Monday, August 23, 2010

Hurricane Danielle and another Atlantic Blob: August 23, Update A

Hurricane Danielle:
Girls are so well-behaved, aren't they? ;-) Until now (at least) Danielle has been doing as forecast by everyone, which obviously means she must be well-behaved. Oh, and thank you for enquiring, but no, I wasn't feeling ill when I wrote that I agreed with the NHC yesterday... but I might have been confused after experiencing a weekend of warm (!) sunshine (!!) in Manchester, England. ;-)
Danielle developed into a Tropical Storm yesterday (TS wind range: 39-73mph), and has just been upgraded to a hurricane with sustained winds of 75mph. Category 1 hurricane winds: 74-95mph. Her central pressure is estimated to be 987mb and she's currently centered at around 15.4N, 41.5W. Yesterday she took a slightly northwestward turn, but all day today she's been keeping to the west of the center of the cone, so at the moment she's moving WNW at a rapid 17mph.  
Convection remains very strong, as does the vorticity (circulation). The circulation is *really* strong in the lower half of the troposphere. There's still some circulation in the upper half of the troposphere, but it was a bit weaker than yesterday because of a bit of wind shear. However, this looks like it will change and get better organized, so I think this storm will slowly continue to develop. Water temperatures are 28-29 deg C. There is some dry air still to the north but I don't think that will have much impact.  
Although the track continues to take her WNW and recurve out in the Atlantic to the eastern side of Bermuda, I think she might stay on the western side of the center of the cone and could clip Bermuda. The other scenario that is possible is that she'll slow down. The reason for both of these is because there's a high pressure system in front of her, which will cause her to move westward or will slow down her forward movement. In the northern hemisphere storms move in a clockwise direction around an area of high pressure or slow down until the pressure fields change - you can think of the slowing down part as a ball (storm) rolling up a hill (high pressure).  
Oh, and look, I used some more 'parentheses'! ;-) which is a nice, if somewhat obviously contrived, segueway to a slight correction on my last entry. The plural of 'parenthesis' is parentheses. (Thanks to K.F. for pointing that out). The word is of Greek origin, and I found this saying from 1796: "The art of the parenthesis is one of the greatest secrets of eloquence in Society" (Sebastien-Roch Nicolas De Chamfort). Clearly I have a long way to go before I achieve mastery of eloquence in Society! Still, it gives me something to aim for. ;-)
Altantic Blob:
In another interesting development, a blob came off the coast of Africa today and almost immediately developed a nice circulation. It's just off the eastern edge of most of my maps (and my crystal ball), so I can't say too much more about it other than it looked like it was in better shape than Danielle when she came off the coast, and it has a lot of convection. This is the next African Easterly Wave after Danielle, so we can see the edge of it in some images that show Danielle. Tomorrow it should be more visible and I'll be able to get a better assessment hopefully. The next name is Earl.
Before I sign off, I wanted to follow up on "jejune" from a couple of days ago. I know some of you looked it up, but in case the 'jej' page was missing from your dictionaries, it means dull and not interesting (which is how I was using it). It also means juvenile, immature and childish. So I suppose the new Atlantic Blob could be a jejune system. :-) I got this note from Edward M. (thanks!) about a word that is similar in spelling (I hope you scrabble players out there are making notes!): "jejuni, which is a type of food poisoning you get from untreated water or raw food. Campylobacter jejuni. I'd read about it in a CDC pamphlet 20 years ago ... And it sounds anything but jejune (in the dull sense of the word).". Yup. Best not to get those two confused!
Ok, that's it for today. Tomorrow will be another fun storm-filled day!
Blog archives at

These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I was there and was going to "run away, run away" (Monty Python), I'll let you know.

No comments: