As of now from the NHC
urricane Irma Discussion Number 28
NWS National Hurricane Center Miami FL AL112017
1100 PM AST Tue Sep 05 2017

The satellite view of Irma remains quite spectacular, with an
extremely well-defined eye and a large, symmetrical CDO. Reports
from NOAA and Air Force Hurricane Hunter aircraft indicate that the
central pressure had fallen at about 1 mb per hour since this
morning, although very recently the deepening trend has leveled
off. Based on SFMR-observed winds from the aircraft, the current
intensity remains at 160 kt. [color:"red"]The Meteo-France radar imagery
suggests a concentric eyewall structure and observations from the
aircraft hinted at a secondary wind maximum. If an eyewall
replacement becomes more definitive, this would likely halt
additional strengthening, and could even lead to some weakening.[/color]
The official intensity forecast is near or above the model
consensus. Given the favorable atmospheric and oceanic environment,
Irma is likely to remain a Category 4 or 5 hurricane for the next
few days.

Latest center fixes from satellite imagery and the aircraft
indicate that Irma is now moving west-northwestward, or 285/13 kt.
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. In 4 to 5 days, a small trough diving southward over
the east-central U.S. is expected to weaken the western portion of
the ridge, causing Irma to turn poleward. Some of the dynamical
models have shifted northward a bit from the previous cycle, with
the normally reliable GFS looking like a northeast outlier. The
official track forecast leans toward the ECMWF solution. 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.