Skip Navigation Links
NOAA NOAA United States Department of Commerce

Hurricane SALLY

Hurricane Sally Discussion Number  15
NWS National Hurricane Center Miami FL       AL192020
1000 PM CDT Mon Sep 14 2020
After rapidly strengthening earlier today, Sally's intensity has
plateaued for now. Both the NOAA and Air Force Hurricane Hunters
have been investigating Sally this evening and they have found that
the minimum pressure and winds have leveled off, and support
perhaps a generous initial intensity of 85 kt.  Doppler radar
images and reports from both aircraft indicate the inner core of
the hurricane is quite small and that the eyewall is open on the
south side, likely due to some dry air that has wrapped into
that portion of the circulation.
Aircraft and Doppler radar fixes indicate that Sally is moving
very slowly to the west-northwest, with the latest initial
motion estimated to be 300/3 kt.  Weak high pressure ridging to the
north and east of Sally is expected to cause the hurricane to
continue to move slowly west-northwestward to northwestward for
another 12 hours, bringing the center of the storm very near
the northern Gulf coast. By Tuesday afternoon, when the hurricane
will likely be just offshore, the models show the steering currents
collapsing and Sally is likely to drift northward before finally
turning northeastward ahead of a developing mid-level trough over
the central U.S. by late Wednesday.  There continues to be a
significant amount of uncertainty on exactly where and when
Sally turns northward and makes landfall, with model solutions
ranging from a landfall on the Florida panhandle to a landfall in
extreme southeastern Louisiana. It should be emphasized that it is
always challenging to forecast the track of hurricanes in weak
steering currents, and in Sally's case the weak steering is
occurring very near land.  The new NHC track forecast is a little
to the east of the previous one, trending toward the latest
consensus aids.
Sally is still in generally favorable environmental conditions
consisting of very warm SSTs and low wind shear.  Since the
hurricane will likely remain in those conditions through Tuesday
morning, some strengthening seems likely in the short term.  In 12
to 24 hours, when Sally is forecast to be very near the coast, a
combination of an increase in westerly shear and cooler upwelled
shelf waters should limit additional intensification.  After the
hurricane makes landfall, rapid weakening is forecast and Sally
should become post-tropical in 3 to 4 days over the southeast U.S.
The NHC intensity forecast lies at the high end of the model
guidance and is quite similar to the previous one.
Users are reminded to not focus on the exact forecast track or the
specific timing and location of landfall.  Hurricane-force winds,
dangerous storm surge, and flooding rainfall will affect a large
portion of the north-central Gulf Coast during the next few days.
1. It is still too early to determine where Sally's center will move
onshore given the uncertainty in the timing and location of Sally's
northward turn near the central Gulf Coast.  Users should not focus
on the details of the official forecast track, since NHC's average
forecast error at 36 hours is around 60 miles, and dangerous storm
surge, rainfall, and wind hazards will extend well away from the
2. An extremely dangerous and life-threatening storm surge is
expected for areas outside the southeastern Louisiana Hurricane and
Storm Damage Risk Reduction System from Port Fourchon, Louisiana, to
the Okaloosa/Walton County Line in the Florida Panhandle, where a
Storm Surge Warning is in effect. Residents in these areas should
follow any advice given by local officials.
3. Hurricane conditions are expected early Tuesday within the
Hurricane Warning area in southeastern Louisiana and are
expected by late Tuesday and Tuesday night within the Hurricane
Warning area along the Mississippi and Alabama coastlines and the
western Florida Panhandle. Tropical storm conditions are already
occurring in some of these areas.
4. Life-threatening flash flooding is likely with Sally, as well as
widespread minor to isolated major flooding on area rivers, along
and just inland of the Central Gulf Coast. Significant flash and
urban flooding, as well as widespread minor to moderate river
flooding is likely across inland portions of Mississippi and Alabama
and into northern Georgia, southeastern Tennessee and the western
Carolinas through the week.  Sally may continue to produce flash
flooding across the Florida peninsula and prolong existing minor
river flooding across west-central Florida through tonight.
INIT  15/0300Z 28.9N  87.6W   85 KT 100 MPH
 12H  15/1200Z 29.1N  88.1W   95 KT 110 MPH
 24H  16/0000Z 29.6N  88.4W   90 KT 105 MPH
 36H  16/1200Z 30.4N  88.3W   85 KT 100 MPH...INLAND
 48H  17/0000Z 31.3N  87.4W   50 KT  60 MPH...INLAND
 60H  17/1200Z 32.0N  86.3W   30 KT  35 MPH...INLAND
 72H  18/0000Z 32.7N  84.9W   25 KT  30 MPH...INLAND
 96H  19/0000Z 33.1N  82.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  20/0000Z...DISSIPATED
Forecaster Cangialosi