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: 1874 - 1824

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 TampaSpin:


William dig a hole well above sea level....LOL


I'm a-hunkering, fer sure, fer sure.
Member Since: Posts: Comments:
Quoting bluenosedave:


Hey, IKE. I'm remembering last year during Hurricane Ike, and all the ribbing you got because it was coming right at you. I think Orcasystems shows you on his maps as a target icon.

Well, here I sit in Yarmouth, Nova Scotia, dead centre in the cone of Bill. And my middle name is William. ;-)


Being from NS, I'm wondering why you don't finish your posts off with "aye"? j/k :)
Member Since: Posts: Comments:
Quoting bingcrosby:
Bill is definitely hitting some shear in the NW quadrant.


There is an ULL to its North that is causing it...YOu can see it on the Link i put up
Member Since: Posts: Comments:
Where is stormJunkie?
Member Since: Posts: Comments:
Quoting TexasHurricane:
Hi Tampa,

Hear we may have an AOI in the GOM next week. You hearing this? What is your thought on that?
That's 11-12 days out. GFS had Bill (still a wave off Africa) giving direct hit to NO. Models that far out are nearly worthless.
Member Since: Posts: Comments:
Quoting bluenosedave:


Hey, IKE. I'm remembering last year during Hurricane Ike, and all the ribbing you got because it was coming right at you. I think Orcasystems shows you on his maps as a target icon.

Well, here I sit in Yarmouth, Nova Scotia, dead centre in the cone of Bill. And my middle name is William. ;-)


William dig a hole well above sea level....LOL
Member Since: Posts: Comments:
Bill is definitely hitting some shear in the NW quadrant.
Member Since: August 14, 2008 Posts: 0 Comments: 137
Quoting IKE:


Maybe it would be an eye opener to some.

I doubt it would be a problem using it.


Hey, IKE. I'm remembering last year during Hurricane Ike, and all the ribbing you got because it was coming right at you. I think Orcasystems shows you on his maps as a target icon.

Well, here I sit in Yarmouth, Nova Scotia, dead centre in the cone of Bill. And my middle name is William. ;-)
Member Since: Posts: Comments:
Quoting homelesswanderer:


Yep I think so too. And I hope he goes harmlessly out to sea. FWIW my NWS had been saying a weak front would make it to the area this weekend. Now they are back to saying an unseasonably strong cold front will make into the gulf. So I'm taking that as good news. :)


Yep. The trough is more common for May/June time frames across the Great Plains/Midwest.
Member Since: Posts: Comments:
What a Freak of Mother Nature! Wow!
Member Since: Posts: Comments:
Quoting TexasHurricane:


Hi there, local....


Hi there Tex.
Member Since: Posts: Comments:
Quoting TampaSpin:



Yep the GFS is showing that!



Here comes my first sigh of the season. (Claudette didn't give me time to worry bout something in the gulf) Lol.
Member Since: Posts: Comments:
Quoting homelesswanderer:


Yep I think so too. And I hope he goes harmlessly out to sea. FWIW my NWS had been saying a weak front would make it to the area this weekend. Now they are back to saying an unseasonably strong cold front will make into the gulf. So I'm taking that as good news. :)


Hi there, local....
Member Since: Posts: Comments:
Quoting iceman55:
what is Blackout ????


Blackout occurs about 2am. The Satellites are shutdown to conserve the Battery supply. The Satellites run off Solar power. When the Satellites are in the back side where the sun does not hit they function off of battery supply only thing is the battery supply can't get too low to disable the Satellite so they shut it down to conserve its life. I believe this is all correct.
Member Since: Posts: Comments:

EUMETSAT METEOSAT 0
Member Since: Posts: Comments:
watch out if you live in conn big hurricane bill will hit you with winds up to 115 mph..
Member Since: Posts: Comments:
Quoting IKE:


Maybe it would be an eye opener to some.

I doubt it would be a problem using it.
Let's See if new photo is there
Member Since: Posts: Comments:
Quoting Elena85Vet:


Also note that it is an unusually strong trough for this time of year across the plains/midwest. Te NHC has a good handle on Bill.


Yep I think so too. And I hope he goes harmlessly out to sea. FWIW my NWS had been saying a weak front would make it to the area this weekend. Now they are back to saying an unseasonably strong cold front will make into the gulf. So I'm taking that as good news. :)
Member Since: Posts: Comments:
Quoting hunkerdown:
or where it came from...loooooong way out


Yeah, it is...definitely something to watch for next week or so.
Member Since: Posts: Comments:
Quoting sctonya:
Good Morning Tampa...What is your take on Bill at this hour?


Here is very nice Water Vapor Loop to bookmark...Its my most favorite site to view what it happening. When you look at that it seem kinda complicated but, you can see the Low moving East coming out of the MidWest (Oaklahoma now). That will be the kicker for Bill it appears.
Member Since: Posts: Comments:
Quoting TexasHurricane:


Yeah, I saw that. I wonder where it would go...hmmmm
or where it came from...loooooong way out
Member Since: Posts: Comments:
Quoting sctonya:
Wow!! This blog is super-quiet tonite. Where is everybody?


CONUS landfall threat continues to wane. Less spectators.
Member Since: Posts: Comments:
BILL IS MOVING TOWARD THE NORTHWEST NEAR 22 MPH
Member Since: Posts: Comments:
Quoting TampaSpin:



Yep the GFS is showing that!



Yeah, I saw that. I wonder where it would go...hmmmm
Member Since: Posts: Comments:
Aut oh
Member Since: Posts: Comments:
Quoting TexasHurricane:
Hi Tampa,

Hear we may have an AOI in the GOM next week. You hearing this? What is your thought on that?



Yep the GFS is showing that!

Member Since: Posts: Comments:
Quoting homelesswanderer:


Evening all. This shows the trough that Hunker is talking about thats supposed to turn Bill to the north. Hope it helps. :)


Link


Also note that it is an unusually strong trough for this time of year across the plains/midwest. Te NHC has a good handle on Bill.
Member Since: Posts: Comments:
Ya'll, I'm headed to bed. I have a 5 a.m. wakeup tomorrow, and I need to get at least a couple hours nod-time in....

Don't let Bill stress u out....
Member Since: Posts: Comments:
Hi Tampa,

Hear we may have an AOI in the GOM next week. You hearing this? What is your thought on that?
Member Since: Posts: Comments:
Quoting hunkerdown:
barring some unforeseen change, he is currently about as close to the Bahamian chain as he will get.
Thank u for ur support....
Member Since: Posts: Comments:
Quoting IKE:
Blackout hasn't started yet...looks like some shear, maybe.

if he cleans some of his hair up, or gets it cut, he eerily resembles Andrew prior to landfall.
Member Since: Posts: Comments:
moving west
Member Since: Posts: Comments:
Wow i have had Internet Explorer problems today...i think i got it all fixed.....what a bunch of crap
Member Since: Posts: Comments:
1839. sctonya
Good Morning Tampa...What is your take on Bill at this hour?
Member Since: Posts: Comments:
Quoting TexasGulf:
I don't like the GFS official track. Look at the GFS ensemble models. Nearly 1/2 are showing a track which makes landfall in New England states. The majority of rest are around 70W at 40N, really close to New England.

The official GFS track is almost an outlier to the EAST of all of its own ensemble tracks. That doesn't make sense. If the official track was the average of all the ensembles, the GFS track would be about 5 degrees West of current track when it crosses 40N.

What gives?
One must always remeber weather is a complex system of patterns moving and changing, weakening and strengthening. Models use the best tech available at the time to give an accurate "estimation" of where things will go. As with weather storms or anything else in life it is always the best plan to stick with the boyscout motto of "Be Prepared"
Member Since: Posts: Comments:
Quoting medicroc:

Robert Herbert stressed the point that not every hurricane that went through his hypothetical boxes hit Florida. Nevertheless he stressed that every storm that went through either box should be monitored closely.
Please out there, be my guest in correcting me if I'm wrong.
Quoting medicroc:

Robert Herbert stressed the point that not every hurricane that went through his hypothetical boxes hit Florida. Nevertheless he stressed that every storm that went through either box should be monitored closely.
Please out there, be my guest in correcting me if I'm wrong.
First, it was Paul Hebert, a former forecaster at the NHC, who came up with his theory regarding the two boxes. The main theory with a cane passing through them is that they had the optimal conditions to intensify and make landfall in Florida, outside the box and the steering would usually take them elsewhere. Two caveats to this, 1935 Labor Day storm and Andrew, both missed the box.
Member Since: Posts: Comments:
1836. IKE
Blackout hasn't started yet...looks like some shear, maybe.

Member Since: Posts: Comments:
Quoting reedzone:


Actually it's peak is right now if anything, has the lowest pressure so far.

03 GMT 08/19/09 17.2N 53.4W 125 952 Category 3 Hurricane
09 GMT 08/19/09 18.0N 54.9W 135 948 Category 4 Hurricane
15 GMT 08/19/09 18.7N 56.3W 135 950 Category 4 Hurricane
21 GMT 08/19/09 19.8N 57.6W 135 947 Category 4 Hurricane
03 GMT 08/20/09 20.7N 58.9W 135 945 Category 4 Hurricane


Based on pressure...sure.

But ADT has shown a gradual weakening phase.

Member Since: June 9, 2007 Posts: 4 Comments: 15947
Early good morning everyone!
Member Since: Posts: Comments:
1833. sctonya
Wow!! This blog is super-quiet tonite. Where is everybody?
Member Since: Posts: Comments:
Quoting Stormchaser2007:
EWRC is really taking its toll.

It looks like last night was the peak for Bill.

Shear should increase over the next 24 hours.


Actually it's peak is right now if anything, has the lowest pressure so far.

03 GMT 08/19/09 17.2N 53.4W 125 952 Category 3 Hurricane
09 GMT 08/19/09 18.0N 54.9W 135 948 Category 4 Hurricane
15 GMT 08/19/09 18.7N 56.3W 135 950 Category 4 Hurricane
21 GMT 08/19/09 19.8N 57.6W 135 947 Category 4 Hurricane
03 GMT 08/20/09 20.7N 58.9W 135 945 Category 4 Hurricane
Member Since: July 1, 2008 Posts: 13 Comments: 7432
1831. IKE
Quoting eyesontheweather:
I have this really cool picture taken post Katrina in New Orleans where the home floated/drifted across the street and ended up plowing into the front door of the house across the street amazingly the house was completley intact incl the slab. Not my home and am afraid I could bi infringing on someone if I posted it on this venue...


Maybe it would be an eye opener to some.

I doubt it would be a problem using it.
Member Since: Posts: Comments:
11:00 PM AST Wed Aug 19
Location: 20.7°N 58.9°W
Max sustained: 135 mph
Moving: NW at 17 mph
Min pressure: 945 mb

I see Bill slowed down...that is good right? And still moving NW.
Member Since: Posts: Comments:
I don't like the GFS official track. Look at the GFS ensemble models. Nearly 1/2 are showing a track which makes landfall in New England states. The majority of rest are around 70W at 40N, really close to New England.

The official GFS track is almost an outlier to the EAST of all of its own ensemble tracks. That doesn't make sense. If the official track was the average of all the ensembles, the GFS track would be about 5 degrees West of current track when it crosses 40N.

What gives?
Member Since: Posts: Comments:
I have this really cool picture taken post Katrina in New Orleans where the home floated/drifted across the street and ended up plowing into the front door of the house across the street amazingly the house was completley intact incl the slab. Not my home and am afraid I could bi infringing on someone if I posted it on this venue...
Member Since: Posts: Comments:
EWRC is really taking its toll.

It looks like last night was the peak for Bill.

Shear should increase over the next 24 hours.
Member Since: June 9, 2007 Posts: 4 Comments: 15947
1825. IKE
Quoting eyesontheweather:
I hope you are not holding your breath.


LOL.
Member Since: Posts: Comments:
1824. jpsb
Quoting hunkerdown:
The second trough may or may not have any additional northerly influence on him...it should be the trough currently over the states that turns him away.
Yea, I was just wondering if I had all the pieces of the forecast right in my head. I've been watching that ull here http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?wv_east_enhanced+12 and noticed that it is not looking as vigorous as it did 2 days ago. Still should do the job of turning bill more to the north. Also the big trof over the eastern US has slowed a bit hopefully it will get over the east coast in time to carry bill away.
Member Since: Posts: Comments:

Viewing: 1874 - 1824

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
47 °F
Overcast