Bill is gone; Invest 92 pops up

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

Share this Blog
3
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 698 - 648

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33Blog Index

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.
Member Since: Posts: Comments:
696. IKE
Quoting Dakster:
Ike - I wish the Heat and Humidity comment was applicable to steaming, burning, South Florida...

It rains and steam rises from the pavement. Please send the cold front down here...


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

Tonight
Partly cloudy. Lows around 59. Light winds.
Member Since: Posts: Comments:
NO, LA NWS seems to be stepping a bit outside their area of expertise there IKE.
Member Since: August 22, 2006 Posts: 0 Comments: 1462
693. IKE
From the NO,LA afternoon discussion....

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.

Member Since: Posts: Comments:
Ike - I wish the Heat and Humidity comment was applicable to steaming, burning, South Florida...

It rains and steam rises from the pavement. Please send the cold front down here...
Member Since: Posts: Comments:
Quoting stormsurge39:
Why do forcasters start using forcast tracks now, when it isnt developed yet? I know theres a reason, but it seems to cause alot of confusion on this blog.


Because they're the best way they have to predict future movements, but again, weak, "low" storms don't forecast very well; once they acheive hurricane status forecasting becomes considerably easier and more acurate
Member Since: Posts: Comments:
Quoting reedzone:


I know, I was just surprised they put higher chances on it. Though I guess with all the model support...


....and lessening that shear. That ULL will move to the southwest and weaken, giving 92L favorable conditions to develop in.
Member Since: Posts: Comments:
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...
Member Since: Posts: Comments:
we have a new TD in the E PAC TD 12E
Member Since: Posts: Comments:
Quoting sctonya:


It is still Orange on the NHC site.


I know, I was just surprised they put higher chances on it. Though I guess with all the model support...
Member Since: Posts: Comments:
Quoting hurricanejunky:


NoGaps is a wishcaster!
might be a wishcaster but that is the god of all models for the NHC.
Member Since: Posts: Comments:
684. IKE
Mobile,AL. extended....

"LONG TERM...(THURSDAY ON)THURSDAY...THE CLOSED UPPER LOW OVER THE
LOWER MISS RIVER VALLEY BEGINS TO BREAK DOWN AS A SHORTWAVE HEADS
SOUTHEAST FROM OVER THE PLAINS. THIS WILL KICK THE LOWER MISS RIVER
SYSTEM THROUGH THE UPPER TROUGH WHICH HAS SET UP OVER THE MISS RIVER
VALLEY BY THIS TIME. GFS IS ADVERTISING A GAP IN THE PRECIP FRIDAY
INTO FRIDAY NIGHT...THEN ANOTHER ROUND AS THIS SECOND ROUND OF UPPER
ENERGY APPROACHES THE AREA...DRAGGING A FRONT WITH...WHICH IS BEING
ADVERTISED MOVING SLOWLY OVER THE FA SUNDAY INTO MONDAY.

Member Since: Posts: Comments:
Quoting stormsurge39:
Why do forcasters start using forcast tracks now, when it isnt developed yet? I know theres a reason, but it seems to cause alot of confusion on this blog.


great question..i would like to know myself!!
Member Since: Posts: Comments:
18z NAM 78-hour
Member Since: Posts: Comments:
Quoting reedzone:


Yep, plus this invest is really getting sheared right now. Until that upper level low moves out of the way, no development at all. I was actually surprised to see an orange code then a yellow one.


It is still Orange on the NHC site.
Member Since: Posts: Comments:
92L looking like a disorganized area of thunderstorms flared up by an upper level low, hold on that is what it is, if any development where to happen it will probably take more than 72 hours, imo.

-CanesRule1.
Member Since: Posts: Comments:
According to the SHIPS model, Danny will be born in 3-5 days.
Member Since: Posts: Comments:
Why do forcasters start using forcast tracks now, when it isnt developed yet? I know theres a reason, but it seems to cause alot of confusion on this blog.
677. IKE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
254 PM CDT MON AUG 24 2009

.DISCUSSION...

STRANGE SUMMER CONTINUES AS WE ARE DEALING WITH PLEASANT WEATHER
INSTEAD OF THE TYPICAL LATE AUGUST HEAT AND HUMIDITY. FOR NOW AND
THE NEXT DAY OR SO...THE WEATHER LOOKS TO REMAIN RELATIVELY
BENIGN WITH HIGHS AT OR BELOW NORMAL AND THE HUMIDITY VALUES ON
THE RISE...BUT STILL BELOW NORMAL FOR THIS TIME OF YEAR.

THE ONLY MONKEY IN THE WRENCH IS THE FAINT REMNANTS OF THE UPPER
LEVEL TROF HUGGING THE EAST COAST. MODELS CONTINUE TO INDICATE
THAT WHILE THE BULK OF THE TROF AXIS EXITS STAGE RIGHT...THE
SOUTHERN MOST TIP ACTUALLY RETROGRADES WESTWARD OVER MUCH OF THE
SOUTHEAST THROUGH THE BULK OF THE WORK WEEK. THIS WILL CREATE A
VERY MESSY FORECAST AS THIS REMNANT LOW BECOMES A SLIGHTLY DEEPER
CLOSED LOW BY TOMORROW AS IT CONTINUES ON ITS WESTWARD PATH. THIS
MAY SEEM TO BE A SMALL DETAIL...BUT IT WILL EVENTUALLY PLAY A
MAJOR ROLE AS WEATHER MAKER BY WEDNESDAY AND ESPECIALLY INTO
THURSDAY. AS THIS LOW PULLS JUST TO OUR WEST IT WILL ACT TO CREATE
A HEIGHT FALLS SURFACE LOW WHICH WILL RAPIDLY PULL ATLANTIC AND
GULF AIR BACK OVER THE REGION. THIS WILL CREATE A MORE CONDUCIVE ENVIRONMENT
FOR SHOWERS AND THUNDERSTORMS FROM WEDNESDAY THROUGH AT LEAST
FRIDAY. IT WILL HAVE A RATHER STRANGE LOOK AS THE POSITION OF THIS
LOW WILL PULL MOISTURE AND STORMS FROM THE SOUTHEAST...SO WILL
HAVE THE UNUSUAL SOUTHEAST TO NORTHWESTERLY STORM TRACK. THIS SYSTEM HAS
THE POTENTIAL TO BE A FORECAST BUSTER...EVEN AS I TYPE SHOWERS
ARE FORMING ALONG THE TRAILING EDGE OF THE SYSTEM AS AN ALMOST
WEDGE FRONT INDUCED LINE.

WHILE THIS SEEMS A BIT COMPLEX THINGS TREND MORE TOWARDS THE 2009
SUMMER AS YET ANOTHER STRONG COLD FRONT PLUNGES SOUTH OVER THE
WEEKEND...AND WE COULD BE LOOKING AT MORE RECORD LOWS BY THIS TIME
NEXT WEEK.
NORMALLY...I WOULD NOT BITE ON THIS
SCENARIO...HOWEVER...GIVEN THIS SUMMER ONE COULD AND SHOULD EXPECT
THE UNEXPECTED.

Member Since: Posts: Comments:
Quoting stormsurge39:
Why does Nogaps have it going so far west?


NoGaps is a wishcaster!
Member Since: Posts: Comments:
Quoting NEwxguy:
((sigh)) we need a system before we can start projecting tracks,doesn't that make sense?


I guess for me, these "quick-trigger" systems tend to keep us on our toes in emergency management. Being in the Cntral Florida area, we're kind of forced to ask "what-if" a lot. Mostly because the ramp-up of operations is based on 3-day notifications.

BTW...afternoon, all!
Member Since: Posts: Comments:
Please no lighting...I look bad in black...
Member Since: Posts: Comments:
Quoting NEwxguy:
((sigh)) we need a system before we can start projecting tracks,doesn't that make sense?


Yep, plus this invest is really getting sheared right now. Until that upper level low moves out of the way, no development at all. I was actually surprised to see an orange code then a yellow one.
Member Since: Posts: Comments:
Quoting Alockwr21:
Seems like whenever a storm "rides" up the east coast, the OBX of NC are always effected somehow.


Of course it has nothing to do with how the coast is shaped and that OBX is kind of sticking istelf out to the east...

Member Since: Posts: Comments:
I wonder where the models think 92L's center is... It's massive bunch of clouds, converging in towards each other.

Member Since: Posts: Comments:
((sigh)) we need a system before we can start projecting tracks,doesn't that make sense?
Member Since: Posts: Comments:
Seems like whenever a storm "rides" up the east coast, the OBX of NC are always effected somehow.
Member Since: Posts: Comments:
Quoting stormsurge39:
This may be a dumb question, but if 92L gets as far as the central Bahamas, wont it hit land somewhere on the east coast from S Carolina on up, even with the trough?


Depends how strong the trough is, it could sharply recurve... Yet you could have a Floyd (1999) and recurve it long and slow up the coastline. It's just wayy to early to make assumptions right now, check back in a few days but most of all, check your local news station for the best coverage. :)
Member Since: Posts: Comments:
Quoting justalurker:
hey guys, dont you think WS had enough humiliation for one day..give a guy a break. He may seem a little off the wall sometimes, but no one deserves this...


I agree. While we all know that JFVWS tends to get to the annoying status pretty quick, we are also now getting the benefit of being annoyed in absentia by people who can't let go even when he's not here. C'mon people..at least wait until he's here to rag on him and enjoy the quiet when he's not.
Member Since: Posts: Comments:
Quoting rareaire:
flood we good for a visit to the carolin--- oops! north or south carolina?


Yep...just takes the right set of circumstances
Member Since: Posts: Comments:
Again 92L is nothing to worry about yet, once or IF it forms, that's when we need to watch it more. Although as it says in the Flhurricane site, there's basically a 50/50 chance of it heading out to sea. Really depends on the timing of the trough and the speed of the invest.
Member Since: Posts: Comments:
This may be a dumb question, but if 92L gets as far as the central Bahamas, wont it hit land somewhere on the east coast from S Carolina on up, even with the trough?
Lets wait until we get a well defined center to make track and intensity predictions.
Member Since: Posts: Comments:
Quoting IKE:


She's not a dude.

$$


oops my mistake..
Member Since: Posts: Comments:
TPC/TAFB 72 hour surface forecast. Additional +24 hrs position has 92L ~30N 73W on friday morning.


Member Since: Posts: Comments:
Quoting LBAR:


ULL is moving away...shear should be decreasing. I'm nervous for the SC coast...although a tropical storm dropping some rain wouldn't be a bad thing by any means.


You're definitely sure it's going to the SC coast?
Member Since: Posts: Comments:
Quoting StormChaser81:


We dont deserve his bable, and crazy ideas.


Quoting StormChaser81:


We dont deserve his bable, and crazy ideas.


ignoring his comments is one thing..but humiliating a human being is another..just move on bro.
Member Since: Posts: Comments:
flood we good for a visit to the carolin--- oops! north or south carolina?
Member Since: Posts: Comments:
654. IKE
Quoting justalurker:


dude this has been posted 3 times today..its gets old after a while.


She's not a dude.

$$
Member Since: Posts: Comments:
Quoting Floodman:


Some of the models are calling for some development in that area soon; that msut be the energy they're calling for...


Well, if it does develop, it's going to be a large one (diameter), judging from how large of an area is feeding into it. Shear looks low in the area. Needs a lot more convection, though. If convection flares up, I'd expect it to take off.
Member Since: Posts: Comments:
Quoting StormChaser81:


We dont deserve his bable, and crazy ideas.


Creativity comes from seeming 'nonsense'.
Member Since: Posts: Comments:
649. JLPR
Quoting Relix:
I just want to know if it posses a threat to PR =(


I don't think so
92L will be already to our north once the ULL gets away and then is when 92L will really start getting going
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Quoting caneswatch:


Where is the Euro track taking it?


Wouldn't you like to know? lol

Lets just say it effects someone in the CONUS. Trying to keep it cool here.
Member Since: Posts: Comments:

Viewing: 698 - 648

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33Blog Index

Top of Page

About

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

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron