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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Quoting Jeff9641:
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_108.shtml


I think the Northern part of Florida could easily see a good bit of snow. From Tallahassee Northward
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Quoting Jeff9641:
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_108.shtml


Your link :0)
Link
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Jeff9641, your link below:

Link
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Member Since: June 28, 2006 Posts: 25 Comments: 8306
Quoting Orcasystems:


Still warmer then Florida... mind you, thats not saying much



Hopefully not too much of the Arctic air spills over! IF it does, it's NOT in your forecast (wouldn't be a big surprise), it's gonna get a "wee bit nippy"!! NWS Seattle, WA has NO mention of cooler temps, either. It must be hard to forecast the Arctic air over the Canadian Rockies, no sarcasm intended!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
#466 -- xxxxxxxxxxxxx Bob yup
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Quoting Seastep:


But you don't hear about it much. Doc and Astro's posts made me look into it all.

Did you read the link? Would welcome your thoughts.

EDIT: Off board works.

OK, but L8R.
*getting dragged off to bed by the sandman*
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Bob Hope. What a great guy. Thanks, AIM.
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Quoting Chicklit:
AIM, now that is funny.
Congrats TampaSpin.
Me too. Goodnight.
Thanks for the memories, as Dean Martin used to sing...was it Dean?

G'night, Chicklit, if I didn't miss you.
Bob Hope, I think?
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Hard Freeze Warning for Tampa now......too late for farmers that went to bed...

... Hard freeze warning in effect until 9 am EST Wednesday...
... Freeze watch remains in effect from late Wednesday night
through Thursday morning...
... Freeze warning is cancelled...

The National Weather Service in Tampa Bay area - Ruskin FL has
issued a hard freeze warning... which is in effect until 9 am EST
Wednesday. The freeze warning has been cancelled. A freeze watch
remains in effect from late Wednesday night through Thursday
morning.

Cold and dry air remains in place across the region. Temperatures
will fall below freezing for 3 to 4 hours Wednesday morning.
Lowest temperatures will be over interior Pasco and Hillsborough
counties... and northern central Polk County where it could drop into the
lower to middle 20s before sunrise. Coastal locations will see a
bit more cloud cover... moving in from the Gulf... and may not reach
criteria durations. Similar conditions will exist for Thursday
morning.
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Quoting Bordonaro:
Where's Orca, the Arctic front spilled over to his side of the Canadian Rockies. Curious how cold the temps are there?


Still warmer then Florida... mind you, thats not saying much

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Quoting tiggeriffic:
talked to a guy in Virginia a little while ago...said their high for thursday is gonna be 9 degrees....

Hush yo' mouth. That's gotta' be in the Blue Ridge?


Oh really?
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This is for me :)

1014 PM EST TUE JAN 5 2010

...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE WEDNESDAY NIGHT
THROUGH FRIDAY MORNING...

A WINTER STORM WATCH REMAINS IN EFFECT FROM LATE WEDNESDAY NIGHT
THROUGH FRIDAY MORNING.

* ROADS MAY BECOME TREACHEROUS DUE TO SNOW AND DRIFTS...BLOWING
SNOW WILL REDUCE VISIBILITY AND TRAVEL MAY BECOME VERY
HAZARDOUS.

* ACCUMULATIONS OF FOUR TO SEVEN INCHES OF SNOW ARE POSSIBLE.

* THE STORM WILL BEGIN LATE WEDNESDAY NIGHT AND LINGER THROUGH
FRIDAY MORNING. THE HEAVIEST SNOW WILL FALL DURING THURSDAY
MORNING AND AFTERNOON.

* THE HEAVIEST SNOWFALL WILL BEGIN BEFORE THE THURSDAY MORNING
RUSH HOUR. ROADS WILL BECOME SNOW COVERED AND SLIPPERY AND
TRAVEL IS EXPECTED TO BE TREACHEROUS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

&&
Member Since: June 28, 2006 Posts: 25 Comments: 8306
Quoting tiggeriffic:
talked to a guy in Virginia a little while ago...said their high for thursday is gonna be 9 degrees....

Hush yo' mouth. That's gotta' be in the Blue Ridge?

Silver Spring, MD
Thursday: A mix of clouds and sun in the morning followed by cloudy skies during the afternoon. High 36F. Winds W at 5 to 10 mph.
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Where's Orca, the Arctic front spilled over to his side of the Canadian Rockies. Curious how cold the temps are there?
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting AwakeInMaryland:

LOL! Love it!
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This is totally irrelevant to the discussion.... I just saw it...and almost died laughing

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Quoting tiggeriffic:
ok...to bed i go...work by 7am...not cool with as cold as it is in the mornings lately... :(


have a good one! (:
Member Since: June 28, 2006 Posts: 25 Comments: 8306
AIM, now that is funny.
Congrats TampaSpin.
Me too. Goodnight.
Thanks for the memories, as Dean Martin used to sing...was it Dean?
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Daughter goes to school at Georgia Southern.....in Statesboro.....Florida born girl....she is freezing her booty off.

Here is her forecast:
Saturday Night
Mostly clear. Lows 15 to 20. Wind chill values as low as 5 above
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Quoting Chicklit:
Florida PanHandle, you ain't da owny one.
Daytona Beach (Ponce Inlet), FL, Daytona Beach, Florida (PWS)
Updated: 2 sec ago
33.9 °F
Clear
Windchill: 29 °F
Humidity: 69%
Dew Point: 25 °F
Wind: 3.0 mphfrom the West
Wind Gust: 6.0 mph
Pressure: 30.23 in (Rising)
Visibility: 10.0 miles
UV: 0 out of 16
Clouds: Clear -
(Above Ground Level)
Elevation: 12 ft


I know chicklit.. its goin to b cold for most CONSUS.. ;) i sure would like sum snow :P
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Quoting atmoaggie:


The idea that excessive fresh water in the Arctic would disrupt the sinking of cooling surface waters (which is heavily dependent on salinity) and stop the Atlantic thermohaline has been around for quite a while. This is one we covered back in college.


But you don't hear about it much. Doc and Astro's posts made me look into it all.

Did you read the link? Would welcome your thoughts.

EDIT: Off board works.
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ok...to bed i go...work by 7am...not cool with as cold as it is in the mornings lately... :(
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Quoting AwakeInMaryland:


LOL!!!
Member Since: June 28, 2006 Posts: 25 Comments: 8306
460. jipmg
dropping like a rock in miami

45 now..

36 is the forecast
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NWS Indy:

Wednesday Night: Snow likely, mainly after 1am. Cloudy, with a low around 13. Light and variable wind. Chance of precipitation is 60%. New snow accumulation of around an inch possible.

Thursday: Snow. High near 23. Light wind becoming north northwest between 11 and 14 mph. Chance of precipitation is 100%.

Thursday Night: Snow likely. Cloudy, with a low around 9. Blustery, with a north northwest wind around 21 mph, with gusts as high as 28 mph. Chance of precipitation is 70%.

Friday: A 40 percent chance of snow showers. Cloudy and cold, with a high near 13.

Friday Night: A 30 percent chance of snow showers. Mostly cloudy, with a low around 0.

Saturday: A 20 percent chance of snow showers. Mostly cloudy and cold, with a high near 11.

Saturday Night: Partly cloudy, with a low around -2.

Sunday: Mostly sunny, with a high near 17.
Member Since: June 28, 2006 Posts: 25 Comments: 8306
Quoting atmoaggie:
t-dude just had 50% of triple posts...
(sry)
Quoting atmoaggie:
t-dude just had 50% of triple posts...
(sry)
Quoting atmoaggie:
t-dude just had 50% of triple posts...
(sry)
Member Since: August 19, 2008 Posts: 32 Comments: 1918
talked to a guy in Virginia a little while ago...said their high for thursday is gonna be 9 degrees....
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Quoting atmoaggie:
t-dude just had 50% of triple posts...
(sry)


lol yeah, ill stick to the computer :P
Member Since: June 28, 2006 Posts: 25 Comments: 8306
Quoting atmoaggie:
t-dude just had 50% of triple posts...


He's playing with his new phone option.
Controlling his thumb and index finger is a challenge.
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Lafayette, Purdue University Airport
Lat: 40.43 Lon: -86.93 Elev: 623
Last Update on Jan 5, 10:54 pm EST

Overcast

12 °F
(-11 °C)
Humidity: 77 %
Wind Speed: W 9 MPH
Barometer: 30.24" (1025.1 mb)
Dewpoint: 6 °F (-14 °C)
Wind Chill: -0 °F (-18 °C)
Visibility: 10.00 mi
Member Since: June 28, 2006 Posts: 25 Comments: 8306
t-dude just had 50% of triple posts...
(sry)
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you haven't seen our weather man...my 5 year old could take him! roflmbo!!!
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Florida PanHandle, you ain't da owny one.
Daytona Beach (Ponce Inlet), FL, Daytona Beach, Florida (PWS)
Updated: 2 sec ago
33.9 °F
Clear
Windchill: 29 °F
Humidity: 69%
Dew Point: 25 °F
Wind: 3.0 mphfrom the West
Wind Gust: 6.0 mph
Pressure: 30.23 in (Rising)
Visibility: 10.0 miles
UV: 0 out of 16
Clouds: Clear -
(Above Ground Level)
Elevation: 12 ft

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Quoting tiggeriffic:
all i know is that if it doesn't snow...my 5 year old is going to the tv station to beat up the weather man! lol


If that happens, I'm sure your 5 yr old will make the CNN News Headlines, j/k!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting tiggeriffic:
just teasin ya tornado... :P


haha its all good, I definitely deserve my fair share of teasing (;
Member Since: June 28, 2006 Posts: 25 Comments: 8306
just teasin ya tornado... :P
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all i know is that if it doesn't snow...my 5 year old is going to the tv station to beat up the weather man! lol
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Quoting tiggeriffic:


this is why i still use my pc...rofl


haha lesson learned :P
Member Since: June 28, 2006 Posts: 25 Comments: 8306
Quoting tornadodude:


should have haha (back to computer)


this is why i still use my pc...rofl
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Quoting Seastep:
Interesting academic take from 2003 and related to Doc's post on the Arctic Dipole and AstroHurricane001's posts tonight on ocean currents.

This jumped out at me and what the scientific community will hopefully be observing very closely:

"Our limited knowledge of ocean climate on long time scales, extracted from the analysis of sediment cores taken around the world ocean, has generally implicated the North Atlantic as the most unstable member of the conveyor: During millennial periods of cold climate, North Atlantic Deep Water (NADW) formation either stopped or was seriously reduced. And this has generally followed periods of large freshwater discharge into the northern N. Atlantic caused by rapid melting of glacial or multi-year ice in the Arctic Basin. It is thought that these fresh waters, which have been transported into the regions of deep water formation, have interrupted the conveyor by overcoming the high latitude cooling effect with excessive freshening."

Emphasis added.


The idea that excessive fresh water in the Arctic would disrupt the sinking of cooling surface waters (which is heavily dependent on salinity) and stop the Atlantic thermohaline has been around for quite a while. This is one we covered back in college.

A bigger source of freshwater is anomalously high river discharges from N. Europe and NW Asia (specifically, that part of Russia that is in either Europe or Asia, depending on whom you ask)
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Quoting tornadodude:
this is from my new phone(:

ROFLMBO...yeah, I read something here about getting double & triple posts if you don't clear it every time, or get out and back in blog(? is that right?)...someone with crackberry pls. advise T-Dude...
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting atmoaggie:
Hah! I knew he would have the same refresh issue everyone does when posting by mobile device...thought about putting up a wager with that prognostication. Should have.


should have haha (back to computer)
Member Since: June 28, 2006 Posts: 25 Comments: 8306
Quoting tornadodude:
this is from my new phone(:

hey i had the same problem by sending the same comment from my phone everytime i refresh.. so u cant refresh or it will send the same message.. just to let u know ..
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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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