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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Hey guys whats up with this Herbert Box theory I heard on here today..
Member Since: Posts: Comments:
Quoting Tazmanian:
guys can we get back to bill???


Gone Fishing
Member Since: July 14, 2006 Posts: 0 Comments: 1144
Quoting Tazmanian:
guys can we get back to bill???

Get back to Bill? I don't want him anywhere near me. I'm stuck on a island with 8 million residents and 12 million tourists. Many of them French(not that there's anything wrong with them). you can have Bill!(By the way Taz, always thought you were a cool guy.Still do)
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Quoting IKE:


Survivor....




Hurricane on NY, I think.


Wasn't it Hurricane on NOLA but they never showed it because 2 days before airing it Hurricane Katrina made landfall so they showed it 2 years later
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1770. IKE
Quoting medicroc:

Me and my wife have had only one fight in 16 years. Started in 1992 and is still going on!


Survivor....


Quoting HopquickSteve:
What was season 1, episode 1 of "It Could Happen Tommorow"?


Hurricane on NY, I think.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
1769. sctonya
OK I have to have the graphics...what is the website?????

Please, please, please???? Orca?? PcolaDan??
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Quoting hunkerdown:
wouldn't that be 17 years ?

Who's counting.And whats the point It's like counting the wnw/nw jogs of Bill. Ah,let me stop she may be reading this.Shhhhh!
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guys can we get back to bill???
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Quoting Orcasystems:


Blog is all blocked up


The one and only time you hope the XTRAP is right? LOL
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It has been a very informmative and fun night! Alot of intelligent thinkers who actually have passion and compassion for the tropics and it residents. Hope everyone has a safe and blessed night!
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Oh and is it just me or is the trof hanging a little too far north for my comfort?
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1763. KEEPEROFTHEGATE (Mod)
Quoting lovesdanger:
storm w sir i already said the same info you are saying erlier this evening from a friend a met i spoke to in bermuda..he told me trough is very weak not as strong as they thought it would be and it was bad news for new york..sir im really concerned everything he said so far to meis true and he also said they would issue a hurricanr watch late friday for the new york area and the ne east..it seems he knows what hes talking about sir and you have a good evening..
just dont panic follow advice of local auth regarding the matter take all precautionary measure if odered to do so the last thing we need is mass panic things can and will change wait till 29n 68w to know more
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1762. centex
Note: When puttng in the forecast track to loop be aware it may be new track, like now, and not the previous forecast. So since they update each 6 hours it's not a very good way to determine if they are doing good. You need to look at previous cast and compare to current.
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Quoting PcolaDan:

I don't think that's the one to turn Bill. There is a bigger one over land still that will do that. I think that's what he said previously.

Here's what he said:
One last touch on Bill...recent satellite loop imagery would indicate he is beginning to recover from the EWRC. I've been analyzing water loop imagery, and here's my take...that first shortwave that was pulling on him is bye, bye. He is now heading for that second shortwave off the east coast. Looking at it, he could eat that too. I'm thinking once he gets closer to 65W, he should begin to slow his forward speed. I would almost look for another shift left in the guidance models.

I'll have another synopsis in th
e a.m.
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What was season 1, episode 1 of "It Could Happen Tommorow"?
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Quoting medicroc:

Me and my wife have had only one fight in 16 years. Started in 1992 and is still going on!
wouldn't that be 17 years ?
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Quoting IKE:


Fight? oops....hope you patched things up.

Me and my wife have had only one fight in 16 years. Started in 1992 and is still going on!
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Quoting Alockwr21:
So Storm thinks Bill might have a chance at eating the second wave that's supposed to curve bill??

I don't think that's the one to turn Bill. There is a bigger one over land still that will do that. I think that's what he said previously.
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Quoting IKE:


You're right.

I remember because I was supposed to be on a cruise there at the same time. Wife and i had a fight and we canceled the trip
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No wonder Bill is so large. He's getting full eating all these shortwaves :)
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.
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1743. IKE
Quoting medicroc:

There was also a reading of 45kt winds. From where? A carnival Cruise ship.


You're right.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
So Storm thinks Bill might have a chance at eating the second wave that's supposed to curve bill??
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1741. Droab92
Mainly a "lurker/listener", but recently posted my first blog to celebrate or mourn the anniversary of my '92 Andrew experience in Cutler Ridge. If you haven't seen a storm yet, this will give you a vivid idea in whats in store for you if Bill is coming your way. Hope you enjoy.

I do have one question. I just looked at the forecast track of Andrew, and trying to remember what caused it to make the hard left after it was destined to go out to sea? Was it a building Bermuda high I am hopeful someone could enlighten me. The location of Bill is very similar. Nite
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Lets wait a few days for the all clear for anywhere on the east coast. This is a big boy and spinning its bottom off. It only needs to get somewhat close to make for a bad day with those winds.
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Quoting PcolaDan:


eeewwwwww

only kidding. Dramatic effect. I really never go to the bathroom.
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Quoting rareaire:
conch your phone working?
yeah I am upstairs.. I'm packin my red sleeping bag and my old wooly pully...
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Quoting IKE:


And there will be a few that drown by not listening to the proper authorities about staying out of the water.

There were 3 people out in a boat in the GOM when Claudette was out there, approaching the panhandle. Two of them were rescued. One still hasn't been found.

There was also a reading of 45kt winds. From where? A carnival Cruise ship.
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Based on what Ive seen I think the storm will pass about 100-150 miles east of Nantucket leaving them wil minimal TS winds, I think the worst case scenario for New England is a Cat 2 strike on Marthas Vineyard, whats everyone thinking?
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1734. Melagoo


Looks like Bill is performing an EWR ... what a big storm!
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1733. centex
Bill has moved to E of track to back on track by moving W recently. So W wobble not significant yet.
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Quoting medicroc:

Put it to you this way. Sort of like I disregarded the advice "when you visit, don't drink the water". Hope that clears it up for ya;)


eeewwwwww
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#1723

where did you get the pic of Geraldo?
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1730. rv1pop
Quoting SCwannabe:


Do we all need to know about every little wobble? We obviously are all looking at the same satellite pictures!!


Pardon a new-bee with family in the affected area. I think "what was that?" and immediately I see : "There was a wobble"! and I think OK nothing to worry about.
Show me a pressure map and T-Heads and I will get there brush fire trucks ready. But a tropical storm is Hebrew to me.
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My NC weatherman just said no problem with Bill being near NC. Just a few waves and rip currents bad on weekend.
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1728. IKE
Quoting Alockwr21:
Our local met here in NC just said "life threatening rip currents" over the weekend, coastal flooding and some beach erosion for the outer banks...even though the center will be a couple hundred miles away!


And there will be a few that drown by not listening to the proper authorities about staying out of the water.

There were 3 people out in a boat in the GOM when Claudette was out there, approaching the panhandle. Two of them were rescued. One still hasn't been found.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
conch your phone working?
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Quoting lopaka001:

Man! you kill me with those graphics!lol
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Quoting Orcasystems:


I don't even want to know how I should take that remark

Put it to you this way. Sort of like I disregarded the advice "when you visit, don't drink the water". Hope that clears it up for ya;)
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Our local met here in NC just said "life threatening rip currents" over the weekend, coastal flooding and some beach erosion for the outer banks...even though the center will be a couple hundred miles away!
Member Since: Posts: Comments:

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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.

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