As noted in the previous posts today, the forecast track for Isaias is balanced between the high pressure to the east, and an approaching trough/boundary to the west. As the afternoon progressed, in the great scheme of things that balance didn’t shift much – but it’s enough to cause angst and a threat to the Florida coast. With the new 5pm Official NHC Forecast (Key Messages regarding Hurricane Isaias (en Español: Mensajes Claves)), the current forecast is for Isaias to make a sort of landfall on the Treasure Coast of Florida near West Palm before scooting up the coast offshore from the GA/SC coast then North Carolina, brushing DelMarVa, NJ, NY/Long Island, and Cape Code before smacking Nova Scotia as a strong tropical storm. Here’s the obligatory map of doom (click for more detailed terror):
Despite the track changes, NHC also decreased the forecast intensity a bit. So the net effect isn’t actually that different from the 11am forecast in practical terms. This is a minor change, not a freak out ZOMG the forecast is blown! The Bahamas should still prepare for for Category Two conditions, the Florida coast south of Cape Canaveral for a Category one hurricane. the First Coast and Georgia/SC Low Country coast for tropical storm winds and an extra foot or two above normal high tides. The storm may slow down in the turn just offshore from Saint Augustine/Daytona, which will be unpleasant. You should also pay attention to your local emergency managers; most of the time they are advising you to do the safest thing. COVID19 is making Emergency Managers do what they should have been doing all along, be more selective and careful in their evacuation orders. The main thing to keep in mind is to shelter from wind (with an important caveat), evacuate from water. The caveat is the strength of your shelter; mobile homes can be deadly in even minimal hurricane force winds and the weaker tornado-like effects they spawn (much less actual tornadoes). If you are in a place with a flood risk from storm surge, move to higher ground. If in a mobile home or structure you have doubts about, then get out. But otherwise, with COVID, evacuating for convenience so you can avoid a few days of being without power isn’t an option.
I’ll again remind folks in the US not to overlook The Bahamas – unfortunately they are already experiencing the storm and are still recovering from Dorian. Please keep them in your thoughts and be prepared to help out in the aftermath. And don’t forget our fellow citizens in Puerto Rico – power is out over large areas of the Island, and there is considerable flood damage.