Ike holds course, hits Cuba
Hurricane Ike made landfall in Cuba near Punto de Sama at 9:45 PM EDT last night, then passed this morning over Camaguey, the nation's third-largest city with a population of 324,921. Ike came ashore during an eyewall replacement cycle, which lowered its maximum sustained winds to 125 mph as of the time of landfall. Winds are now estimated at 105 mph as land interaction takes its toll.
It turns out yesterday's "wobble" was just that -- a wobble -- and Ike is now holding true to its expected course, directly across the spine of Cuba. As Alan Sullivan writes, "The devastation is surely immense."
If Ike continues to follow the forecast track as it crosses Cuba, it will weaken severely. The Hurricane Center forecasts Ike to weaken only to a strong tropical storm, with 70 mph winds, in 36 hours, but acknowledges that this is a hedge against the possibility that Ike will re-emerge over water sooner than expected: "IF IKE FOLLOWS THE FORECAST TRACK, IT WILL BE OVER LAND FOR ABOUT 36 HOURS...AND WOULD ALMOST SURELY BE WEAKER IN THE SOUTHEASTERN GULF THAN SHOWN HERE."
Conditions are still expected to be favorable for re-stregthening over the Gulf, but, as the NHC acknowledges, "THE MAJOR UNKNOWN IS HOW DISRUPTED IKE WILL BE WHEN IT EMERGES." It is possible Cuba will essentially destroy the storm, and it will never re-develop into anything significant. On the other hand, Ike could emerge weakened but structurally intact, and spin back up quickly. We just don't know, and until we do, it's almost pointless to speculate about future intensity in the Gulf.
Is it also difficult to talk meaningfully about Ike's track through the Gulf, since we have no idea what Ike's intensity will be, and a major hurricane is sometimes steered differently than a weak tropical storm or remnant low. However, this bit at the end of the discussion is interesting:
THE GFS IS AN OUTLIER IN CALLING FOR A SHARP SHORT WAVE TROUGH TO MOVE THROUGH THE PLAINS STATES ON DAYS 4-5. THE GFDL AND HWRF...WHICH USE THE GFS FOR BOUNDARY CONDITIONS...MAY BE PICKING UP ON THAT AND SHOW A BEND TO THE RIGHT AT THE END OF THE FORECAST PERIOD. THE OTHER GLOBAL MODELS...SUCH AS THE ECMWF...SHOW MUCH MORE RIDGING OVER THE EASTERN UNITED STATES AT THOSE RANGES AND HAVE A MORE WESTWARD TRACK. EVEN THOUGH THE GFDL HAS PERFORMED VERY WELL WITH IKE SO FAR...I'VE CHOSEN NOT TO ADJUST THE TRACK EASTWARD GIVEN THAT THE LARGE-SCALE FIELDS IN THE GFS HAVE NO SUPPORT FROM THE OTHER MODELS.
As you can see here, the result of this divergence is that the GFDL and HWRF models take Ike toward Louisiana, while most of the other models take it toward Texas. The official NHC forecast implies a track roughly toward Houston.
Eric Berger explains why the models disagree:
[T]he computers are still having a difficult time with deciding when to turn Ike northwest, and there's little confidence in where the storm will actually travel in five days time, when the hurricane might be approaching a landfall.
In addition to the high pressure ridge steering Ike, which is now slowly retreating eastward, there's a low-pressure system moving south along the east coast that will complicate matters (possibly by allowing another high pressure ridge to build in its wake), as will a Pacific cool front forecast to reach the Texas coast this weekend.
All of these complicated atmospheric dynamics mean that we simply don't know where Ike's going, and that the Gulf coast, especially Texas and Louisiana, need to pay close attention to the storm's progress.
Bottom line, as the NHC says, "IT IS STILL TOO SOON TO KNOW WHAT PORTION OF THE GULF COAST WILL ULTIMATELY BE AFFECTED BY IKE" -- or, for that matter, whether there will be much of anything left of Ike to be affected by.
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URL to article: http://pjmedia.com/weathernerd/2008/9/8/ike-holds-course-hits-cuba