NHC increases hurricane forecast lead times
The National Hurricane Center (NHC) announced today that beginning with the 2010 hurricane season, their hurricane and tropical storm watches and warnings for the U.S. coast will be extended in time by an additional 12 hours. Warnings will now be issued 36 hours in advance instead of 24 hours, and watches will be issued 48 hours in advance, instead of 36 hours. The increase in lead time for watches and warnings has been made possible by the tremendous improvement in hurricane track forecasts, which have improved by over 50% in the past twenty years (Figure 1). "With increases in population and infrastructure along vulnerable U.S. coastlines, emergency managers need more lead time in order to make life-saving decisions regarding evacuations", said Bill Read, director of NOAA's National Hurricane Center, in today's press release.
Figure 1. Average track errors for NHC Atlantic tropical storm and hurricane forecasts issued between 1990 - 2008. Track errors have improved by over 50% in the past 20 years. Image credit: National Hurricane Center.
Commentary
NHC has been debating for a number of years how best to "invest" the gains accrued from the steady improvement in hurricane track forecasts. One obvious savings from these better hurricane forecasts has come from the reduced evacuation costs. When a hurricane warning is issued 24 hours before the expected arrival of hurricane-force winds at the coast, 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). According to a 2007 presentation at the 61st Interdepartmental Hurricane Conference, the length of coast warned decreased significantly in the past decade. During the decade of the 1990s, the average length of a hurricane warning was 455 miles, but that fell to just 335 miles between 2000 - 2006. Thus, an average of 120 fewer miles of coast were warned, at an average savings of $120 million per hurricane warning issuance. During this period, 17 storms requiring 25 hurricane warnings occurred. If the costs of coastal evacuations are indeed $1 million per mile, the improved hurricane forecasts between 2000 - 2006 resulted in savings of $3 billion compared to what the forecasts of the 1990s would have cost.
However, the new increased lead times for hurricane watches and warnings will lead to an increase in the length of coast warned, due to the higher uncertainties in hurricane tracks at longer forecast lead times. Between 2004 - 2008, approximately 25% of the coast that was placed under a hurricane warning actually received hurricane force winds; this percentage was 20% for areas placed under a hurricane watch. These percentages will decline with the new increased watch and warning lead times, costing money in unnecessary evacuations, and leading to increased complacency in the warned population due to too much "crying wolf".
Balanced against these increased costs is the potential disastrous loss of life should a hurricane hit an unprepared, heavily populated shoreline. With the U.S. population continuing to increase rapidly in coastal regions, the time needed to evacuate vulnerable populated regions is increasing. For example, evacuation times for the major urban areas of Texas are 28 - 34 hours for a major hurricane. Though the costs of overwarning the coast is significant, the savings in both human lives and dollars from increased warning times should outweigh these costs. In the 2002 book, Hurricane: Coping With Disaster, Dr. Hugh Willoughby, former director of the Hurricane Research Division of NOAA's Atlantic Oceanographic and Marine Laboratory, analyzed hurricane death statistics. In 1950, about 70 U.S. residents died per year in hurricanes. In the 50 years since, the coastal population expanded by a factor of 3.2, so if we were managing the hurricane problem the way we did in 1950, we would be losing about 220 people a year. The long-term average is still about twenty per year, not including the deaths due to the levee failures during Katrina. That means we're preventing about 200 deaths per year compared with 1950. How much are these saved lives worth? A life, is, of course, priceless, but in the cold world of economics, the value of life-saving scientific research and government regulations is estimated using statistics of what people are willing to pay to avoid certain risks, and what extra money employers pay their workers to take on additional risks. This data comes primarily from payroll statistics, but opinion surveys also play a role. In 2004, the Environmental Protection Agency (EPA) valued an American life at $8 million. EPA cut the value of a life by 8% that year, and a further 3% in May 2008, making the economic value of a life $6.9 million in today's dollars. The Department of Transportation gives a lower figure of a life as being worth $5.8 million. Using this number implies a savings of about $1.2 billion per year for the 200 lives saved per year by better hurricane warnings and evacuations. Today's decision by NHC to increase warning times should continue this trend of saving lives, which will also provide considerable monetary benefit. Despite the increased costs and dangers of "crying wolf" too often due to overwarning the coast, I believe that the double value of saving lives--for both the intrinsic and monetary value of a human life--makes NHC's move of increasing warning and watch times the right call.
References
Whitehead, J.C., 2003: "One million dollars per mile? The opportunity costs of Hurricane evacuation", Ocean and Coastal Management 46, 1069.
I'll have a new post on Thursday or Friday.
Jeff Masters
Reader Comments
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It looks like the models have come a long way. The models have always had trouble with stalling storms. I am surprised it made such a big difference. Your explanation was good.
We are forecast to break daily cold temperatures tomorrow but the predictions have been consistently colder than measured.
AOI
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AOI
Humor in Comments
Slab house, my well pipes are wrapped and my faucets are each covered by a styrofoam box. No problems here.
(The faucets get some warmth from the exterior wall of the house using these...the open part goes there.)
Its scheduled to stop before the 13th :)
Nice jab!
MOdel 06 GENS zdp Image Loop
Thats exactly what I'm using
As suspected the models were too quick in trying to shift the massive arctic high eastward over the weekend…hence will need to cut highs on Saturday and Sunday and lower lows for Sunday and Monday mornings. We will be looking at 3 mornings with hard freezes with Sat and Sun mornings looking the coldest.
Yup, looking like another round of high 20's to low 30's for SE FL.
Then again broken pipes are not cheap either.
I sure hope we don't have medieval fair practice in the snow this weekend. I will find out if you can fit a parka under a monk's outfit and if those chemical hand warmers work.
Orcasystems, good morning, can you post another updated temp map.
Those temperatures over the Nothern Rockies and Northern Plains looks real nasty :0(
Hey Tampa! I notice on that model it shows round two on Sat for the Panhandle/Ala/Miss gulf coast! Whats up with that? Is that our shortwave moving thru? Or whats left of it?
Of further note is that now the Canadian and NAM models are predicting a shortwave disturbance to go over SETX Friday... when it doesn't get above freezing, or stays very close to freezing.
That would be bad. And snowy/icy.
Feel lucky...does anyone here remember the old Highway 60 through WV? I ran it in January 1981 in an 18 wheeler and thought sure we were going to go over the edge for a solid 2 hours
yeah, pretty darn cold!
Lovely, wonderful, fantastic, great!! Looks like a snow event?
If we get snow in Tampa, I will just die. LOL
Possible. The GFS is still incredibly dry on it, and the GFS has been excellent both long- and short term this winter. The NWS here in Houston went with the GFS forecast for now, waiting on the Euro and GFS to change.
Also, not sure what DFW will get, the shortwave is expected to stay south either way. (the Siberian high is muscling everything out of the way, and may actually help to dissapate the shortwave)
On 12-27-09, when NWS DFW, TX started talking about Siberian Air and the Polar Vortex, it came a "big shock/surprise".
On 1-6-10, a whopping 10 calendar days since they mentioned this, HERE IT COMES!! Talking about a LOW NEAR 12F EARLY SAT. Now, I am beginning to think ALL the NWS offices in TX are probably being CONSERVATIVE with the morning lows. Might be single digits for N TX??
GFS
36 hrs
48 hrs
60 hrs
Highly doubt it, but you never know what mother nature can do.
I don't think the NWS offices are being intentionally conservative with the temps. The wildcards right now are the positioning of the high, and also the shortwave coming in. If the shortwave comes in and spreads clouds like the Canadian is predicting, lows are higher. If it doesn't, like the GFS is predicting, lows are lower.
The NWS here in Houston has been following the GFS pretty closely, and actually extending out the super-cold low temps through Sunday. Also, keep in mind the most cold air is 24-36hr out, and exact numbers will be hard to pin down this far out.
edit- to clarify, by "exact numbers", I mean that right now, the NWS is using a range for low temps, and just putting down the midpoint. (for example, the low forecast for Friday night is "lows near 20")
Well if it does ill be about 10 miles north of Orlando in Winter Park Florida and ill take pictures and post them. That would be amazing. =)
May have to take a short drive up north with the family if that comes to pass. Any chance of the snow line moving south of lake o a tad and east :-D ?
That'll sure be an interesting Saturday if it happens. I'll have my Camera ready just in case... hehe.
They are just a few short miles from where I live, and I registered a morning low of 20.6 degrees. Makes sense the temps registered the same.
I did see the latest GFS runs and I can't believe what I saw, which is a possible storm brewing just off the NE FL coast, which definitely would make weather here in Jax exteremely interesting.
What a turnaround with the models for the past 24 hours.
Hey, I live in Palm Coast. I wonder if the GFS will back it west more and create a "Florida snowstorm".. Guess it's a wait and see thing, looks like a nor'easter right off our doorstep.
Forecast for Rapid City
Updated: 3:26 am MST on January 6, 2010
Winter Weather Advisory in effect until 5 am MST Thursday...
chancesnow
Today
Windy...cloudy. Snow in the morning...then chance of snow in the afternoon. Blowing snow in the morning...then areas of blowing snow in the afternoon. Snow accumulation around 1 inch. Highs around 8. Northwest winds 25 to 35 mph. Chance of snow 80 percent. Wind chill readings 17 below to 27 below zero.
Viewing: 651 - 701
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