Grading the forecasts for Irene; Katia organizing; threat of a Gulf of Mexico storm

By: Dr. Jeff Masters , 4:38 PM GMT on August 31, 2011

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Recovery from the destruction left behind by Hurricane Irene continues in the mid-Atlantic and New England states today. Irene's storm surge, winds, and record rains likely did $3 - $6 billion in insured damage to the U.S., according to AIR-Worldwide. Since actual damages are typically double insured losses, Irene's total price tag will likely be $6 - $12 billion, making it one of the top 20 most expensive hurricanes to hit the U.S. Irene will be one of the most expensive Category 1 hurricanes ever; the record is held by 1972's Hurricane Agnes, which did $11.8 billion in damage (2010 dollars.) As AIR Worldwide notes in their press release, part of this damage is due to the costs of evacuation for the 2 million people that were evacuated. It costs approximately $1 million to evacuate each mile of U.S. coast warned (Aberson et al., 2006). This number will be higher for more densely populated areas of the coast, such as Miami, and may be a factor of six lower for the North Carolina coast (Whitehead, 2003). So were we over-warned during Irene? Could the costs of the storm been lower due to better forecasts and fewer evacuations?


Figure 1. The National Hurricane Center forecast for Hurricane Irene issued five days before it hit Long Island, NY, compared with the actual track of Irene. The landfall locations along the coasts of North Carolina, New Jersey, and New York were pretty much spot-on, though the time of arrival was off by a few hours. The NOAA Environmental Visualization Laboratory has a nice satellite animation of the storm's track superimposed on the NHC's cone of uncertainty forecast.

Well, the official NHC track forecast for Irene was remarkably good; the 5-day forecast was pretty much spot-on for landfall locations, though the timing of when the storm would arrive at the coast was off by a few hours (Figure 1.) This remarkably accurate forecast undoubtedly reduced the costs of unnecessary preparations, and probably saved many lives. NHC track forecasts have improved by over 50% since 1990. The average error in a 24-hour forecast was about 105 miles in 1990, and has averaged near 50 miles the past few years. NHC director Bill Read stated in a interview this week that had Hurricane Irene come along before the recent improvements in track forecasting, hurricane warnings would have been issued for the entire Florida, Georgia, and South Carolina coasts. At an average cost of $1 million per mile of coast over-warned, this would have cost over $700 million. We can credit the investments made in hurricane research, improved satellites, and better computer models for the majority of this improvement. When we consider that government funding for hurricane research has averaged $20 million per year during much of the past two decades, the roughly $200 million spent on hurricane research over the past 20 years was paid back by over a factor of three during just one storm. According to a 2007 presentation at the 61st Interdepartmental Hurricane Conference, the improved hurricane forecasts between 2000 - 2006 resulted in savings of $3 billion compared to what the forecasts of the 1990s would have cost.

What about intensity forecasting?
Progress in making better intensity forecasts of hurricanes, though, has lagged. Over the past twenty years, there has been virtually no improvement in forecasting how strong or weak a hurricane will grow. NHC predicted Irene would hit North Carolina as a Category 3 storm, but it hit at Category 1 strength. Had the intensity forecast been better, many evacuations that were done for Irene could have been avoided. The failure of the intensity forecast led to many accusations that the storm was over-hyped, and an unnecessary amount of expensive preparations and evacuations were done. While I did see some over-hype by the media, I did not think it was more excessive than what has been the case for previous hurricanes. Nate Silver of the New York Times makes some interesting comparisons of the media attention given to Irene versus previous storms, and finds that Irene had about the same amount of media attention as hurricanes Ike and Gustav of 2008. Given in inexperience of the mid-Atlantic and New England coasts with hurricanes, our lack of skill in making intensity forecasts, and the potential for high storm surge damage due to the size of Irene and its landfall during the highest tides of the month, I thought that the overly-cautious approach to evacuations along the coast was warranted.

Better intensity forecasts threatened by budget cuts
Better intensity forecasts of hurricane are possible, but it will take a large investment in hurricane research over an extended time to do that. Such an effort is underway; we are currently in year three of a ten-year program called the Hurricane Forecast Improvement Project (HFIP), funded at just over $1 million per year. The goals of the HFIP are to reduce the average errors of hurricane track and intensity forecasts by 20% within five years and 50% in ten years with a forecast period out to 7 days. In an interview I did last fall with the leader of the project, Dr. Frank Marks of NOAA's Hurricane Research Division, he expressed to me optimism that the program could meet its objectives, provided it remains fully funded. Some of the experimental computer models developed by HFIP have done very well so far during the 2011 hurricane season, so I see reason for optimism, too. However, this project is in serious danger of failure, due to the current budget-cutting emphasis in Washington D.C. A key tool we need to make better intensity forecasts is to have detailed measurements inside the core of the hurricane from instrumented aircraft. Without detailed observations, there is no hope of making a good intensity forecast, no matter how good your model is. During Hurricane Irene, the two P-3 hurricane hunter aircraft and G-IV jet operated by NOAA's Aircraft Operations Center flew continuously into the storm, taking detailed measurements via dropsonde and Doppler radar that were fed in real time to the experimental HFIP computer models. In theory, these measurements by the Hurricane Hunters should be able to significantly improve our intensity forecasts over the coming years. However, the current proposed budget from the House of Representatives mandates a $400 million cut for NOAA, and the NOAA Hurricane Hunters are slated to have their budget cut by 40%, from $29 million to $17 million per year. If these cuts materialize, the ability of the NOAA Hurricane Hunters to continue to aid improvements in hurricane forecasting will be seriously impacted. Many of the critical technologies used operationally now by the Air Force Hurricane Hunters and NOAA jet to improve hurricane forecasts--dropsondes, real-time high-density observations, and the SFMR surface wind measuring instrument--were developed on the NOAA P-3s as research projects, then were migrated to operational use once they proved their worth. The cost of hurricane damages in the U.S. has been doubling every ten years since the 1960s, and is expected to continue to double every ten years, even without the likely coming increase in storm surge damages due to accelerating sea level rise. A Category 1 hurricane doing $10 billion in damage should be a wake-up call that we need to continue our investments in hurricane research to reduce the costs of the inevitable coming storms. Slashing funding by 40% for a research group that was instrumental in saving $700 million in costs from just one storm makes no sense, and I hope Congress will reconsider the proposed cuts for NOAA's Aircraft Operations Center.

References
Whitehead, J.C., 2003: "One million dollars per mile? The opportunity costs of Hurricane evacuation", Ocean and Coastal Management 46, 1069.

Tropical Storm Katia
Tropical Storm Katia continues its long trek across the Atlantic Ocean today, and is expected to arrive at a position several hundred miles north of the Northern Lesser Antilles Islands by Monday. At this time, it appears unlikely that the islands will receive tropical storm-force winds from Katia. Satellite images show that Katia is a well-organized storm with plenty of heavy thunderstorms. The storm has good upper-level outflow channels to the north and south, is under light wind shear, and is traversing warm waters, so it should be able to overcome any dry air problems by Thursday and intensify into a hurricane. It is looking less likely that Katia will affect land. Dr. Bob Hart's Historical Tropical Cyclone Probability web page suggests shows that tropical storms in Katia's current position have an 11% chance of hitting North Carolina, a 12% chance of hitting Canada, a 5% chance of hitting Florida, and a 62% chance of never hitting land. It will be two more days before our computer models will be able to assess the threat to land, though, as Katia is currently still very far out at sea.


Figure 2. The morning run of the GFS Ensemble prediction. The ensemble prediction was done by taking a lower-resolution version of the GFS model and changing the initial distributions of temperature, pressure, and humidity randomly by a few percent to generate an ensemble of 20 different computer projections of where Katia might go. The operational (highest-resolution) version of the GFS model (white line) is usually more accurate, but the ensemble runs give one an idea of the uncertainty in the forecast. Very few of the ensemble members are currently showing a threat to the U.S. Canada is more at risk than the U.S., according to this model.

Gulf of Mexico disturbance a threat to develop
Surface winds over the Gulf of Mexico are rising today in advance of the approach of a tropical wave currently over the Western Caribbean, western tip of Cuba, and Mexico's Yucatan Peninsula. This wave is headed west-northwest at 10 - 15 mph, and is under a high 20 - 30 knots of wind shear. The wave is slowly beginning to build an increased amount of heavy thunderstorms, and this process will accelerate on Thursday when the wave enters the Gulf of Mexico. By Friday, when the wave will be near the Louisiana or Texas coast, wind shear is expected to drop to low to moderate levels, and the wave may be able to organize into a tropical depression. This process will likely take several days, and formation of a tropical depression is more likely Saturday or Sunday. NHC is giving the wave just a 10% chance of developing into a tropical depression by Friday morning. Regardless, this system will spread heavy rains to portions of the Gulf Coast by Friday, with the Upper Texas coast and the coast of Louisiana the most likely recipients of heavy rain. Strong onshore winds raising tides to 1 - 2 feet above normal are likely over Louisiana beginning on Friday, and coastal flood statements have been issued for the region. Three of our four top models for predicting tropical cyclone development forecast that a tropical depression will form this weekend or early next week, and I think it is at least 50% likely we will have Tropical Depression 13 on our hands by Monday. However, steering currents will be weak in the Gulf, and it is difficult to predict where the storm might go.The GFS model has a possible tropical depression forming by Sunday off the coast of Mississippi, then moving east-northeast over the Florida Panhandle on Monday. The ECMWF model forms the storm on Monday off the coast of Texas, and leaves the storm stalled out there through Wednesday. The UKMET model forms the storm Saturday off the coast of Louisiana, and leaves it stalled out there through Monday. If the storm did remain in the Gulf of Mexico for three days as some of the recent model runs have been predicting, it would be a threat to intensify into a hurricane.

Related posts:
Big money for hurricane research? My October 27, 2006 post.

Jason Samenow at the Washington Post has an excellent post, Hurricane Irene hype: over the top media coverage or justified?

Andrew Freedman at the Washington Post talked earlier this month how lack of funding to replace an aging weather satellite may degrade weather forecasts beginning in 2016. Michael Conathan at climateprogress.org had a more detailed analysis of the issue in a February blog post.

Andy Revkin at the New York Times discussed in his Dot Earth blog yesterday how cuts in the USGS stream gauge network will hamper flood forecasting.

Jeff Masters

Lincoln Road (31337)
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Quoting cheetaking:
93L is what scares me at this moment. There is a VERY warm Loop Current eddy dominating the central Gulf of Mexico, as seen in the following image. So if 93L does develop into a TD within the next couple of days, we could have explosive intensification as a very real possibility.



With the current steering map, odds are very good that this storm will be steered NNW along the high over the Bahamas, and then blocked by the Texas high and turned west. As the pressure drops, the steering becomes weaker and weaker, so it will likely slow down as it develops.



So, yeah, we might really have to keep our eyes on this one. If it can get its act together and organize into a depression before reaching the eddy, we may very quickly have a hurricane on our hands headed for north Texas. The only thing keeping it from doing so at the moment is the 20-30 kts of shear it's under.







If it explosively intensified which IMO it won't because of the shear and lack of organization, it would be more prone to turn northward much earlier. This would bring LA-Mississippi under the gun.
Member Since: August 25, 2011 Posts: 0 Comments: 54
The three of them that go right are practically right over the top of my house in NW Florida, oh no what should I do LOL! BTW, my house was newly built in 2005 after Ivan thankfully and up to the new code. We moved in late May and took a direct hit from Dennis in July of 2005 and suffered no damage other than a couple shingles flipping up and breaking off. So unless we get something stronger than that I'm not really too worried!

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836. 7544
two ull to the nw of katia could this change her path
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Quoting HoustonTxGal:
UGH!! stop with the politics already or take it somewhere else. This is a WEATHER blog!

It is, usually--though today it's also a blog about Congress slashing funding for NOAA's Aircraft Operations. That's an issue obviously near and dear to many of this forum's users, so I suppose it's natural and expected that people will talk about it.
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Quoting AtHomeInTX:


Lol. A friend of mine has a theory, there's so many people in Houston because they can't find their way out. Lol. :)


That is so true!!
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Really not seeing alot of organization to this thing entering the central GOM. Also, no real surface center so no idea of the true motion, although its something like NNW-N most likely. GFS continuing to say a Florida or LA storm. Nogaps still wants a Houston storm.


Whats interesting is that all the models want a storm, despite the lack of organization.
Member Since: August 25, 2011 Posts: 0 Comments: 54

Quoting HoustonTxGal:


The Hardy and Beltway 8 have helped, but there is no escaping Houston Rush Hour.. LOL

Lol. A friend of mine has a theory, there's so many people in Houston because they can't find their way out. Lol. :)
Member Since: August 24, 2010 Posts: 0 Comments: 258
Quoting nrtiwlnvragn:
717. Seastep

Page 37


Thanks. I'll check it out.
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Ok, Im trying to understand 93Ls track. I want Texas to get 93L/Lee. The high over Texas is going to retreat some, but not long enough for 93L to be drawn inland. So its going to sit in the GOM watering the Texas and La coast. If the trough does not pick up 93L to the N, then the high will fill back in to the N and shoot 93L SW to Mexico, Hopefully giving Texas some much needed RAIN! Is this right?
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Quoting Patrap:
Plan of the Day


000
NOUS42 KNHC 311730 AMD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0130 PM EDT WED 31 AUGUST 2011
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 01/1100Z AUGUST TO 02/1100Z SEPTEMBER 2011
TCPOD NUMBER.....11-092 AMENDMENT

I. ATLANTIC REQUIREMENTS -- ADDED
1. FLIGHT ONE --TEAL 70--SUSPECT AREA IN CNTRL GULF
A. 01/1800Z
B. AFXXX 01HHA INVEST
C. 01/1630Z
D. 25.0N AND 90.0W
E. 01/1730Z TO 01/ 2300Z
F. SFC TO 10,000FT

FLIGHT TWO --TEAL 71
A. 02/0600Z ,1200Z
B. AFXXX 0213A CYCLONE
C. 02/0430Z
D. 25.5N AND 95.5W
E. 02/0530Z TO 02/1200Z
F. SFC TO 15,000FT

2. OUTLOOK FOR SUCCEEDING DAY: CONTINUE 6 HRLY FIXES IF
SYSTEM DEVELOPS AT 02/1800Z.


when will recon be available for Katia?
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Quoting islander101010:
no rules this yr odd storms and irene 957 mb tropical storm? it would seem if the gulf system ramps up he could draw katia in


That's a scary thought.
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Katia is heading west. not wnw

just RGB observations.
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93L is what scares me at this moment. There is a VERY warm Loop Current eddy dominating the central Gulf of Mexico, as seen in the following image. So if 93L does develop into a TD within the next couple of days, we could have explosive intensification as a very real possibility.



With the current steering map, odds are very good that this storm will be steered NNW along the high over the Bahamas, and then blocked by the Texas high and turned west. As the pressure drops, the steering becomes weaker and weaker, so it will likely slow down as it develops.



So, yeah, we might really have to keep our eyes on this one. If it can get its act together and organize into a depression before reaching the eddy, we may very quickly have a hurricane on our hands headed for north Texas. The only thing keeping it from doing so at the moment is the 20-30 kts of shear it's under.



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821. 7544
the blob is moving nne right the one off the west coast of fl ? is that 93l too
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Quoting AtHomeInTX:




Gulp! Oh boy. No, no I can do this. Lol. Sorry I'm usually a half empty person. No problem. Cheer up  Tex!  : D  We don't know all hope is lost yet. Ok, so that's half way optimistic. I'm trying! Lol. ;-)


:) lol....
Member Since: July 2, 2009 Posts: 0 Comments: 2811
no rules this yr odd storms and irene 957 mb tropical storm? it would seem if the gulf system ramps up he could draw katia in
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Plan of the Day


000
NOUS42 KNHC 311730 AMD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0130 PM EDT WED 31 AUGUST 2011
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 01/1100Z AUGUST TO 02/1100Z SEPTEMBER 2011
TCPOD NUMBER.....11-092 AMENDMENT

I. ATLANTIC REQUIREMENTS -- ADDED
1. FLIGHT ONE --TEAL 70--SUSPECT AREA IN CNTRL GULF
A. 01/1800Z
B. AFXXX 01HHA INVEST
C. 01/1630Z
D. 25.0N AND 90.0W
E. 01/1730Z TO 01/ 2300Z
F. SFC TO 10,000FT

FLIGHT TWO --TEAL 71
A. 02/0600Z ,1200Z
B. AFXXX 0213A CYCLONE
C. 02/0430Z
D. 25.5N AND 95.5W
E. 02/0530Z TO 02/1200Z
F. SFC TO 15,000FT

2. OUTLOOK FOR SUCCEEDING DAY: CONTINUE 6 HRLY FIXES IF
SYSTEM DEVELOPS AT 02/1800Z.
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Quoting TexasHurricane:


Now it is your turn. :)



Gulp! Oh boy. No, no I can do this. Lol. Sorry I'm usually a half empty person. No problem. Cheer up  Tex!  : D  We don't know all hope is lost yet. Ok, so that's half way optimistic. I'm trying! Lol. ;-)
Member Since: August 24, 2010 Posts: 0 Comments: 258
in which round of invests is this new 93L?
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shear is really high right now over 93L. bath water or not, until the UL pattern changes, nothing major will happen. shear should lessen in the next couple days.
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812. Skyepony (Mod)
Quoting wunderweatherman123:
Hello Everyone! its been 4 days without power from Irene! whats cookin in the tropics?


Welcome back..We got 93L in the GOM & Katia simmering in the Atlantic.
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Quoting Skyepony:


That's why I say probably..could surprise us yet..definitely starting to look like a 9.


Knowing how this season has been, could be Lee. LOL
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I think the rule of thumb for me at least in terms of cyclones affecting land is around 20n: 60w.

Katia is a potential East Coast landfall storm. Potential exists for a peak in intensity within 4 days and thereafter some appreciable weakening is possible do to the presence of the upper level low over the central Atlantic Ocean creating the weakness in the ridge. However models forecast this feature to weaken before Katia is within the shear axis so this needs to be watched, perhaps the reasoning for the NHC to only show a peak intensity of 120mph in 5 days.
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Quoting Some1Has2BtheRookie:


True, very true. It is a bit of a misnomer to call it "rush hour". There does not appear to be much rush involved and it can last for mare than hour. Kinda like the way it was this morning. LOL


I have found Houston Rush Hour to be just about any time I try to get across town! LOL
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It's marked 93L now in the Gulf.
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Hello Everyone! its been 4 days without power from Irene! whats cookin in the tropics?
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Quoting scott39:
I think it formed alot farther E than that Earlier?


I'm not sure. You could be right. I missed earlier discussions. Everyone still grasping at straws at this point.
Member Since: August 24, 2010 Posts: 0 Comments: 258
801. Skyepony (Mod)
Quoting P451:


It's trying to develop sub-tropical. There is some model support for it to do so. Although the models develop it rather quickly when we all know STS development from such features takes 3-5 days or more. So I don't know what to make of it really.


That's why I say probably..could surprise us yet..definitely starting to look like a 9.
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Quoting scott39:
It looks like 93L wants to go W but is pulled back to the NE due to the trough. I dont see, with the future growing intensity of 93L and the trough pulling it N, how it can go W and inland into S Texas. IMHO Texas.


Depends on how quickly it organizes into a deeper low. I've seen GOM blobs like this explode into a strong TS overnight and catch people unprepared. Ironically, this happened almost exactly 10 years ago right after 9/11. Remember Gabrielle? This was the first TS I ever shot ... and it shows :-)

TS Gabrielle Sarasota FL sept 14, 2001

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Quoting HoustonTxGal:


The Hardy and Beltway * have helped, but there is no escaping Houston Rush Hour.. LOL


True, very true. It is a bit of a misnomer to call it "rush hour". There does not appear to be much rush involved and it can last for mare than hour. Kinda like the way it was this morning. LOL
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The key thing to look for with Katia regarding a recurve or affecting land is if she is at 15N/45W or just below 15N at 45W, If at 15N/45W or just below 15, then chances of affecting land greatly increases, if above 15N at 45W, chance of affecting land go way down, another one of John Hope rules I think, could be wrong though!
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Quoting Some1Has2BtheRookie:


Actually, it is better than it was before they built them. The main factor is, I believe, there are fewer cars on the road now, around Houston. Three years ago there were many more cars on the roads and much more congestion.


The Hardy and Beltway 8 have helped, but there is no escaping Houston Rush Hour.. LOL
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792. DFWjc
Quoting AtHomeInTX:


The high is supposed to back off to our west. When that high builds back in it will turn the storm SSW. That's another high. I think. Lol


(sighs)
Member Since: July 19, 2011 Posts: 1 Comments: 1006

Quoting DFWjc:


But i thought the Texas High was coming back through the panhandle pushing anything East?

The high is supposed to back off to our west. When that high builds back in it will turn the storm SSW. That's another high. I think. Lol
Member Since: August 24, 2010 Posts: 0 Comments: 258
Quoting tropicfreak:



Let's compare
img src="">
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Quoting DFWjc:


But i thought the Texas High was coming back through the panhandle pushing anything East?


So is that good for the TX rain chance? OH I SURE HOPE SO!!
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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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