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

By: Dr. Jeff Masters , 03:28 PM GMT on Αύγουστος 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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1322. HadesGodWyvern (Mod)
90 knots (10 mins) is around 105 knots but the JMA intensity is lower than other RMSC

Vamco is around 115 knots (135 mph)
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Quoting cajunmoma:
reedzone...from the image you posted it appears that you think the weakness between the two highs will pull bill north. Is this what you are seeing, and is it possible that the high will keep him down and move west?? I ask this as an amature, our local stations haven't mentioned much about a frontal boundary...only a strong high building to the east of us around sunday. I live in louisiana, so I am a little confussed at the moment??? Amy response is welcomed, just trying to understand the events that are unfolding.


Correct! He is pulling northwest through the weakness and a trough should recurve him near New England. I'm looking for landfall on NS, Canada.
Member Since: Ιούλιος 1, 2008 Posts: 13 Comments: 7365
Quoting WxLogic:
Well with this DLM High strengthening out in the SE US coast... I see Bill making more of a NNW turn and getting it closer to Bermuda in the next 12HR to 24HR.



What I'm almost seeing is that the High preventing much progress of Bill to the E US coast and once this high weakens enough to slide underneath the trough... then the trough will do it's job at "kicking" Bill to the N and then NNE. I believe this is what NHC might be hinting towards and not having their forecasted track shift W and actually taking it closer to Bermuda.


I look at that and I can see Bill getting stalled by that high, then getting pulled right up the east coast and not turning when everyone wants it to.

I've seen it happen before. But I'll wait until Friday. No sense trying to predict now. Bill will do what Bill's gonna do.

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Quoting StSimonsIslandGAGuy:
Both Carols are too far north and too far east, presslord :) Georgia is where the REAL south begins :)


yea ...but y'all have a Governor named "Sonny"...although...I suppose I don't wanna be holding my Governor up as an example of much...
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1316. HadesGodWyvern (Mod)


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1315. GatorWX
Bill looks just like Palmoma to me on satellite. 6
Quoting HadesGodWyvern:
Japan Meteorological Agency
Tropical Cyclone Advisory #25
TYPHOON VAMCO (T0910)
9:00 AM JST August 20 2009
=========================================

SUBJECT: Category Four Typhoon Minamitori-sima

At 0:00 AM UTC, Typhoon Vamco (945 hPa) located at 18.6N 157.4E has 10 minute sustained winds of 90 knots with gusts of 130 knots. The typhoon is reported as moving north slowly

RSMC Dvorak Intensity: T6.0

Storm-Force Winds
================
70 NM from the center

Gale-Force Winds
===============
200 NM from the center in northeastern quadrant
160 NM from the center in southwestern quadrant

Forecast and Intensity
=====================
24 HRS: 19.8N 157.1E - 100 knots (Cat 4/Typhoon)
48 HRS: 22.4N 156.1E - 100 knots (Cat 4/Typhoon)
72 HRS: 22.4N 156.1E - 95 knots (Cat 4/Typhoon)


What are the one minute sustained? Do they only give 10 min at JMA?
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Quoting StSimonsIslandGAGuy:
My mouth to god's ear? I didn't bring anything up like that, I was just talking about the unlikelyhood of a serious New England impact from Bill. What is this God's ear stuff coming from?


Dude! It's just an old saying...means...I hope what you say comes true...
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Thanks Press! Seeing as how I teach high school I am sure my students are appreciative I am not a complete dingbat ;)

They are sick to death of Bill. We spend 15-20 minutes on it every day.

And the unit we are on is geology :) (I like weather better)
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reedzone...from the image you posted it appears that you think the weakness between the two highs will pull bill north. Is this what you are seeing, and is it possible that the high will keep him down and move west?? I ask this as an amature, our local stations haven't mentioned much about a frontal boundary...only a strong high building to the east of us around sunday. I live in louisiana, so I am a little confussed at the moment??? Amy response is welcomed, just trying to understand the events that are unfolding.
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1309. NARCHER
recon noaa just reported 939 mb
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Quoting P451:


Sooo....we're not allowed to discuss the storm on our terms?

Wow, okay. Let me know what other guidelines you may have for us so we can make sure not to upset you in the future.
discuss facts, nit your terms as you put it or yur wishes. You also need to knwo and understand to discuss if you truly want to discuss facts.
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Quoting P451:


I disagree. It clearly moved NW for hours today, then WNW-erly for about 90 full minutes, and then shot back NW the past hour. Only the past hour has the eye become messy looking. I don't think that WNW movement was part of an impending EWRC because at the same time the east and north side of the storm became eroded. Something else was at work.

If you look at the past history of this storm it has frequently made course changes every few hours. Post 1202 shows some of those nicely (second image).

Not saying I'm right but it is what I see in the loops. It was a very steady WNW motion not just a quick jog or wobble.
you are looking for a straight line which it is not doing, as most majors don't. The wobble considerable. Don't follow the wobbles but instead the average of the movement, which has been NW for hours now.
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1306. WxLogic
Well with this DLM High strengthening out in the SE US coast... I see Bill making more of a NNW turn and getting it closer to Bermuda in the next 12HR to 24HR.



What I'm almost seeing is that the High preventing much progress of Bill to the E US coast and once this high weakens enough to slide underneath the trough... then the trough will do it's job at "kicking" Bill to the N and then NNE. I believe this is what NHC might be hinting towards and not having their forecasted track shift W and actually taking it closer to Bermuda.
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1305. Makoto1
Well this "Monster trough" decided to pick up remnant moisture of Claudette... And I heard reports of floating cars in parts of downtown Dayton, Ohio. We have 2.64 inches of rain here so far today and it's raining again, reports of funnel clouds north of town, and there's still a tornado watch here until 1AM. Been one heck of a night so far... Feels like Florida out there really.
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Quoting carolinamomma:
NC is better we're on top ;)

I am not 'coastal' but I am 'eastern' NC- quite close to Greenville. At this point I am not worried, but am aware that things can change overnight.

We are 80% prepared. Nothing a quick trip to walmart and run around the yard picking up wouldn't remedy. Although if Bill 'eyed' us down... I would go visit the pretty mountains for the duration of Bills stay! I was in Raleigh through Fran, and it was the scariest thing EVER. Pitch black, trees cracking all around.. stars twinkling as the eye passed over knowing good and well all hell was going to break lose again... thanks but no thanks!


gee...you're pretty smart...for a North Carolinian ; )
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there are no guarentees with mother nature she will do what she wants so just cuase the models say bill will go east doesnt always mean mother nature will listen so living here in southeastern mass always think what if bill gets a mind of his own and just plows thru so im listerning to what everyone is saying here and watching the maps learning to understand them
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1302. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #25
TYPHOON VAMCO (T0910)
9:00 AM JST August 20 2009
=========================================

SUBJECT: Category Four Typhoon Minamitori-sima

At 0:00 AM UTC, Typhoon Vamco (945 hPa) located at 18.6N 157.4E has 10 minute sustained winds of 90 knots with gusts of 130 knots. The typhoon is reported as moving north slowly

RSMC Dvorak Intensity: T6.0

Storm-Force Winds
================
70 NM from the center

Gale-Force Winds
===============
200 NM from the center in northeastern quadrant
160 NM from the center in southwestern quadrant

Forecast and Intensity
=====================
24 HRS: 19.8N 157.1E - 100 knots (Cat 4/Typhoon)
48 HRS: 22.4N 156.1E - 100 knots (Cat 4/Typhoon)
72 HRS: 22.4N 156.1E - 95 knots (Cat 4/Typhoon)
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
KEH I'm not quite sure what you mean :)
Not sure if you are j/k, but... from your mouth to God's ear, just does not work for a blog.
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reed -- I can see my path on my screen.
Member Since: Ιούνιος 29, 2009 Posts: 13 Comments: 5313
NC is better we're on top ;)

I am not 'coastal' but I am 'eastern' NC- quite close to Greenville. At this point I am not worried, but am aware that things can change overnight.

We are 80% prepared. Nothing a quick trip to walmart and run around the yard picking up wouldn't remedy. Although if Bill 'eyed' us down... I would go visit the pretty mountains for the duration of Bills stay! I was in Raleigh through Fran, and it was the scariest thing EVER. Pitch black, trees cracking all around.. stars twinkling as the eye passed over knowing good and well all hell was going to break lose again... thanks but no thanks!
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1298. amd
Quoting StSimonsIslandGAGuy:
However I am not excluding the possibility of a Halifax Howler.


one thing that concerns me about the storm's potential impact onto Canada is the high rate of speed that Bill will be moving because of the possible north/south orientation of the trough. It could be possible, depending on the exact orientation of the trough, that Bill may be moving at a high rate of speed (approx. 50 mph plus as it approaches Canada), meaning that the amount of time over the much cooler waters of the north Atlantic may only be a few hours.
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VARob, thank you but that wasn't it. The page is actually black and green. I just don't have the link anymore? Does anyone know the website that has hurricane recon reports on it amongst other things that is black with green letters?
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1295. tramp96
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Quoting fwblinda:
Press -
I am going to have to get you a T-shirt that says something like "there is no, are no Carolinas!!"


Linda...I can pose in it...wet...to raise funds for Portlight!
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Quoting StSimonsIslandGAGuy:
I still doubt a serious New England impact. Bill will be moving around 30 kts and New England will be on the left, weaker side. So I doubt there will be much impact.
I have to agree. It looks like right now that New England may only get TS winds and alot of rain.. but you never know in the tropics.
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1290. Prgal
Sorry about the double post. Dont know why it happened.
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Quoting Ossqss:



What if you owned homes in both? Would you not then be from Carolina? LoL


many people do...and, no...ya still have to pick one...
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Quoting StSimonsIslandGAGuy:
I still doubt a serious New England impact. Bill will be moving around 30 kts and New England will be on the left, weaker side. So I doubt there will be much impact.
From your keyboard to God's eyes.
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1286. Prgal
Quoting stormwatcherCI:
Anyone know what conditions are in the northern islands right now ?

Here in the northern part of PR things are pretty quiet. We are having occasional showers but that's about it. Haven't seen the wave action though.
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Press -
I am going to have to get you a T-shirt that says something like "there is no, are no Carolinas!!"
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1284. Ossqss
Quoting presslord:


South of Broad...just came out...there is no such place as "Carolina"



What if you owned homes in both? Would you not then be from Carolina? LoL
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Quoting KimberlyB:


I don't always agree with you Reed, but I will stand up and say your NOT a "wishcaster." There is a big difference between how you present your opinions and views versus someone like, say, apocalypse (or however they spell it.)


Thanks, I really do try my best to get it right. Besides, i'm only 20 and a 1/2 years old :p
Member Since: Ιούλιος 1, 2008 Posts: 13 Comments: 7365
1281. Prgal
Quoting stormwatcherCI:
Anyone know what conditions are in the northern islands right now ?

Here in the northern part of PR things are pretty quiet. We are having occasional showers but that's about it. Haven't seen the wave action though.
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Quoting carolinamomma:
Haven't read that one yet. I know theres not such place as Carolina.... but NorthCarolinamomma was too long for me :)
I am curious. Are you coastal? If so, are you concerned about Bill? Do you have a hurricane supply shelf - and do you have books on it!
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Quoting carolinamomma:
Haven't read that one yet. I know theres not such place as Carolina.... but NorthCarolinamomma was too long for me :)


Very nice! I'm quite proud of you...
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I worry about Bill on the East Coast, and also of TWC, and Alexandra Steele. She is suffering from a bad eating disorder. She's skinner than a-last-season-of-Growing-Pains Tracey Gold, and it wasn't always so. It's shocking that they allow her on the air...she's skin and bones.
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Haven't read that one yet. I know theres not such place as Carolina.... but NorthCarolinamomma was too long for me :)
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1275. HadesGodWyvern (Mod)
782
TCNA21 RJTD 200000
CCAA 20000 47644 VAMCO(0910) 13186 11574 12244 260// 93504=

0:00 AM UTC August 20

TY VAMCO (0910)
18.6N 157.4E
Dvorak Intensity: T6.0

---
Same Dvorak Intensity as Bill now, I believe
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1274. 7544
is the the ull trying to fizzle out and moving n. bills moving at 22 mph and getting larger in size the gap in the two highs look close together than they did in early runs could he fit thru there or approch it and stop and wait for the trof to get him could taz be right
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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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