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

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

Share this Blog
2
+

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

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: 674 - 624

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 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46Blog Index

I am thinking that the NHC has been dead on so far !!
Member Since: Posts: Comments:
Looks like the NHC is becoming east of the guidance envelope.

Member Since: Posts: Comments:
Looking at the new models, anyone that says the North East is off the hook really needs to readjust their thinking. They need to look out for Bill, it could easily be a Category 2 or 3 if it makes it up there.
Member Since: July 8, 2005 Posts: 259 Comments: 24579
Quoting Orcasystems:


Landfall locations.. NY is in play


Hey look I'm on that map.... crap.
Member Since: Posts: Comments:
Quoting klaatuborada:


Why thank you so much! "let the east coast deal", how lovely! I didn't know you held us in so high regard!


Shhhh...don't agitate the trolls...if you do it will start to sound like a monkey house in here...
Member Since: Posts: Comments:
Quoting HurricaneCavalier:


Yeah most snobs have extensive hate lists.


It has nothing to do with being a snob. It has everything to do with trying to learn a few things and weeding through the garbage.
Member Since: Posts: Comments:
Quoting K8eCane:
Im in southeast coastal NC and our local mets are all over this thing. Never hurts to be prepared and if you arent it isnt becuz food lion doesnt have batteries and water shoved in your face today
Ah, Food Lion..... those were the days.....

U know no hurricanes hit NC or SC the entire 3 years I was living in NC????

LOL

Member Since: Posts: Comments:
Quoting seminolesfan:
Baby chickens...on a weather blog... Nothing here surprises me anymore so, sure, why not!


Watch out, definately don't go messing with Laboy's chick. We were reassured the other day or about a week ago that this is not E-Harmony.
Member Since: Posts: Comments:
For those who have not read yet,
I posted my first blog today. Comments would be appreciated if you have not read yet

Thanks!

reedzone: looks like one of the GFS ensembles takes Bill towards Delaware/NY, and making landfall! Hope other models do not shift left like that!
Member Since: June 29, 2009 Posts: 13 Comments: 5315


Landfall locations.. NY is in play
Member Since: October 1, 2007 Posts: 81 Comments: 26516
"...just because he is right it makes him a newcaster...you people are just mad because he hit bill better then the nhc did...good job reedzone.."

for one thing i am joking when i call him a newcaster...

but more to the point...how are you declaring him to be "better than nhc" when the storm is still way out to sea? no prediction about hitting the US/Bermuda or not is correct yet.
Member Since: Posts: Comments:
Out for now, bbl :)

Be nice everyone
Member Since: Posts: Comments:
GOES now in SRSO.
Member Since: Posts: Comments:
Quoting Floodman:


After clearing a few from last year out I have 97...the list just extends itself is all


Thanks flood. I really enjoy the blog but I have gotten really handy with the ignore user. It's really a pain when you are trying to learn something here and keep getting all the *R*p.
Member Since: Posts: Comments:
Quoting HurricaneCavalier:
Somebody said this blog was a good spot to pick up chicks.
Baby chickens...on a weather blog... Nothing here surprises me anymore so, sure, why not!
Member Since: Posts: Comments:
Quoting HurricaneCavalier:
Somebody said this blog was a good spot to pick up chicks.


That was me!
Any luck yet?

You may want to try a new icon!
Member Since: Posts: Comments:
Quoting tramp96:



What do you think it is going to do?


My current thinking right now, might change is models continue to westward shift tonight.
Photobucket
Member Since: Posts: Comments:
654. slavp
Quoting jeffs713:

And that joyous whooping you hear is the people at Accuweather rejoicing about a *possibility* of a storm *maybe* impacting the NEUS.
LOL You mean their 1 out of 10?
Member Since: Posts: Comments:
Quoting Crawls:
Does anyone know if there is a limit on how many "ignores" you can have. My list is almost full!!!


After clearing a few from last year out I have 97...the list just extends itself is all
Member Since: Posts: Comments:
Quoting reedzone:
Latest GFS Ensebles have lots of landfall in the Northeast..


And that joyous whooping you hear is the people at Accuweather rejoicing about a *possibility* of a storm *maybe* impacting the NEUS.
Member Since: Posts: Comments:
Again, my forecast does NOT make landfall in the USA. It's a straight up good forecast for right now, but if trends continue showing a weaker trough pulling more northward in Canada, I might have to nudge it more to the left unfortunately.
Member Since: Posts: Comments:
Quoting lovesdanger:
i for one hope bill continues further west that will spare bermuda from a major hit...great news let the east coast deal with it..bill will definitely be a cat 5 sometime thursday..


Why thank you so much! "let the east coast deal", how lovely! I didn't know you held us in so high regard!
Member Since: Posts: Comments:
Quoting Crawls:
Does anyone know if there is a limit on how many "ignores" you can have. My list is almost full!!!


Who's is left to post. when you look at the blog is there like three people posting. j/k
Member Since: Posts: Comments:
Quoting lovesdanger:
i for one hope bill continues further west that will spare bermuda from a major hit...great news let the east coast deal with it..bill will definitely be a cat 5 sometime thursday..


Wow, what great attitude. "Let it be someone else's problem."

What a joke.
Member Since: Posts: Comments:
Quoting reedzone:
Latest GFS Ensebles have lots of landfall in the Northeast..



Your boring us now. Wait a few days then start talking about the East coast.
Member Since: Posts: Comments:
"If a tree falls in a forest and no one is around to hear it, does it make a sound"

Logically the question that follows is...

If everyone here has apocalyps2 on ignore is he really posting.......?
Member Since: Posts: Comments:
Those one minute updates are awesome.
Thanks for the link
Member Since: Posts: Comments:
Quoting centrfla:
frances in 04 is approximately at the same place as bill is now (19.0 56.8)...what makes the difference in their forecast track????


w/o even reading your name i had a good idea where you were from... there are quite a few differnces in the set ups between the two storms, but the biggest would be the gaping weekness and it not closing off would be my guess
Member Since: Posts: Comments:
Wobble maybe but, Bill is right of the forecast track for now.
Member Since: Posts: Comments:
Does anyone know if there is a limit on how many "ignores" you can have. My list is almost full!!!
Member Since: Posts: Comments:
Quoting centrfla:
frances in 04 is approximately at the same place as bill is now (19.0 56.8)...what makes the difference in their forecast track????


And bills is a lot bigger boy.
Member Since: Posts: Comments:
Quoting rwdobson:
@625, hmmm...northeast is definitely not out of the woods. I'm back to being a NewCaster with you reed...


It's not about being a wishcaster or Newcaster.. I warned people that models do change and that they might be overdoing the "monster trough" like they did with other storms. People can't let there guard down on Bill, even when the models were a bit East of Bermuda, I told people in the Northeast to watch it. I forecast by pattern, steering and some models. The NHC will definitely shift there cone to the left by 5 p.m.
Member Since: Posts: Comments:
Quoting reedzone:
Latest GFS Ensebles have lots of landfall in the Northeast..



Not good.
Member Since: Posts: Comments:
frances in 04 is approximately at the same place as bill is now (19.0 56.8)...what makes the difference in their forecast track????
Member Since: Posts: Comments:
633. Prgal
@630 LOL!!!!
Member Since: Posts: Comments:
Quoting reedzone:
Latest GFS Ensebles have lots of landfall in the Northeast..



Now Stop That!
Member Since: Posts: Comments:
Quoting philliesrock:
1-minute satellite updates for Bill...pretty cool stuff:

Link


Wobble, wobble, wobble.

It's going North, no West, no North, now West.

I love this stuff.
Member Since: Posts: Comments:
@625, hmmm...northeast is definitely not out of the woods. I'm back to being a NewCaster with you reed...
Member Since: Posts: Comments:
Quoting sfla82:
Everyone who forecasted alot of rain for S Fla from the remenants of Ana, where way off!!!! No rain at all!!!! LOL! Go figure.


I'm actually outside grillin and chillin, it's overcast, breezy and not too hot, oh and I don't have to watch Bill anymore, so it's a good day.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Im in southeast coastal NC and our local mets are all over this thing. Never hurts to be prepared and if you arent it isnt becuz food lion doesnt have batteries and water shoved in your face today
Member Since: Posts: Comments:
Latest GFS Ensebles have lots of landfall in the Northeast..

Member Since: Posts: Comments:
Quoting CaneWarning:


Tampa was even told we'd get over an inch today.

over to the west side of defuniak...just clouds and sun
Member Since: Posts: Comments:

Viewing: 674 - 624

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 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46Blog 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