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 kmanislander:


No more so than the NHC if anyone from there were ever to read the post LOL


which is a distinct possibility
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Atlantic, 2 Sept 2008




Be prepared now as we head into the Heart of the 09 season in the Atlantic..
Member Since: July 3, 2005 Posts: 415 Comments: 125628
Quoting presslord:


Dude! You mean...You're not impressed with his broad vocabulary and stunning command of English?!?!?!?!?!


No more so than the NHC if anyone from there were ever to read the post LOL
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Those models are from the Storm2k site.By the way does anyone use the Storm2K site?
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Once Again I post Dr. Masters Late Sunday afternoon entry from 28 August 2005..it was this post that encouraged many still waffling on staying..to Leave.

Without a doubt this entry in itself saved Lives.

And for that we and I are forever grateful to Dr. Jeff Masters for it.

Katrina stronger than Camille

Posted by: JeffMasters, 5:52 PM CDT on August 28, 2005




The 6:30pm EDT NOAA Hurricane Hunter mission found a central pressure of 904 mb, up from the 902 measured at 3:30pm. These pressures make Katrina the fourth strongest hurricane ever, and the strongest hurricane ever observed in the Gulf of Mexico, surpassing Camille. However, the winds of Katrina are 165 mph, far from Camille's 190 mph winds at landfall.

Although the pressure has stopped falling, there is no indication that Katrina is about to undergo weakening, like we saw yesterday during her eyewall replacement cycle. When that cycle started, the eye diameter was 9 nm, but the present eye diameter is 28 nm. Eyewall replacement cycles usually begin when the eye shrinks below 10 nm, and there are no indications that Katrina's eye is going to shrink.

The list of strongest hurricanes of all time now reads:

Hurricane Gilbert (888 mb, 1988)

The Great Labor Day Hurricane (892 mb, 1935)

Hurricane Allen (899 mb, 1980)

Hurricane Katrina (902 mb, 2005)

Hurricane Camille (905 mb, 1969)

Landfall location and intensity
Katrina has continued to expand in size, and now rivals Hurricane Gilbert and Hurricane Allen as the largest hurricanes in size. When hurricanes reach such enormous sizes, they tend to create their own upper-air environment, making them highly resistant to external wind shear. The global computer models are not really hinting at any wind shear that might affect Katrina before landfall, and the only thing that might weaken her is an eyewall replacement cycle. Even if one of these happens in the next 12 hours, the weakest Katrina is likely to get before landfall is a Category 4 hurricane with 145 mph winds. Katrina is so huge and powerful that she will still do incredible damage even at this level. The track forecast has not changed significantly, and the area from New Orleans to the Mississippi-Louisiana border is going to get a catastrophic blow. I put the odds of New Orleans getting its levees breached and the city submerged at about 70%. This scenario, which has been discussed extensively in literature I have read, could result in a death toll in the thousands, since many people will be unable or unwilling to get out of the city. I recommend that if you are trapped in New Orleans tomorrow, that you wear a life jacket and a helmet if you have them. High rise buildings may offer good refuge, but Katrina has the potential to knock down a high-rise building. A 25 foot storm surge and 30 - 40 foot high battering waves on top of that may be able to bring down a steel-reinforced high rise building. I don't believe a high rise building taller than six stories has ever been brought down by a hurricane, so this may not happen Monday, either. We are definitely in unknown waters with Katrina.

I have focused on New Orleans in much of my discussions about this storm, but Katrina will do tens of billions in damage all along the coast of Louisiana, Mississippi, Alabama, and Florida. Mobile Bay could well see a 10-foot storm surge. And inland areas will take heavy damage as well; Katrina will still be a hurricane 180 miles inland, and cause widespread flooding throughout the Tennessee Valley.

My thoughts and prayers go out to all of you in Katrina's way, and I urge all readers of this blog to do the same.

Jeff Masters
Member Since: July 3, 2005 Posts: 415 Comments: 125628
Quoting kmanislander:


If it maintains the same speed and heading.


A couple of big ifs! I would like to see that thing moving a little more north but it hasn't yet.
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Quoting Hurricane009:
Isabel was a Cat. 2 at landfall


you're right
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Quoting JamesSA:


That has it at the Antilles front door Monday morning.


If it maintains the same speed and heading.
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Wind shear axis along the east coast of North and South Carolina is providing the necessary ingredient for updraft sustainment causing thunderstorms to erupt in this shear axis. I will have a blog out in the coming days providing what the track of the ultimate hurricane would do.
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197. Bonz
'those temperatures are nice, won't be down here for another few months, I hate Florida."

Me too. I can't wait 'til housing picks up so I can move out of here.

94L doesn't look as good as it had been looking.
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Oh no...
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Quoting kmanislander:


One degree every 3 hours at the present time


That has it at the Antilles front door Monday morning.
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Quoting Hurricane009:
Hurricane Fran was the last major hurricane to hit NC, that was 13 years ago!


ah...Isabel...2003
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Quoting Hurricane009:
That means 10 degrees every 30 hours


Only on a due W heading of 270.

Anything N of 270 would result in a slower traverse across each degree
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Quoting lamanzanilla:

Thanks for replying! We're located about a day's drive south of you (maybe you know
La Manzanilla?) - near Barra de
Navidad and Melaque - on Tenacatita Bay. Vive Invest 94!

The west coast of Mexico has very few people compared to the Atlantic side. Lots of rain...good. Flooding and wind...not so good. Let's hope for the best.
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Member Since: July 3, 2005 Posts: 415 Comments: 125628
Member Since: July 3, 2005 Posts: 415 Comments: 125628
Quoting KEHCharleston:
94L has been moving along at a pretty good clip

DATE/TIME LAT LON CLASSIFICATION STORM
28/1745 UTC 10.2N 37.9W TOO WEAK 94L
28/1145 UTC 10.2N 35.6W TOO WEAK 94L
28/0600 UTC 10.3N 34.0W TOO WEAK 94L
28/0000 UTC 9.8N 28.0W TOO WEAK 94L


One degree every 3 hours at the present time
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18z gfs much faster and further west than the 12z
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181. HadesGodWyvern (Mod)
Central Pacific Hurricane Center
Tropical Cyclone Outlook
10:00 AM HST August 28 2009
========================================

An area of disturbed weather (95C) about 1250 miles west southwest of Kauai is moving west near 10 mph. Organization has continued to increase and it could become a tropical depression later today or Saturday as it continues moving west.

Tropical Cyclone Formation Potential
=====================================
There is a HIGH risk of this disturbance to form into a significant tropical cyclone within the next 48 hours
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"The possible long-term threat to the U.S. East Coast is impossible to evaluate at this time." J. Masters

I'm gonna post this every 10 minutes or so for the next week...
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179. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #6
TROPICAL STORM KROVAHN (T0911)
6:00 AM JST August 29 2009
=========================================

Subject: Category One Typhoon Near Ogasawara Shoto

At 21:00 PM UTC, Tropical Storm Krovahn (996 hPa) located at 25.1N 148.3E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The storm is reported as moving north at 12 knots.

RSMC Dvorak Intensity:

Gale-Force Winds
================
180 NM from the center in eastern quadrant
90 NM from the center in western quadrant

Forecast and Intensity
======================
24 HRS: 27.4N 145.0E - 45 knots (CAT 1/Tropical Storm)
45 HRS: 28.9N 141.9E - 50 knots (CAT 2/Severe Tropical Storm)
69 HRS: 32.1N 138.0E - 55 knots (CAT 2/Severe Tropical Storm)
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Still saying the caribean is sucking in energy from all sides and trying to spin from what it looks like on WV loop. Starting to get big O thing going on.
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Quoting mazgreg:
I'm in Mazatlan

Thanks for replying! We're located about a day's drive south of you (maybe you know
La Manzanilla?) - near Barra de
Navidad and Melaque - on Tenacatita Bay. Vive Invest 94!
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Swell showing here on the fl east coast with an offshore wind today, to bad I had to watch it from work.
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Quoting reedzone:


Yep I believe it will be a strong Nor'easter. those temperatures are nice, won't be down here for another few months, I hate Florida.

Um okay?I hate where ever you live too?Can we all just accept every place all they have to offer.
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Quoting reedzone:


Yep I believe it will be a strong Nor'easter. those temperatures are nice, won't be down here for another few months, I hate Florida.


uh oh, he said the FL word! some people dont like it when florida is mentioned on this blog. ha im just giving you s hard time, nothing personal. on a side note, im from indiana :P
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Quoting StormFreakyisher:
Danny doesn't even matter to me anymore. Dr.Lyons said it won't even create waves larger than Bill did even if Danny is closer to shore.Plus all the convection is on the east side, so the East coast has been spared of any flooding or heavy downpours for a continuos time.You guys may just get some squally rain bands from time to time of 40mph or not even.


the waves were just as deadly tho
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Quoting P451:


It does look better and I have felt that once it begins to move with the shear and at an accelerated pace it will have a chance to organize. It is still in an overall poor environment so even if it works with that environment to perfection I wouldn't expect much intensification anymore.

What is going to happen is that there is lot of energy in the form of multiple disturbances all up and down the east coast and mid west. This in addition to Danny seems to be coming together from the Carolinas to the Canadian Maritimes.

In that we're going to see a lot of rain and maybe some breezy conditions at the coast.

Already been getting dumped on in NJ and expecting many inches of rain the next 60 hours or so.

After that hello fall! 70s/50s for the splits all next week! Yeah man!


Yep I believe it will be a strong Nor'easter. those temperatures are nice, won't be down here for another few months, I hate Florida.
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168. Relix
I am confident 94L will not affect the Antilles directly. The first through will surely miss it, maybe provide a step for it to go north a bit then resume west. The second one should pull it out over the antilles. Then it will be an East Coast game in my opinion. Factors that could affect this are:
1) Slower development. The weaker, the more westerly it will move. This would make the models shift east.
2) Stronger High.
3) Flat out dies soon.
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Funkadelic - We all lost someone that dreadful day. I am sure that no disrespect was intended.

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Danny doesn't even matter to me anymore. Dr.Lyons said it won't even create waves larger than Bill did even if Danny is closer to shore.Plus all the convection is on the east side, so the East coast has been spared of any flooding or heavy downpours for a continuos time.You guys may just get some squally rain bands from time to time of 40mph or not even.
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Speaking of E Pac tropical systems: mid and hi level moisture from ex-Ignatio runs into OR, WA, BC coast.
Link

Shower and scattered thundershower warning in effect :)
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Quoting Funkadelic:

Mmm can we not mention that date around here. I lost a loved one on that dreadfull day, may who ever was involved in those attacks rot in hell.
Let me get my hands on them , they will wish they were in Hell.
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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.