Must-Read: Forecaster Beven: Hurricane Irma Forecast Discussion: "The hurricane is currently being steered by the subtropical ridge to the north.... After 48 h, a mid- to upper-level trough digging into the eastern United States is expected to create a break in the ridge and allow Irma to turn northward... http://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/070257.shtml?
...The timing of the turn is the most important question and one still filled with uncertainty. The UKMET, UK Ensemble mean, and the NAVGEM are the models showing the latest turn, and they forecast Irma to move into the southeastern Gulf of Mexico and near the west coast of the Florida Peninsula. The ECMWF and ECMWF Ensemble mean are in the middle of the model pack and show Irma moving over the southeastern portion of the Florida Peninsula. The GFS, Canadian, and GFS Ensemble mean show the earliest turn and show Irma moving east of the coast of Florida toward the southeastern United States. The new forecast track will best follow the ECMWF, as well as the Florida State Superensemble and the HFIP Corrected Consensus, and it calls for the center to move over portions of the southeastern Florida Peninsula between 72-96 h and then across the Atlantic into southern South Carolina by 120 h.
Users are again reminded not to focus on the exact track since the average NHC track errors at days 3, 4, and 5 are about 120, 175, and 225 miles, respectively.
Irma should remain in warm-water, and a low shear environment for about the next three days, and thus is expected to remain a strong hurricane, most likely Category 5 or 4....
KEY MESSAGES:
Irma is a potentially catastrophic category 5 hurricane and will bring life-threatening wind, storm surge, and rainfall hazards to the northern coast of Hispaniola today, and the Turks and Caicos and southeastern and central Bahamas tonight and Friday.
Hurricane watches are in effect for the northwestern Bahamas and much of Cuba. Irma is likely to bring dangerous wind, storm surge, and rainfall to portions of these areas on Friday and Saturday.
The threat of direct hurricane impacts in Florida over the weekend and early next week continues to increase. Hurricane watches will likely be issued for portions of the Florida Keys and the Florida peninsula later this morning...
