NOAA hurricane forecast : 14-23 named storms

[Alacane2]

Wow! If we get to the top end (23 Tropical Storms), we will get to the Greek letter Beta. Only the second time to have to use the Greek alphabet.

[KWT]

In theory yes but the long range models certainly aren't suggesting that, the CFS only gets to average in the Azores region for August before the pressures drop basin wide...and I'd iamgine the ECM long range is every bit as impressive in that respect.

So I don't think we are really going to have to worry about that being an issue Crazy, I personally can't really anything that will prevent a hyperactive season...

[Blown Away]

This is what is more important than the numbers,the pattern shaping up for a busy season.

I know this graphic is suppose to give us a general idea, but it is confusing showing the high pressure to the east and the storm tracks continue west. I guess the westward expanding upper level easterlies is the difference.

[clfenwi]

Kudos to TreasureIslandFLGal for the explanation of the statistical framework behind the forecast.

Expanding on what she said, it is almost inevitable that a forecast so designed that calls for an
extremely active season is going to have a wide spread. The opposite is true for an
extremely quiet season.

Let's say I were to come out and promise, 100% probability, that we were going to have across
the board one of the 10 quietest seasons in the past 50 years. This is what I would be implying:

0-7 named storms (actual bottom 10 is 4-7)
0-4 hurricanes (actual bottom 10 is 2-4)
0-1 major hurricanes.

Now let's say the opposite, I guarantee, 100% probability, that this season is going to be one of the ten most active seasons in 50
years across the board. Here are the possibilities

14-28 named storms (or more)
8-15 hurricanes (or more)
4-7 major hurricanes (or more)

If I could rule out a 2005/1995/1969 repeat, then the spreads in the two groups would be
identical. However, if I thought we are going to see at least a repeat of 1969, then there
would be a large spread After all, 1969, number 3 for named storms in the past 50 years, had 18,
while 2005 had 28. That's a ten storm difference right there.

[artist]

Seriously though, how awful have these predictions been the last few years?

Not all that awful, actually.

2008 May forecast: 80% chance of 12-16/6-9/2-5
2008 actual: 16 named storms, 8 hurricanes, 5 majors - right on the dot

2009 May forecast: 70% of 9-14/4-7/1-3
2009 actual: 9 named storms, 3 hurricanes, 2 majors - not all that shabby

Not that hard though when you know that nearly all neutral seasons in the ative phase of the Atlantic was between 12-16 storms in 2008, and the El Nino average in the active phase also usually is in that 9-14 range...

So thats just pure common sense really!

That range is so large I see no possible way it won't be correct, and if the season ends up outside that range then it'll be no doubt a bad bust, esp given the large range of numbers involved.

yeah, I figure they are upping their accuracy numbers with this forecast!

[thetruesms]

I think that folks are getting mixed up witih what NOAA has actually presented. Their product was not a forecast so much as a statistical solution based on a 70% likelihood of accuracy.
Based on the conditions and statistical representation of storm numbers, a bell curve of storm numbers was represented for the season. They were then given a criteria in which to report the resulting bell curve of probability. The numbers represent the high and low threshhold of numbers representing the volume of the statistical curve that results from the desired condition. One could also reach the conclusion, based on their statement, that there is a 15% probability of there being less storms than their lowest number, and a 15% likelihood that there will be more than 23 storms. In other words, we have a 30% chance that the actual number of storms this year will fall outside their statistically constrained number.
70% is pretty acceptable for accuracy. Would the public accept a 60% accuracy rate though? If they said, "we have a 60% chance that the numbers will be between, say, 16 and 21?" Or how do you think the public would react to a "forecast" of, "we have a 50% likelihood of having between 17-20" storms?" -that seems like a complete guess! -to those that don't understand the statistical bell curve.
What they have done is homed in on a statistically acceptable likelihood while still aiming for a publically acceptable constraint.

However, as a product to release to the public, they should have avoided the bell curve altogether and simply made a statement, such as, "there is a very high probability of an above normal to hyperactive storm season, where we could expect to see 4-9 more named storms than we would in a normal year."

(I just read this back to myself...boy am I a geek!!! But, I guess I did earn that A is Stats last year! haha. -and I've just seen how hard it is to try to explain it without using the formulas and drawings that would make it much easier to comprehend!)

Yes, I think (perhaps hope is more appropriate?) many understand the statistics behind it. But, ultimately, what is the point of being "right" with an outlook when that outlook is so broad as to be useless? It certainly is interesting information, but it isn't much more than that. I would much better appreciate a smaller range with a lower probability and an in-depth discussion of the uncertainties involved. It doesn't necessarily have to be instead of this 70% band, but could be in addition to.

[gatorcane]

The best part is that if this season performs just under 2005, their gigantic range may still bust.

I see absolutely nothing good about that..

Neither do I.....but that quote expresses my sentiment about how poor of a forecast I believe this is.

Bingo cycloneye. The NHC's overall message to the public is that they are expecting an active or hyperactive season so be prepared. It's that simple. Why dwell on the numbers so much?

As far as the 2005 comparison which I see some discussing, if you look at SST anomalies, they are quite similar and one could argue that they are running more above normal this year than 2005, which is downright scary.

However, we will have to wait and see what kind of atmospheric conditions present themselves (it's more than just SSTs) to see just how active or hyperactive this season becomes.

That said, I do think it will be active indeed, nothing like last year at all.

[johngaltfla]

But they're not predicting "23 storms and 14 hurricanes." That's the top end of a range that has a predicted 70% chance of verifying.

Exactly. That's the problem with the numbers. People use them as they please.

Agreed. That's why I called their release today aggressive rather than focusing on the numbers. In all the years I've been following this, I don't recall such a high number at the upper end of the range. Then again, we haven't been in normal times for a decade now either..

[Category 5]

But they're not predicting "23 storms and 14 hurricanes." That's the top end of a range that has a predicted 70% chance of verifying.

Exactly. That's the problem with the numbers. People use them as they please.

Agreed. That's why I called their release today aggressive rather than focusing on the numbers. In all the years I've been following this, I don't recall such a high number at the upper end of the range. Then again, we haven't been in normal times for a decade now either..

2005 changed the game significantly as well. Before 05 a prediction like this would be written off as insanity. Remember in 06 that 20+ was a trendy prediction.

[KWT]

Its just quickly worth noting that we could go all of June and most of July without a NS and still end up between 15-18 quite easily, the greatest example of that was 1969 and obviously 2004, though both 98/99 also showed this was possible...

so even if the fast start doesn't happen (I think the first 2 months will probably be close to average, maybe 1 NS faster then normal, so say 3 NS before August) I'm sure the rest of the season will race away.

[JTE50]

For me I'm looking to see where the Bermuda High sets up and how strong it will be for this season. Sure all the other factors (lack of El Nino, upper air, warmer than average Atlantic seas surface temps) favor formation. Bottom line for me is the more storms the greater the chances of a Gulfcoast landfall if that High is in the right spot. The plan is the same this season: I want to be in all the hurricanes that hit land.

[arkestra]

Just like every year, nobody agrees with NOAA forecasts. Allright. But what should they do?
In my opinion, people at NOAA are not in the same game we are into. They are national forecasters, meaning somewhere between the general public, politicians, medias... other scientists. They also know that, even they're speaking 2 hours, what people will remember is the numbers. So what did they have to do?
I believe, if I was working at NOAA, that I would do the same as they do.

[StormClouds63]

These seasonal forecasts are often butchered by local and national media. One of the local stations here lead into the NOAA story by stating that "23 storms are predicted in 2010." Never mind that's not what the forecast truly is.

True headline should be very simple:
"Above average season anticipated. Impossible to Determine Where Landfalls Will Be. Make preparations now in case your area is threatened." End of story.

[KWT]

Yep thats the problem cloud, to get ratings they will simply go for the highest of the possible range because it sounds more dangerous then a lower number, esp when they put in words like "2010 could rival 2005" etc.

[Acral]

Conditions are setting up for an active season. How Active, hard to say. Some of the local media are trying to play up the oil spill as a possible catalyst, yet they do not understand how much water is moved (even deep sea) during a storm. I feel that we should remain vigilant in our efforts but not buy into the "doom and gloom" that some media outlets suggest.