Irma | 5 p.m. Update Tuesday Sept. 5 | News | The Press and Standard
by The Press and Standard | September 5, 2017 5:52 pm
From the National Hurricane Center:
Fixes from the latest satellite and radar imagery suggest that Irma is moving a little north of due west.
A strong ridge extending southwestward from the central Atlantic is expected to steer Irma west-northwestward during the next couple of days. A large mid-latitude trough over the eastern United States is forecast to lift northeastward, allowing the ridge to build westward and keep Irma on a westward to west-northwestward heading through Friday.
Over the weekend, a shortwave trough diving southward over the east-central U.S. is expected to weaken the western portion of the ridge, causing Irma to turn poleward.
The dynamical model guidance is in good agreement through 72 hours, but there is increasing spread thereafter. The HWRF, UKMET, and ECMWF show a more southerly track and a sharper turn around day 5, while the GFS is farther north and east late in the period. The NHC track is near a consensus of these models and close to the HFIP corrected consensus.
Users are reminded to not focus on the exact forecast track, especially at the longer ranges, since the average NHC track errors are about 175 and 225 statute miles at days 4 and 5, respectively.