Danny still weak

By: Dr. Jeff Masters , 7:32 PM GMT on August 28, 2009

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Tropical Storm Danny continues to look unhealthy, with an exposed low-level center and the main heavy thunderstorms well to the east. The center is oval instead of circular, which may portend that this center will dissipate and a new center will form under the heaviest thunderstorm activity. Danny has more of the appearance of a subtropical storm than a tropical storm on satellite imagery, and this structure will slow down any potential intensification. The amount of heavy thunderstorm activity has increased in the past few hours, though no thunderstorms have formed near the center. The latest Hurricane Hunter mission found one small spot of 45 mph surface winds between 1 - 3 pm EDT today, so Danny may barely qualify as a tropical storm. Danny's center may have begun moving to the north over the past hour, giving confidence that the storm's strongest winds and rain will stay offshore of North Carolina tonight and Saturday morning.


Figure 1. Afternoon satellite image at 3:03 pm EDT of Danny, showing the exposed swirl of clouds where Danny's center is, well displaced from the heaviest thunderstorm activity to the east. The center is oval-shaped and not circular, the sign of a weak circulation.

The forecast for Danny
With wind shear at 15 knots this afternoon, and forecast to increase to 20 knots tonight and 30 knots Saturday morning, it is unlikely Danny will be able to strengthen to more than a 50 mph tropical storm. Dry air from the upper-level low that has been keeping Danny disorganized continues to be a problem for the storm, as well. Most of the intensity forecast models continue to insist Danny will strengthen, but they have been doing a very poor job forecasting the intensity of Danny. With Danny's heavy thunderstorms all on the east side of the storm, it is unlikely that North Carolina or New England will feel tropical storm force winds from Danny when it scoots past on Saturday. Large swells from Danny creating high surf along the beaches of New England will be the primary hazard from the storm.

Massachusetts hurricane history
Two tropical storms have affected Massachusetts in the past decade, though neither of these storms brought sustained winds of tropical storm force (39 mph) to the state. Tropical Storm Beryl of 2006 just missed Cape Cod as a weak tropical storm with 45 mph winds. Beryl brought wind gusts to tropical storm force to Nantucket Island, and a 1 foot storm surge. Tropical Storm Hermine hit southeast Massachusetts on August 31, 2004, as a minimum-strength tropical storm with 40 mph winds. No land stations in Massachusetts reported tropical storm force winds during Beryl. The last time Massachusetts measured tropical storm force winds was in 1997 during that year's version of Tropical Storm Danny. Chatham recorded sustained winds of 44 mph, and Nantucket had 43 mph winds. The last time Massachusetts had hurricane force winds was in 1991 during Hurricane Bob, which hit Rhode Island as a Category 2 hurricane. Provincetown, Massachusetts measured sustained winds of 98 mph, gusting to 115 mph, and Buzzard's Bay received a 15 foot storm surge.

Invest 94L
The well-organized tropical wave (94L) mid-way between Africa and the Lesser Antilles Islands continues to be a threat to develop into a tropical depression in the next day or two. Water vapor satellite loops show that 94L has moistened the region surrounding it considerably today, and the storm is not ingesting as much dry air as this morning. However, visible satellite loops show only a small amount of heavy thunderstorm activity near the circulation center, which is broad and elongated from east to west. Shear is low, about 10 knots, and is expected to remain low, 5 - 10 knots, over the next five days. The waters are warm enough to support development, 27°C, and are expected to remain in the 27 - 28°C range over the next five days. It appears that 94L needs another 1 - 3 days to develop a well-formed circulation and become a tropical depression, given the favorable environment. NHC is giving 94L a medium (30 - 50% chance) of developing into a tropical depression by Sunday. Most of the models predict 94L will Be affected by two troughs of low pressure over the next week, which will pull the storm far enough north so that it will miss the Lesser Antilles Islands. It is then probable that 94L will be forced to the west again as the high pressure ridge steering the storm builds back in. The possible long-term threat to the U.S. East Coast is impossible to evaluate at this time.

I'm in New York City this weekend for my cousin's wedding, so will not be blogging again until Monday morning. In my absence, wundergound's severe storms expert, Dr. Rob Carver, will be posting in my blog Saturday and Sunday.

Jeff Masters

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Quoting IKE:
Navy hasn't updated on Danny since 2215UTC, so it's more than just 94L.


Maybe 2 RIP's?
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The most accurate model for 94L so far is XTRP. ;-)
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Quoting IKE:
Navy hasn't updated on Danny since 2215UTC, so it's more than just 94L.
huh
659. IKE
Navy hasn't updated on Danny since 2215UTC, so it's more than just 94L.
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Quoting BenBIogger:



TCHP


Thanks. I had heard that funding for this had been discontinued since May but good to see it back up. Don't like the TCHP for the NW Caribbean as I am sitting in the middle of it .

Let's hope nothing comes this way.
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00z model I'm using for tracking Danny is the NOGAPS model.
------------------------------------------------

00z model I'm using for tracking 94L is the SHIP model.
Quoting StormW:
Good evening!


Norm!
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Appears to have been reinstated...

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Quoting kmanislander:


I thought this link was inactive since May ?. No longer on the WU home page.



TCHP
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Quoting StormW:
Good evening!

Greetings earthling!
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ice formation cleared for the launch
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The spread from BAMS to BAMD tells me that, like usual, if 94 would go ahead and develop a little, we would have to worry about it a bit less.

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Quoting BenBIogger:


I thought this link was inactive since May ?. No longer on the WU home page.
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647. Relix
The development is going nicely and it wouldn't surprise me if we saw a TD tomorrow going into the northern caribbean (Yes, into it). It's taking its time to develop and it should eventually step up a bit but not pulled out over the islands. It's my new point of view from analyzing the steering layers right now and having water vapor loops open through the whole day haha. I am still split 50/50 on into the caribbean or into the atlantic.
Member Since: August 3, 2006 Posts: 0 Comments: 2645
646. IKE
Quoting kmanislander:


SSD just updated to 1:15


Yup....thanks.....

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img src="Photobucket" alt="" />
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Quoting kmanislander:
It looks like status quo for 94L for at least 12 to 24 hours. Nothing more to watch for tonight so will sign off until tomorrow.

Easterly shear is still a problem pushing the convection to the West of the low and also causing the fast motion to the W. Until these two factors ease off 94L will not likely make it to TD status.

BINGO!!! the year of the shear. Easterlies are going to eat away at those beautiful waves behind 94L as well. People forget this El Nino = shear. By the time they get further west more shear ULLs or trough kills em. I hate boring years like this. 94L is a mess and convection doesn't mean impressive. The last quikscat showed it all. A very broad center with MULTIPLE imbedded developing lows. It's real disorganized right now.
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NASA launch update:

Countdown Update
Fri, 28 Aug 2009 08:46:10 PM EST

Launch managers are still discussing an ice formation detected earlier in the area of the liquid hydrogen T-0 umbilical. It is similar in size and shape to those spotted on previous launch attempts. Its size has been determined not to be a debris hazard.

The weather is favorable, overall. We're currently "green" on all launch weather constraints, although pop-up showers within 20 nautical miles could pose a concern for return-to-launch-site abort rules.

The Closeout Crew is ready to begin closing space shuttle Discovery's hatch
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Quoting IKE:


I don't get it. I'm puzzled.


SSD just updated to 1:15
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002:06:02
Quoting tornadofan:


Are a bunch of clouds around their spot. It better disipate fast to be able to see it.

Yeah we're screwed here in So. Fla. for this one. All the the other scrubbed attempts had perfectly clear skies and tonight is drizzly and cloudy, slim chance of seeing it. It may not even launch, we'll see in 2:03.
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Quoting IKE:
TWC just did their tropical update and didn't even mention 94L.


Really? I retract my RIP.
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NASA TV is reporting rapid dissipation of thunderstorms in the launch area. Appears to be more favorable on this try.

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638. IKE
Quoting kmanislander:


And the best quikscat image since it left the W coast of Africa.


I don't get it. I'm puzzled.
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Quoting IKE:
TWC just did their tropical update and didn't even mention 94L.


Guaranteed to develop !
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635. IKE
TWC just did their tropical update and didn't even mention 94L.
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Quoting IKE:


I don't know of another reason?




I agree, since the NHC is still calling for some development(30-50% chance).


And the best quikscat image since it left the W coast of Africa.
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633. IKE
Quoting tornadofan:


RIP?

(Running for shelter to avoid stones from 94L-lovers...)


I don't know of another reason?


Quoting kmanislander:


I noticed that. Very odd. Can't imagine they are dropping it


I agree, since the NHC is still calling for some development(30-50% chance).
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Quoting IKE:
Navy hasn't updated an image of 94L since 1915UTC.

SSD hasn't updated an image of 94L since 2345UTC(over an hour).

WTH?



I noticed that. Very odd. Can't imagine they are dropping it
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Quoting IKE:
Navy hasn't updated an image of 94L since 1915UTC.

SSD hasn't updated an image of 94L since 2345UTC(over an hour).

WTH?



RIP?

(Running for shelter to avoid stones from 94L-lovers...)
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Quoting tornadofan:
Looks like a late fall/winter satellite shot if you live in New England

Whad'did I say this morning? LOL!
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629. IKE
Navy hasn't updated an image of 94L since 1915UTC(nearly 7 hours ago).

SSD hasn't updated an image of 94L since 2345UTC(over an hour ago).

WTH?

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No Lighting Storms at the launch
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Quoting LightningCharmer:
Watching thunderstorms again just like on the first try. Hoping for clear skies in south Florida so we can have a peak down our way.

NASA TV


Are a bunch of clouds around their spot. It better disipate fast to be able to see it.

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Quoting tornadofan:
Thingamabobbercane - from the Washington Post


Lol. Thanks. I couldn't remember where I heard that. Just kinda sticks in your head. :)
Member Since: August 15, 2008 Posts: 10 Comments: 3665
Increasing shear ahead for 94L

This reinforces my belief that it will not make TD before 50W
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Quoting LightningCharmer:
Watching thunderstorms again just like on the first try. Hoping for clear skies in south Florida so we can have a peak down our way.


Yup. I'm hoping these clouds continue moving NE. Looks like it will be close.
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Quoting edmac:
Conditions are favorable for 94l, and will be for the next few days, as Dr. Master says. How are conditions forecasted to be next week for 94l, assuming 94l tracks north, and then west. Anyone heard anything.
Dont understand 94l been moving quickly west or s. of due west,then nogaps comes along then tracks it northwest..I think I can predict better then this computer model..
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It looks like status quo for 94L for at least 12 to 24 hours. Nothing more to watch for tonight so will sign off until tomorrow.

Easterly shear is still a problem pushing the convection to the West of the low and also causing the fast motion to the W. Until these two factors ease off 94L will not likely make it to TD status.
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Quoting IKE:
Discovery launch set to go at 11:59 pm EDST tonight.
Watching thunderstorms again just like on the first try. Hoping for clear skies in south Florida so we can have a peak down our way.

NASA TV
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If you look at this same quikscat pass its another rotation to the ENE of 94L can't say its totally closed but if you look at 12N/26W on the wide Tropical Atlantic Rainbow loop you can see the rotation in the same area as reflexed on the quikscat, even though its a few hours old.
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617. IKE
Discovery launch set to go at 11:59 pm EDST tonight.
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Quoting tornadofan:
Thingamabobbercane - from the Washington Post


Hehe:

That seems to leave only one other possibility, namely a "Thingamabobbercane," a term coined by Weather Underground blogger Jeff Masters.
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Thingamabobbercane - from the Washington Post
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Quoting K8eCane:



oh my gosh
this is a WEATHER BLOG
not a mental health center
Hmmm,

A.D.D. -> Atmospheric Denial Disorder
H.A.C. -> Hurricance Anxiety Complex

T.W.C.D.D -> Tropical Wave Cyclogenesis Denial Disorder

D.X.M.S. -> Delusional Extrapolation Model Syndrome

M.C.P.P -> Multiple Cylone Panic Psychosis

etc., etc., etc...
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613. edmac
Conditions are favorable for 94l, and will be for the next few days, as Dr. Master says. How are conditions forecasted to be next week for 94l, assuming 94l tracks north, and then west. Anyone heard anything.
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612. Skyepony (Mod)
Danny is having his COC shoved back under his convection thanks to the trough coming off FL. This should initially strengthen him, til the trough interacts. Then expecting some baroclonic strengthening..which also eventually forces him to go extratropical, probably late tomorrow. I expect to see him a much stronger storm with a lower pressure after he goes extra tropical & gets over the gulf stream then what he is now. CMC makes a pretty good picture other than..maybe not quite that low of pressure.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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