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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You know the ensembles shifted to the west today and NHC still saying a WNW motion. That is making me a little nervous. I expected a NW to NNW movement already. The big models still holding to same track but htey are the eastern outliers on the ensembles.
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Station 41044 - Atlantic South Image
21.652 N 58.695 W

Wild Bill =19/1745 UTC 19.3N 56.8W T6.0/6.5

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Quoting lovesdanger:
i just talk to friend of mind in bermuda who is a met..he said that the trough is not moving right now and they dont expect it to start moving again until early friday..he also said new york is in big trouble they will issue watches sometime friday...he also said the trough is only a 300mb one very scary for the new york area...
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1171. breald
Quoting Drakoen:
A slow EWRC may be beginning with Bill as shown on satellite images and microwave images which are beginning to show concentric circles.






What does that mean?
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1170. Adawg14
Well bill is still holding strong at this hour. Will the trough hold? Lots of questions still to be answered.

P.S. Lurkin4yrs is quite the looker. ;)
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bill is no longer a fish storm
Member Since: May 21, 2006 Posts: 5091 Comments: 114792
One thing is for sure the smog problem in the NE will be over soon..
☠☢☣☤
Member Since: February 19, 2007 Posts: 0 Comments: 239

EUMETSAT - Meteosat 0 Loop
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Quoting Tazmanian:
if bill dos not turn soon and the movent at 20mph or so it wil most likey be in the Bahamas in 24 to 36hr this will be a vary tight turn and a hard right when he dos or if he dos turn


Are you crazy! That sounds like Andrew.. How can you say that now especially since its 17 year anni is in 4 to 5 days... LOCO...
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1162. hydrus
With all those model tracks going over Nova Scotia and Newfoundland,you cant see them.
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1161. Ossqss
I recall a question as to how the trough would be positioned at the East coast also. For lack of better words, straight up and down or angled. Where can we go to see what the models are predicting for that?
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1160. Suwanee
Quoting Orcasystems:


Personally I prefer a NE hit to a NS one.


why?
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Member Since: February 19, 2007 Posts: 0 Comments: 239
How much shift in models could we possibly see over the next few days? Is that trough still supposed to be as strong as predicted?
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I am going to ask a "what if" question. If Bill misses the trough and the high is still strong, will it continue towards the Northeast coast, or will it take a more westerly direction? Trying to understand the possibilities if the trough gets hung up basically. TIA
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Quoting photonchaser:
Not good for New England either.


Personally I prefer a NE hit to a NS one.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
1154. Drakoen
A slow EWRC may be beginning with Bill as shown on satellite images and microwave images which are beginning to show concentric circles.



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Quoting reedzone:


No, it's passing very close to Cape Cod and hitting Canada. This is a good possibility though.
Not good for New England either.
Member Since: June 3, 2004 Posts: 1 Comments: 134
Quoting CybrTeddy:


Bill hasn't gone under one yet.


i think it has...earlier today or was it last night?
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1151. lopaka001
11:26 PM GMT on August 19, 2009
Member Since: February 19, 2007 Posts: 0 Comments: 239
1150. Orcasystems
11:26 PM GMT on August 19, 2009
Quoting Ossqss:
This loop shows a defined something going on. I don't think it is an EWRC, but who am I. Anyone ?

http://www.ssd.noaa.gov/goes/east/catl/flash-wv.html


No, your a someone Oss.. not an anyone :)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
1149. stormpetrol
11:26 PM GMT on August 19, 2009
Quoting stormpetrol:

The Stadium affect is when the eye is sort funnel shaped like you're looking right down at ocean, about pointing westward well I'm not sure , but I noticed that the "eye" of a hurricane sometimes point North, East, straight down , South and westward, I have noticed that when it point north or east, the hurricane tends to track NW/N , when the eye point west or south it tends to move more W to WNW, don't know if anyone else ever noticed this or its significance regarding a track.

Read my quote from a few comments back, I'm still wondering if anyone else ever noticed this trend, sames farfetched, maybe, maybe not!
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1148. reedzone
11:26 PM GMT on August 19, 2009
Quoting bajelayman2:


So, the NOGAPS is putting Bill into NY?


No, it's passing very close to Cape Cod and hitting Canada. This is a good possibility though.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1147. Ossqss
11:25 PM GMT on August 19, 2009
This loop shows a defined something going on. I don't think it is an EWRC, but who am I. Anyone ?

http://www.ssd.noaa.gov/goes/east/catl/flash-wv.html
Member Since: June 12, 2005 Posts: 6 Comments: 8185
1146. srada
11:22 PM GMT on August 19, 2009
Quoting Tazmanian:
on the track that bill is moveing it will hit NC in about 3 to 4 days
I hope not..that would be a last minute evacuation and that wont be pretty at all
Member Since: August 17, 2006 Posts: 1 Comments: 772
1145. alcomat
11:22 PM GMT on August 19, 2009
Quoting P451:
Ending 2215Z
WV - Seems to be getting eroded on the East/NE quadrant. Still seems to have jogged a bit west in its motion.

the erosion on the right side is what is pulling it more to the west.something is surely pulling bill to the west,or there would not be no erosion on the right side.the way I see it the side that builds the most convection,is the general direction the storm moves[favors]...[just my opinion]
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1144. WaterWitch11
11:22 PM GMT on August 19, 2009
Quoting P451:


It will if that trend continues. That's the first time I've seen the core penetrated in over a day now.

Also, whatever is causing that, would probably also be the cause for the westward shift in movement.



but what could be causing it?
Member Since: August 11, 2008 Posts: 3 Comments: 1583
1143. bajelayman2
11:20 PM GMT on August 19, 2009
Quoting reedzone:
18Z NOGAPS

84 hours


96 hours


So, the NOGAPS is putting Bill into NY?
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1142. AllStar17
11:20 PM GMT on August 19, 2009
5 pm NHC ADVISORY Graphic:
Member Since: June 29, 2009 Posts: 13 Comments: 5302
1141. stormpetrol
11:19 PM GMT on August 19, 2009
Quoting CybrTeddy:


Bill hasn't gone under one yet.

You got be joking on this one, Bill has been going EWRC about every 4-5 hours, imagine a major hurricane since yesterday and this is the first C'mon you pulling my leg!
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1140. lopaka001
11:19 PM GMT on August 19, 2009
Quoting JadeInAntigua:
From StormW's blog today:
"BILL completed another EWRC (EyeWall Replacement Cycle) a little earlier this morning."


Bill this morning became his strongest a Cat 4 when did the eye go under replacement?
I haven't see EWRC yet so I am confuse there..
Maybe I missed it..
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1139. VARob
11:18 PM GMT on August 19, 2009
Quoting stormwatcherCI:
He has gone through several.


I know of one not to say there hasn't been more.
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1138. photonchaser
11:17 PM GMT on August 19, 2009
Quoting CaicosRetiredSailor:

Bill going to Bermuda


Clintons plan secret trip to Bermuda, says paper
Posted: August 19th, 2009 05:42 PM ET

From CNN Ticker Producer Alexander Mooney

The Clintons are reportedly headed to Bermuda this weekend.

(CNN) — President Obama isn't the only member of his administration planning an island getaway this month.

Secretary of State Hillary Clinton is slated for a four-day stay in Bermuda this weekend with husband Bill, the Bermuda Sun reports.

According to the paper, it's the first trip back to the island for the famous political couple since a stay in the summer of 1979, before the birth of daughter Chelsea.



http://politicalticker.blogs.cnn.com/2009/08/19/clintons-plan-secret-trip-to-bermuda-s ays-paper/
Thier going this week? What a bad time for a vacation there
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1137. CaicosRetiredSailor
11:15 PM GMT on August 19, 2009

Bill going to Bermuda


Clintons plan secret trip to Bermuda, says paper
Posted: August 19th, 2009 05:42 PM ET

From CNN Ticker Producer Alexander Mooney

The Clintons are reportedly headed to Bermuda this weekend.

(CNN) — President Obama isn't the only member of his administration planning an island getaway this month.

Secretary of State Hillary Clinton is slated for a four-day stay in Bermuda this weekend with husband Bill, the Bermuda Sun reports.

According to the paper, it's the first trip back to the island for the famous political couple since a stay in the summer of 1979, before the birth of daughter Chelsea.



http://politicalticker.blogs.cnn.com/2009/08/19/clintons-plan-secret-trip-to-bermuda-says-paper/
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1136. TayTay
11:14 PM GMT on August 19, 2009
Looks like dry air could be disrupting the flow.
1135. pearlandaggie
11:14 PM GMT on August 19, 2009
i hate to say this to you folks in eastern Canada, but those models are useless this far out. we learned that from Ike.
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1134. JadeInAntigua
11:14 PM GMT on August 19, 2009
From StormW's blog today:
"BILL completed another EWRC (EyeWall Replacement Cycle) a little earlier this morning."
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1132. stormwatcherCI
11:13 PM GMT on August 19, 2009
Quoting jasoniscoolman10:
hurricane bill is moving faster now over 21 mph..wow..she is moving little move faster.
She is a he.
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1131. stormwatcherCI
11:13 PM GMT on August 19, 2009
Quoting TayTay:


I don't think Bill has even gone through one yet.
He has gone through several.
Member Since: October 9, 2008 Posts: 0 Comments: 8288
1130. TayTay
11:12 PM GMT on August 19, 2009
Quoting stormpetrol:

EWRC(Eye wall replacement cycles ) I never seen a hurricane go through so many as BILL.


I don't think Bill has even gone through one yet.
1127. pearlandaggie
11:11 PM GMT on August 19, 2009
1108. LOL...did i say that out loud? i thought that was just a mumbled utterance...

oh no, i guess i will be burned at the stake for the heretic within!
Member Since: September 14, 2007 Posts: 3 Comments: 3963
1126. stormpetrol
11:10 PM GMT on August 19, 2009
Quoting CybrTeddy:
Looks like an EWRC is about to take place.

WOW, we wrote that about the same time!
Member Since: April 29, 2007 Posts: 0 Comments: 7729
1125. photonchaser
11:10 PM GMT on August 19, 2009
Quoting CybrTeddy:


Bill hasn't gone under one yet.
I'm sure he has gone through one and this maybe another
Member Since: June 3, 2004 Posts: 1 Comments: 134
1124. Ossqss
11:10 PM GMT on August 19, 2009
Quoting reedzone:
18Z NOGAPS

84 hours


96 hours


Like walking a tight rope :(

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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.