Update on Eta:
This is the key message from the NHC: Eta is forecast to regain tropical storm strength over the northwestern Caribbean Sea in a day or so. Although the details of the future track and intensity of Eta are uncertain, there is an increasing risk of impacts from wind and rainfall in portions of the Cayman Islands, Cuba, southern Florida and the Florida Keys this weekend and early next week.
Here are some highlights from the NHC which explains the uncertainty in track and strength:
While the models are in good agreement with the synoptic pattern, they are in poor agreement on the details of the track. The forecast tracks show possible landfalls in Cuba anywhere between 77W-83W, and after the turn some of the tracks are as far north as southern Florida while other stay over Cuba. In addition, there is a significant speed difference between the faster GFS/HWRF/HMON and the slower Canadian/ ECMWF/ UKMET. The low-confidence official forecast compromises between these various extremes and is not changed much from the previous forecast.
From 72-120 h, there is a possibility that Eta will take on subtropical or hybrid characteristics as it interacts with the developing upper-level low. The intensity forecast will be held at 50 kt during that time due to this interaction. The new intensity forecast has only minor tweaks from the previous forecast. However, it lies below the bulk of the intensity guidance for the first 60 h and above the bulk of the guidance from 72-120 h.
FORECAST POSITIONS AND MAX WINDS INIT 05/2100Z 15.7N 87.7W 30 KT 35 MPH...INLAND 12H 06/0600Z 16.4N 87.8W 30 KT 35 MPH...OVER WATER 24H 06/1800Z 18.1N 86.3W 35 KT 40 MPH 36H 07/0600Z 19.1N 84.8W 40 KT 45 MPH 48H 07/1800Z 20.1N 83.1W 45 KT 50 MPH 60H 08/0600Z 21.3N 81.5W 45 KT 50 MPH 72H 08/1800Z 22.4N 80.1W 50 KT 60 MPH...INLAND 96H 09/1800Z 23.5N 82.0W 50 KT 60 MPH...OVER WATER 120H 10/1800Z 24.5N 84.5W 55 KT 65 MPH
I have included the Euro ensembles (2nd image), early 18Z track guidance (3rd image), and projected rainfall for the next 7 days (4th image).