Since Isaac does not have a well-defined
 center, it no longer meets the NHC definition of a tropical cyclone
 and this is the last advisory.
 
 The strongest SFMR winds found by the plane were around 30 kt,
 mainly to the north of the deep convection, so the intensity has
 been set at that value.  Although some of the regional hurricane
 models suggest that small short-lived circulations like the ones
 found by the plane could temporarily spin up within the larger
 envelope of the tropical wave over the next several days, none of
 the dynamical models currently show any significant redevelopment of
 Isaac. The wave will likely continue westward across the Caribbean
 Sea over the next few days, producing gusty winds and occasional
 heavy rains over portions of Hispaniola and Jamaica.
 
 This is the last public advisory issued by the National Hurricane
 Center on Isaac. Additional information can be found in High Seas
 Forecasts issued by the National Weather Service, under AWIPS header
 NFDHSFAT1, WMO header FZNT01 KWBC, and available online at
 https://ocean.weather.gov/shtml/NFDHSFAT1.shtml.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  15/0900Z 14.8N  70.8W   30 KT  35 MPH
  12H  15/1800Z...DISSIPATED
 
 $$
 Forecaster Zelinsky
 
 
 
 247 
 WTNT43 KNHC 150841
 TCDAT3
 
 Tropical Storm Helene Discussion Number  32
 NWS National Hurricane Center Miami FL       AL082018
 500 AM AST Sat Sep 15 2018
 
 Helene appears to be maintaining its strength.  Recent microwave
 images show that the storm has an eye feature, but the vortex is
 significantly tilted in the vertical due to southwesterly shear.
 Deep convection is most organized in bands to the north and west of
 the center. Based on the tropical storm's appearance in microwave
 images, the initial intensity is again held at 60 kt, near the high
 end of the satellite intensity estimates. Helene is expected to
 gradually weaken during the next few days due to the influences of
 southwesterly shear, drier air, and much cooler SSTs along the
 forecast track. These conditions should also cause Helene to lose
 tropical characteristics, and the storm is forecast become
 extratropical in 24 to 36 hours.
 
 The tropical storm is moving north-northeastward at a fairly fast
 pace, 19 kt.  The center of Helene is expected to pass to the west
 of the Azores by tonight.  However, Helene has a fairly large wind
 field, and tropical-storm-force winds are expected across the
 western Azores as the storm passes by. A shortwave trough to the
 northwest of the system is expected to approach Helene by tonight,
 and that should cause the cyclone to turn northeastward and then
 speed up in that direction as it heads toward Ireland and the United
 Kingdom late this weekend and early next week.  The models are in
 fair agreement, and only small changes were made to the previous NHC
 track forecast.
 
 Helene is expected to be a post-tropical cyclone when it approaches
 Ireland and the United Kingdom in two to three days. Interests in
 those locations should consult products from their local
 meteorological service for information about potential impacts from
 Helene.  Local forecasts and warnings for the UK can be found on the
 website of the UK Met Office at https://www.metoffice.gov.uk/.
 Local forecasts and warnings for Ireland can be found on the website
 of Met Eireann at https://www.met.ie/.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  15/0900Z 37.7N  34.8W   60 KT  70 MPH
  12H  15/1800Z 39.7N  32.7W   60 KT  70 MPH
  24H  16/0600Z 41.8N  29.2W   55 KT  65 MPH
  36H  16/1800Z 44.1N  24.3W   55 KT  65 MPH...POST-TROP/EXTRATROP
  48H  17/0600Z 46.7N  18.1W   55 KT  65 MPH...POST-TROP/EXTRATROP
  72H  18/0600Z 55.8N   5.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
  96H  19/0600Z...DISSIPATED
 
 $$
 Forecaster Cangialosi