Hurricane Ivan Discussion Number 54
Statement as of 5:00 PM EDT on September 15, 2004
satellite imagery this afternoon shows an expansion of cold eyewall
convection...especially on the west side...and a clearing out of
the eye. The Air Force hurricane hunter aircraft reported an
central pressure of 933 mb...and the NOAA aircraft reported peak
winds at 7000 ft of 132 kt. Underneath that flight-level wind the
stepped frequency microwave radiometer reported 108 kt. It appears
that Ivan is beginning to respond to the warm pool over which it
has been traversing today. The maximum winds have not yet increased
but may do so over the next few hours. However...slightly cooler
waters exist just offshore...and little net change in strength is
expected prior to landfall.
Ivan remains basically on track...with an initial motion estimated
at 355/12. There has been essentially no change to the track
forecast...with landfall expected in about 9 hours. However...Ivan
has a very large windfield and damaging winds will move onshore
much sooner than that. The ECMWF model finally gave up on a New
Orleans landfall today...resulting in a well-clustered guidance
envelope until well after landfall...where there are a variety of
possible solutions for the remnants of Ivan. The official forecast
continues to show the possibility of a major flooding event over
the southern Appalachians late in the forecast period.
The large circulation of Ivan can be expected to bring hurricane
force winds well inland...perhaps 150 miles or so.
Forecaster Franklin
forecast positions and Max winds
initial 15/2100z 28.4n 88.3w 115 kt
12hr VT 16/0600z 30.2n 88.3w 115 kt...on the coastline
24hr VT 16/1800z 32.2n 88.0w 65 kt...inland
36hr VT 17/0600z 33.8n 87.2w 35 kt...inland
48hr VT 17/1800z 35.0n 86.0w 25 kt...inland
72hr VT 18/1800z 36.0n 84.0w 20 kt...inland
96hr VT 19/1800z 36.0n 84.0w 20 kt...dissipating
120hr VT 20/1800z...dissipated
$$
Hurricane force winds as much as 150 miles inland... WOW!
I hope there are no traffic jams.