for a more recent update on Hurricane Ike and Hanna, CLICK HERE
I’m dispensing with Hanna. If you want to find something about Hanna, look to the previous post. This is devoted to Hurricane Ike which, in my view, is the far more threatening storm, though it’s probably not a good idea for East Coast residents to not just blow off the storm completely.
I was snooping about looking at some models regarding Hurricane Ike. The NHC
mentions them both, among others. The 12Z GFS wants to take Ike and turn it out to sea, before getting to the US coastline by turning it in the Bahamas and then north and northeast. The 12Z ECMWF wants to take it across Cuba, into the Gulf and then ultimately to the mouth of the Mississippi River. What is interesting to me about this are two things. One is that the GFS took forever to even recognize that Gustav existed when it was blowing and going. So I wonder about its value, though it clearly has picked up on Ike.
The ECMWF was the first model to indicate a turn a few days ago. The official forecast had the storm heading toward the Florida Straits with many models taking a route across Cuba and into the Gulf. Now, its the ECMWF
that has flip flopped and now is going along with the Cuba solution and become quite ominous with a track toward New Orleans. The National Hurricane Center has chosen a track in between the extremes, which is not unusual this many days out, and takes an ominous track toward Miami.
Here’s the two schools of thought as computers think. One is that the big front coming across the country will be fast enough and deep enough to catch Ike in the
flow and turn it. If Ike is late or the front is fast and deep, then it catches Ike and turns it away before it gets to land. The other idea would be that Ike is too slow or the front too fast and the trof misses it….or the trof is not deep enough and misses it. In that scenario, Ike gets caught up in a building ridge and it goes farther west. In examining the GFS, what seemed odd to me was that it had the front coming fast, the trof coming and going and then turned the storm when it looked to me as if the trof was well into lifting out. Seems tough to me to have the storm turn that sharply when the trof had already gone by. Here’s something to consider. If you look at the Intensity Probability Table at the left, you will note that on the out periods, the highest probability is for a Cat 3 storm. The Cat 4 probability is the second highest….just something to consider.
So…there are many variables, as usual. Options are still on the table and it will remain to be seen how the environment changes or what environment Ike finds when it gets to the Bahamas. Hurricane Ike is getting close enough for the Hurricane Hunters to begin reconnaissance flights tomorrow.
Here is the National Hurricane Center Forecast Discussion for Hurricane Ike.
HURRICANE IKE DISCUSSION NUMBER 16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008
1100 PM EDT THU SEP 04 2008
IKE REMAINS A SMALL…BUT IMPRESSIVE HURRICANE IN SATELLITE IMAGERY. THE OUTFLOW IS GOOD OVER THE SOUTHERN SEMICIRCLE… BUT THERE IS SOME EVIDENCE OF THE ANTICIPATED NORTHEASTERLY SHEAR…AS THE OUTFLOW HAS BECOME A LITTLE RESTRICTED OVER THE NORTHERN HALF OF THE HURRICANE. DESPITE THE EVIDENCE OF SHEAR….THE EYE HAS CLEARED AND REMAINS SURROUNDED BY -70 DEGREES CELSIUS CLOUD TOPS. BOTH OBJECTIVE AND SUBJECTIVE DVORAK INTENSITY ESTIMATES SUPPORT AN INITIAL INTENSITY OF ABOUT 115 KT. NORTHEASTERLY SHEAR IS PREDICTED TO INCREASE DURING THE NEXT DAY OR SO…WHICH IS ANTICIPATED TO CAUSE SOME WEAKENING. THE INTENSITY FORECAST… WHICH IS UNCHANGED FROM THE PREVIOUS ADVISORY…IS AGAIN BETWEEN THE STATISTICAL GUIDANCE THAT CALLS FOR MORE WEAKENING AND THE DYNAMICAL MODELS WHICH MAINTAIN AN INTENSE HURRICANE. IN ABOUT 2 DAYS…THE SHEAR IS FORECAST TO WEAKEN WHICH SHOULD ALLOW IKE TO RE-STRENGTHEN. IT APPEARS THAT IKE HAS TURNED WESTWARD THIS EVENING OR 275/12… HOWEVER A SHORTER TERM MOTION IS ESSENTIALLY DUE WESTWARD. IKE IS EXPECTED TO MOVE WEST TO WEST-SOUTHWESTWARD DURING THE NEXT 2-3 DAYS…TO THE SOUTH OF A STRONG MID-LEVEL RIDGE TO THE NORTH OF THE CYCLONE. THEREAFTER…IKE IS FORECAST TO APPROACH THE WESTERN PERIPHERY OF THE RIDGE AND BEGIN TO TURN WEST-NORTHWESTWARD. THE BIG QUESTION IS WHEN WILL THE TURN TAKE PLACE. THE TRACK GUIDANCE IS IN TWO DISTINCT BRANCHES…THE GFS…NOGAPS…AND UKMET SHOW THE TURN OCCURRING OVER THE BAHAMAS….WHILE THE HWRF…GFDL…AND ECMWF TAKE IKE OVER CUBA OR THE STRAITS OF FLORIDA. UNTIL IT BECOME CLEAR AS TO WHICH ONE OF THESE SOLUTIONS WILL PREVAIL… THE OFFICIAL FORECAST REMAINS BETWEEN THEM…CLOSE TO THE MODEL CONSENSUS AND THE PREVIOUS ADVISORY. AS A REMINDER…4 AND 5 DAY FORECASTS ARE SUBJECT TO POTENTIALLY LARGE ERRORS IN BOTH TRACK AND INTENSITY.
FORECAST POSITIONS AND MAX WINDS
INITIAL 05/0300Z 23.6N 59.5W 115 KT 12HR VT
05/1200Z 23.6N 61.5W 105 KT 24HR VT
06/0000Z 23.4N 64.0W 95 KT 36HR VT
06/1200Z 22.9N 66.6W 95 KT 48HR VT
07/0000Z 22.5N 69.2W 100 KT 72HR VT
08/0000Z 22.5N 73.5W 105 KT 96HR VT
09/0000Z 24.0N 77.0W 110 KT 120HR VT
10/0000Z 26.0N 80.0W 110 KT $$