Bill intensifies to Category 4; globe has 5th warmest July on record
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
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 | 46 — Blog Index
Could be...taken a turn more northwesterly.
Number 2 in eye
It could also be that it is moving more quickly than forecasted
The storm is almost north of PR already. Bill will be way off to the north-east of Florida by Friday night.
Yeah good luck with that. I just usually lurk to read a few of the bloggers post that I feel know what they are talking about. I read the rest of the junk for entertainment purposes only. lol
The data could have been during an eye wall cycle and winds might not be as high during these cycles.
Huh. Because mine begins with an earthquake:
"The Earth will shake
In two will break
And death all around
Will be your dowry"
;)
The GFS ensemble runs are what you get when you run the GFS under a variety of slightly tweaked initial conditions. It gives you a good idea of how unpredictability can throw things off in different directions.
And yes, they've gotten worse, and they're not pretty
I see the NW turn also. Those are great news, not for Bermunda tho.
I see it that way too.... doesn't look good for Nova Scotia
Maybe, but its evident that he is missing the forcast points and taking the east side of them. We will see.
Nope, still WNW.. Even the NHC discussion says it's moving WNW.
I had the same question. Just go to the top(filter) drop down box and click "show all".
Apparently the NHC thinks the HH have been getting some good data.
Do love watching and studying it though, but makes it tough for those who want to be able to have total prior knowledge of what it's going to do. We've gotten better at our guessing, but each storm has it's own "personality" that throws that monkey-wrench into the game. Thus my earlier comment re: Schrodinger's Theory of Quantum Physics as Al Osborne used in in Rogue wave theory, and how it might be applicable in weather forecasting.
Yea the north-east and the south-east side is a classic signature of a strong hurricane. The west side is not the best, probably telling us it will weaken over the next few days as it approaches high shear from the trough.
I saved a image of Bill because of its excellent structure to see later on before it weakens over the next 2days.
At 11am...that was 4 hours ago. Maybe it started the turn, I dont know. That or my loops are broken...and Ike's too.
At 11am...that was 4 hours ago. Maybe it started the turn, I dont know. That or my loops are broken...and Ike's too.
AXNT20 KNHC 191802
TWDAT
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED AUG 19 2009
TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.
BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.
...SPECIAL FEATURES...
HURRICANE BILL IS A CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON
SCALE. THE EYE OF HURRICANE BILL WAS LOCATED 18.7N 56.3W...OR
ABOUT 380 MILES/610 KM TO THE EAST-NORTHEAST OF THE LEEWARD
ISLANDS...AND ABOUT 1080 MILES/1735 KM TO THE SOUTH-SOUTHEAST
OF BERMUDA. BILL IS MOVING TOWARD THE WEST-NORTHWEST 16 KT.
THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 950 MB. THE MAXIMUM
SUSTAINED WIND SPEEDS ARE 115 KT WITH GUSTS TO 140 KT.
BILL IS A LARGE HURRICANE. HURRICANE FORCE WINDS EXTEND OUTWARD
UP TO 80 MILES/130 KM FROM THE CENTER...AND TROPICAL STORM FORCE
WINDS EXTEND OUTWARD UP TO 175 MILES/280 KM PRIMARILY TO THE
NORTHEAST OF THE CENTER. PLEASE READ THE LATEST FORECAST/
ADVISORY UNDER AWIPS/WMO HEADERS TCMAT3/WTNT23 KNHC FOR MORE
DETAILS. STRONG SHOWERS AND THUNDERSTORMS ARE FROM 17N TO 20N
BETWEEN 56W AND 58W. SCATTERED MODERATE SHOWERS AND
THUNDERSTORMS ALSO GO FROM 22N TO 23N BETWEEN 54W AND 57W.
BROKEN TO OVERCAST MULTILAYERED CLOUDS AND OTHER POSSIBLE
PRECIPITATION COVER THE ATLANTIC OCEAN FROM 9N TO 28N BETWEEN
48W AND 61W.
Thanks P451
I agree NW
They don't need another Jean that's for sure.
That was an hour ago!
Gustav was pretty neat last year, before land interaction with Cuba and wind shear soon after toppled his chimney.
That's a very good point. The eye was open to the SW in both vortex fixes from the last mission - the first one elliptical, the second one circular.
And I don't suppose there is another flight today. In any event, Bill is not getting any less interesting with the passage of time.
On the loop it starts out at 18.7N and 50.7W. It ends at 19.4N and 51.9W. Moved .7N and 1.2 W. It's moving slightly north of a WNW motion.
I would say it's moving at about a 305 degree angle.
Your confusing me with someone else. There were lots of people saying ti was heading west. It's been heading West-Northwest since Sunday. Also with Hurricanes, the track points are normally on the south part of the eye. Hurricane centers are on the south part fo the eye.
I agree that Bill is right of the points now but using the gimmick I have mentioned above I think you will see that the angle of the paper across the screen is still WNW.
I was in a dart leauge once myself. Those were the good ole days.
Looks WNW to me, too.
Those would be ones that fail to meet your filter level based on the poster's score...determined by the '+' and '-' at the top of the post. There are a number here that I do not see with the "show bad" filter setting, which means that all but the worst posters' musings are shown to me by default.
Only folks that have accumulated a lot of '-' hits are hidden. Newbs are visible, so I figure the show bad only hides the worst kind, the infectious type we would collectively be happier without.
My forecast as of now.
Viewing: 501 - 551
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 | 46 — Blog Index