Is the Atlantic hurricane season getting longer?
It seems like there have been an unusual number of early and late season tropical storms and hurricanes in the Atlantic in recent years. In 2008, we had four named storms in July, and the second most powerful November hurricane on record. Both 2007 and 2005 had rare December storms, and 2003 featured Tropical Storm Anna, the first April tropical storm ever recorded. This year, Hurricane Tomas made 2010 the fourth straight year with a November hurricane, something that has never occurred in the Atlantic since accurate records began in 1851. Is hurricane season getting longer? Dr. Jim Kossin of the University of Wisconsin published a 2008 paper in Geophysical Research Letters, "Is the North Atlantic hurricane season getting longer?" He concluded that yes, there is a "apparent tendency toward more common early- and late-season storms that correlates with warming Sea Surface Temperature but the uncertainty in these relationships is high".
Figure 1. Observed sea surface temperature (SST) trends during the official North Atlantic hurricane season (June-November) for the period 1950-2007. Units are °C per century. The dashed rectangle denotes the tropical storm formation region south of 30° North latitude and east of 75° West longitude. Data are from the NOAA Extended Reconstructed Sea Surface Temperature V3 product [Smith et al., 2008]. Image credit: Kossin, J., 2008, "Is the North Atlantic hurricane season getting longer?", Geophysical Research Letters, Vol. 35, L23705, doi:10.1029/2008GL036012, 2008.
Methods
Dr. Kossin utilized the "best track" database of Atlantic tropical cyclone activity going back to 1851. However, since lack of satellite and aircraft reconnaissance data before 1950 makes the early part of this record suspect, he limited his analysis to the period from 1950 onward. The era of best data--the satellite era beginning in 1980--was also looked at separately, to ensure the highest possible data quality. The area studied was only a portion of the Atlantic--the tropical storm formation region south of 30° North latitude and east of 75° West longitude. This region has shown considerable warming of the Sea Surface Temperatures (SSTs) since 1950, in excess of 1°F (0.6°C) (Figure 1). A statistical method called "quantile regression" was employed. The method looked at how certain thresholds that mark the beginning and end of hurricane season have changed over the years. For example, the date where 5% of all tropical storms form earlier than that date, was called the 0.05 quantile, and the date where 5% of all tropical storms form later than that date, was called the 0.95 quantile. Kossin was able to show that the date of the 0.05 quantile got steadily earlier and the date of the 0.95 quantile steadily got later since 1950. Hurricane season for both the period 1950-present and 1980-present got longer by 5 to 10 days per decade.
Figure 2. Trends in tropical storm formation dates, in the region south of 30° North latitude and east of 75° West longitude, at the 0.05.0.95 quantiles. Trends are based on the periods (left) 1950-2007, and (right) 1980-2007. The dates (month/year) associated with the 0.05, 0.25, 0.50, 0.75, and 0.95 quantiles for each period are shown on the top axis (these threshold dates are based on the full sample for each period). Shading denotes the 90% confidence interval. Image credit: Kossin, J., 2008, "Is the North Atlantic hurricane season getting longer?", Geophysical Research Letters, Vol. 35, L23705, doi:10.1029/2008GL036012, 2008.
Relationship with Sea Surface Temperature
The broadening of the Atlantic hurricane season found was strongly dependent upon Sea Surface Temperatures. Both the onset and end of hurricane season shifted by 20 days per degree C of warming of the SST. With global warming projected to increase tropical Atlantic SSTs 1-2°C by the end of the century, can we then expect a 40-80 day increase in the length of hurricane season? Dr. Kossin doesn't explore this possibility, and doesn't blame the observed increase in the length of the season on human-caused global warming of the oceans. There is reason to believe that future warming of the Atlantic SSTs won't necessarily broaden the area over which tropical storms will form, though. Papers by Henderson-Sellers et al. (1998) and Knutson et al. (2008) theorize that as SSTs warm, the lowest temperature at which tropical storms can form will also increase. The current minimum temperature of 26.5°C (80°F) may increase to 28.5°C for a 2°C warming of Atlantic SSTs. Johnson and Xie (2010) have found observational evidence that the lowest temperature at which tropical storms can form has indeed been increasing at about 0.1°C per decade in the Atlantic, in line with climate model predictions.
References
Henderson-Sellers, A., et al., 1998, "Tropical Cyclones and Global Climate Change: A Post-IPCC Assessment", Bull. Am. Meteorol. Soc. 79, 19–38.
Johnson, N.C., and S.P. Xie, 2010, "Changes in the sea surface temperature threshold for tropical convection", Nature Geoscience doi:10.1038/ngeo1008
Knutson, T.R., J.J. Sirutis, S.T. Garner, G.A. Vecchi, and I.M. Held, 2008, Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions", Nature Geoscience 1, 359 - 364 (2008), doi:10.1038/ngeo202
Kossin, J., 2008, "Is the North Atlantic hurricane season getting longer?", Geophysical Research Letters, Vol. 35, L23705, doi:10.1029/2008GL036012, 2008.
Jeff Masters
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Tropical Cyclone Advice Number FOUR
TROPICAL LOW (02U)
11:00 AM ACST December 18 2008
=====================================
At 9:30 AM Australia CST, a Tropical Low [1002 hPa] located at 13.8S 128.3E, or 135 kms west-northwest of Port Keats and 190kms east northeast of Kalumburu at 10 minute sustained winds of 25-30 knots with gusts of 45 knots. The low is reported as moving southeast at 6 knots.
There is the possibility of a tropical cyclone developing in the Joseph Bonaparte Gulf later on Friday. GALES are not expected in coastal areas within the next 24 hours, however gales could develop later.
Tropical Cyclone Watch
=====================
A Cyclone WATCH is now current for coastal and island communities from Cockatoo Island in Western Australia to Port Keats in the Northern Territory.
It's Cinda
Also snowing 6-10" just east of San Diego, CA.
Still hanging Christmas lights - and still sweating while we are doing it. Don't know whether I prefer the warm temps or the ability to stay cool for a while.
Our daughter in Maine finally got power back last night. We were threatening to fly up and get the baby, poor guy doesn't know what to do with only cold water.
Hey surfmom!!
The tan I got :)
Pictures I have...
I also Have SNOW... WTF??
Mother nature was very rude when we got back here.. from Tequila to a snow shovel :(
FURTHER SNOWFALL ACCUMULATIONS UP TO 15 CM OVER MAINLY VICTORIA AND SOUTHERN SECTIONS OF EAST VANCOUVER ISLAND WITH ADDITIONAL ACCUMULATIONS NEAR 5 CM OVER MUCH OF THE INNER SOUTH COAST. THIS IS A WARNING THAT SIGNIFICANT SNOWFALL IS EXPECTED OR OCCURRING IN THESE REGIONS. MONITOR WEATHER CONDITIONS..LISTEN FOR UPDATED STATEMENTS.
Tropical Cyclone Warning Number TEN
FORTE TEMPETE TROPICALE CINDA 04-20082009
10:00 AM Reunion December 18 2008
======================================
At 6:00 AM UTC, Severe Tropical Storm Cinda (985 hPa) located at 12.2S 66.8E has 10 minute sustained winds of 50 knots with gust of 70 knots. The storm is reported as moving south at 5 knots.
Dvorak Intensity: T3.5
Storm Force Winds
===================
20 NM radius from the center
Gale-Force Winds
====================
30 NM radius from the center extending up to 40 NM in southern semi-circle
Near-Gale Force Winds
=====================
80 NM in the southern semi-circle
Forecast and Intensity
=========================
12 HRS: 13.2S 66.3E - 50 knots (Forte Tempête Tropicale)
24 HRS: 14.0S 65.4E - 40 knots (Tempête Tropicale Modereé)
48 HRS: 14.6S 63.0E - 30 knots (DEPRESSION TROPICALE)
Additional Information
======================
Satellite imagery analysis leads to T=CI T3.5 however 85 ghz microwave and infrared/visible imagery are much more impressive than 37 ghz microwave imagery. 85 ghz imagery (F17/0052z, F15/0156z, F16/0325z) actually displays a rather well defined eye. but on the 37 ghz, this eye is eroded on the northern edge. Moreover these imagerires show a tilt between the low level and the upper level center. This shows the system is undergoing a northerly constraint. The environment remains however slightly favorable. Located beneath the western periphery of the upper level ridge, the system benefits from still rather weak vertical wind shear, while the upper outflow is restricted to a moderately potent poleward channel (ahead of an upper trough to the west). This environment is still forecast to become less and less favorable with the strengthening of northern to northwestern winds and the loss of the upper level ridge. About the forecast track, it seem that current steering flow are from the mid-level (700/500 HPA) - where they are somewha weak as the system is located on the western edge of a mid level ridge. As the system should gradually weaken, it should be steered by a more low level steering flow and then track west-southwestwards.
Tropcial Cyclone Advice Number FIVE
TROPICAL LOW (02U)
5:00 pm ACST December 18 2008
===============================
At 3:30 pm Australia CST, a Tropical Low [997 hPa] located at 14.1S 128.6E or 100 kms west of Port Keats and 215 kms east of Kalumburu has 10 minute sustained winds of 30 knots with gusts of 45 knots. The low is moving southeast at 5 knots.
There is the possibility of a tropical cyclone developing in the Joseph Bonaparte Gulf tonight or early on Friday. GALES may develop between Port Keats and Kalumburu overnight or early on Friday.
Widespread heavy rainfall is likely over the southern Darwin-Daly district, the northern Victoria River district, and northern parts of the Kimberley over the next 3 days. Significant stream rises and local flooding are expected in these areas on Friday, extending westwards to the north Kimberley over the weekend.
Tropical Cyclone Warnings/Watches
===================================
A Cyclone WARNING has been declared for coastal and island communities from Kalumburu in Western Australia to Port Keats in the Northern Territory.
The Cyclone WATCH from Cockatoo Island to Kalumburu in WA has been cancelled.
The next advice will be issued by 11:00 pm ACST
These little statistical things we do now may come in handy three hundred years from now.
Fact is the patterns on earth are far more intwind in time then some think .the big huricane season of 2005 was a pivital point inwhitch people in the future will say.
that was the turning point and i remember it .we are in a cooling period !!!!!
This period will last anywhere from 35 to 70 years ,that is if it doesnt last 300 hundred years.
Drought is the worst of it all . cooling periods are laiden with drought.that will be the greatest misery in it . remeber the great potato famine.
our cycles and patterns are not i repeat not the cause of man!!!!!!!!!!!!!!!!!
the patterns on earth are a direct result of our sun and the patterns in our planets and moon. the earth is growing in size .that can be proved by looking at the land masses and how they spread from each other .
science isnt and exact science if you know what i mean . he he just don't think that anything you here in regards to hurricane activity is rock solid .
Fact is the earth was as close to the Sun as it has b een in 40,000 years it would if you use commen sence that the Earth would be warmer. Note that heat rises and brings into it cold so keep that in mind too .
Another words everything I have said here has just as much likely hood of happening as any other . keep the faith
dew
---------------------------------
TROPICAL LOW
Forecast and Intensity
======================
12 HRS: 14.4S 128.8E - 40 knots (CAT 1)
24 HRS: 14.6S 128.7E - 40 knots (CAT 1)
48 HRS: 14.7S 127.3E - 25 knots (Tropical Low)
72 HRS: 16.1S 124.7E - 25 knots (Tropical Low)
Additional Information
======================
The low has undergone significant development during the day, whilst tracking steadily to the southeast. Dvorak analysis at 06Z has DT2.5 [0.55 curved band wrap], MET=PT=FT=2.5.
The system is located under the upper ridge, so vertical shear is not a problem. Standard development rate has the low reaching TC intensity early on Friday, just prior to crossing the coast.
30 knots 1000 MB
hmm will JTWC issue a TCFA in time before BOM names it "Billy", LOL
The fact is that Dr. Gray does not subscrible to the Global Warming theory and that presents a wall for those that would like it propagated to be hurtled.
That being said and knowing this /: I would be sceptical as to the forecast they stamp with Dr. Grays appoval.
It will most certainly be scaled to more then what it would be if the Globalist wasnt present.
The next decade i would in my ipinion be sceptical of anythingyou here in regards to global warming or as it is refered to now as climate change.
These people arent interested in the science .They have an adjenda and that my friends is a fact.scientist are being pushed in directions they would not persue other wise because of the politics of the time.
don't think this is a new thing ; It has went on for hundreds of years. The bad thing about it in a time of the greatest tech era of the ages is here ;yet it still goes on.
What a shame it is !True Science will have to be done on low budget personal wage of the scientist will have to be used to conduct even unbiased science.
follow the money and you will find the villon as always . Just think of the damage that will be done in the name of science for political ends. i don't post much here but thought sence there is a lul in activity ;this would be a good time to introduce the activities as some as fraudulent as they are.
Hope you all take it all with a grain of salt and keep in mind that some science inst science at all.
have a good day last post see ya .
dew
We all know the feeling after going through the 2008 and 2007 Hurricane seasons. System's out of the blue rapidly intensifying. I still will never forget Dean or Ike..
LOL, don't worry, next year the Atlantic will have "Bill" according to the list.
our local-radar composite
Wilmington is 58 and partly cloudy
Forecast is sunny and 65!!!
preping for the storm here
Let It Snow
Let It Snow
Let It Snow
the weather in Santo Domingo feels like 62 (17)
That is cool!!!!!!!!!!!!!!!!!!!!!!
That would be great.....please let me know the song and whom you want that sings it....I will try to produce about 30 songs on one hit if i can and have enough time....LOL
At this moment is totally clear and breezy
How about Drummer Boy?
Uh, any cheerleaders need private lessons???
LOL......
This data looks messed up on that link. How can 1998 be colder than now? The El Nino of 1998 was the warmest on record.
Tropical Cyclone Advice Number SEVEN
TROPICAL CYCLONE BILLY
11:00 PM ACST December 18 2008
=====================================
At 9:30 pm Australia CST, Tropical Cyclone Billy, Category One [993 hPa] located at 14.5S 128.8E or 85 kms west-southwest of Port Keats and 130 kms northeast of Wyndham has 10 minute sustained winds of 40 knots with gusts of 55 knots. The cyclone is reported moving southeast at 4 knots and is expected to slow and begin moving towards the south or southwest later.
Tropical Cyclone Billy is expected to cross the coast between Wyndham and the NT/WA border during Friday.
GALES with gusts to 120 kilometres per hour are expected to develop on the coast between Kalumburu and Port Keats on Friday morning and may extend further inland into the east Kimberley region later on Friday or early Saturday. Abnormally high tides could cause minor flooding at the coast between Wyndham and Port Keats during Friday.
Widespread heavy rainfall is likely over the southern Darwin-Daly district, the northern Victoria River district and northern parts of the Kimberley over the next 3 days. Significant stream rises and local flooding are expected in these areas on Friday, extending westwards to the north Kimberley over the weekend.
Tropical Cyclone Warnings/Watches
===================================
A Cyclone WARNING has been declared for coastal and island communities from Kalumburu in Western Australia to Port Keats in the Northern Territory.
Tropical Cyclone Technical Bulletin (1200z 18DEC)
---------------------------------
Forecast and Intensity
======================
12 HRS: 14.7S 128.8E - 45 knots (CAT 1)
24 HRS: 15.0S 128.5E - 40 knots (CAT 1)
48 HRS: 15.4S 126.5E - 30 knots (Tropical Low)
72 HRS: 17.2S 123.6E - 30 knots (Tropical Low)
Additional Information
======================
The tropical low has intensified rapidly during the day, with well defined spiral banding evident on Wyndham radar and has been named Tropical Cyclone 'Billy'. The system continued to track slowly towards the southeast, but has recently moved in a series of loops while intensifying. Dvorak analysis at 1200 UTC based on a shear pattern with a radar-derived LLCC on the edge of an area of
deep cold cloud.
FT based on DT=3.0, MET=2.5, PAT=3.0. The cyclone is expected to continue intensifying in a favourable low shear environment despite close proximity to the coast. It is forecast to turn slowly towards the southwest or west during the next 12-24 hours under the influence of a strengthening mid-level ridge to the southwest and move inland over the eastern Kimberley region.
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