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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Quoting iluvjess:
I hope that the Westward shift in the model guidance is just that and not a new trend. How mant times have we seen one nudge left followed by more and more shifts towards the West.


Ohh no,, I am sure you don't have to be too worried, So far it has followed the models pretty well. Saty vigilant always, but I can tell you that the chances of Bill hitting th East Coast are diminishing by the hour.. If you live in Nova Scotia then you should be worried. My prayers got to them and I am gratefull we did not get it :o)
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I'd be interested to hear what StormW or Dr Masters thought about the frontal explanation Frank from Accuweather gave.
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Quoting apocalyps2:


It would be very logical if Billy West surprises us at least once.


I still haven't seen a surprise tactic/ crazy tactic from Bill yet..still wantin, maybe it will be not turnin north on Friday
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Quoting KarenRei:


Yeah, you missed the last meeting. First an earthquake, then birds and snakes and aeroplanes.


Okaty, well that makes more sense, I guess; the birds and snakes that is...got to make it to the meetings! LOL
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Quoting klaatuborada:
18 years ago today and tomorrow, when Bob came up he started to do the old curve as well, but that stalled and brought him right up into us. He was more West to begin with, but....



...we were hoping he'd keep curving out, which was what forecasters at the time were saying was a possibility. My friend and I looked at the weather map and said, that thing is going to come right up and get us. We went shopping that night, by morning there was nothing left in the stores.

Bob was not fun, and not that strong a hurricane. Bill looks like less fun. Please start turning, Bill, please start turning.


Nicto....... :)
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its no Jog.. lets give NHC credit where its due.. since monday they have been saying WNW till Wednesday and they have seemed to nail it.. I am a bit more confident that New York and northern states might be out of the danger.. Not so sure about Bermuda..
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18 years ago today and tomorrow, when Bob came up he started to do the old curve as well, but that stalled and brought him right up into us. He was more West to begin with, but....



...we were hoping he'd keep curving out, which was what forecasters at the time were saying was a possibility. My friend and I looked at the weather map and said, that thing is going to come right up and get us. We went shopping that night, by morning there was nothing left in the stores.

Bob was not fun, and not that strong a hurricane. Bill looks like less fun. Please start turning, Bill, please start turning.
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I think we're going to see another round of intensification here soon with Bill.

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Quoting AllStar17:


When are you going to give up?


When Bills finally dissipated.
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Quoting Floodman:


An earthquake? I thought it was an asteroid impact followed by global thermonuclear war...you know, you miss a few meetings and they re-write the manual on you


Yeah, you missed the last meeting. First an earthquake, then birds and snakes and aeroplanes.
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Quoting WatchingThisOne:
So wind speeds are Cat 3, and minimum central pressure is knocking on the door of Cat 4.

Anyone have a handle on storm surge?

And what ever happened to Total Kinetic Energy? Is the experimental SS scale (in use for 2009) an attempt at capturing that?


Here is the windfield from 3:30 AM EDT this morning. IKE(0-6) = Wind=3.1 Surge/Waves=4.8


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My first blog, for anyone who has not read
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Quoting Weather456:
Hurricane Bill Update

I can see Bill getting close to the NE, probably a bullet braze.


Yep, that's my current thinking.
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what is the white area above the center of Bill?

http://wwwghcc.msfc.nasa.gov/GOES/IHG12-17452009231.jpg

i don't know if my picture will work
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Same thing year after year. Folks put way too much faith in long range forecasts.

1. Always be prepared.
2. Never trust models over 48 hours out.
3. Don't focus on just the black line.
4. Refer to #1.
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Quoting apocalyps2:


It is just a jog.Trend will continue WNW untill friday.


When are you going to give up?
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Hurricane Bill Update

I can see Bill getting close to the NE US, probably a bullet braze.
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Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 19th day of the month at 18:19Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 303)
Storm Number & Year: 03L in 2009
Storm Name: Bill (flight originating in the North Atlantic basin)
Mission Number: 2
Observation Number: 12
A. Time of Center Fix: 19th day of the month at 17:57:30Z
B. Center Fix Coordinates: 19°16'N 56°55'W (19.2667N 56.9167W)
B. Center Fix Location: 601 miles (968 km) to the E (84°) from San Juan, Puerto Rico (USA).
C. Minimum Height at Standard Level: 2,665m (8,743ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 102kts (~ 117.4mph)
E. Location of the Estimated Maximum Surface Wind: 24 nautical miles (28 statute miles) to the NE/ENE (56°) of center fix
F. Maximum Flight Level Wind Inbound: From 134° at 135kts (From the SE at ~ 155.4mph)
G. Location of Maximum Flight Level Wind Inbound: 27 nautical miles (31 statute miles) to the NE (55°) of center fix
H. Minimum Sea Level Pressure: 948mb (27.99 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 11°C (52°F) at a pressure alt. of 3,045m (9,990ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 3,047m (9,997ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 6°C (43°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Open in the southwest
M. Eye Shape & Diameter: Circular with a diameter of 32 nautical miles (37 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 700mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 0.5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 135kts (~ 155.4mph) in the northeast quadrant at 17:48:30Z
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NATIONAL WEATHER SERVICE TAUNTON MA
1219 PM EDT WED AUG 19 2009

HURRICANE BILL IS LIKELY TO PASS WELL EAST OF NANTUCKET SOMETIME SUNDAY. ITS MAIN EFFECTS ON SOUTHERN NEW ENGLAND WILL BE IN THE FORM OF HIGH SURF AND DANGEROUS RIP CURRENTS TO OCEAN BEACHES BEGINNING LATE FRIDAY AND CONTINUING
THROUGH THE WEEKEND.

LONG TERM /FRIDAY THROUGH TUESDAY/...
MEDIUM RANGE MODELS IN FAIR AGREEMENT THIS MORNING THROUGH FRIDAY...THEN WIDE VARIETY OF SOLUTIONS WITH REGARDS TO THE TRACK OF
HURRICANE BILL. ALL MODELS DO KEEP THE HURRICANE OFFSHORE...BUT SOME ARE MUCH CLOSER TO THE COAST THAN OTHERS. ONCE THE HURRICANE PASSES LATE THIS WEEKEND...APPEARS FAIR AND COOLER WEATHER WILL RETURN.

SWELLS ON THE WATERS WILL LIKELY RAPIDLY INCREASE LATER SATURDAY AND CONTINUE THROUGH SUNDAY AS A RESULT FROM BILL. THIS WILL RESULT IN HIGH RISK OF DANGEROUS RIP CURRENTS ON THE OCEAN BEACHES STARTING LATER SATURDAY AND LASTING THROUGH SUNDAY.

CURRENT NHC TRACK KEEPS HURRICANE BILL WELL OFFSHORE...AND ABEAM OF NANTUCKET EARLY SUNDAY. STILL SOME QUESTIONS ON POSITION SO STAY TUNED.
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Quoting apocalyps2:


Ofcourse not just the end of the east coast.


Dr. Masters' Blog Content Rules

Due to the high amount of traffic that Dr. Masters' blog receives, a special community standard has been established for the blog. The following list comprises the "Rules of the Road" for Dr. Masters' blog.

... 3. No monomania.

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Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 19th day of the month at 18:19Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 303)
Storm Number & Year: 03L in 2009
Storm Name: Bill (flight originating in the North Atlantic basin)
Mission Number: 2
Observation Number: 12
A. Time of Center Fix: 19th day of the month at 17:57:30Z
B. Center Fix Coordinates: 19°16'N 56°55'W (19.2667N 56.9167W)
B. Center Fix Location: 601 miles (968 km) to the E (84°) from San Juan, Puerto Rico (USA).
C. Minimum Height at Standard Level: 2,665m (8,743ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 102kts (~ 117.4mph)
E. Location of the Estimated Maximum Surface Wind: 24 nautical miles (28 statute miles) to the NE/ENE (56°) of center fix
F. Maximum Flight Level Wind Inbound: From 134° at 135kts (From the SE at ~ 155.4mph)
G. Location of Maximum Flight Level Wind Inbound: 27 nautical miles (31 statute miles) to the NE (55°) of center fix
H. Minimum Sea Level Pressure: 948mb (27.99 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 11°C (52°F) at a pressure alt. of 3,045m (9,990ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 3,047m (9,997ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 6°C (43°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Open in the southwest
M. Eye Shape & Diameter: Circular with a diameter of 32 nautical miles (37 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 700mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 0.5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 135kts (~ 155.4mph) in the northeast quadrant at 17:48:30Z
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Alright, I am finally getting to put some tracking dots on my cardboard Aquafiina Hurricane Tracking Map. I know it's pretty high tech but, I like to have a hard copy back up.
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Quoting klaatuborada:
Today is the 18th anniversary of Bob, Bill's cousin. Lots of similarities.

I'm on Cape Cod. Bill is big, and a force of nature. Nature doesn't always do what we think it's going to do. I wonder if the Quantum Physics, specifically Schrodinger's Equation can be applied to weather patterns?

As it is now, I'm still watching. This spring and summer so far, most weather that has s'pose to hit here has gone to our West then scooted up North, more Westerly than predicted. It seems to be the pattern. Let's hope not now.
just know that by the time it is as close as it is going to get to cape cod it will be getting torn apart by wind shear over 40 knots... and it would really have to go at least 200 miles more to the west than the national hurricane center predicts for hurricane force winds to occur. im no expert but it just doesn't seem bill should hit cape cod with much force.
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Quoting WatchingThisOne:
Eyewall dropsonde was 85 knots at the surface (98 mph). Saw 125 knots (144 mph) at 1400 ft.


They're going to keep it at the same intensity except for the pressure.
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Quoting Thundercloud01221991:
So we could have anywhere from a 120 knt storm to a 130 knt storm or even as low as a 110?

Most of these think he is fairly close to his peak (except that one ensemble member), but they have been known to be quite wrong frequently and to great extents. Bill is still, believe it or not, a wait and see game.



Those guys up there in Canada and New England usually do not have much of a real idea of what will be coming their way until it is coming and doing so at 60 mph. They just have to doubly err on the side of caution when the threat exists. I don't envy them. I'll take a hurricane coming at me at 15 mph any day over that.
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Quoting juniormeteorologist:
Frank from AccuWeather, has me kinda suspicious about that trough..He said Bill may be hot enuf to push the trough around instead of the trough pushin Bill around


He's pretty cool, accurate when it comes to severe weather, but sometimes off with tropical activity.
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Quoting TampaSpin:
Gettin might close to the Coastline....HUM.



Looks to be another "tropical" area of concern in the GOM at the end of this....
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Quoting P451:
12KM WV



Wow so looks like this thing is going at about 325 degrees which is a little more North of NW.. I am glad to see it take such a sharp turn to the NW.. its a bit of a relieve.
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Eyewall dropsonde was 85 knots at the surface (98 mph). Saw 125 knots (144 mph) at 1400 ft.
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390. bcn
Quoting yonzabam:
Let's suppose Bill makes it to borderline cat 4/5. How strong do you think it would be by the time it reached Nova Scotia?


Tropical Storm, in the worst case, Cat1.
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Quoting Thundercloud01221991:
So we could have anywhere from a 120 knt storm to a 130 knt storm or even as low as a 110?


They're going to keep it at 135mph
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Quoting Floodman:


An earthquake? I thought it was an asteroid impact followed by global thermonuclear war...you know, you miss a few meetings and they re-write the manual on you


I didn't get the memo either...
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Quoting iluvjess:
I hope that the Westward shift in the model guidance is just that and not a new trend. How mant times have we seen one nudge left followed by more and more shifts towards the West.


Well, about half the emsemble call for US landfall where only two did not too long ago.
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Quoting WatchingThisOne:
So wind speeds are Cat 3, and minimum central pressure is knocking on the door of Cat 4.

Anyone have a handle on storm surge?

And what ever happened to Total Kinetic Energy? Is the experimental SS scale (in use for 2009) an attempt at capturing that?


Winds speeds are Cat 4 and the pressure is usual cat 4, what are you referring too?
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385. slavp
Quoting lurkn4yrs:



I just went to there.. For a second I thought it was Drew Carey giving the info.. scared me..
LOL!!!
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Today is the 18th anniversary of Bob, Bill's cousin. Lots of similarities.

I'm on Cape Cod. Bill is big, and a force of nature. Nature doesn't always do what we think it's going to do. I wonder if the Quantum Physics, specifically Schrodinger's Equation can be applied to weather patterns?

As it is now, I'm still watching. This spring and summer so far, most weather that has s'pose to hit here has gone to our West then scooted up North, more Westerly than predicted. It seems to be the pattern. Let's hope not now.
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Quoting yonzabam:
I think Bill will turn out to be the biggest of the season.

But then, he got to cat 4 strength over water that was only slightly above the usual minimum for cyclogenesis, so you never know.



I hope He is the only big one of season; one of these is enough....
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Quoting tramp96:
Might want to watch Frank Strait on AccuWeather. He is talking about how the heat from a hurriccane can push a trough around.

http://www.accuweather.com/video-on-demand.asp?video=34605198001&channel=VBLOG_STRAIT&title =Wednesd ay Bill Update



I just went to there.. For a second I thought it was Drew Carey giving the info.. scared me..
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So we could have anywhere from a 120 knt storm to a 130 knt storm or even as low as a 110?
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Frank from AccuWeather, has me kinda suspicious about that trough..He said Bill may be hot enuf to push the trough around instead of the trough pushin Bill around
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I think Bill will turn out to be the biggest of the season.

But then, he got to cat 4 strength over water that was only slightly above the usual minimum for cyclogenesis, so you never know.

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Why? No one should ever die because of a Hurricane. I know that it happens bless their souls but it should not.
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Quoting yonzabam:
Let's suppose Bill makes it to borderline cat 4/5. How strong do you think it would be by the time it reached Nova Scotia?


Depends on how fast it's moving when it starts hitting cold water and high shear. Juan struck Nova Scotia in 2003 as a 100-mph storm, so that's not out of realm of possibility. The latest NHC track has it as a Cat 3 well east of the Maryland coast, then a Cat 1 on the doorstep of Newfoundland, so if that were to hold (and who knows?), a borderline 1/2 would not be an unreasonable thing to prepare for.

For it to strike as a major, it would have to be at least a 160-mph Cat 5 at its peak, still be a 4 north of the 35-degree latitude line, and be moving towards the coast at something like 35-40 mph or more. At least that'd be my guess.
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Quoting Thundercloud01221991:
Flight Level Winds of 135 knts which translates to 120 knts at the surface if you take 90% of flight level

I heard that is what you do when they are in the eyewall

According to Mark Powell's study detailed in his June 2009 Weather and Forecasting Paper, that can actually range from 0.6 to 1.1, but is heavily populated in the 0.8 direction.

The differences are largely dependent on the stadium effect and the difference between where the flight level wind is measured and the corresponding point at the surface.
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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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