Saturday, September 01, 2012

Tropical Storms Captain Kirk and Leslie: September 1, Update A

Sorry I missed yesterday. I accidentally got caught up in some time travel.  After dinner I closed my eyes for a second and was whisked forward through time by a few hours. Funny how these things happen on Fridays. I expect it’s because I still can’t quite get the hang of Thursdays. ;-) Luckily, despite all this zipping through time, there weren’t any big surprises yesterday – Captain Kirk and Leslie behaved themselves (which is quite unusual for Captain Kirk and <insert female humanoid name>! ;-)).

Tropical Storm Captain Kirk
As expected, he did get a little stronger yesterday, but still remained a cat 2 storm with winds of 105mph (cat 2 range: 96-110mph). However his intensity has steadily declined over the last 24 hours and he was just downgraded to a Tropical Storm in the 11am advisory, with estimated winds of 70mph, central pressure 989mb. I think as a Tropical Storm he is actually weaker than this indicates. Here is the latest infra-red satellite image of the North Atlantic:

You can see Kirk in the middle around 37.4N, 46.5W and Leslie, who currently has the same wind speed, farther south at 18.3N, 55.7W. They don’t quite look the same, do they?

I think the reason the NHC are keeping Kirk at that intensity is because he is caught up in that low pressure front I mentioned in my last update (the one that you could see with clouds streaming across the north Atlantic). The NHC also include the forward speed of a storm when they are figuring out a storm’s wind speed, and Captain Kirk is now moving at warp speed 9 (25mph)! Obviously he’s in a rush to get to Ireland and the UK… he must be out of PG Tips and jelly babies (why yes, since you ask, I am watching the Dr. Who marathon on BBC America). He may not be much by the time he gets there though because of some strong wind shear in his path.

Tropical Storm Leslie
Officially (at the 11am advisory) she was at 18.3N, 55.7W, heading WNW at 18mph. Winds speed is 70mph, central pressure 996mb, which makes her a very strong Tropical Storm/borderline Cat 1 storm (TS range: 39-73mph, cat 1 range: 74-95mph).

Her circulation is strong in the lower troposphere and she’s got circulation in the upper troposphere as well now so I would agree with this borderline strong TS/cat 1 assessment. Although she is over some lovely warm water (surface temperature 27-29 deg C) and the upper 100m or so of the ocean is warmer than 26 deg C, there is some dry air to the north and west of her and she does have a bit of wind shear which is stopping her from intensifying too quickly. You can see the impact of this in the latest visible and infra-red satellite images of Leslie:

there are clouds streaming off to the northeast (wind shear) and the center is north of the main area of convection and the north/west quadrants have less convection than the south/east quadrants (dry air).

Although the track forecast keeps her well to the north of the Caribbean, she is going to be close enough to bring some breezy weather with maybe a drop or two of rain to that northeast corner. It looks like the outer bands are almost at the islands already. The forecast track also keeps her to the east of Bermuda, waving as she passes by next Friday/Saturday. The pressure fields I look at don’t have enough resolution at the moment for me to be able to figure out the track, so I’m going with the official word for now.

Last words on Isaac
I hear that some people are still without power in the northern Gulf – hope it gets restored soon! (although Nicole L. in Louisiana  just said they were told that it may not be back until Sept. 6th. Eeek.). I always appreciate the power trucks and people sent in from other states and power companies to get power re-established as quickly as possible… I assume that is also the case in LA.

Isaac was a big story because of the RNC and then the shadow of Katrina. There were a couple of TV media reports that were brought to my attention (naming no names of course ;-))…

First, a weather reporter was heard saying that the Saharan dust is why Isaac is not moving northwards. This is Not Correct, I repeat, this is Not Correct. Dust keeps the intensity low because it is dry air and prevents strong convection from developing. The track is determined by the pressure fields. Completely different things!

Second, on a different station, a weather anchor was heard to say that “we still have to take this threat [or storm] serious.” Twice. Now I may not have the best control of the English language, being British and all, but even I can tell that this is grammatically WRONG!! It should be “we still have to take this threat seriousLY”.   For those who “felt a disturbance in the Force… as if a million voices suddenly cried out in terror…” (Star Wars), it was probably English teachers from around the world. With respect (and in my not-always-very-humble-opinion), if you are on TV and have the responsibility of talking to thousands of people, please have a good command of the language. It’s as important as the content information you are imparting. I can’t take you serious otherwise (ummm… which, in case you didn’t realize, is also wrong and should be ‘seriously’… It’s called sarcasm).

And that is my last word on Isaac.

Time to watch some Dr. Who. Again. J

Ciao for now!

Blogs archived at
Twitter @JyovianStorm
DISCLAIMER: 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 "run away, run away" (Monty Python), I'll let you know.

No comments: