Bill intensifies to Category 4; globe has 5th warmest July on record

By: Dr. Jeff Masters , 3:28 PM GMT on August 19, 2009

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Category 4 Hurricane Bill is now the the fourth strongest tropical cyclone to appear on the planet so far this year, and may grow even stronger. Visible and infrared satellite imagery continue to show an impressive, well-organized, hurricane, with plenty of low-level spiral banding and upper-level outflow well-established on all sides except the west. On Bill's west side, upper-level winds from the west are creating a modest 10 knots of wind shear, which is giving the hurricane a bit of a squashed appearance there.

Wind shear is forecast to remain low to moderate, 5-15 knots, for the next four days. Sea Surface Temperatures (SSTs) will rise steadily from 28.5°C today to 29°C on Friday. Total ocean heat content is at a maximum today, and will gradually decline over the next four days. Bill should be able to take advantage of these favorable conditions a remain a major hurricane the next three days.


Figure 1. Visible satellite image from NASA's Aqua spacecraft at 12:40pm EDT Tuesday August 18, 2009. Image credit: NASA GSFC.

Water vapor satellite loops show a small "short-wave" trough of low pressure to the north-northwest of Bill, and this trough has turned Bill on a more northwesterly track over the past two days. Bill will miss the Lesser Antilles Islands, and the main impact of the hurricane on these islands will be high waves. The short wave trough (so called because it has a relatively small amplitude and wavelength) is not strong enough to turn Bill due north, and Bill is also expected to miss Bermuda. High waves and sustained winds of 20 - 30 mph are the worst that Bermuda is likely to get from Bill.


Figure 2. Visible satellite image of Bill's eye zoomed in, taken from NASA's Aqua spacecraft at 12:40pm EDT Tuesday August 18, 2009. Image credit: NASA GSFC.

An unusually strong "long wave" trough of low pressure (called long wave because of its large amplitude and wavelength) is expected to develop along the U.S. East Coast late this week. This trough will turn Bill to the north, and also bring high levels of wind shear in the 40 - 65 knot range on Sunday. Exactly where this turn occurs is still not clear. The models continue to be in two camps: an eastern camp (GFS, GFDL, HWRF, and ECMWF) that takes Bill 300 - 500 miles east of Cape Cod, and a more western camp (NOGAPS, UKMET) that bring Bill within 150 - 200 miles of Cape Cod. Both sets of models bring Bill ashore over the Canadian provinces of Newfoundland or Nova Scotia. Bill will be weakening rapidly as it makes landfall, and is likely to be a Category 1 hurricane if it hits Nova Scotia, or strong tropical storm if it hits Newfoundland.

Bill's big waves
Large swells from Bill will begin impacting the U.S. East coast from Florida to Maine beginning Friday night or Saturday morning. Seas will build to 5 - 10 feet in the offshore waters from central Florida northwards to South Carolina, and to 10 - 15 feet from North Carolina to Cape Cod. Near shore, waves will be about 40% less. This will cause a significant coastal erosion event along some portions of the coast. The latest run of the NOAA Wavewatch III model suggests that significant wave heights near Bill's center will reach 50 feet on Sunday. Since maximum wave height is typically about a factor of 1.9 greater than the significant wave height (which is the average trough-to-crest height of the top 1/3 largest waves), a few huge waves near Bill's center may reach 95 feet high.

Possible impacts to New England
The current set of computer model runs predicts that the center of Bill will pass Cape Cod, Massachusetts Sunday afternoon or evening. Tropical storm-force sustained winds of 39 mph or greater currently extend out 185 miles to the west of Bill's center, so that if Bill maintains its current wind distribution, Cape Cod could see sustained winds of about 40 mph Sunday night if the models predicting a more westerly path are correct. However, Bill will not keep this same radius of winds. The hurricane will weaken considerably beginning Sunday morning, once the storm gets caught up in the approaching long wave trough. High wind shear of 40 - 65 knots due to strong southwesterly winds aloft will act to compress the hurricane in the east-west direction, keeping the hurricane's strongest winds away from Cape Cod. The highest winds are likely to be no more than 30 mph on Cape Cod from Bill, if the storm follows the track of the western camp of models nearest to the Massachusetts. A few rain squalls may affect coastal Massachusetts, but the main impact of Bill on New England is likely to be coastal erosion from high waves.

Elsewhere in the tropics
The remains of Tropical Storm Ana are bringing scattered heavy rain showers to the Bahamas and Florida today. The remains are disorganized, and are not likely to re-develop. The only model calling for a new tropical cyclone to develop in the Atlantic over the next seven days is the GFS model, which predicts development off the coast of Africa about 7 days from now.

Fifth warmest July on record globally; a cold July in the U.S.
The globe recorded its fifth warmest July since record keeping began in 1880, according to NOAA's National Climatic Data Center. NOAA rated the period January - July 2009 as the sixth warmest such period on record. NASA's Goddard Institute for Space Studies rated July 2009 as the 2nd warmest July on record, behind July of 1998. For the second month in a row, global ocean Sea Surface Temperatures (SSTs) in July were the warmest on record, 0.59°C (1.06°F) above the 20th century average. This broke the previous July record set in 1998. The record July SSTs were due in part to an ongoing El Niño event in the Eastern Pacific, which has substantially warmed a large stretch of the tropical Eastern Pacific Ocean. As El Niño conditions mature during the coming months, near-record global ocean and land temperatures will probably continue. Now that El Niño conditions have been well-established for three months, the atmosphere has begun to heat up in response. It typically takes up to seven months for the atmosphere to heat up in response to ocean heating from an El Niño. This may explain why June of 2009, which independent assessments by NOAA, NASA, and the UK Hadley center agreed was the 2nd or 3rd warmest June on record at the surface, recorded only average satellite-measured temperatures in the lower atmosphere. In contrast, the July satellite-measured temperatures in the lower atmosphere were the 2nd or 3rd warmest on record, in agreement with the assessments that surface temperatures were the 2nd to 5th warmest on record.


Figure 3. Departure of temperature from average for July 2009. Image credit: NOAA/NCDC.

A cold July for the U.S.
For the contiguous U.S., the average July temperature of 23.1°C (73.5°F) was the coolest since 1994, and July temperatures were the 27th coolest in the 115-year record, according to the National Climatic Data Center. Ohio, Illinois, Indiana, Pennsylvania, Iowa, and West Virginia experienced their coolest ever July. Kentucky, Missouri, Michigan, and Wisconsin recorded their second coolest July in history. A strong trough of low pressure parked itself over the eastern portion of the U.S. in July, funneling down plenty of cold air from Canada. In the western U.S., a ridge of high pressure dominated, bringing unusually hot conditions. Arizona recorded its 3rd warmest July on record, and Seattle, Washington recorded its hottest day in history on July 28, notching a 103°F reading. This was 3°F above the previous record set in 1994.

U.S. precipitation was near average in July, with the month ranking 40th wettest in the 115-year record. U.S. tornado activity was above average in July, according to NOAA's Storm Prediction Center. However, no tornado deaths occurred in July.

At the end of July, 14% of the contiguous United States was in moderate-to-exceptional drought. This is a drop from the 19% figure observed at the beginning of the year. These extreme drought regions were exclusively in South and Central Texas.

I'll have an update Thursday morning.

Jeff Masters

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774. Prgal
Statement as of 5:00 PM AST on August 19, 2009


...Bill remains an extremely dangerous category 4 hurricane...now
moving northwestward...

Interests in the northern Leeward Islands and Bermuda should monitor
the progress of Bill.


For storm information specific to your area in the United
States...including possible inland watches and warnings...please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States...please monitor products issued
by your National meteorological service.


At 500 PM AST...2100 UTC...the center of Hurricane Bill was located
near latitude 19.8 north...longitude 57.6 west or about 335 miles...
535 km...northeast of the Leeward Islands and about 970 miles...1565
km...south-southeast of Bermuda.


Bill is moving toward the northwest near 20 mph...32 km/hr...and
this general motion is expected for the next day or so with a turn
toward the north-northwest forecast by late Friday.


Maximum sustained winds are near 135 mph...215 km/hr...with higher
gusts. Bill is a category four hurricane on the Saffir-Simpson
scale. Some additional strengthening is possible during the next
couple of days.


Bill is a large tropical cyclone. Hurricane force winds extend
outward up to 85 miles...140 km...from the center...and tropical
storm force winds extend outward up to 230 miles...370 km.


The latest minimum central pressure reported by an Air Force Reserve
hurricane hunter aircraft was 947 mb...27.96 inches.


Large swells associated with Bill will be impacting the islands of
the northeast Caribbean Sea during the next day or two. Large
swells associated with Bill should also begin to affect Bermuda and
portions of the eastern coast of the United States Friday and
Saturday.


...Summary of 500 PM AST information...
location...19.8n 57.6w
maximum sustained winds...135 mph
present movement...northwest or 305 degrees at 20 mph
minimum central pressure...947 mb


the next advisory will be issued by the National Hurricane Center at
1100 PM AST.


$$
Forecaster Blake
Member Since: Posts: Comments:
I am not saying that the NHC should not move the cone westward to include these locations.

My point is they really better be entertaing the fact that bill could SIGNIFICANTLY impact the U.S. wheras they have been saying all along that this would remain out at sea and not affect the U.S. other than just minor wave action and beach erosion.

Making a decison such as this would significantly increase national media coverage and creat a sense of panic. We all in here are very well aware of the situation at hand, however I would imagine the average person has NO clue what Bill is doing.
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I
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Quoting stormwatcherCI:
After Ivan in 2004 before the supermarkets could open or ships could bring in goods a lot of the local people were glad for the front yard chickens(NOT ME).


Or the backyard dog? :(
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Member Since: July 1, 2008 Posts: 13 Comments: 7436
Hey Atmoaggie: Are you adding subliminal messages? Only getting one word at a time!! lol
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lol... just noticed 456 had the imaged linked to that FTP server.
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next page..
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Maggie... were on the next page..

Good idea though
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2
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Quoting BahaHurican:
LOL..... I mentioned the Cayman front yards because they've been "featured" in the blog recently...... those front yard chickens don't show up in Nassau same way any more.....
After Ivan in 2004 before the supermarkets could open or ships could bring in goods a lot of the local people were glad for the front yard chickens(NOT ME).
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page
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761. IKE
456...please delete...

Not sure if getting to the next page will help...
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Quoting atmoaggie:


456, you need to fix this.
Do not embed anything from a NOAA ftp server. Copy it to some image hosting site and do it, if you must have the image.


It will keep hitting it to maintain the image on this blog.
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on
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I'm not getting the pop up anymore.
Member Since: July 1, 2008 Posts: 13 Comments: 7436
it
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W456

Please delete post 717.
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Quoting seminolesfan:
Come on reed, don't be so hard on yourself.


No no no... lol.. Sorry I am I was receiving ti to.. weird.
Member Since: July 1, 2008 Posts: 13 Comments: 7436
get
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Quoting atmoaggie:

Post 717 is the problem


Thanks.
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us
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Quoting lovesdanger:
people cant you see the headlines for friday cat 5 dangerous hurricane bill heads for the big apple...it sounds like a movie ..


TWC has had that scenario on "it could happen tomorrow" I think!
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Let
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Quoting hahaguy:
Who posted a link or image that needs you to type in a password ?
Every time I refresh it keeps popping up.

Post 717 is the problem
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Quoting atmoaggie:
Someone needs to pull down whatever is coming from ftp.aoml.noaa.gov. That is an ftp server that has limited number of allowable connections. People that need to access that server to do their job will not be able to get in.


Hehe... I was wondering about that too... quite interesting that I don't yet see any links on this page pulling out that FTP server.
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Quoting seminolesfan:
It's not limited to the Caymans. There are plenty of front yards in Miami with chickens, too. It isn't the nice front yards in the nice neighborhoods, but the chickens are pretty friendly.
LOL..... I mentioned the Cayman front yards because they've been "featured" in the blog recently...... those front yard chickens don't show up in Nassau same way any more.....
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Quoting MobileMob:

The pigeon seems not bothered at all...
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Quoting reedzone:


I am too weird...
Come on reed, don't be so hard on yourself.


{edit:Before I get flamed; Yes, i changed his quote; Yes, it is a joke; No, you don't need to get bent out of shape}
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Who posted a link or image that needs you to type in a password ?
Every time I refresh it keeps popping up.
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And if they didn't warn of a landfall in NE and it happened? It would be bigger than the FEMA broohaha over Katrina.
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Quoting IKE:
530 Sorry, max 50 users -- try again later



Somebody has linked something that needs to delete it.

Like I said. That is the message others that actually need to access that server are getting right now, too.
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How odd, I am not getting the pop-up...
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Quoting TexasHurricane:


Maybe something that developes in the Carribean,maybe...?


IDK... here is a question for whoever can answer it..
How can you tell if there is an area of low pressure? Can you physically see that on a satellite loop?
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Quoting Weather456:


This is the cause of the login popup.
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736. IKE
530 Sorry, max 50 users -- try again later



Somebody has linked something that needs to delete it.
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Quoting Weather456:


456, you need to fix this.
Do not embed anything from a NOAA ftp server. Copy it to some image hosting site and do it, if you must have the image.
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Quoting Floodman:


LOL, I like you...you're funny


Like you too, Floodman. Taking a break.
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.
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732. IKE
Quoting CybrTeddy:
Anyone else getting a popup about a password? Strange.


Yes....scared the you-know-what out of me...not sure what's going on...
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Quoting Orcasystems:


Landfall locations.. NY is in play
next ya will be telling me its coming to toronto as a gully washer
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Quoting CybrTeddy:
Anyone else getting a popup about a password? Strange.


I am to.. weird...
Member Since: July 1, 2008 Posts: 13 Comments: 7436
You have to consider the NHC's spot when considering a shift westward with the cone. This would put places such as Boston and NYC in the cone.

So far, the national media coverage has for the most part be nonexistent on Bill, other than in the weather updates.

IF you start considering the ramifications of even a CAT 2 hurricane striking NYC or Boston, evacuations would creat MASS panic.

The NHC has to be very careful in what it does with that cone....
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Quoting BahaHurican:
I'd have thought a farm, or even the front yard of certain Cayman Islanders' residences, might have been a more effective place to look, myself.
It's not limited to the Caymans. There are plenty of front yards in Miami with chickens, too. It isn't the nice front yards in the nice neighborhoods, but the chickens are pretty friendly.
Member Since: Posts: Comments:
Someone needs to pull down whatever is coming from ftp.aoml.noaa.gov. That is an ftp server that has limited number of allowable connections. People that need to access that server to do their job will not be able to get in.
Member Since: Posts: Comments:
Anyone else getting a popup about a password for Authentication ? Strange.
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Quoting szqrn1:


yea I was looking at that too.... that would be too soon to be the new wave developing.


Maybe something that developes in the Carribean,maybe...?
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Quoting weathersp:


Hey look I'm on that map.... crap.


Welcome to the club!

I'm going to take a break and come back later.

New mantra for today:

"West, North, West, North, Wobble, Wobble."
repeat 3x and breathe
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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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