Sunday, November 08, 2009

Hurricane Ida: November 8 Update A

Well there's a couple of bits of good news for you all in this entry.
First, Ida's circulation (technically the vorticity) is beginning to
diminish. Yesterday, when I said she was a hurricane, the vorticity was
strong throughout almost the entire troposphere (lowest ~10-15km of our
atmosphere). Today it looks like the highest levels have lost it, which is
an indication that she won't intensify much further. The second piece of
good news is that although I tried, I couldn't think of any 'original'
jokes today so you are spared that. ;-)

Ida was officially (finally) named a hurricane late last night. Again, a
number of hours after I think she became one. She's got winds of 90mph at
the moment, making her a strong cat 1 (range: 74-95 mph). I think she
might be a weak cat 2 actually (range: 96-110mph). Currently centered at
about 21.2 N, 86 W, she's moving NW at 10mph. Central pressure 983mb.

I know the forecast now has her as a hurricane until Tuesday, when she
reaches the northern Gulf coast. But I'm not convinced that she will be a
hurricane by the time she gets up there. There are a number of reasons I
think this, apart from the circulation issue. The wind shear is stronger
in the Gulf, which will take it's toll. Although the surface water temps
are high enough in the southern Gulf, they begin to cool off in the
northern Gulf. Also, the deeper warm water that she has just crossed in
the Caribbean does not extend into the Gulf as much as it has done in
previous years (the Loop Current). The only factor I see that will keep
her as a hurricane in the northern Gulf is the fast speed she's forecast
to move at. Having said all this, even if she does decrease in intensity,
the interaction with the front will create some wet & windy conditions
around the Gulf. It will be like a normal day in Scotland ;-).

Of course, please ignore me and listen to your Emergency Managers & NWS &
NHC. I know those of you who are in the watch zones will be prepared. Drop
me a line if you have any questions.

Ciao for now,

Updates archived at

DISCLAIMER: These are my opinions only and not those of any organization I
represent. I wrote the other half of this in the main text above.


kdumaine said...

Thanks for you insight but I have a question for you....I live in Tampa and was wondering what your thoughts are at this point as far as the conditions we will see when Ida stops in to vacation with us in the sunshine state.

Jyo said...

Hello there. In the Tampa Bay area it looks like you'll get some cloud and occasional heavy bands of rain, but not too much. In the panhandle area of Florida however, it looks like there will be hravy rain and possible thunderstorms. If there's room, I'll add a link or two for you in the next update so you can monitor the weather yourself.