CSU predicts highly active hurricane season; Cyclone Phet approaching Oman

By: Dr. Jeff Masters , 2:00 PM GMT on June 03, 2010

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A very active Atlantic hurricane season is on tap for 2010, according to the seasonal hurricane forecast issued June 2 by Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU). The CSU team is calling for 18 named storms, 10 hurricanes, and 5 intense hurricanes, and an Accumulated Cyclone Energy (ACE) 185% of average. Between 1950 - 2000, the average season had 10 named storms, 6 hurricanes, and 2 intense hurricanes. But since 1995, the beginning of an active hurricane period in the Atlantic, we've averaged 14 named storms, 8 hurricanes, and 4 intense hurricanes per year. The new forecast is a step up from their April forecast, which called for 15 named storms, 8 hurricanes, and 4 intense hurricanes. The new forecast calls for a much above-average chance of a major hurricane hitting the U.S., both along the East Coast (51% chance, 31% chance is average) and the Gulf Coast (50% chance, 30% chance is average). The risk of a major hurricane in the Caribbean is also high, at 65% (42% is average.) This is the most aggressive early June forecast ever issued by the CSU group; the previous most aggressive such forecasts were for the 2006 and 2007 seasons, when the CSU team predicted 17 named storms, 9 hurricanes, and 5 intense hurricanes. Both of these forecasts did poorly, particularly the 2006 forecast, as only 10 named storms, 5 hurricanes, and 2 intense hurricanes were observed.

The forecasters cited four main reasons for an active season:

1) Weak La Niña conditions should develop by the most active portion of this year's hurricane season (August-October). The expected trend towards weak La Niña conditions should lead to reduced levels of vertical wind shear compared with what was witnessed in 2009.

2) Current SST anomalies are running at near-record warm levels. These very warm waters are associated with dynamic and thermodynamic factors that are very conducive for an active Atlantic hurricane season.

3) A weaker-than-normal Azores High prevailed during April-May. Weaker high pressure typically results in weaker trade winds that are commonly associated with more active hurricane seasons.

4) We are in the midst of a multi-decadal era of major hurricane activity, which began in 1995. Major hurricanes cause 80-85 percent of normalized hurricane damage.

Analogue years
The CSU team picked four previous years when atmospheric and oceanic conditions were similar to what we are seeing this year: weak El Niño to neutral conditions, well above-average tropical Atlantic SSTs, and above-average far North Atlantic SSTs during April - May. Those four years were 2005, the worst hurricane season of all time; 1969, the 3rd worst hurricane season of all time, featuring Category 5 Hurricane Camille which hit Mississippi; 1966, a relatively average year that featured Category 4 Inez that killed 1,000 people in Haiti; and 1958, a severe season with 5 major hurricanes. The mean activity for these five years was 17 named storms, 10 hurricanes, and 5 intense hurricanes, almost the same as the 2009 CSU forecast.

How accurate are the June forecasts?
The June forecasts by the CSU team over the past 12 years have had a skill 19% - 30% higher than a "no-skill" climatology forecast for number of named storms, number of hurricanes, and the ACE index (Figure 1). This is a decent amount of skill for a seasonal forecast, and these June forecasts can be useful to businesses such as the insurance industry and oil and gas industry that need to make bets on how active the coming hurricane season will be. Unfortunately, the CSU June 1 forecasts do poorly at forecasting the number of major hurricanes (only 3% skill), and major hurricanes are what do 80 - 85% of all hurricane damage (normalized to current population and wealth levels.) This year's June forecast uses the same formula as the past two years, which did quite well predicting the 2008 hurricane season (prediction: 15 named storms, 8 hurricanes, 4 intense hurricanes; observed: 16 named storms, 8 hurricanes, 5 intense hurricanes) and 2009 hurricane season (prediction: 11 named storms, 5 hurricanes, 2 intense hurricanes; observed: 9 named storms, 3 hurricanes, 2 intense hurricanes.) An Excel spreadsheet of their forecast skill (expressed as a mathematical correlation coefficient) show values from 0.44 to 0.58 for their June forecasts, which is respectable.


Figure 1. Comparison of the percent improvement over climatology for May and August seasonal hurricane forecasts for the Atlantic from NOAA, CSU and TSR from 1999-2009 (May) and 1998-2009 (August), using the Mean Squared Error. The British firm Tropical Storm Risk (TSR) will issue their outlook for the 2010 Atlantic hurricane season on June 4. Image credit: Verification of 12 years of NOAA seasonal hurricane forecasts, National Hurricane Center.

NOAA's 2010 hurricane season forecast
NOAA issued their forecast for the upcoming Atlantic hurricane season last week. As I discussed in my post on their forecast, NOAA is calling for very active and possibly hyperactive season. They give an 85% chance of an above-normal season, a 10% chance of a near-normal season, and just a 5% chance of a below-normal season. NOAA predicts a 70% chance that there will be 14 - 23 named storms, 8 - 14 hurricanes, and 3 - 7 major hurricanes, with an Accumulated Cyclone Energy (ACE) in the 155% - 270% of normal range. If we take the midpoint of these numbers, NOAA is calling for 18.5 named storms, 11 hurricanes, 5 major hurricanes, and an ACE index 210% of normal. A season with an ACE index over 175% is considered "hyperactive."


Figure 2. Visible satellite image of Tropical Cyclone Phet on Thursday, June 3, 2010.

Tropical Cyclone Phet the 2nd strongest Arabian Sea storm on record
Record heat over southern Asia in May has helped heat up the Arabian Sea to 2°C above normal, and the exceptionally warm SSTs helped fuel Tropical Cyclone Phet into the second strongest tropical cyclone ever recorded in the Arabian Sea. Phet peaked at Category 4 strength with 145 mph winds yesterday, and has weakened slightly to 135 mph winds this morning. Only Category 5 Cyclone Gonu of 2007, which devastated Oman, was a stronger Arabian Sea cyclone.

Phet is over very warm waters of 30 - 31°C, and is under moderate wind shear of 10 - 20 knots. However, the storm is wrapping in dry air from the Arabian Peninsula, which has caused weakening. Visible satellite imagery from this morning (Figure 2) shows that the heavy thunderstorms on the north side of Phet have been eroded away by dry air. Phet is a small storm, and could fall apart fairly quickly if dry air can penetrate into its core. This should happen later today, since wind shear is on the increase, and the shearing winds should be able to disrupt the circulation enough that dry air can force its way into Phet's eyewall. Phet is fairly small, will miss the most heavily populated areas of Oman, and will likely undergo significant weakening before landfall, so the storm is unlikely to cause the kind of catastrophic flooding that Category 5 Cyclone Gonu of 2007 brought to Oman. Gonu killed 50 people and did $4.2 billion in damage. Phet's heaviest rains will be confined to a relatively sparsely populated region of Oman's coast. Rainfall amounts in excess of 6 inches in 18 hours (Figure 3) can be expected along Oman's coast today, which will likely cause extreme flooding.

After Phet's encounter with Oman, the storm will probably be at tropical storm strength when it makes its second landfall in Pakistan. Heavy rains from Phet will be the major danger for Pakistan, and serious flooding can be expected over southern Pakistan.


Figure 3. Forecast rain amounts for the 18-hour period ending at 2am EDT June 3, 2010. Image credit: NOAA/NESDIS.

Oil spill update
Onshore winds out of the south, southwest, or west are expected to blow over the northern Gulf of Mexico over most of the next week, resulting increased threats of oil to Alabama, Mississippi, and the Florida Panhandle, according to the latest trajectory forecasts from the State of Louisiana. The latest ocean current forecasts from the NOAA HYCOM model show that these winds will generate a 0.5 - 1 mph current flowing from west to east along the Florida Panhandle coast Sunday and Monday. If this current develops as predicted, it will be capable of bringing light amounts of oil as far east as Fort Walton Beach, Florida, by Monday. If you spot oil, send in your report to http://www.gulfcoastspill.com/, whose mission is to help the Gulf Coast recovery by creating a daily record of the oil spill.

Oil spill resources
My post, What a hurricane would do the Deepwater Horizon oil spill
My post Wednesday with answers to some of the common questions I get about the spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami

I'll be back Friday with an analysis of the new TSR hurricane forecast and a new forecast by a promising Florida State University model.

Jeff Masters

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1080. pottery
Quoting WatchingThisOne:


Could be dispersent being injected into the choke or kill ports. Since they had access anyways and what better place to put it?

True! Good thinking Batma...er never mind
back to the vid LOL
Member Since: October 24, 2005 Posts: 0 Comments: 24390
Quoting StormW:
Hey 456!


hey, hows it going.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1077. xcool





new ngp
Member Since: September 26, 2009 Posts: 2 Comments: 15684
1076. NRAamy
I was not going to go there Amy... We know we can count on you :)

I aim to please....

:)
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High set up for the next 2 weeks in June, which basically, much of what's left of the month.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
5 live feeds at once if you need!
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Quoting pottery:

YEAH!! LOLOL
Quit being so controlling.That's Amys job....LOL
Member Since: February 27, 2010 Posts: 0 Comments: 1125
Quoting CaicosRetiredSailor:
Pottery,

In reference to your discussion earlier concerning the "brown portion" of the escaping plume, the best theory I have seen is that is the portion which is coming up the drill pipe, and it has a different composition.


Could be dispersent being injected into the choke or kill ports. Since they had access anyways and what better place to put it?
Member Since: July 15, 2005 Posts: 3 Comments: 1269
1071. Ossqss
Quoting nrtiwlnvragn:
Anyone else find themselves trying to tell the ROV what to do?


It is interesting that the operators are using a PC in a very similar way, but have joysticks. Video game like. I guess that is a long answer for Yes :)

Thanks again for your help on with the contest stuff!
Member Since: June 12, 2005 Posts: 6 Comments: 8186
1069. pottery
Quoting nrtiwlnvragn:
Anyone else find themselves trying to tell the ROV what to do?

YEAH!! LOLOL
Member Since: October 24, 2005 Posts: 0 Comments: 24390
1068. xcool


Member Since: September 26, 2009 Posts: 2 Comments: 15684
Might i suggest we all say a little Prayer about right now.............
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Oh NO we are sunk ........we got the green stuff coming out now.......LOL
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Quoting stormhank:
Id expect first storm of season no earlier than June 21st or so....do u all agree??


Agreed.
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Anyone else find themselves trying to tell the ROV what to do?
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1063. HadesGodWyvern (Mod)
India Meteorological Department
Tropical Cyclone Advisory Number TWENTY-SIX
VERY SEVERE CYCLONIC STORM PHET (ARB02-2010)
23:30 PM IST June 3 2010
=======================================

At 18:00 PM UTC, Very Severe Cyclonic Storm Phet over west central Arabian Sea moved northward and lays centered near 20.5N 59.5E, or about 1020 kms west southwest of Naliya, Gujarat, 950 kms southwest of Karachi, Pakistan, 250 kms south of Sur, Oman, and 50 kms east northeast of Masirah Island, Oman.

3 minute sustained winds near the center is 65 knots with a central pressure of 978 hPa. The state of the sea is phenomenal around the system's center.

The Dvorak intensity of the system is T4.0. Associated broken/solid intense to very intense convection observed over area between 17.5N to 24.5N and west of 62.0E. The lowest cloud top temperature due to convection is about -80C in association with the system.

Vertical wind shear of horizontal wind over the region is low to moderate. The system lies to the south of tropospheric ridge, which roughly runs along 21.0N over the region.

The system is interacting with land surface. Ocean heat potential over the northwest Arabian Sea is relatively less, which is not favorable for intensification.

Considering all the above, the system would move slowly in a northerly direction and cross Oman coast near 21.5N by 06:00 AM UTC, today. It would then weaken gradually, recurve northeastward and then emerge into northwest Arabian Sea by night and move northeastwards towards Pakistan.

Gale winds of 60-70 knots with gusts of 75 knots would occur along and off of Oman coast at the time of landfall.

Storm Surge Guidance For Oman Coast
====================================
Storm surge of about 2 meters above the astronomical tide would occur around the time of landfall.

Forecast and Intensity
============================
12 HRS: 21.5N 59.5E - 60 knots (Severe Cyclonic Storm)
24 HRS: 23.0N 61.0E - 60 knots (Severe Cyclonic Storm)
48 HRS: 24.5N 65.0E - 50 knots (Severe Cyclonic Storm)
72 HRS: 26.0N 69.0E - 40 knots (Cyclonic Storm)
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1062. Ossqss
Quoting NRAamy:
They had a dingling line problem


a what?!


Kinda like one of those dingling participles, but different, LoL, I was not going to go there Amy... We know we can count on you :)

ROV's are really terminatorish in this case for sure. Let's hope they succeed..
Member Since: June 12, 2005 Posts: 6 Comments: 8186
Id expect first storm of season no earlier than June 21st or so....do u all agree??
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...best SciFi flick I have watched in a long time.
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Quoting NRAamy:
They had a dingling line problem


a what?!
LOL
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1056. pottery
Quoting CaicosRetiredSailor:
Pottery,

In reference to your discussion earlier concerning the "brown portion" of the escaping plume, the best theory I have seen is that is the portion which is coming up the drill pipe, and it has a different composition.

Could be. I think more gas. But I dont really know.
These ROV vids are totally awesome.....
Member Since: October 24, 2005 Posts: 0 Comments: 24390
1055. Ossqss
Quoting TampaSpin:


They had a dingling line problem......not sure but it looked like one fell all the way to the bottom....not sure if they cut it or not by mistake.


Thanks TS, we need this to work!
Member Since: June 12, 2005 Posts: 6 Comments: 8186
Quoting Baltimorebirds:
Hey weather456.A little quite on the blog today.


Well this blog works with the tropics so activity in both go hand in hand
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1053. NRAamy
They had a dingling line problem


a what?!
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Quoting Ossqss:
Hi all, just got back and popped on the ROV thing, anything good happen yet? Looks like they are going to drop it soon? TIA


They had a dingling line problem......not sure but it looked like one fell all the way to the bottom....not sure if they cut it or not by mistake.
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Thinking of 10n 50w I knew if I mentioned it, I could kill that system to your east pottery. So that being said look at the backup of convection and energy in the sw Caribbean,
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1049. Ossqss
Hi all, just got back and popped on the ROV thing, anything good happen yet? Looks like they are going to drop it soon? TIA
Member Since: June 12, 2005 Posts: 6 Comments: 8186
I don't even see mention of strong storms, much less severe.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Pottery,

In reference to your discussion earlier concerning the "brown portion" of the escaping plume, the best theory I have seen is that is the portion which is coming up the drill pipe, and it has a different composition.
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good evening 15!!!!!!
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Today I spent most of the day with the national disaster preparedness team to assess tropical cyclone damage to the Leeward Islands. The last major hurricane to really affect the Leeward Islands was Georges of 1998, almost 12 years ago and since then, a huge amount development and population growth occurred. Damages estimated to be in the tens of millions of ECD dollars from a strike this season which is higher than normal for the islands. One the upside, infrastructure is up to code.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
if they hold we could have some waterspouts or short lived isolated tornado IMO as some land friction would occur w/such a strong westerly surge..
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1042. xcool
Weather456 HEY
Member Since: September 26, 2009 Posts: 2 Comments: 15684
1041. pottery
I wonder what the guys have up on the surface?
When the flow from that 21" pipe gets into what looks to be about 10" on that cap, they gonna have a gusher topside!
Member Since: October 24, 2005 Posts: 0 Comments: 24390
All NO I think they severed a line......dam it
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Good evening guys
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1037. pottery
Quoting skepticall2:


I went there and had problems too loading the player.

Go to CNN website, click the link. Thats all I did. Been good for days.
Member Since: October 24, 2005 Posts: 0 Comments: 24390
hey storm,what do you think about isolated severe chances tonight along SWFL's coast as that area of convection in the gulf moves asshore???
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1034. pottery
Quoting skepticall2:


It might be a MAC problem. Still having it here.

Having an issue here too, on a Mac.
Go to CNN, working fine
Member Since: October 24, 2005 Posts: 0 Comments: 24390
Quoting stillwaiting:




any storms from the west should arrive after midnight,any storms in the next 2/3hrs would be from seabreezes,the real fun would occur after midnight as a surface trough passes thru...


I'm not too concerned about the storms to be honest. They always look impressive until they hit the coast and then fall apart.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting Jeff9641:
Very strong Storms set to move into Tampa in about 3 hours. Get ready Tampa your turn is coming.


They will likely diminish by then sorry to burst your bubble.
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Interesting system NE of Hispanola, is this associated with ex-91L?

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

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