The satellite presentation of Michael has continued to improve
overnight and this morning, with the center well embedded within an
area of cold cloud tops. An eye is becoming apparent in visible
imagery, and this was also confirmed by a recent SSMIS microwave
overpass and the Air Force Reserve reconnaissance aircraft. The
aircraft reported a minimum pressure around 982 mb during the most
recent pass through the center, and also found flight-level
winds that support upgrading Michael to a a 65-kt hurricane for this
advisory.
Although the outflow is still somewhat restricted over the western
portion of the circulation, it has been expanding in that
direction. The global models suggest that the shear will relax a
little more while the hurricane moves over the very warm waters of
the southeastern Gulf of Mexico. Now that Michael has developed an
inner core, steady to rapid strengthening is predicted during the
next 24 to 36 hours. The SHIPS Rapid Intensification Index and
DTOPS give a 55-60 percent chance of rapid intensification during
the next 24 hours. The updated NHC forecast is near the upper-end
of the guidance and calls for rapid strengthening over the next 24
hours, and brings Michael to major hurricane status. After
that time, most of the intensity guidance slows down the rate of
intensification, perhaps due to a slight increase in southwesterly
shear. Weakening is expected after landfall, but the forecast track
keeps a portion of the circulation over water along the southeast
U.S. coast, so Michael is predicted to remain a tropical storm
through 72 hours. The system should become a powerful extratropical
low off the U.S. Mid-Atlantic coast in about 4 days.
Reconnaissance aircraft fixes indicate that Michael is still moving
a little east of due north. The hurricane should move northward or
north-northwestward over the next couple of days while the storm
crosses the eastern Gulf of Mexico. By 48 hours, Michael should
turn northeastward ahead of a trough moving into the central
United States. The cross-track spread in the guidance has
decreased since yesterday, but there continue to be differences in
how fast Michael moves northward over the Gulf of Mexico. The HWRF
and GFS remain among the faster models, while the ECMWF is still
much slower. The NHC track is along the eastern side of the
guidance through 24 hours due to the recent motion of the storm,
and is remains near the various consensus aids after that time. The
post-tropical portion of the track and intensity forecast is based
on guidance provided by the Ocean Prediction Center.
Key Messages:
1. Michael is forecast to be a dangerous major hurricane when it
reaches the northeastern Gulf Coast on Wednesday, and life-
threatening storm surge is possible along portions of the Florida
Gulf Coast regardless of the storm's exact track or intensity.
Residents in the storm surge and hurricane watch areas should follow
any advice given by local officials, as storm surge and hurricane
warnings will likely be issued later today.
2. Heavy rainfall from Michael could produce life-threatening flash
flooding from the Florida Panhandle and Big Bend region into
portions of the Carolinas through Thursday.
3. Hurricane conditions will spread over portions of western Cuba
this afternoon, where a hurricane warning is now in effect.
Tropical storm conditions are expected over the northeastern Yucatan
Peninsula and the Isle of Youth today.
4. Michael is expected to produce heavy rainfall and flash flooding
over portions of western Cuba and the northeastern Yucatan Peninsula
of Mexico during the next couple of days.
FORECAST POSITIONS AND MAX WINDS
INIT 08/1500Z 21.2N 84.9W 65 KT 75 MPH
12H 09/0000Z 22.6N 85.3W 85 KT 100 MPH
24H 09/1200Z 24.4N 85.9W 95 KT 110 MPH
36H 10/0000Z 26.4N 86.4W 105 KT 120 MPH
48H 10/1200Z 28.6N 86.1W 105 KT 120 MPH
72H 11/1200Z 33.0N 82.5W 45 KT 50 MPH...INLAND
96H 12/1200Z 37.8N 73.6W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 13/1200Z 42.8N 59.0W 55 KT 65 MPH...POST-TROP/EXTRATROP
credit: National Hurricane Center
