Bill is gone; Invest 92 pops up

By: Dr. Jeff Masters , 2:08 PM GMT on August 24, 2009

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Hurricane Bill is no more. The hurricane swept past Canada's Nova Scotia province Sunday afternoon, then made landfall early this morning in southeastern Newfoundland as a borderline tropical storm/Category 1 hurricane. Bill's waves claimed two lives over the weekend, a 54-year old swimmer that drowned in Florida, and a 7-year old girl in Maine that got swept into the sea by a big wave. The first death of the 2009 Atlantic hurricane season occurred on August 16, when a swimmer drowned in the rough surf from Tropical Storm Claudette at Pananma City Beach, FL.

Nova Scotia misses a direct hit
The center of Bill scooted parallel to the coast of Nova Scotia Sunday afternoon, and never quite came onshore. Since the storm's forward speed was so rapid--about 35 mph--this resulted in a highly asymmetric wind distribution. Since the top winds of a hurricane include the forward motion of the storm, Bill's top winds of 85 mph observed in the offshore, right front quadrant of the storm meant that the winds on the weak side of the storm, over Nova Scotia, were 85 mph minus 35 mph, or just 50 mph. Winds along most of the coast stayed below 39 mph, the borderline for tropical storm-force winds. The strongest winds measured in Canada were at Sable Island, which lies 150 miles offshore of Nova Scotia. Winds on the island hit 61 mph, gusting to 77 mph, between 4 - 5 pm ADT Sunday afternoon. A few islands along the Nova Scotia coast, such as Beaver Island and Hart Island, reported sustained winds of 39 - 40 mph. The big story for Nova Scotia was the waves from Bill. Buoy 44258 at the mouth of Halifax Harbor recorded significant wave heights of 29.5 feet and maximum wave heights of 49 feet as Bill passed 50 miles offshore. The buoy recorded top sustained winds of 35 mph, gusting to 51 mph. The waves combined with a 1.5 - 3 foot storm surge flooded many coastal roads. Buoy 44150, about 160 miles offshore of of the southwest tip of Nova Scotia, was in the east eyewall of Bill between 10 - 11 am ADT, and reported sustained winds of 62 mph, gusting to 85 mph, with significant wave heights of 44 feet. The buoy recorded a maximum wave height of 87 feet, according to Environment Canada. The highest official rain report on Nova Scotia was 2.6" (65 mm) at Yarmouth. Rainfall cause some localized flooding and road damage. Bill's winds cut power to about 40,000 people at the height of the storm. At Peggys Cove, three men were hit by a giant wave but were not hurt. A gift shop and attached home in the village were swept off of their foundation.

Newfoundland gets hit, but damage is minor
The southeast corner of Newfoundland took a direct hit from Bill. The storm made landfall early this morning as a borderline tropical storm/Category 1 hurricane. Top winds on the island were measured at Cape Race, which recorded sustained winds of 58 mph, gusting to 76 mph, between 1:30 and 2:30 am NDT. A storm surge of 1.2 meters (4 feet) was estimated by Environment Canada for Placentia Bay where Bill made landfall. Damage was minor on Newfoundland, with no major flooding reported. Bill dumped up to three inches of rain on Newfoundland.


Figure 1. The eye of Hurricane Bill on August 19 at 2157 UTC, from a NOAA P-3 Hurricane Hunter aircraft flying at 10,000 feet. Photo credit: Jack Parrish of NOAA's Aircraft Operations Center.

Kelvin-Helmholtz instability waves in the eye of Bill
Flight Director Jack Parrish of NOAA's Aircraft Operations Center snapped a cool photo in the eye of Hurricane Bill on Friday, showing the existence of a Kelvin-Helmholtz instability wave (Figure 1). The photo was taken on August 19 at 2157 UTC, from a NOAA P-3 Hurricane Hunter aircraft flying at 10,000 feet. The photo is taken looking WNW towards the eyewall. The towering clouds of the eyewall extend up to 50,000 - 55,000 feet in the photo, and the ocean surface is not visible, due to stratocumulus clouds covering the bottom of the eye. The center of the photo shows that the top of one of these stratocumulus clouds has a feature that looks like a breaking wave in the ocean. Well, that is an example of a breaking wave in the atmosphere known as a Kelvin-Helmholtz instability wave. The atmosphere behaves as a fluid, and thus has wave-like motions. When there is a sudden change of wind speed along the top of a cloud (wind shear), the flow can become unstable and cause breaking waves to form. One can see Kelvin-Helmholtz in the sky several times per year, and several alert wunderphotographers have uploaded photos of these waves over the years. However, it is uncommon to see these waves in the stratocumulus clouds covering the eye of a hurricane.


Figure 2. Water vapor satellite image for 8:15 am EDT 8/24/09. A tropical wave is approaching the Northern Lesser Antilles Islands, but is running into high wind shear from an upper-level cold low to the west of it. Image credit: NOAA/SSD.

Tropical wave approaching Lesser Antilles becomes Invest 92
A tropical wave with a moderate amount of shower activity is moving west-northwest at 20 - 25 mph and is approaching the northern Lesser Antilles Islands. This wave was designated "Invest 92" (92L) by NHC this morning. The wave is under about 20 - 30 knots of wind shear due the strong upper-level winds from the west. These winds are being created by the counter-clockwise flow of air around an upper-level cold-cored low north of Puerto Rico (Figure 2). This low is expected to move west-southwest and slowly weaken over the next two days, allowing shear to drop to the moderate 10 - 20 knot range beginning Tuesday night, according to the SHIPS model. By Wednesday, the upper low is predicted to be weak enough and far enough away from 92L that it will have a chance to develop. Most of the models show some degree of development of 92L by Thursday, when it is expected to be a few hundred miles off the coast of South Carolina. This wave could turn northward and give a wet weekend to New England, though it is too early to be confident of this. NHC is giving 92L a low (less than 30% chance) of developing into a tropical depression by Wednesday morning. The upper-level low will create plenty of wind shear and dump cold, dry air into 92L over the next two days, so Wednesday is probably the earliest we can expect the system to begin organizing into a tropical depression.

Several models predict the development of a tropical wave coming off the coast of Africa late this week.

I'll have an update Tuesday.

Jeff Masters

Beach Wall wave 1 (BeachBecky)
Waves from Hurricane Bill crashing on the sea wall during high tide in Lynn, MA
Beach Wall wave 1
Hurricane Bill Waves Day 2 # 9 (RIWXPhoto)
Hurricane Bill Waves Day 2 # 9
Kelvin-Helmholtz Instabilities (btangy)
Kelvin-Helmholtz Instabilities to the S of Boston. Wavy like pattern in clouds is caused by a difference in winds between the cloud layer and the layer just above (called wind shear). The manifestation of this at the top of the altostratus deck is quite a beautiful and rare sight!
Kelvin-Helmholtz Instabilities

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Quoting largeeyes:
NC Beach wedding next Friday(Sep 4th). Looking forward to some models that far out.


beach + wedding + models
Sounds like a good time.
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futuremet what site did ur pic come from please
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Quoting CatastrophicDL:
WOW! I go out of town for a couple of days and come back wondering what I missed - especially after reading a few posts. NRAamy beautiful work on that graphic! LOL!!!


Hey Press, you missing a hat?
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Well, I'm out folks...play nice
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508 kmanislander "Different times I guess. Sounded like a case of soap and water with the toothbrush!"

517 ConchHondros "No toothbrush though...yeah I did that when she was young...16 on up...I think they take "how to cuss like a Marine" as a prerequisite for english comp2"

Just different eras. A postInternet teen is no more likely to translate 'OMG' , 'WTFO' , 'BFD' , etc into actual words than her preInternet elders would think to translate 'snafu' or 'fubar' or '86' into actual words. ie While she probably knows the type of situation to which such a word is applicable, it's quite plausible that she may not know that the word is linked to a specific phrase.

Betcha that ya don't know what "lord love a duck" or "bob's your uncle" actually mean. And that your guesses (especially from official etymologies) will be no closer than 'pig' being derived from "pride, integrity, and guts".
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Quoting Patrap:


Looks lik ethe ULL its keeping dry air away and to hte south of 92l for now.
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Hawaii....dont take your eye off Hilda yet.

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Quoting futuremet:
Pugnacious much?

Sometimes.


Afternoon, all.

"Please do not engage in personal attacks or bickering. Material not conforming to these standards should be flagged with the button and ignored." - Admin Notice

This thing w/ WS seems rather a bit like dweeby 5th graders attacking somebody who wears purple socks instead of pink to me... but if this is your humour level, could we ask u to try a different forum?
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It looks like 92l will go into the box of doom possibly as well. "THE PLOT THICKENS?!?!?!?!?"
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Its been rather pleasent weather in the southeast this year. Hope it doesn't mean a colder than average winter.
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Quoting Grothar:


Hey, that is the image I have been trying to post 3 times now and can't do it. I believe you are the who directed me to itinitially. Thanks


It can be done direct. Can't do it by copying the address bar. Just have to right-click the graphic and "copy image location." After pasting into the image box, remove the "s" in the end of https://. Apparently WU won't accept an https, but can be worked around. Hope this helps.

Like this:

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Hiya, DL...like the new avatar...
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Right now, atmospheric dynamics are uncertain, and any forecast for 92L would be doubtful, especially since it isn't even developed yet. Some models hint at a building Bermuda High, some hint a trough creating enough of a weakness to steer 92L away. At this point. it's too uncertain. Models won't really have a good idea until 92L actually develops into a TD, if it does.
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Quoting Vortex95:
yey waiting is fun.
And yet, it's the name of our game...LOL
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yey waiting is fun.
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731. 7544
Quoting nrtiwlnvragn:
Miami Forecast Discussion

.WEDNESDAY THROUGH THURSDAY...SLIGHTLY MORE DIFFICULT FORECAST
DURING THIS PERIOD. MOST GLOBAL MODELS INITIALIZE THE TROPICAL
WAVE JUST EAST OF THE LESSER ANTILLES QUITE WELL. HOWEVER, THEY
SHOW RATHER DIFFERENT OUTCOME AS THE TIME PROGRESSES. GFS DEVELOPS
A SFC LOW AND MOVES NORTHWESTWARD WELL EAST OF THE BAHAMAS WITH NO
EFFECTS OVER THE LOCAL AREA...WHILE THE ECMWF DEVELOPS A RATHER
MORE SIGNIFICANT SFC LOW AND MOVES IT FURTHER WEST TO OVER THE NRN
BAHAMAS, WHILE NAM IS KIND OF IN BETWEEN BOTH OF THEM. THIS, OF
COURSE, POSES PROBLEMS WITH THE FORECAST. HOWEVER, GIVEN THAT
ECMWF HAS THE BEST INIT, WL TEND TO GO CLOSER TO THAT SOLUTION.
STILL THAT WILL KEEP THE LOCAL AREA UNDER THE SUBSIDENCE SIDE OF
THIS SYSTEM SO WILL GO WITH MAINLY SCT POPS FOR THE TIME BEING.


so its still undecided at this time another waiting game
Member Since: May 6, 2007 Posts: 0 Comments: 6871
Quoting Grothar:


Hey, that is the image I have been trying to post 3 times now and can't do it. I believe you are the who directed me to itinitially. Thanks


Not sure which image you are referring to. To post an image right click on the image and select properties, right click again over the URL, select all, right click again and copy.

When you click on Image in WU, delete the http that comes up initially and then paste the URL you copied into the address. The URL must end in .gif or .png.
Member Since: September 23, 2005 Posts: 14 Comments: 11255
New blog entry for the anniversary of Andrew and Fran
000
NOUS42 KNHC 241445
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1045 AM EDT MON 24 AUGUST 2009
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 25/1100Z TO 26/1100Z AUGUST 2009
TCPOD NUMBER.....09-088

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (NORTH OF PUERTO RICO)
FLIGHT ONE - TEAL 70
A. 25/2100Z
B. AFXXX 01AAA INVEST
C. 25/1900Z
D. 22.0N 67.0W
E. 25/2000Z TO 26/0001Z
F. SFC TO 10,000 FT

FLIGHT TWO - TEAL 71
A. 26/0600Z
B. AFXXX 0205A CYCLONE
C. 26/0400Z
D. 23.0N 71.0W
E. 26/0530Z TO 26/1000Z
F. SFC TO 10,000 FT

2. OUTLOOK FOR SUCCEEDING DAY: BEGIN 6-HRLY FIXES
AT 26/1800Z IF SYSTEM DEVELOPS.

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.
JWP
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Well...you guys party too hard for me, I'm going home. :-)

I'll be lurking this evening from home. You all play nice, now.

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Is there any models out there developing the area in the Carribean? Just curious...Thanks.
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Quoting nrtiwlnvragn:


Hey, that is the image I have been trying to post 3 times now and can't do it. I believe you are the who directed me to itinitially. Thanks
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Miami Forecast Discussion

.WEDNESDAY THROUGH THURSDAY...SLIGHTLY MORE DIFFICULT FORECAST
DURING THIS PERIOD. MOST GLOBAL MODELS INITIALIZE THE TROPICAL
WAVE JUST EAST OF THE LESSER ANTILLES QUITE WELL. HOWEVER, THEY
SHOW RATHER DIFFERENT OUTCOME AS THE TIME PROGRESSES. GFS DEVELOPS
A SFC LOW AND MOVES NORTHWESTWARD WELL EAST OF THE BAHAMAS WITH NO
EFFECTS OVER THE LOCAL AREA...WHILE THE ECMWF DEVELOPS A RATHER
MORE SIGNIFICANT SFC LOW AND MOVES IT FURTHER WEST TO OVER THE NRN
BAHAMAS, WHILE NAM IS KIND OF IN BETWEEN BOTH OF THEM. THIS, OF
COURSE, POSES PROBLEMS WITH THE FORECAST. HOWEVER, GIVEN THAT
ECMWF HAS THE BEST INIT, WL TEND TO GO CLOSER TO THAT SOLUTION.
STILL THAT WILL KEEP THE LOCAL AREA UNDER THE SUBSIDENCE SIDE OF
THIS SYSTEM SO WILL GO WITH MAINLY SCT POPS FOR THE TIME BEING.
Member Since: September 23, 2005 Posts: 14 Comments: 11255
Quoting fmbill:


I'm real proud of our team; we do pretty good being prepared and anticipating these things. You just hate to activate, then nothing happens. But worse would be doing nothing and later saying, "Oops!"





And the budget types especially hate it if you activate then nothing happens...
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Quoting IKE:


8 pm EDST.
Thanks
Member Since: September 23, 2005 Posts: 14 Comments: 11255
I'm not expecting any significant development to occur with 92L until that large Upper Level Low slides to the South of the disturbance.
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NWS TAUNTON MA...DISCUSSION...could get a little interesting ..?????

SATURDAY THROUGH MONDAY...CONSIDERABLE UNCERTAINTY EXISTS REGARDING
THE DETAILS OF THE FORECAST. A TROPICAL WAVE LOCATED NEAR THE
LEEWARD ISLANDS IS MODELED TO INTENSIFY...BUT ITS EVOLUTION AND
TRACK REMAIN UNCERTAIN. A LONG WAVE TROUGH DIGGING ACROSS THE GREAT
LAKES...ITS ASSOCIATED COLD FRONT AND PROMINENT RIDGE ACROSS THE
WESTERN ATLANTIC WILL HAVE AN IMPACT ON THIS POTENTIAL TROPICAL
SYSTEM. CURRENTLY FOLLOWED HPC GUIDANCE WHICH ATTEMPTS TO MINIMIZE
THE ENVELOPE OF UNCERTAINTY AT THIS POINT. HAVE INSERTED HIGH CHANCE
POPS SATURDAY AND SUNDAY...WITH AT LEAST A COLD FRONT EXPECTED TO
ADVANCE NEAR THE AREA LATE IN THE PERIOD...KEPT SLIGHT CHANCE TO LOW
CHANCE POPS ON MONDAY.
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Catastrophic...I can't take credit for it...and please don't re-post it as I'm already apologizing to George Forman as I type...

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NC Beach wedding next Friday(Sep 4th). Looking forward to some models that far out.
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715. IKE
Quoting Hurricane009:
anybody know when the next update is?? 5pm or 8pm?


8 pm EDST.
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Quoting Grothar:


Hey Allstar, I hope I did it right this time. Can't wait to look myself. The tracks do not look like they know where they want to go.


Dont see the image
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18Z NAM... still hinting towards a strong enough Bermuda high to stall out 92L east of the US SE coast.
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anybody know when the next update is?? 5pm or 8pm?
WOW! I go out of town for a couple of days and come back wondering what I missed - especially after reading a few posts. NRAamy beautiful work on that graphic! LOL!!!
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Hey Allstar, I hope I did it right this time. Can't wait to look myself. The tracks do not look like they know where they want to go.
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Quoting reedzone:
Again, it's just too early to make a confident forecast. things can change in a few days, or the track may change. We just don't know yet, we do have some small hints of recurvature.


Exactly...we can be confident in the short term, but if the track modeling includes the higher atmosphere then the modeling becomes less accurate, until the system develops further
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Why are there two TD-12E's on the NHC site.
xD
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WITN, also out of eastern NC, is even more of a downcaster.

The next chance for significant showers comes late in the week and the weekend. Right now it's not looking like a widespread event, with 30-40 percent chances for showers and thunderstorms by Friday into Saturday.
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Quoting IKE:


It's nice up here. I've got 83 degrees outside.

Tonight
Partly cloudy. Lows around 59. Light winds.
here lows around 80, ughhhhh, why is miami so hot?
Quoting rwdobson:
Fireman bill, yeah, i can see how that would strain Em Ops, the potential of a system forming right offshore...luckily if you get that little warning, it's probably a weak system, but still...


I'm real proud of our team; we do pretty good being prepared and anticipating these things. You just hate to activate, then nothing happens. But worse would be doing nothing and later saying, "Oops!"



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WCTI12 out of Eastern NC:

Wednesday and then develops into a low pressure area that will move north-northeast out of the Bahamas passing just east of Cape Hatteras on Saturday. Some of the computer models develop this into a significant weather feature (tropical cyclone). At present, I do see it moving in our direction, but I don't see it as a big tropical system. Saturday is 5 days off and a lot can happen in 5 days, so we will be watching and tracking it carefully for you.
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18z NAM. Hello Danny.

Link
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Just a reminder that the color codes are for 48hr probability, not "right now" probability.

Shear is forecast to relax and the ULL to move out. Models support development. Some early intensity models have it at TS by 36 hours.

The orange makes sense to me.
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Hi! Rit on Cape Cod. I'm so looking forward to this heavy humidity clearing out of here. It looks like we have 2 more days of it, then 2 nice days, and then Invest 92. Looks like we're on the track for these developing storms this year.

Here's hoping this blows out to sea as well.
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AS FOR THE TROPICS...NHC HAS INCLUDED A WAVE WITH A MEDIUM CHANCE
OF DEVELOPMENT IN THE TROPICAL WEATHER OUTLOOK. EVEN IF THIS
SYSTEM DOES DEVELOP INTO A TROPICAL STORM OR HURRICANE...ALL MODEL
GUIDANCE CURRENTLY AGREES THAT THE EAST COAST TROUGH WILL REMAIN
IN PLACE LONG ENOUGH TO FORCE THIS SYSTEM TO RECURVE BEFORE
AFFECTING THE CONTINENTAL UNITED STATES.


A bit overconfident there...
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Again, it's just too early to make a confident forecast. things can change in a few days, or the track may change. We just don't know yet, we do have some small hints of recurvature.
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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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