Are We Getting A Hurricane?
Back on September 9th I posted that the GFS & ECMWF models were projecting Hurricane Jose to hang around for a while, then possibly move toward the northeastern U.S. Six days later and nothing has really changed. Jose is only half as strong as it was on the 9th in terms of maximum wind (now a tropical storm with wind up to 70 mph), however the forecast models still project it to get uncomfortably close to us early next week and the National Hurricane Center expects it to become a hurricane again shortly. If you take away one thing (in terms of forecasting) from Hurricane Irma it should be this: Hurricane forecasting has improved materially since the early days, however outlooks for hurricanes are issued as probabilistic forecasts not deterministic forecasts. The difference is that the former indicates the range of possibilities and the likelihood of each whereas a deterministic forecast says the storm will be located here at this time and there at that time and will be this strong in 24 hours and that strong in 48 hours. Although it is a little more complicated to present, probabilistic forecasting is the most accurate way to convey forecasts and is becoming the standard way that forecasts will be presented going forward. It is important to understand the concept of probabilistic forecasts to have the best idea of what your future weather is most likely to be. For example, although it initially looked like the center of Hurricane Irma would track up along the east coast of Florida, then decided to track up the west coast, the final track was still within the "cone of uncertainty" (margin of error) that was issued by the Hurricane Center days earlier. Anyone who claims that the NHC track forecast for Irma was "wrong" doesn't understand the difference between probabilistic and deterministic forecasting or the limitations of the science.
Right now the models (images below) are forecasting the center of Jose to move to a point southeast of our region by Monday evening (GFS) or Tuesday evening (ECMWF). The GFS tracks the storm northeast from there, bringing fringe effects to parts of the region. The ECMWF actually has the storm center performing a loop-the-loop from there, then moving into the mid-Atlantic coast next weekend (see annotated image below). So what can we expect? There are still a range of possibilities. At this time is appears the most likely time we would be affected (if we are) would be Tuesday/Wednesday (4-5 days out). Each day that we get closer, the range of possibilities should narrow and hopefully by Sunday or Monday we will have a fairly good idea of what Jose will do. Right now, I'd say the odds favor the center of Jose remaining to our south & east, with us feeling fringe effects of the storm and southeastern New England and eastern Long Island feeling the most significant effects. Dangerous rip currents will be developing along the shore. Btw, there are two other systems with tropical characteristics behind Jose to keep an eye on.
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Jose would like to move out to sea, however a large ridge of high pressure will "bottle up" the storm, preventing it from doing so for a while. (GFS 850 mb Forecast below).
GFS Spaghetti Plots