NHC's 2010 Seasonal Outlook

[Frank2]

I had to chuckle when reading the NHC seasonal forecast, which ranges from just average to exceptionally above average - apparently NHC is "playing the field" when it comes to not wanting to be wrong, and is why the NHC Directors of the 1980's did not subscribe to the coming trend of making weather forecasts 6 months into the future...

If you think that comment doesn't hold (rain) water, just look at the 7 day extended outlook, and how much that varies from day to day...

Unfortunately those at the NHC must have been pressured to come up with a forecast that would not embarrass anyone, and in trying to do so they instead decided to have a forecast that reads like:

"The final score might be 14-0 - but on the other hand it could be 49-0"...

As one meteorologist once told me, "That kind of thinking is fool proof, since a person will always be no more than 50 percent wrong!"...

And I can understand their thinking, because to vary the predicted number of storms is safer than giving a solid number (as the others did), but to make such a wide variation also gives the public the idea that they are not sure at all, and are just being safe by forecasting every range of the spectrum...

Again, I'm pretty sure what the former folks would say about all of this - with a smile, I'm sure...

Frank

[SFLcane]

TPC does not issue seasonal forecasts NOAA does. I think there's a pretty decent consensus between CSU,TSR, and NOAA on an above average year across the tropical Atlantic based on some very favorable parameters that favor tc formation. Regardless what the seasonal predictions call for one should always prepare the same way you did the previous year. Just takes that (one) single storm over your area.

[SFLcane]

Also keep in mind it's a seasonal outlook and the range represents the most likely (70% or greater) outcomes around the mean. It's not to be taken at some deterministic face value.

[Macrocane]

There is already a thread about it and some members gave very good reasons why NHC has such a wide range, SFLcane mentioned one of them.

http://www.storm2k.org/phpbb2/viewtopic.php?f=31&t=107977

[Andrew92]

I think it should also be said that the NHC, when making its forecasts, mentions degrees of uncertainty when models disagree on the track. They then come up with what they think is the best forecast with what they have given. But at the end of the season, they also verify how those forecasts played out.

That kind of concept is similar here. Sure, they are playing the game that it will either be average or above average. They are saying that because that's what all the other forecasts are saying. There is a lot of uncertainty just exactly how many storms will form. But I would expect them to likely give a report of how their season forecasts verified at the end, too.

If I'm playing, I likely go with 18/10/6. Doesn't mean that happens, but it's well in the window of possibility along with everything else.

-Andrew92

[Category 5]

Seasonal outlooks are taken way too seriously, I have no problems with what the NHC does on theirs.

[wxman57]

Most people don't understand the concept of a standard deviation to express uncertainty in a forecast. NOAA is saying that there is a 70% chance that the number of named storms falls between 14 and 23. They are not saying that we could see "up to 23 named storms this season" as some news organizations report. NOAA could just as easily expressed the range in terms of several standard deviations to encompass 90% of the uncertainty. That may have meant a range of from 9 to 30 named storms, but they wouldn't be forecasting "up to 30 named storms". The forecast number always lies in the middle of the range, or about 18-19 named storms for NOAA's forecast (with 10 hurricanes and 5 majors). That's the same as everyone else, but just expressed differently using standard deviation. I think it's a mistake to give such a range to people who don't understand what it means.

The number itself doesn't mean much, but the patterns we're seeing out there and the analog year tracks strongly suggest a major impact from southeast LA to the FL Panhandle this year (and FL Peninsula, too). You folks in that area had better have an evacuation plan in order and all of the supplies you'll need in your hurricane kit (see my thread in the hurricane preparation section of the forum). And don't think you can ride out any hurricane if you live on the coast. A large enough Category 1 or 2 could produce a surge similar to what Katrina produced in the same region. You can't use Saffir-Simpson to predict surge height.

[brunota2003]

Texas also stands an increased threat risk during a La Nina year

[Ixolib]

TRUER WORDS WERE NEVER SPOKEN!!!!

.....And don't think you can ride out any hurricane if you live on the coast. A large enough Category 1 or 2 could produce a surge similar to what Katrina produced in the same region. You can't use Saffir-Simpson to predict surge height.

[Frank2]

TPC does not issue seasonal forecasts NOAA does.

The TPC (NHC) is a part of NOAA - you might be referring to the forecast issued by NWS Headquarters (CPC):

http://www.noaanews.noaa.gov/stories201 ... tlook.html

True, they are the ones who issue that forecast, but to say the TPC/NHC does not have any involvement in putting that forecast together would be incorrect...

And I understand what was mentioned about the numbers themselves, but the average person doesn't think along those lines (nor has the patience to try to understand it as a meteorologist does), and instead sees the forecast as meaning it either can be an average season - or well above average...

And there are so many variables that can affect a season - aside from El Nino or La Nina, there are unexpected long-wave patterns that can completely change the track of tropical systems, frequent SAL and dust outbreaks not previous forecast, etc., and that's why meteorologists from prior generations were not eager to issue or embrace long-range forecasts that could just as easily be totally wrong, since scientists like to hold to things in nature that they at least believe will behave a certain way for a certain reason...

When in that business the some meteorologists used to refer to the early CSU forecasts as "crystal ball meteorology", since it was believed that the forecaster was doing nothing more than trying to predict events many months in advance - while that might seem the same as trying to predict the weather a day in advance it isn't, since it was often mentioned to me that in that case the weather itself (a distant cold front, for example) already existed somewhere in the world, unlike someone trying to issue a forecast based on weather features that would not even exist for many months in the future...

True, forecast models have come a very long way over the past 25 years, but per the current oil spill crisis (and the trouble many are having when it comes to forecasting exactly where the oil will go and when), the Earth is thankfully a very complex environment, and often cannot be completely understood when it comes to knowing what will happen next...

Personally, I like it that way, since it'd be a bland life if God gave us all the answers in advance (or at all), and as the man in the movie once said, "life is like a box of chocolates"...

Frank

[Stormcenter]

I agree 100% with your post.

I had to chuckle when reading the NHC seasonal forecast, which ranges from just average to exceptionally above average - apparently NHC is "playing the field" when it comes to not wanting to be wrong, and is why the NHC Directors of the 1980's did not subscribe to the coming trend of making weather forecasts 6 months into the future...

If you think that comment doesn't hold (rain) water, just look at the 7 day extended outlook, and how much that varies from day to day...

Unfortunately those at the NHC must have been pressured to come up with a forecast that would not embarrass anyone, and in trying to do so they instead decided to have a forecast that reads like:

"The final score might be 14-0 - but on the other hand it could be 49-0"...

As one meteorologist once told me, "That kind of thinking is fool proof, since a person will always be no more than 50 percent wrong!"...

And I can understand their thinking, because to vary the predicted number of storms is safer than giving a solid number (as the others did), but to make such a wide variation also gives the public the idea that they are not sure at all, and are just being safe by forecasting every range of the spectrum...

Again, I'm pretty sure what the former folks would say about all of this - with a smile, I'm sure...

Frank

[Stormcenter]

The great thing is we'll be able to measure how successful these predictions were in reference to numbers and landfalls (if there are any) at the end of this season. Recent history has proven that the normally these predictions don't pan out most of the time. IMO