Thoughts on 2013 Atlantic Hurricane Season

[ninel conde]

I've said before I don't see the value in landfall predictions. You could have a season denoted by troughs pulling every system out to sea, then by chance one storm develops that gets caught by a fleeting ridge and hits land. Timing, as they say, is everything. Seems to me the only thing a low landfall risk forecast could do is decrease the number of people who are prepared for a surprise event, like an Andrew.

As far as this season goes, we can complain the forecasts are a bust, but by claiming the season is a bust we are making the very forecast that we say can't be made. Good luck with that.

If the experts are confused as to why the season has been a bust so far then I am confused as well. I think it's extremely foolish and ignorant to think any of us amateurs can, with the help of the mighty interweb, see things scientists and forecasters who do this for a living could not.

herd mentality. once one organization forecasts a big season others fall in line and start looking for reasons it will be active. there should have been one pro, or group that forecast a slow season.

[tolakram]

wilma was in 2005, and this isnt 2005. if florida gets hit by anything it will be from a strung out weak TS battling against the trof.

I think that's an extremely foolish statement to make. Past performance is not an indicator of future events, and to make a statement like that, without any data to back it up, is quite frankly jarring.

[tolakram]

herd mentality. once one organization forecasts a big season others fall in line and start looking for reasons it will be active. there should have been one pro, or group that forecast a slow season.

You have no evidence to back that up, and no proven expertise to show that happened. In my opinion you have just insulted just about every professional organization who makes forecasts by telling us they looked at someone else instead of their own data. Seriously ninel, these kind of statements are not productive in the least.

[ninel conde]

im certainly sorry if i offended anyone. my point is that we all agree seasonal forecasting for hurricanes is far from an exact science. therefore, one should expect a wide range of forecasts from slow to busy, perhaps weighted in one direction or other. i cant recall any forecast from a major group saying the season would be slow.

again, i apologize.

[Portastorm]

im certainly sorry if i offended anyone. my point is that we all agree seasonal forecasting for hurricanes is far from an exact science. therefore, one should expect a wide range of forecasts from slow to busy, perhaps weighted in one direction or other. i cant recall any forecast from a major group saying the season would be slow.

again, i apologize.

This is a faulty assumption and sketchy logic, IMO. You make the assumption that because seasonal forecasting is an inexact science that automatically equates to forecasts which "should" have a wide range of outcomes. If the tools used by the scientific community are the same and the incoming data is the same, then forecasts will be similar with some smaller differences. There is no guarantee that you will have a wide range of outcomes and I don't think we should expect as much. Using your logic, every season would have forecasts with a wide range of outcomes.

[Ntxw]

I think this is a very good learning season for forecasters. Not over yet but there's a good chance it may finish with the lower ACE count seasons (think Nino years). Finishing with normal activity won't get us back to "normal" count we'll need one of the most active endings to climb back up. I'll go back and look at data closer but I think all years without a major hurricane by mid Sept (a little past peak) or later were all in the lower percentile of ace come the end.

As for the forecasts I think it was a tough season for many of the major institutions, even in August when they did their adjustments, but kudos to klotzbach and others who admitted a bust was likely. One big indicator that was overlooked by many was how historically low the activity was across the globe, sometimes years like this just happens we've had a string of them the past few years when you take a look at global ACE.

[vbhoutex]

As an admin I am going to say one thing here. If you are going to downplay or for that matter go the other way and "wishcast" the Hurricane Season or an individual system/storm, then PLEASE BACK UP YOUR STATEMENTS WITH FACTS. If you are going to do the above PLEASE THINK BEFORE YOU POST MAKING SURE YOU ARE BEING RESPECTFUL in your posting. EVERYONE on this site is due their opinions as long as the above is adhered to.
Now, as a poster on this site I have to ask, what to me is the obvious. WHAT IS THE BIG BUST? We are basically half way through the season, we have three active tc at the moment, and we are more than likely going to use the I name starting later today. That is 9 TC at this point in the season(if Ingrid forms). I am not a TC historian, but iirc we normally have about the same number after the peak of season, 3 days ago. That would suggest that at least the total TC numbers may be reachable as long as we aren't talking number of hurricanes. Landfalls is a whole other ball of wax imo and I do not even attempt to work with those when I do look at a season on an overall basis. IOW, imo we are having an active season so far, we just aren't having the number of Hurricanes previously predicted. JMHO, and feel free to counter.

[wxman57]

One thing I'd point out is even though the forecast numbers/intensity appear to be a bust, the seasonal predictors that we use verified great.

We thought that there would be no El Nino, likely cooler than normal water in the Nino 3.4 region. That certainly verified well.

We predicted lower-than normal pressures in the deep tropics this year, and that verified excellently through August.

Warmer water in the deep tropics (vs. subtropics) verified well.

But still the storms didn't form as expected. I think the global downturn in activity, particularly in the Northern Hemisphere is being caused by some very dry mid-level air which circles the globe in the tropics. Could be something to do with decreased solar activity. The Atlantic may also be impacted by the very cool water in the western Indian Ocean, which appears to have reduced the strength of tropical waves moving off of Africa.

[Ntxw]

That would suggest that at least the total TC numbers may be reachable as long as we aren't talking number of hurricanes. Landfalls is a whole other ball of wax imo and I do not even attempt to work with those when I do look at a season on an overall basis. IOW, imo we are having an active season so far, we just aren't having the number of Hurricanes previously predicted. JMHO, and feel free to counter.

The bust lies in the forecast put out. I'm going to use CSU as an example since it was the most respected source that most of us rely on.

For June the forecast was 18/9/4 with an ACE of 165. It was revised to 18/8/3 and ACE of 142 in August. We are at 9/1/0 and ACE about 17, average for this date being 56 (should've collected 60% of the seasonal ace by now). The numbers may get there but that ACE gap is ridiculously far apart. An above normal season is regarded as 111 (or 120%) of ACE, below normal season is 66 (71%), and anything in between the two is considered normal which is around 93 on average. We're talking about a hyperactive season was forecasted, lots of storms and lots of storms becoming hurricanes and major hurricanes to achieve those ACE values. 2001 had an extremely active late start but still did not achieve those kind of ACE finishes. Hurricanes are everything when you look at ACE they rack up the majority of it in any given season. IMO number of storms is not as important as ACE in a statistical standpoint for activity.

Disclaimer: This is looking at a statistical standpoint for a season overall, not individual systems and their impacts as said over and over one system can change everything regardless of statistical values depending on where it goes.

Edit: And as wxman57 mentioned, the factors that we typically see use to predict a season all turned out correct and pointed to a very active season which makes it even more mind boggling. One of the rare non-El Nino seasons to see this happen.

[WeatherGuesser]

For June the forecast was 18/9/4 with an ACE of 165. It was revised to 18/8/3 and ACE of 142 in August. We are at 9/1/0 and ACE about 17, average for this date being 56 (should've collected 60% of the seasonal ace by now). The numbers may get there but that ACE gap is ridiculously far apart. An above normal season is regarded as 111 (or 120%) of ACE, below normal season is 66 (71%), and anything in between the two is considered normal which is around 93 on average. We're talking about a hyperactive season was forecasted, lots of storms and lots of storms becoming hurricanes and major hurricanes to achieve those ACE values.

So, who says you have to have half the average normal at the half way point? Who says the season can't be lopsided and gain more of the numbers in the second half? Or (as I postulated earlier), that the season isn't abnormally skewed on the calendar as some of the other seasons seem to have been this year?

[Ntxw]

So, who says you have to have half the average normal at the half way point? Who says the season can't be lopsided and gain more of the numbers in the second half? Or (as I postulated earlier), that the season isn't abnormally skewed on the calendar as some of the other seasons seem to have been this year?

Key word here is statistical standpoint. To get to normal of what we typically could see the rest of the season would have to be very very active (possible). If we are to get to the forecasted value (hyperactive) you are crunching entire seasons like 2008 into a 2/3 month period if you believe the season will go straight through to late December and still produce hurricanes. Is that really a realistic way to look at it? It could happen but the odds are not in that favor and would be a once in a lifetime event which do not happen often.

[Ptarmigan]

One thing I'd point out is even though the forecast numbers/intensity appear to be a bust, the seasonal predictors that we use verified great.

We thought that there would be no El Nino, likely cooler than normal water in the Nino 3.4 region. That certainly verified well.

We predicted lower-than normal pressures in the deep tropics this year, and that verified excellently through August.

Warmer water in the deep tropics (vs. subtropics) verified well.

But still the storms didn't form as expected. I think the global downturn in activity, particularly in the Northern Hemisphere is being caused by some very dry mid-level air which circles the globe in the tropics. Could be something to do with decreased solar activity. The Atlantic may also be impacted by the very cool water in the western Indian Ocean, which appears to have reduced the strength of tropical waves moving off of Africa.

I notice there are severe droughts in Northeast Brazil, Northern Canada, Northern Russia, and Northwest Africa. The Canada and Russia are large and wonder if the dry air from those areas are contributing to the dry mid-level air circulating around the globe. The only thing is, most of the dry air is in the tropics, not northern areas.

http://drought.mssl.ucl.ac.uk/drought.html?map=%2Fwww%2Fdrought%2Fweb_pages%2Fdrought.map&program=%2Fcgi-bin%2Fmapserv&root=%2Fwww%2Fdrought2%2F&map_web_imagepath=%2Ftmp%2F&map_web_imageurl=%2Ftmp%2F&map_web_template=%2Fdrought.html

http://www.wunderground.com/blog/24hourprof/comment.html?entrynum=66

[WeatherGuesser]

the season will go straight through to late December and still produce hurricanes. Is that really a realistic way to look at it?

That's kind of the point for discussion of the theoretically shifted/late season. Look at it as if this were early August instead of mid-September ---- where would we be with the stats then?

Or better yet, look at it in terms of number of weeks into the season with the season starting a month late.

[cycloneye]

Here is an excerpt from CSU admitting a bad seasonal forecast.

Seasonal Forecast

The most recent seasonal forecast called for an above-average season. Obviously, at this
point, we realize that the seasonal forecast was a significant over-prediction, and we
therefore do not expect to see the levels of activity this year that we earlier anticipated.

[WeatherEmperor]

Here is an excerpt from CSU admitting a bad seasonal forecast.

Seasonal Forecast

The most recent seasonal forecast called for an above-average season. Obviously, at this
point, we realize that the seasonal forecast was a significant over-prediction, and we
therefore do not expect to see the levels of activity this year that we earlier anticipated.

+10000000 on this. Thanks for posting this Luis!

Instead of arguing back and forth about who is right or wrong...we need to figure out where the mistakes were made and find a way to get better at this. Remember...hurricanes can destroy property and human lives. It is important that we get forecasts and other information right because the public needs this to protect themselves. Lets learn from this and get better!

Sent from my HTC EVO 4G LTE

[ConvergenceZone]

One thing I'd point out is even though the forecast numbers/intensity appear to be a bust, the seasonal predictors that we use verified great.

We thought that there would be no El Nino, likely cooler than normal water in the Nino 3.4 region. That certainly verified well.

We predicted lower-than normal pressures in the deep tropics this year, and that verified excellently through August.

Warmer water in the deep tropics (vs. subtropics) verified well.

But still the storms didn't form as expected. I think the global downturn in activity, particularly in the Northern Hemisphere is being caused by some very dry mid-level air which circles the globe in the tropics. Could be something to do with decreased solar activity. The Atlantic may also be impacted by the very cool water in the western Indian Ocean, which appears to have reduced the strength of tropical waves moving off of Africa.

Good points WXMAN regarding the global dry air.... . In spite of the very dry air out there, I still think there will be a couple of more tropical storms this year before the season ends . I wouldn't be at all surprised if one of those makes a run at a minimal hurricane before the season is over....

[hurricanetrack]

Let's play what if for a moment.

What if the forecasts for ACE of 165 were dead on? We had all the majors, etc to make that happen but not a single one came anywhere close to the United States. What then? Would people be "upset" that no one saw "that" coming? It's a no-win situation for these forecasting groups unless they get it just right it seems. Gotta hit the numbers and hurricanes must hit the USA for them to be considered accurate.

Let's not forget the truly epic "bust" in 2005 that went the other way. That season was extraordinarily under-predicted no matter how you cut it. No one saw that coming and look what happened.

I personally do not see the value for the public at all in having a seasonal forecast. Until such time that a group can say that on such and such a date X hurricane will come knocking, then what's the point? Every key ingredient can be there and nothing substantial materializes and really, is the public running out in a season like this was supposed to be and stocking up on supplies, buying hurricane shutters, purchasing flood insurance, etc etc etc just because everyone said it was going to be an active season? A few people might have stepped it up some but the vast majority of the populous from TX to ME probably did nothing different this season than they have the past 10.

Gotta hand it to the people who are trying. One day, they just might get it down to knowing when, where and how bad. Until then, we have satellites in space to tell us when the bleep is about to form that could ultimately hit the fan - and a couple of decent computer models that sometimes sniff out development far enough in advance to give us ample warning.

[ConvergenceZone]

Let's play what if for a moment.

What if the forecasts for ACE of 165 were dead on? We had all the majors, etc to make that happen but not a single one came anywhere close to the United States. What then? Would people be "upset" that no one saw "that" coming? It's a no-win situation for these forecasting groups unless they get it just right it seems. Gotta hit the numbers and hurricanes must hit the USA for them to be considered accurate.

Let's not forget the truly epic "bust" in 2005 that went the other way. That season was extraordinarily under-predicted no matter how you cut it. No one saw that coming and look what happened.

I personally do not see the value for the public at all in having a seasonal forecast. Until such time that a group can say that on such and such a date X hurricane will come knocking, then what's the point? Every key ingredient can be there and nothing substantial materializes and really, is the public running out in a season like this was supposed to be and stocking up on supplies, buying hurricane shutters, purchasing flood insurance, etc etc etc just because everyone said it was going to be an active season? A few people might have stepped it up some but the vast majority of the populous from TX to ME probably did nothing different this season than they have the past 10.

Gotta hand it to the people who are trying. One day, they just might get it down to knowing when, where and how bad. Until then, we have satellites in space to tell us when the bleep is about to form that could ultimately hit the fan - and a couple of decent computer models that sometimes sniff out development far enough in advance to give us ample warning.

Yea, honestly I don't even pay attention to the forecasted numbers. It's a joke to me, but it does provide for good entertainment.....

[Sanibel]

Scraping for disturbances out of Africa. The Cape Verde Belt has dried up for now.

[Stormcenter]

Time is running out and I'm so happy about it.....just a few more weeks. IMO