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
RE: African Waves. As someone noted yesterday, if Bill does turn and miss everything he's set the Atlantic up as a prime birthing room for some great storms.
Also note: "Analyses
from CIMSS at the University of Wisconsin show that Bill has been
experiencing 10-15 kt of westerly vertical wind shear. This may be
starting to diminish...as the cirrus outflow is increasing in the
western semicircle.
The initial motion is 305/16."
This one Ike :)
That's a heat low. it ain't gonna develop into something tropical.
Oops...wrong one...here it is...
Thanks, but that image is at 05Z which is about 9 hours old.. :)
I'm sorry if this is a dumb question:
About where is the "cutoff" for extra-tropical? Or does it just depend on SSTs? Is there a latitude by which you can more-or-less say, "Okay, a tropical system that comes this far north is going to be extratropical by the time it passes XYZ point"?
(Thanks for all your great info. I'm still learning!)
As the debate here RE: Wind towers out in the Sound, how would a storm like this affect them? How much damage to them and to the area around them?
My comment re: going to work was not meant to be flippant. I understand how a storm can effect people. Hopefully putting it on a personal level reminds us all what's at stake.
what kind of "bad stuff", that is where my family is...
It has to do with the core (warm / cold) and other structural features, and not necessarily latitude. :)
Link
http://nowcoast.noaa.gov/
AGNT40 KWNM 201235
MIMATN
MARINE WEATHER DISCUSSION
NWS OCEAN PREDICTION CENTER WASHINGTON DC
830 AM EDT THU 20 AUG 2009
.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.
WITH TRPCL STORM OR HURCN CONDITIONS ALREADY INCLUDED IN
APPROPRIATE OFSHR ZONES...MAIN TASK WITH THIS MORNINGS UPDATE
WILL BE WHETHER TO INCLUDE THE FAR E PART OF THE WRN HUDSON TO
BALT CNYN ZONE WITH ANY TRPCL STORM CONDITIONS. AND OF COURSE
THIS WILL BE BASED ON THE UPCOMING FORECAST TRACK OF BILL IN 15Z
TPC ADVISORY. IF TRACK OF BILL IS SHIFTED ANY FURTHER W WILL
LIKELY HAVE TO INCLUDE ABOVE MENTIONED ZONE. 06Z GFS IS TO THE
LEFT OF AT LEAST ITS PAST THREE PREVIOUS RUNS WITH THE TRACK...
AND TAKES BILL JUST W OF 70W AND THEN WITHIN 60-70 NM OF CAPE
COD EARLY SUN. GFS NOW IS IN LINE WITH 00Z CANADIAN AND W OF
UKMET/ECMWF.
MEANWHILE...WEAK COLD FRONT HAS PUSHED OFSHR INTO GLF OF ME AND
JUST S OF LONG ISLAND...BUT SHUD STALL THIS AFTERNOON AND LIFT N
AND BACK INLAND AS WARM FRONT TNGT. AND OVER NEXT 36HRS OR SO
PREVAILING S TO SW FLOW 15 KT OR LESS WILL DOMINATE OFSHR
WATERS...UNTIL THE ARRIVAL OF HURCN BILL.
LONG PERIOD SWELL...3 FT AT 16 SEC...ASSOICATED WITH GILL
APPEARS TO HAVE ARRIVED AT NOAA BUOY 41048...LOCATED ABOUT 250
NM W OF BERMUDA. EVEN GFDL BASED WAVEWATCH III IS ABOUT 12HRS
TOO SLOW WITH THIS SWELL TRAIN AS IT DOES NOT BRING LONGER
PERIOD TO THAT AREA UNTIL EARLY TNGT. BASED ON THIS MAY HAVE TO
MAKE SOME TIMING ADJUSTMENTS OVER OFSHR WATERS. NOT PLANNING ON
SIGNIFICANT CHANGES TO PREVIOUSLY FORECAST SIG WV HGTS
ASSOCIATED WITH BILL.
NAEFS (North American Ensemble Forecast System)
forecast meteograms for Halifax, NS.
the Public forecast: "Rain. Windy".
We tell a lot less than we know...
There isn't much on Sable Island except for a few Weather Canada guys and about 300 horses. Its basically a sandbar.
FROM TPC.
.WARNINGS/FORECAST CONFIDENCE...WARNINGS ARE PRELIMINARY AND ARE
SUBJECT TO CHANGE. ANY CHANGES WILL BE COORDINATED THROUGH AWIPS
12 PLANET CHAT OR BY TELEPHONE.
.NT1 NEW ENGLAND WATERS...
.GULF OF MAINE...T.S. SUN FAR SE PORTION.
.GEORGES BANK...HURCN SUN SE PORTION.
.S OF NEW ENGLAND...T.S. LATE SAT INTO SUN E PORTION.
.NT2 MID ATLC WATERS...
.HUDSON TO BALT CNYN...NONE.
.BALT CNYN TO HAGUE LINE...HURCN LATE SAT AND SUN E PORTION.
.BALT CNYN TO HATTERAS CNYN...T.S. SAT INTO SUN E PORTION.
.HATTERAS CNYN TO CAPE FEAR...T.S. SAT E PORTION.
.CAPE FEAR TO 31N...NONE.
.FORECASTER CLARK/PROSISE. OCEAN FORECAST BRANCH.
We've already experienced hurricanes.
Cape for Little Rock Arkansas......sheeshhh
In short, there is a 99.999999% certainty this thing will not even approach florida.
Yes,lovely, you really can see it. But I can also see the possibility of a, (gosh I hate this word), "stall", then instead of swooping away and missing everything, Bill gets pulled up and hits something a little bit stronger than what we'd like to see. I've seen that scenario happen as well. Still to early to tell. How far West he goes, how long he stalls for, and the speed and location of the Northern influence will all be interesting to watch.
I'm not really getting what information you're trying to share with the graphics...
It just seems boolean (as in true/false) versus wave heights or anything else...
Not to pick on it... :(
Not fun. I went through Bob. Bob was 18 years ago yesterday and today. Happy Anniversary Bob! You're cousin Bill's coming to celebrate!
Also, following October 31 was Halloween Storm aka The Perfect Storm.
Neither one fun.
We get so many N'orEasters that seem much worse than the usual blows of dying hurricanes that come through here, but Bob scared me. So far Bill only worries me.
Yesterday someone here helped put Cape Cod's weather into perspective. It's it's own special micro-climate. Anything can happen, and too often it does.
Seriously, we've been in a world of hurt in Tulsa. I'm glad we didn't have tornados from our Tornado Watch last night. But we had strobe lightning. It was like being in a night club for 2 hours last night. Amazing and disturbing. I've been in some 60 strike a minute weather. And this was like 3 a second for a while. And watching the huge anvils on these small state sized cells were inspiring as the just seemed to pulse with electricity.
Isn't his answer so much more sexy? :)
I remember Bob and Gloria was in 1985.
I know what you mean about the climate. It can be 85 one day and 65 the next.
The point of it is to show who will be experiencing LARGE waves at different points in Bills path. Such as, when Bill is approaching from the southeast, The narrow channel north of Long Island will not experience big waves.
Is it ok for me to ask a question about another hurricane?
I was in Atlanta during Hurricane Opal. I know that the actual hurricane was no where near - we are so far inland. But I do remember chaise lounges flying up into the sky and hitting the side of the apartment building - power outages for 5 days! I remember it was related to Opal.
I realize this has nothing to do with Bill. I am just trying to educate myself a little more on weather - the whys and the hows.
Can anyone tell me the path Opal took that led up to us? I guess it came up from the Gulf? It seems like a long time ago - I've forgotten.
Thanks!
Viewing: 2201 - 2251
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