NHC increases hurricane forecast lead times

By: Dr. Jeff Masters , 7:27 PM GMT on January 05, 2010

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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

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There is something seriously wrong with this picture......




How is it suppose to snow with all the sunny skies :(
Member Since: Posts: Comments:
Quoting AussieStorm:

is that -17F or -17C????


-17F
Member Since: July 14, 2008 Posts: 1 Comments: 9628
Tallahassee's overnight low on Sat into Sunday is predicted to be 14 degrees atm!
Member Since: Posts: Comments:
Quoting unclemush:
This is just wrong.You people down there are about the same temp as I am up here.49801

We (in SE LA) have been colder than my mom's location in southern Wyoming since yesterday evening, now, too. Yes, seems wrong, doesn't it?
Member Since: August 16, 2007 Posts: 6 Comments: 12461
My car said it was 33 degrees this morning. They say on the news we face another full week of cold temps here. It's crazy!
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Tallahassee got down to a warm and toasty 17 degrees last night. Now 28 degrees.
Member Since: Posts: Comments:
Quoting IKE:
Nice pictures Aussie.

Good evening to you.

Good Evening IKE

BTW IKE, they are not pictures. They are streaming cams.
Member Since: Posts: Comments:
632. IKE
Nice pictures Aussie.

Good evening to you.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
If I'm wrong...crow me.


Taste like chicken!
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Notice how close the GFS is with snow in Northeast Florida. It's like a Nor'easter forming off the East Coast. Just 50 miles east with that batch, heavy snow would be flying in my area. Wow, wonder if it will continue to move west.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
Storgatan Street, Morbylanga,Sweden
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Brest, France
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Quoting RitaEvac:
-17 in Havre, Montanna

is that -17F or -17C????
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626. IKE
Quoting mossyhead:
Crestview's forecast calls for snow, while Defuniak's call for rain. I go for Crestview's more because they are on the east side of their forecast zone, while Defuniak's is on the west side of their forecast zone. There is only 30 miles between Crestview and Defuniak.


I noticed the difference too. Someone is going to be right or wrong. Or maybe they zero in tonight on their forecasts.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
-17 in Havre, Montanna
Member Since: July 14, 2008 Posts: 1 Comments: 9628
Quoting IKE:


I still see a chance of rain changing to snow here in Defuniak Springs,FL. before it ends.

Then a 2nd chance for flurries on Friday or Friday night with the 2nd piece of energy.

I'll say that between now and Saturday it at least flurries here.

If I'm wrong...crow me.
Crestview's forecast calls for snow, while Defuniak's call for rain. I go for Crestview's more because they are on the east side of their forecast zone, while Defuniak's is on the west side of their forecast zone. There is only 30 miles between Crestview and Defuniak.
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623. unf97
Doug, I am assuming you are referring to our Northern Mexico shortwave. Yeah, I took at look at the water vapor imagery and Doug you may be right. It appears that the confluent flow is beginning to "flatten out" the shortwave. Compared to yesterday, the s/w doesn't appear nearly as vigorous on WV imagery.
Member Since: September 25, 2007 Posts: 0 Comments: 1193
Good Evening everyone.
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15 Here in Knoxville. Looks like it got to 36 back home. I'm only a few miles from the Gulf there too. Very cold...Interested to see the models get a handle on the approaching shortwave and Low
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618. IKE
Quoting Jeff9641:
32 here in Orlando. I am very intrigued with this powerful piece of energy arriving in cold air on Saturday across Florida. I have a feeling that there will be snow with this disturbance as it crosses Florida Saturday and Saturday night. A lot of lift with this disturbance to maybe produce thunder with this as well. INTERESTING!!


I still see a chance of rain changing to snow here in Defuniak Springs,FL. before it ends.

Then a 2nd chance for flurries on Friday or Friday night with the 2nd piece of energy.

I'll say that between now and Saturday it at least flurries here.

If I'm wrong...crow me.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
617. unf97
Well, the mercury bottomed out at 20.6 degrees for the morning low.

The temp now at 22.7 degrees.


Member Since: September 25, 2007 Posts: 0 Comments: 1193
Looks like our shortwave is getting squashed pretty good.
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615. IKE
You can see the mother-lode racing through the northern plains. Should be interesting to watch.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
I got ya by 2 tenths of a degree Ike!

22.1F
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612. IKE
Quoting unf97:
Ike, the temp now at 20.7 degrees.

My morning low should be occuring right now.

By far the coldest temp of the season.

One thing for sure. This extended extreme cold spell will certainly kill off the mosquitos and bugs.

Looks like max temps today will only rebound to the mid 40s.

The high yesterday was 44.7 degrees.


My low was 22.3. Lowest of the season.

Sun now shining brightly in the eastern sky.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Member Since: Posts: Comments:
609. unf97
Ike, the temp now at 20.7 degrees.

My morning low should be occuring right now.

By far the coldest temp of the season.

One thing for sure. This extended extreme cold spell will certainly kill off the mosquitos and bugs.

Looks like max temps today will only rebound to the mid 40s.

The high yesterday was 44.7 degrees.
Member Since: September 25, 2007 Posts: 0 Comments: 1193
Good Morrrrrrningggg.

That graph begs two questions to me, what happened in 1994 that made everything so badly forecast, and why the improvement in long-term estimations in 2003?
Also can we cash in one of the 1.2 billion buck years to get a new scatterometer?
How many years would it have to work to pay for itself in human lives?
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Good Morning...

27.9F (rising slowly) in this rather cold CFL day.
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605. IKE
Quoting unf97:
Good morning Ike


What a frigid morning uh?


It is cold. The few weeds that I hadn't mowed in my front yard...gone....

22.5 my morning low...so far.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Checking in nw dade now 38 at sunrise.
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603. unf97
Good morning Ike


What a frigid morning uh?
Member Since: September 25, 2007 Posts: 0 Comments: 1193
602. IKE
Make that 22.6 for a low. Thirty minutes til I can see the sun looking out my window...in the eastern sky.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
601. unf97
Current temp now down to 21.2 degrees.
Member Since: September 25, 2007 Posts: 0 Comments: 1193
Morning all. We had 58 degrees outside my house in Nassau, Bahamas at 6:50 this morning.

Airport is reporting 59 as of 7 a.m. with a high of only 66. I think I need an extra layer....

Have a good day, all!
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Quoting leftovers:
e cent florida still no freeze this yr coldest of the yr so far 38 this beautiful morning



Close but no cigars in inland Palm Beach, 34.
In my 46 years of living in Jax, Fl., I've never seen cold like this last this long...never. I've never seen such a widespread area of the nation with such temps this long either.

Any one care to explain how global warming and the current conditions match up to each other.

Freezing my butt off in Mayport Naval Station, windchill of 20 degrees.
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596. IKE
Season low at my house....down to 22.8.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Here at the Delaware/Pennsylvania border it is 30 degrees. Wow Florida is colder then up here. Not too often I see that.
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594. IKE
Morning low here of 23.4...so far.

My low so far this season was yesterday morning at 22.9.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
593. IKE
Tampa Executive, Florida (Airport)
Updated: 16 min 7 sec ago
Clear
27 °F

Clear
Windchill: 23 °F
Humidity: 74%
Dew Point: 19 °F
Wind: 4 mph from the North
Pressure: 30.25 in (Rising)
Visibility: 10.0 miles
UV: 0 out of 16
Clouds:
Clear -
(Above Ground Level)
Elevation: 20 ft
Member Since: June 9, 2005 Posts: 23 Comments: 37858
591. IKE
AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
436 AM CST WED JAN 6 2010

.DISCUSSION...

AND SO THE WAITING BEGINS.

COLD CONDITIONS CONTINUE THIS MORNING...AND WILL LET THE HARD
FREEZE WARNING CONTINUE UNTIL ITS SCHEDULED 10 AM EXPIRATION...
WHILE NOTING THAT THE 10Z TEMP IN HALEYVILLE WAS 10 F. ALSO
INTERESTING TO NOTE THAT (AT THE SAME TIME)...IT WAS 3 DEGREES
COLDER IN MIAMI THAN IN SEATTLE...AND BHM WAS 9 DEGREES COLDER
THAN ANCHORAGE.

THE STORM SYSTEM THAT WE HAVE BEEN ANTICIPATING FOR QUITE SOME
TIME NOW HAS ENTERED THE LOWER 48...AND WAS DROPPING SOUTHEASTWARD
THROUGH THE NORTHERN PLAINS EARLY THIS MORNING. GFS AND ECMWF ARE
CONVERGING ON A SOLUTION FOR THE TIMING OF THE SYSTEM FOR OUR
AREA...WITH THE GFS SLOWING ITS SOLUTION DOWN JUST A BIT MORE THAN
THE ECMWF HAS SPED UP. THERE`S STILL A SMALL CHANCE THAT SOME
WESTERN COUNTIES COULD GET SOME PRECIPITATION BEFORE 12Z
THURSDAY...BUT THE BULK OF THE EVENT WILL HAPPEN DURING THE 07/12Z
TO 08/02Z TIME FRAME.

BASED ON MODEL SOUNDINGS...I STILL THINK THAT THE PREDOMINANT
PRECIP TYPE WILL BE SNOW GENERALLY NORTH OF A LINE FROM GEIGER
(NORTHERN SUMTER COUNTY)...TO CLANTON...TO OPELIKA. ALL SIGNS
CONTINUE TO POINT TO A BROAD 1 INCH ACCUMULATION IN THIS AREA.
THIS MAY BE ONE OF THOSE RARE EVENTS WHERE THE "SWEET SPOT" IS A
FAIRLY BROAD AREA...RATHER THAN A SMALLER OR BETTER DEFINED BAND.
HAVING SAID THAT...THERE VERY WELL MAY BE A COUPLE OF POCKETS OF
UP TO 2 INCHES OF SNOW ACCUMULATION. BUT I THINK THAT WILL BE MORE
OF THE EXCEPTION RATHER THAN THE RULE. SOUTH OF THE AFOREMENTIONED
LINE...THE PRECIP TYPE FORECAST IS A TOUGHER CALL. IT MAY BOUNCE
BACK AND FORTH BETWEEN RAIN AND SNOW A COUPLE TIMES IN CITIES SUCH
AS DEMOPOLIS...SELMA...AND MONTGOMERY. THIS COULD ACTUALLY LEAD TO
BIGGER PROBLEMS ONCE WE GET INTO THURSDAY NIGHT...SINCE THE
PREVIOUSLY STANDING WATER FROM THE DAY`S RAIN MAY FLASH FREEZE IN
THE WAKE OF THE COLD FRONTAL PASSAGE.

GRAPHICAL DETAILS OF SNOW AMOUNTS AND TIMING CAN BE FOUND IN OUR
MULTIMEDIA BRIEFINGS AND (EVENTUALLY) OUR GRAPHICASTS ON OUR WEB
PAGE.

MODELS SHOW SOME WRAPAROUND MOISTURE IN THE LOW LEVELS LASTING
THROUGH THE DAY FRIDAY...AND THEN ANOTHER RATHER STRONG SHORTWAVE
ROTATES THROUGH HERE ON SATURDAY. WOULDN`T BE SURPRISED TO SEE
SOME SNOW FLURRIES IN (AT LEAST) THE NORTHERN COUNTIES AT ANY TIME
DURING THIS STRETCH. PLUS...EVEN THOUGH I WOULDN`T ACTIVELY
FORECAST IT TO HAPPEN...WOULDN`T IT BE INTERESTING IF THE COLD
TEMPS AND WIND DIRECTION WERE JUST RIGHT TO CAUSE A LITTLE RIVER
EFFECT SNOW OFF THE TENNESSEE RIVER?

SATURDAY MORNING STILL LOOKS LIKE THE COLDEST OF THIS OUTBREAK. WE
SHOULD START CLIMBING OUT OF THE DEEP FREEZE ON SUNDAY...WITH THE
MODERATING TREND CONTINUING INTO THE START OF NEXT WEEK. LONG
RANGE MODELS ARE IN REMARKABLY GOOD AGREEMENT ON THE OVERALL LOOK
AND TIMING OF THE NEXT SYSTEM TO AFFECT US...CURRENTLY FORECAST
FOR THE MIDDLE OF NEXT WEEK.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
590. unf97
Good morning everyone!

I have a current temperature of 22.6 degrees at my home location in north Jacksonville this morning.

This is by far the coldest of the season, and it will probably drop another degree or two up through sunrise.

Also, this is the 4th morning in a row of hard freezes at my location.

I haven't had a chance to look at the model runs. But, I am expecting changes of course in regards to the developing GOM system.

BRB
Member Since: September 25, 2007 Posts: 0 Comments: 1193
589. IKE
I see the system now in the northern plains...dropping toward the ESE or SE.
Member Since: June 9, 2005 Posts: 23 Comments: 37858

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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.