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: 1074 - 1024

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

Quoting CaicosRetiredSailor:
...yet another "page read" recorded by Google Adds for payment purposes:

ERROR
There was a problem opening this user's Wunder Blog files. Please try again later.


Page read for payment purposes? ??

Edit: And when I sent this

I got -
ERROR
There was a problem opening this user's Wunder Blog files. Please try again later.

Member Since: Posts: Comments:
1073. hydrus
WEATHER-456-It does look like good news for the Northern Antilles.Were you starting to wonder about the distance before the turn?
Member Since: Posts: Comments:
if only warming were really occurring......
Member Since: Posts: Comments:
...yet another "page read" recorded by Google Adds for payment purposes:

ERROR
There was a problem opening this user's Wunder Blog files. Please try again later.
Member Since: Posts: Comments:
How similar are Bill's characteristics to those that created the 'perfect storm' in 1991? The path of Hurricane Grace, the east coast low (actually closer to Sable Island) and the cold front coming down from Canada - all are looking a little like Bill's situation, even the close approach to Bermuda. Anyone with those stats on hand?
Member Since: Posts: Comments:
Quoting drg0dOwnCountry:
Looks like he lost a huge chunk to the north.
The cloud formation look, almost reassembles the main storm.
Member Since: September 22, 2005 Posts: 11 Comments: 2032
5:00 PM AST Wed Aug 19
Location: 19.8°N 57.6°W
Max sustained: 135 mph
Moving: NW at 20 mph
Min pressure: 947 mb

This is good right? NW not WNW...
Member Since: Posts: Comments:
Quoting TexasHurricane:
As of right now, does that trough look like it will make it there in time to push Bill away and out to sea?Quoting Engine2:

Thats the million dollar question right now
Quoting TexasHurricane:
As of right now, does that trough look like it will make it there in time to push Bill away and out to sea?


In my opinion I feel that Bill will outrun the trough....timing truly is everything but for those in the northeast I would be sweating bullets. I live in West Ky and we are just about to start feeling the trough moving through
Member Since: Posts: Comments:
Bill reminds me of Bertha just by how the models predicted him in advanced. the ECMWF was outstanding this year.
Member Since: Posts: Comments:
1063. amd
the surface fronts in the midwest are still moving at a good pace:

Link

Member Since: Posts: Comments:
Quoting victoria780:
Well its official,75 days this year of 95 degrees or hotter here in Corpus Christi,Tx Been here 35 years and never have gone through this before..
And with more warming this will become average ...
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Bright & sunny day here in Barbados generally, but there have occasionally been, as right now, some dark thick clouds, most likely Bill's stray feeder band spill offs, overhead.

Just goes to show how big this thing is, as we are one of the lowest islands, only lower is Trinidad and also Tobago.
Member Since: Posts: Comments:
#1045

Yeah, maybe he will go to sleep and weaken...
Member Since: Posts: Comments:
Quoting photonchaser:
Hurricane Gloria almost resembles Bill's path so far. The only difference is that Gloria made a direst hit on the CONUS and Bill may only brush the CONUS


Hurricane Gloria's path at where Bill is now doesn't resemble Bill at all...

The plot of the 1893 hurricane 4 that was posted back in comment #987, however, is unfortunately a very close match. That storm crossed 20 degrees at about where it looks like Bill will and crossed 65 degrees just south of 25 degrees like Bill is currently forecast to do. Here's hoping that's where the similarities end.

Member Since: Posts: Comments:
1058. Engine2
Quoting TexasHurricane:
As of right now, does that trough look like it will make it there in time to push Bill away and out to sea?

Thats the million dollar question right now
Member Since: Posts: Comments:
If Bill does make an inpact on the Northeast here is something to think about. Even if he is a cat 2 at landfall he will be pushing a lot of wave action and the storm surge will be pushing like a cat 4.
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Bill has caused some serious upwelling in the CATL.


Hey good sword fishing there and some wahoo in that cold water..
Member Since: February 19, 2007 Posts: 0 Comments: 239
Quoting JadeInAntigua:


Good evening Weather456. How's the weather looking over there now? Our skies have gotten really dark the past hour or so and heavy rain with some distant thunder has rolled in now.


its raining now
Member Since: Posts: Comments:
Quoting Melagoo:
RBG of Bill



I love the RBG loop as the sun starts to set Bill really is awesome!
Looks like he lost a huge chunk to the north.
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Well its official,75 days this year of 95 degrees or hotter here in Corpus Christi,Tx Been here 35 years and never have gone through this before..
Member Since: Posts: Comments:
As of right now, does that trough look like it will make it there in time to push Bill away and out to sea?
Member Since: Posts: Comments:

Bill

Bill

AOI
Member Since: Posts: Comments:
Quoting New2SOFLA:


That one model all the way to the left with Bill Making landfall on Atlantic City....Thats scary!!! it makes me nervouse until i see that go away


No problem.. it would downgrade a bit going over the Carols outer islands.
Member Since: Posts: Comments:
ADT has been showing a general weakening trend.

Member Since: Posts: Comments:
I'ma push back from the keyboard for a while, maybe get a bite of something.... bill is stringing me out...

BB8r...
Member Since: Posts: Comments:
there is an area of unsettled waether in the eastern gomex this afternoon. although there is nothing imminent pressures are low 1010 MB SST are high and the upper level environment is getting more conducivefor development. this area needs to watch for any signs of cyclogenesis
Member Since: Posts: Comments:
<

Well that is my concern. The person that sounds the alert is setting him/herself up for a big fall if nothing happens. Imagine displacing that many people, closing down the financial mecca of the world. My concern is that after their finished dotting all the i's and crossing all the t's it'll be too late. The political ramifications could be enormous


Welcome to New Orleans. ;)

Seriously, cities like Houston, Tampa, and New Orleans deal with this problem almost yearly. NYC, not so much, so that's why I'm so curious as to what's going on up there. The logistics alone boggles, not to mention transportation, traffic flows, food & water supplies, emergency services, the whole "finacial mecca" thing...oh yeah, and the idiots that don't evacuate.

I'm pulling for that trough.

Member Since: Posts: Comments:
1045. Melagoo
RBG of Bill



I love the RBG loop as the sun starts to set Bill really is awesome!
Member Since: Posts: Comments:
A question concerning wave height, not surge, but wave height. How is wave height measured? Is it from the mean level of the sea to the peak of a wave, or is it from the lowest dip to the peak? And are there actual dips below the mean level or is that an optical illusion? Also, in a hurricane, is the wave height measured from the top of the surge? Thanks.
Member Since: Posts: Comments:
Quoting Orcasystems:


That one model all the way to the left with Bill Making landfall on Atlantic City....Thats scary!!! it makes me nervouse until i see that go away
Member Since: Posts: Comments:
Quoting P451:


I think he moved a bit westward again, yes, in the final frames of this loop. Most of the loop he's NW and even to the right of the first forecast plot by a bit - but those final frames I think he's gone back a bit more WNW'ward.



When was that last image updated??
I was looking at the RAMMB images and for the last 2.5 hours Bill is riding under the 20 now in the last 5 updates..
Maybe it is those images it just looks like he is moving west..
Normally not a big deal but when the next update comes I will look again..
If it is the same it will be 3 hours of a west drift according to those images..
Maybe it's my eyes..
;=O
Member Since: February 19, 2007 Posts: 0 Comments: 239
Quoting Weather456:
Sorry about the ftp image link earlier, I wasnt on the blog to remove it.


Good evening Weather456. How's the weather looking over there now? Our skies have gotten really dark the past hour or so and heavy rain with some distant thunder has rolled in now.
Member Since: Posts: Comments:
Quoting reedzone:
18Z GFS has shifted slightly eastward



well, that is good.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting KerryInNOLA:
Bill is not a classic annular hurricane. It may have a few annular characteristics,but thats all. Annular hurricanes are not common. Bill is not going to bust the trough either. Sorry all wishcasters.

It can be meassured and on a scale of 1-100 he gets 1.1 (around 20 hrs ago).
Someone posted the eyewall with inner lines winding around and which are also visible on other imagnery and those are not yet forming a "wheel". Correct me if im wrong.
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Sorry about the ftp image link earlier, I wasnt on the blog to remove it.
Member Since: Posts: Comments:
18Z GFS has shifted slightly eastward

Member Since: July 1, 2008 Posts: 13 Comments: 7334
Quoting P451:





I remember Gloria crystal clear here in east central jersey. It was low tide and the houses and buildings at the shore were still flooded up to the second floor. All the barrier island roads were flooded under. We had a period of 75mph winds with very heavy rain. After the passage of the storm we likely had some dry gusts up to 85. Had a lot of trees and branches down and a lot of flooding.
Mind u, that 1893 storm wasn't the only one to impact NYC in some way. Just was the only one to come in and whack it that way. All the others were like Gloria or Donna 1960, coming up the coast, or east of NYC.

Maybe that location wasn't such a bad idea.
Member Since: Posts: Comments:
Quoting medicroc:
nothing irks me more than people coming on to this board with an admonishing tone saying things like "you people are wising for hurricanes, don't you know people die,etc".
But I must say one thing:Why in the hell does anyone think we in NYC need some kind of wakeup call. We are awake, have been since September 11, 2001
Here in Charleston we agree with you. Absolutely amazing. I keep thinking that I must have missed something of the discussion, 'cause it sure sounded spiteful to me. As I remember, after Hugo, there were many Electrical Utility trucks from the North East that came to get us back on the grid. And good lawd, after 911, I think NYC has had more than her share of catastrophe. And NO ONE had an opportunity to evacuate, then
Member Since: August 19, 2008 Posts: 6 Comments: 2490
Hurricane Gloria almost resembles Bill's path so far. The only difference is that Gloria made a direst hit on the CONUS and Bill may only brush the CONUS
Member Since: June 3, 2004 Posts: 1 Comments: 134
Nice view

Member Since: Posts: Comments:
Quoting JLPR:


Thanks for that
I always forget that one xD


This will likely happen, since the ECMWF develops it.

image of the EATL

Member Since: Posts: Comments:
Quoting New2SOFLA:


Im in NYC and Bill would not be a wake up call he would be a catastrophe and we qwill never be able to wake up from ....... you must be joking ....out to sea!!! please


Yes, definitely go out to sea...
Member Since: Posts: Comments:
I laugh at all the bold statements this week.. "Bill is not going to hit the USA, Bill will hit Florida, Bill will weaken, Bill will, Bill will do whatever I say it will do" Seriously people??

You can give your opinion, back them up with facts, but you are NOT always right. Models change, patterns change, the USA now has a small percentage of getting a direct hit from Bill. Let the pattern do what it's going to do and stop wishcasting, downcasting, westcasting, and ect. Just let weather be weather. For all we know the NHC may not be right in the end. we are ALL not perfect. We're only human beings. ;)
Member Since: July 1, 2008 Posts: 13 Comments: 7334
Thanks to all who answered my question regarding "the Long Island Express" watched it quite sometime ago on the History or discovery channels but couldn't exactly remember how it went. Thanks again.
Member Since: Posts: Comments:
Quoting KerryInNOLA:
Bill is not a classic annular hurricane. It may have a few annular characteristics,but thats all. Annular hurricanes are not common. Bill is not going to bust the trough either. Sorry all wishcasters.

Whoa. Someone hijacked his handle and said something right and level-headed.

(teasing you here...good post)
Member Since: Posts: Comments:
.
Member Since: Posts: Comments:

Viewing: 1074 - 1024

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 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.