AccuWeather Hurricane Threat

[Downdraft]

Does anyone have any verifiable data concerning the overall records of forecasting success between Accuweather and the NHC? Since Accuweather makes no secret of the fact they believe the weather service should be privatized I'd be interested in seeing how good their record is when it comes to forecasting track and landfall. I assume they are using the same models the NHC does so the comparison should be fair, it's apples to apples. I have heard Elliott Abrahams say he believes Accuweather should be allowed to issue severe thunderstorm, tornado and tropical alerts to the general public. What makes them think they are better at it then the people doing it now? Not trying to start the yearly war between NOAA and Accuweather but someone must have kept score somewhere?

[vbhoutex]

Accuweather was not the only one bringing Gilbert straignt into our front yards KD. Everyone was to start, and yes it was quite a scare. It is the only time I have contemplated sending my family further inland due to a Hurricane. I, of course, was not worried about storm surge at my location, but concerned that we could experience CAT5 winds even at my house if Gilbert did stay the path and not lose strength and/or intensify.

[Anonymous]

What I don't understand is the possibility of a high potential of hurricane landfalls over South Carolina being in the 3 category, but for Georgia and east coast of Fl the probs drop immediately down to a 10 probability. Really strange ! How can there be such a steep differential in hurricane landfall probs between here and coastal Georgia/Florida ? The west coast of Florida shows the highest prob of hurricanes, meaning many of them would recurve from the Caribbean northward then NE into west coast of FL. Even so, wouldn't these systems then continue moving NE, impacting coastal Georgia and North FL also ?

[Anonymous]

What I don't understand is the possibility of a high potential of hurricane landfalls over South Carolina being in the 3 category, but for Georgia and east coast of Fl the probs drop immediately down to a 10 probability. Really strange ! How can there be such a steep differential in hurricane landfall probs between here and coastal Georgia/Florida ? The west coast of Florida shows the highest prob of hurricanes, meaning many of them would recurve from the Caribbean northward then NE into west coast of FL. Even so, wouldn't these systems then continue moving NE, impacting coastal Georgia and North FL also ?

If a major cane crossed fla moving at 16kts (which by the time they are moving NE, they are usually moving pretty fast), Nearly all of Fla, in the storms path, would experience Hurricane force winds as is shown by this map...

[Anonymous]

What I don't understand is the possibility of a high potential of hurricane landfalls over South Carolina being in the 3 category, but for Georgia and east coast of Fl the probs drop immediately down to a 10 probability. Really strange ! How can there be such a steep differential in hurricane landfall probs between here and coastal Georgia/Florida ? The west coast of Florida shows the highest prob of hurricanes, meaning many of them would recurve from the Caribbean northward then NE into west coast of FL. Even so, wouldn't these systems then continue moving NE, impacting coastal Georgia and North FL also ?

If a major cane crossed fla moving at 16kts (which by the time they are moving NE, they are usually moving pretty fast), Nearly all of Fla, in the storms path, would experience Hurricane force winds as is shown by this map...


I would agree there. Based upon the chart, shouldn't the forecast map then be adjusted to increase the prob of landfalls in east coast of FL, lets say, to a 4 ? Even if hurricane conditions spread over most of FL during a major hurricane recurvature scenario, even coastal Georgia may have a slightly higher probability than indicated on the map (I would think). This would be especially true during very strong (cat >3)hurricane landfalls.

Ken

[Anonymous]

Apparently, they are going by landfalls... A cane moving across fla from gulf to atlantic would not cause near the damage as a cane hitting the ECoast directly--lil/no storm surge cuz its coming from land--mobile home residents and flood prone persons would need to leave however.

[Anonymous]

Makes sense. You would have to have a very intense hurricane moving into FL then recurving into the Atlantic states in order to get the same damage, like a cat.5 or so without weakening much as it crosses the FL peninsula. That would be extremely rare, of course.

[Anonymous]

One more train of thought about future hurricane intensity landfalls is the accumulation of fresh water expected to eventually slow down or shut down the great ocean belt conveyor. It may be in it's infancy, but I have noticed since about 1999, many hurricanes appear to weaken "just prior" to making landfall in the US recently. A Gulf coast hurricane (Isidore ??) in 2002 weakened dramatically overnight from 140 to 100mph just prior to landfall. No one could explain it. I have not seen any "Hugo type" hurricane in quite some time. Then last year, an area of "very cold water" appeared off the East coast for two weeks all-of-a-sudden in early August ??? It was supposedly the coldest water in a century. Is that just pure coincidence lately, or just something else ?

And, according to the latest water temperature profile, an area of cool water has expanded in the last 3 days in various locations across the tropics. Not that this has anything to do with it, but these "cool" pools seem to always re-appear allot lately. Just like last year's surprise off the East coast.

https://www.fnmoc.navy.mil/products/OTI ... nomaly.gif


Ken

[SupertyphoonTip]

One more train of thought about future hurricane intensity landfalls is the accumulation of fresh water expected to eventually slow down or shut down the great ocean belt conveyor. It may be in it's infancy, but I have noticed since about 1999, many hurricanes appear to weaken "just prior" to making landfall in the US recently. A Gulf coast hurricane (Isidore ??) in 2002 weakened dramatically overnight from 140 to 100mph just prior to landfall. No one could explain it.

The hurricane was Lily and there were explanations for it. For example, it is reasonable to believe that it weakened because it passed over the cool wake left by Isidore only a short time before.

I have not seen any "Hugo type" hurricane in quite some time.

That's mostly having to do with luck. Every weakening just before landfall had its own reasons. When the conditions will be right, we'll have another Hugo or Camille or Andrew.

[Aquawind]

I would think Upwelling is a natural thing that can occur anywhere the conditions persist..A persitant east coast trough contributed alot of clouds and precip prior to this as well. As far as the currents changing goes..I would think they can flucuate as well..at least the Gulf Stream intensity and location..A combination of factors as usual..I don't think coastal temps are as important if the system is already well organized..Many systems intensify over cooler waters as they recurve northward over cooler waters and often this is because they are turning in a direction that create less shear..going with the flow if you will..as Derek Ortt pointed out in another post.. the percentage of energy actually tapped from the water is small..

http://web.naplesnews.com/03/08/florida/d958556a.htm

[stormcloud]

Dr. Neil Frank's allegory on Gilbert is the block of wood/house. Throw a block of wood into a slow moving river, and the block of wood moves wherever the current takes it. Throw a house into that same river, and the river has a much more difficult time moving the house. Gilbert was the house.

[HurricaneQueen]

Well, sitting on the coast of SW Florida I hope that Bastardi is wrong! We certainly don't need another Donna. With the population explosion, general complacency and lack of evacuation routes, a landfalling storm of any magnitude would spell huge trouble for this area. Unless you left at the first hint of a storm, there is no way out. The result is sitting in a car in a deadlock with a storm bearing down and "no room at the Inn" until you hit central Georgia. Of course, the same holds true for the Fl. East Coast, as well.

[MWatkins]

Dr. Neil Frank's allegory on Gilbert is the block of wood/house. Throw a block of wood into a slow moving river, and the block of wood moves wherever the current takes it. Throw a house into that same river, and the river has a much more difficult time moving the house. Gilbert was the house.

Yet another great point by Dr Neil...and once again demonstating why he, along with John Hope...are probably the two people I admire(d) the most.

This also helps explain why intense hurricanes are so much eaiser to forecast (track wise). When the intensity variable is minimized it makes the forecast one million times eaiser.

MW

[MWatkins]

Well, sitting on the coast of SW Florida I hope that Bastardi is wrong! We certainly don't need another Donna. With the population explosion, general complacency and lack of evacuation routes, a landfalling storm of any magnitude would spell huge trouble for this area. Unless you left at the first hint of a storm, there is no way out. The result is sitting in a car in a deadlock with a storm bearing down and "no room at the Inn" until you hit central Georgia. Of course, the same holds true for the Fl. East Coast, as well.

Hey HQ...good to see your post...

You're 100% right. It's been a long time since you've seen a serious threat in your neighborhood. Hopefully...if something does close in on you...people will listen. I know you will.

The old adage applies here...hopefully folks will follow it...

Flee the surge...hide from the wind.

MW

[Stormsfury]

One more train of thought about future hurricane intensity landfalls is the accumulation of fresh water expected to eventually slow down or shut down the great ocean belt conveyor. It may be in it's infancy, but I have noticed since about 1999, many hurricanes appear to weaken "just prior" to making landfall in the US recently. A Gulf coast hurricane (Isidore ??) in 2002 weakened dramatically overnight from 140 to 100mph just prior to landfall. No one could explain it. I have not seen any "Hugo type" hurricane in quite some time. Then last year, an area of "very cold water" appeared off the East coast for two weeks all-of-a-sudden in early August ??? It was supposedly the coldest water in a century. Is that just pure coincidence lately, or just something else ?

And, according to the latest water temperature profile, an area of cool water has expanded in the last 3 days in various locations across the tropics. Not that this has anything to do with it, but these "cool" pools seem to always re-appear allot lately. Just like last year's surprise off the East coast.

https://www.fnmoc.navy.mil/products/OTI ... nomaly.gif


Ken

No, it was Lili in 2002 ... but the SST's were only 0.5% of the problem. The s/w upper ridge abated and gave way to a pretty strong ULL over Eastern TX which basically devastated its outflow pattern ... oh, and not to mention Lili was also undergoing an eyewall replacement cycle that never got replaced ...

Last year's (or the year before's, can't remember .. senility in my old age ) much below SST's right along the coast came about due to the prolonged westerly flow from a parked longwave trough over the Eastern U.S. with no change in the pattern for many weeks, and caused quite an upwelling along the coastline. So to answer that question, it was more of a coincidence ... the freshwater theory (or salinity of the water) doesn't hold much water (no pun intended). Sure, there was quite an above average period of rainfall in early/mid 2003 in the Southeast, but I don't remember hearing anything occurring regarding the Great Floods on the Mississippi River in 1993 when those waters drained into the GOM ... and we all know what kinds of prolific rainfalls occurred that year in the Midwest.

[Derek Ortt]

an MM5 simulation from RSMAS shows that Lili was sheared to death http://ams.confex.com/ams/pdfpapers/75749.pdf

[Anonymous]

Thanks guys ! About the research paper on Lili, Derek Ortt participated in this study ! Didn't know that any members here were atmospheric scientists, or maybe PHD's. Good for you ! I remember reading publications from the AMS in the late 80's and they were very hard to understand because of the terminology they used. You guys remind me of AccuWeather's Doctor Joe Sobel !

ken

[wxman57]

Apparently, they are going by landfalls... A cane moving across fla from gulf to atlantic would not cause near the damage as a cane hitting the ECoast directly--lil/no storm surge cuz its coming from land--mobile home residents and flood prone persons would need to leave however.

Yes, only the landfall side of the state is considered. Where a storm might exit Florida is not considered a landfall point, even though it may be a Cat 5 all the way across Florida. Landfall can only occur on one coast. Of course, that doesn't mean that NE Florida isn't at risk for some nasty weather when storms move in from the southwest.

[Stormsfury]

Accuweather was not the only one bringing Gilbert straignt into our front yards KD. Everyone was to start, and yes it was quite a scare. It is the only time I have contemplated sending my family further inland due to a Hurricane. I, of course, was not worried about storm surge at my location, but concerned that we could experience CAT5 winds even at my house if Gilbert did stay the path and not lose strength and/or intensify.

Missed this post last night.

The NHC's official track 72 hours from landfall actually was pretty much spot on and verified much, much closer to reality, while Accuweather's forecast placed Gilbert into the Houston-Galveston region. In fact, the "only" major success I can recall Accuweather having was in regards to Floyd in 1999, with the sharp recuravture to the NNE into North Carolina. (Someone there musta followed the ECMWF's track which turned out to be the best bet ... BTW, the ECMWF showed this SEVEN days out).

Otherwise, I've noticed that Accuweather's tracks seem to have a sharper recurvature bias.

SF

[Steve]

Interestingly, Joe took on this particular thread in a special Sunday post. I hope he wasn't mad at me for defending him with what I put out there. But it was a good read. Goes to show people with agendas will say just about anything. But his point was you can't rip him over 5% of what's out there if you don't know the other 95%. I invited anyone who thought they were better or dismissed his skill in this thread - Ortt, Dericho, MW - to see for themselves. Maybe MW will but the others won't.

Just remember this dudes: NOTHING either of you put out this year remotely resembles Joe's landfall intensity forecast. So you can sit back and comment all you want. Despite your prestige and accumen, you're only peanut gallery until you hang yourself out for riddicule or success. Like it or not, that's REALITY baby.

Steve