National Hurricane Center proposes Storm Surge Warnings

[HURAKAN]

National Hurricane Center proposes Storm Surge Warnings

Posted by: JeffMasters, 3:46 PM GMT on March 10, 2009

"At last week's 63rd Interdepartmental Hurricane Conference, a number of notable news items surfaced regarding doings at the National Hurricane Center (NHC). Some of these are detailed on the NHC web site, and others I learned by talking to the people at the conference and via emails. Of note:

Saffir-Simpson Scale being redefined
NHC is considering removing any mention of storm surge from the familiar Category 1-2-3-4-5 Saffir-Simpson scale, starting this June. The current definition is primarily based upon wind speed, but storm surge flooding is included as well. The new definition will make the Saffir-Simpson scale exclusively keyed to wind speeds. This change will help pave the way for the proposed Storm Surge Warning, discussed next.

New Storm Surge Warning product proposed
The impact of Hurricane Ike on the Texas coast in 2008 underscored the inadequacy of the Saffir-Simpson scale to characterize storm surge threat. Ike was a strong Category 2 hurricane on the Saffir-Simpson scale, yet brought a storm surge characteristic of a strong Category 3 hurricane to the coast. Very high storm surges in excess of ten feet were recorded along portions the Louisiana coast, in regions that did not get hurricane force winds. The water level rose four feet above normal at Pascagoula, MS, some 170 miles to the east of the eastern edge of the Hurricane Warning, well before that warning was issued. To address these concerns, NHC is considering issuing a separate storm surge warning. This is great idea, but there are a number of major technical hurdles to leap before this product can be made operational. NHC director Bill Read indicated that official storm surge warnings are probably 3 - 5 years in the future. Among the concerns:

1) What level of water qualifies? Should it be different depending on the location?
2) Should a level of certainty be used (e.g., 40% chance of the surge reaching 5 feet?)
3) Would a "storm surge watch" be issued beforehand?
4) The storm surge can stay elevated for several days after a storm passes. How long would the surge warning stay in effect?



Figure 1. Example of how the proposed new Storm Surge Warning and Hurricane Warning areas would have looked for Hurricane Katrina. NHC is also considering unifying the "Inland Hurricane Wind Warning" and Hurricane Warning (currently only issued for the coast) into one unified Hurricane Warning. Image credit: National Hurricane Center.

Expanded lead times for hurricane watches and warnings
Currently, NHC issues a Hurricane Watch 36 hours before the potential arrival of hurricane force winds at the coast, and a Hurricane Warning 24 hours in advance. As early as the 2010 season, it is proposed that these lead times be extended to 48 hours for a Watch and 36 hours for a Warning. This would give increased time for people to prepare, at the expense of warning more people unnecessarily. However, hurricane track forecasts have improved so markedly (50% in the past 20 years, with record accuracy again in 2008) that the number of people being over-warned would not significantly change compared to the 1990s.

Cone of Uncertainty reduced in size
For the Atlantic, official NHC forecasts for track in 2008 were the best ever, for both short range (12, 24, 48 hour) and longer range (3 - 5 days). As a result, NHC will be modestly reducing the size of the "cone of uncertainty" for 2009. Recall that the "cone of uncertainty" is set so that 2/3 of all track errors over the past five years will fall inside the cone. You're definitely not safe if you're in the cone, and 1/3 of the time, storms will deviate outside the cone!

Personnel changes
In response to recommendations made from a panel investigating morale problems at NHC in the wake of the July 2007 revolt by NHC employees against then-director Bill Proenza, a new branch chief position--head of the hurricane forecasters-- has been created and filled. The new branch chief of the Hurricane Specialists Unit is former senior hurricane forecaster James Franklin. He will now devote 80% of his time to administrative matters, and will be performing only one shift per week doing hurricane forecasting. Senior hurricane specialist Dr. Rick Knabb is gone, he left last year to head the Central Pacific Hurricane Center. NHC has hired Dr. Michael Brennan, who came on board during the tail end of the 2008 season, was hired to fill this vacancy. NHC will be short one hurricane forecaster during the 2009 season, as senior hurricane forecaster Stacy Stewart has been called up for military reserve duty.

http://www.wunderground.com/hurricane/2 ... arning.jpg

Jeff Masters"

[Ed Mahmoud]

Stewart just got back from reserve duty.

about surge, already new for 2009 from NHC

1)
The Tropical Cyclone Storm Surge Probability products, previously experimental, will become operational. In addition, the products will be available with thresholds of one foot increments ranging from two to 25.
...


8)Storm surge information and forecasts in the Public Advisory will be expressed in terms of “height above ground level” or “inundation”.

ETA on Stewart

Navy Reservist served in Iraq as part of troop surge

By Dennis Feltgen, NOAA NHC Public Affairs Officer

After nearly 20 months of active duty, Commander Stacy Stewart has returned to his civilian job as a Senior Hurricane Specialist at NOAA's National Hurricane Center in Miami.

His biggest adjustment is returning to South Florida traffic. "I was used to driving down the middle of the road in a 15,000 pound Hummer with a .50 caliber machine gun and avoiding any kind of debris," he said.

A 35-year Navy reservist, Stewart was recalled to active duty in January 2007 to aid in the troop surge in Iraq. He was part of the Coalition Army Advisory Training Team, providing advice and mentorship to three Iraqi Army divisions at An Neumaniyah Military Base. That's 20,000 Iraqi soldiers. He also assisted in the training of three Iraqi brigades.

Stewart says his greatest challenge in Iraq was just staying alive during any of the 160 end to end convoy movements in which he participated. "Once you left the base, you were no longer safe, even for just a few miles." During a mission on March 27, 2008, with Stewart serving as the forward machine gunner behind ballistic glass on top of a Hummer vehicle, an IED (improvised explosive device) detonated alongside the vehicle. No one was killed, but Stewart's left leg and knee were injured in the blast. Fortunately, he only required four months of physical therapy and rehabilitation.

Stewart is very adamant about his tour in Iraq. "I was honored to be able to go to Iraq as part of the surge. I saw it from the inside and I am proud of what my four teams accomplished. Iraq is a much better place now."

What he missed most while away was his family and co-workers. Being on an Iraqi base, there was no Post Exchange, post office, or chaplain. A food convoy had to be picked up and escorted 80 kilometers to his base every two weeks. The weather was rather dull, too. "There is not much weather in Iraq, just a lot of sand, dust and 125 degree heat. Sometimes, the sea breeze arrived and knocked it down to 115 in southern Iraq."

Back at the National Hurricane Center, Stewart is rapidly catching up on some of the revised operational procedures used to distribute the routine hurricane products, as well as working with some of the new computer models. He is already back at work with his NHC colleagues and issuing tropical cyclone advisories.

He has been back only about 8 months.

[JonathanBelles]

VERY interesting read, and I have plenty of thoughts on this.

1) I very much like that storm surge and the SSS are being decoupled.
2) I like the fact that new storm surge warnings may be issued. If all of the bugs can be worked out, it will be one of the more-so used products. I know I would use it. If you look at the very large systems-especially in the GOM, these warnings would be of great help for those that TS/Hurricane advisories cannot be issued. Storm surge levels dont usually match wind speeds in coastal effected regions, so this may give us a better indicator of how much surge there will be.
3)The expanded lead times for Hurricane and Tropical Storm Warnings and Watches is badly needed in my opinion. It will provide the case of urgency for those in the public that is needed.
4)I cannot see why the cone of uncertainty should be shrunk at this point. A few years down the line, probably, but not yet. I think errors of prediction are just a bit too high still.
5)I wish Franklin would still be writing advisory packages, he is one of the best there is, and should not be taken out of the public eye (if thats the way to best put it).
6) Is that true that Stewart is leaving again?!

I understand that all of the meteorological matters are "could be's" and "might be's", but I think all of the changes are good. There will be debate on this I'm sure, but I am only stating my opinion.

[Derek Ortt]

didn't the Canadians do this and ran into a cluster you know what with Juan?

What I'd like to see is the HURRICANE WARNING, include all tidal surges over a certain height at a point along the coastline (of course, Miamis height and Mississippi's will be different... maybe 10 feet for Mississippi and 2 for Miami due to the different topography)

[CrazyC83]

The problem that EC had with Juan is that back then, there were no hurricane or tropical storm watches or warnings issued for land areas in Canada. That was changed in 2004 to increase awareness.

They still issue storm surge warnings as necessary though (for both tropical and non-tropical events).

I think the NWS (not NHC) should introduce them for storm surges equal to or greater than the SLOSH-derived Category 2 level (or Category 1 level in heavily populated areas). They could also be used for high storm surges from non-tropical events such as Nor'easters and Great Lakes storms.

[margiek]

Stacy is on another tour of active duty for 2009 (I believe in Afghanistan this time).

They will fill the position left vacant by James' promotion and will be shorthanded one forecaster due to Stacy's leave of absence. However Chris Landsea fills in sometimes so I wouldn't be surprised to see him doing an occasional shift (you may notice that he sometimes will fill in for the TAFB TWD as well).

[Ed Mahmoud]

Stacy is on another tour of active duty for 2009 (I believe in Afghanistan this time).

They will fill the position left vacant by James' promotion and will be shorthanded one forecaster due to Stacy's leave of absence. However Chris Landsea fills in sometimes so I wouldn't be surprised to see him doing an occasional shift (you may notice that he sometimes will fill in for the TAFB TWD as well).

Yup
Stacy Stewart is off to war – again.

Stewart is one of the elite hurricane specialists at the National Hurricane Center in Miami-Dade County.

After spending 14 months in Iraq as a Navy Reserve commander, he has shipped off to Afghanistan.

“Stacy has been called back to active duty, and he’s in our thoughts,” Dennis Feltgen, spokesman for the hurricane center, said today. “We hope to have him back in the fall.”

Because of his military commitments, Stewart was in the Middle East through most of the 2007 hurricane season and part of the 2008 season.

While in Iraq and while on patrol in a military Hummer, an improvised explosive device exploded by the side of the road an injured his left leg. That required four months of rehabilitation.

He also had to endure dusty conditions and stifling heat, sometimes up to 125 degrees.

Yet, in e-mails and interviews, Stewart told me that he was comfortable performing his military duties – and believed strongly that serving his country was top priority.

Here’s wishing him a safe return.

[yzerfan]

I'm liking the decoupling of storm surge from wind warnings. In my neck of the swamp, there was no reason to issue a wind warning for Ike- we weren't going to get anywhere close to big winds for the storm. But we did get enough storm surge to put a number of coastal roads and highways under water, and I think that local EOCs were a little surprised that they had to shut down US 98 for a day or two because of a storm making landfall in Texas.