Early 2013 Atlantic hurricane season forecast

[TropicalAnalystwx13]

Some of the biggest indicators for the upcoming hurricane season present in the October-November-December-January period preceding a particular season. The North Atlantic Oscillation, or NAO for short, is no different. The North Atlantic Oscillation is a teleconnection between the Icelandic low...located over Iceland (pretty self-explanatory)...and the Bermuda high....located over the North Atlantic. It is arguably one of the biggest factors that determines the longevity and intensity of both hurricanes and the season as a whole, and it also dictates steering patterns. Now, there are two phases of the NAO: positive and negative. A positive NAO is associated with a deeper than normal Icelandic low and stronger than normal, yet farther east, Bermuda high. This is why, during the positive phase, that many hurricanes do not hit the United States, or form at all. A stronger than average Bermuda high creates high trade winds across the Main Development Region, cooling sea surface temperatures through evaporational cooling, and causing tropical waves to move at ridiculously high speeds. On the contrary, during a negative NAO, the Icelandic low is weaker than normal and the Bermuda high is weaker than average, yet more displaced to the west. Many of the historic hurricane landfalls on the United States have occurred during this phase. A negative NAO reduces trade winds across the Atlantic, pulls less dust off the continent of Africa, and allows sea surface temperatures to warm steadily to rapidly.

So what does this have to do anything about my thoughts during the hurricane season?

As aforementioned, the biggest indicators of the upcoming season are present during the fall and winter of the previous year. The state of the NAO during this time usually reverses in the spring, but returns to the fall/winter phase by summer. The NAO has been negative for most of this winter and is forecast to stay this way for the coming weeks. My projection is that we will see a reversal to a positive NAO by the spring, but back to a negative NAO by the start and peak of hurricane season. The current TNA index is 0.74C and rising, which would make it the highest since the record in 2010. If the NAO stays negative, this will mean near record level warmth in the eastern Atlantic. Conditions would remain favorable for tropical development for the season, leading to an increase in Cape Verde hurricanes.

Another important player is the ENSO. As of the latest update from the Climate Prediction Center, sea surface temperatures in the equatorial Pacific remain below the levels needed for an El Nino. Many of the climate models show very little change from current to the start of hurricane season several months from now. A Neutral ENSO does not harm the hurricane season and in fact, 2005 started off in this phase.

Overall, given other factors I've not listed here, I am calling for...

- 16 to 20 named storms
- 7 to 11 hurricanes
- 3 to 5 major hurricanes

Vertical instability is key in the number of major hurricanes predicted. If it appears to be trending below average by my next forecast in April, I'll probably trend the number of intense hurricanes down a bit. If it appears to be trending above average, I may leave the numbers the same.

What are your thoughts?

[tolakram]

I think vertical instability is key and I don't understand what drives it, why it's been unusually low for the last few seasons, or if it's going to change. It's one of those things I didn't pay attention too until storms started to struggle. IMO it's key for strength but not overall numbers, similar to your thinking.

I'm a big believer in that make believe law of averages, so I think el nino is a real possibility for next year. It's been a while.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[galaxy401]

I think the 2013 season is going to be like the last two seasons in which it's quanity over quality as well as storms thriving in the subtropics. Main reason I think will be the dry air and instability. There's also a chance of La Nina coming back again so we'll see. Since most of the storms will be out in the open Atlantic, the East Coast might not get lucky again.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[CrazyC83]

I agree re: quantity over quality, although I feel the NW Caribbean and Gulf will be open for business more than the last two years. I still think the deep tropics will remain closed off.

My guess: 22 to 28 named storms, 9 to 13 hurricanes, 3 to 5 major hurricanes.

[Ntxw]

I think vertical instability is key and I don't understand what drives it, why it's been unusually low for the last few seasons, or if it's going to change. It's one of those things I didn't pay attention too until storms started to struggle. IMO it's key for strength but not overall numbers, similar to your thinking.

I'm a big believer in that make believe law of averages, so I think el nino is a real possibility for next year. It's been a while.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Though I do think La Nina might return (clearly I've been wrong many times ) but there is some support to your gut feeling! We should also all consider adding a few to our quantities given the liberal nature of the NHC these days for short lived satellite storms.



The +AMO will probably continue to allow strong subtropical hurricanes as well.

[Cyclenall]

I won't post any numbers until the Spring poll but my prediction is for the 2013 Atlantic Hurricane Season to be the worst season ever for the United States. The wave of highly destructive hurricanes that exceed 100 knots at landfall on US coastlines has been held back by nature so long that when the gates open it will be horrifying (Equilibrium). I've been predicting that for a few years now but I can't envision 2013 being similar to 2011-2012 with the massive quantity over quality ratio because the last time we didn't have weakly storms was either 2010, 2008 or 2005. 2007 was pretty odd but that season's ACE was nothing much. The favorable condition parameters are starting to line up so my guess is next year has a higher then before average chance of carrying out what I think will occur. That even applies if an El Nino comes out of nowhere. To get another season with 19 or so named storms and almost no major hurricanes to note would be truly insane, one season is quite an exception already but two in a row was the last thing I expected and I'll discuss that more in my post-season analysis on the 2012 season. Here are some ideas I posted in the expert's thread:

(About the low vertical instability in the Atlantic) Its annoying how this is now a multi-year problem and there has been given no explanation for why. It wasn't even mentioned in the CSU report (up to page 21 at least) yet its having an effect on the season's performance. If it returns with the very low background pressures then watch out, everything would be lined up for my prediction of the worst hurricane season ever for the United States. Further, if there is strong and anomalous ridging over eastern North America during August to mid-October, that will further exacerbate the threat like in 2004 and 2005. For 7 hurricane seasons now generally its been "troughy" according to NCEP analysis and the CSU during those months and when it flips and it will, recurving systems will be much less likely and combined with mentioned above, the SWHTF.

[tolakram]

The wave of highly destructive hurricanes that exceed 100 knots at landfall on US coastlines has been held back by nature so long that when the gates open it will be horrifying (Equilibrium).

I don't think such an equilibrium exists. Nature does not measure things. The idea that there is some real significance to a 100 knot storm over a 90 knot storm other than wind speed is something we made up. That made up definition continues to catch a lot of people off guard.

Good conditions in the MDR along with an upper air environment that steers storms into the coasts is obviously a rare thing for the Atlantic basin. If history tells us anything it's that rare is normal, and so by that definition, with 2 hits on the east coast in the last 2 years, we can expect nothing to hit the east coast for a while. If one believes in the law of averages.

I am of the strong belief that until we can understand long term patterns better we can never forecast that real risk of storms hitting the east coast. Even if we could it's still a bit of luck that a storm forms in the right location at the right time. It may be that the east coast has a higher risk when the MDR is less favorable. A strong hurricane heading west si going to need a very strong ridge to prevent it from turning north.

All in my opinion, of course.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[CrazyC83]

The wave of highly destructive hurricanes that exceed 100 knots at landfall on US coastlines has been held back by nature so long that when the gates open it will be horrifying (Equilibrium).

I don't think such an equilibrium exists. Nature does not measure things. The idea that there is some real significance to a 100 knot storm over a 90 knot storm other than wind speed is something we made up. That made up definition continues to catch a lot of people off guard.

Good conditions in the MDR along with an upper air environment that steers storms into the coasts is obviously a rare thing for the Atlantic basin. If history tells us anything it's that rare is normal, and so by that definition, with 2 hits on the east coast in the last 2 years, we can expect nothing to hit the east coast for a while. If one believes in the law of averages.

I am of the strong belief that until we can understand long term patterns better we can never forecast that real risk of storms hitting the east coast. Even if we could it's still a bit of luck that a storm forms in the right location at the right time. It may be that the east coast has a higher risk when the MDR is less favorable. A strong hurricane heading west si going to need a very strong ridge to prevent it from turning north.

All in my opinion, of course.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

The Gulf coast shouldn't rest too easy...especially if the deep tropics remain unfavorable. A storm forming in the western Caribbean would likely draw northward if a trough is around.

Still, the east coast looks prime again in 2013. When was the last time the east coast was hit hard in three consecutive seasons?

[Cyclenall]

The wave of highly destructive hurricanes that exceed 100 knots at landfall on US coastlines has been held back by nature so long that when the gates open it will be horrifying (Equilibrium).

I don't think such an equilibrium exists. Nature does not measure things. The idea that there is some real significance to a 100 knot storm over a 90 knot storm other than wind speed is something we made up. That made up definition continues to catch a lot of people off guard.

Good conditions in the MDR along with an upper air environment that steers storms into the coasts is obviously a rare thing for the Atlantic basin. If history tells us anything it's that rare is normal, and so by that definition, with 2 hits on the east coast in the last 2 years, we can expect nothing to hit the east coast for a while. If one believes in the law of averages.

I am of the strong belief that until we can understand long term patterns better we can never forecast that real risk of storms hitting the east coast. Even if we could it's still a bit of luck that a storm forms in the right location at the right time. It may be that the east coast has a higher risk when the MDR is less favorable. A strong hurricane heading west si going to need a very strong ridge to prevent it from turning north.

All in my opinion, of course.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Its true that the tropics and atmosphere has no memory of what has occurred before it so the chances of getting a major hurricane landfall this next season is the same as last season barring major influences like the NAO. I'm not saying its more likely just because its been a long time, because the longer it takes for something to end the streak, the worse it will be whenever that happens. I thought it was going to be this season and it wasn't. I'm just predicting it every year now .

I've seen equilibrium everywhere in weather in all types of categories and timescales. Even everyday people reference this all the time and they aren't weather buffs...they know from experience that if April and May were very warm then June may not be good for warmth. The problem is we have no idea when it will flip, it could be anytime during one of these concentrations of the same pattern. Its strongly correlated to the cycles in meteorology we do understand and then there are the arbitrary ones like 100 knot hurricane landfalls on the US coastline patterns.

The last part of that post is quite true, I think people focus on the steering patterns too much and not enough on the biggest factor...where the tropical cyclones actually form. Compare the chances of a CV hurricane hitting Miami to a TC that forms in the same spot as Katrina did. A big part to the 2005 Atlantic Hurricane Season was where the hurricanes formed and it may be obvious but it needs repeating.

[Ptarmigan]

Not going to make any predictions yet.

[OuterBanker]

No real predictions except the return of the CV and the MDR. Just think what would have happened this year if both were not subdued.

[CrazyC83]

No real predictions except the return of the CV and the MDR. Just think what would have happened this year if both were not subdued.

If storms developed early, most likely it would have been a lot like 2010 with a lot of recurves.

[gigabite]

Though I do think La Nina might return (clearly I've been wrong many times ) but there is some support to your gut feeling! We should also all consider adding a few to our quantities given the liberal nature of the NHC these days for short lived satellite storms.

http://i46.tinypic.com/30l15xk.png

The +AMO will probably continue to allow strong subtropical hurricanes as well.

Nice graphic. I think that ESNO is poorly defined and to narrow of a measure, although I do believe it is affected by the span of the latitude of the moon. Evolutions in topology will probably factor this in somehow, but getting a better understanding of the mechanisms that are mixing the complex need more focus.

My example is the confusion that the population has between the need to find extraterrestrial life verses the need to understand gravity or why does the sun work. We know that the difference in mass keeps a fly on the wall. We don't know how to make it. Just the difference between normal gravity and associated gravity is enough energy to power everything we have with millions of KWH leftover.

My graphic shows that there is a slight relationship between some of the extremes of the moon's range and the ESNO. It is not an apples to apples comparison. The Moon Path is yearly range and the ESNO is a three month event.


Uploaded with ImageShack.us

[gigabite]

The methodology I use will produce a forecast number a hundred years in advance. It is highly dependent on historical data. The older the analog year the larger the field variable multipler has to be. In 2012 it hit at 80% of the measured value. Last year was the first year I used a multipler. NASA's software has been improving not only in sensitivity but also in reliability. Before 2005 The Moon Path method hit 80% regularly.

What ever the methodology there has to be moisture. The early part of next year the longitude of the new moon will be crossing the Sahara Desert that usually doesn't indicate a wet season. After that it will be crossing into the Indian Ocean. There is a plate boundary that is 180 degrees from California. That is at aphelion. That could get an earthquake swarm going in the early part of July 2013. The latitude of the moon at aphelion is at an extreme. That is El Niño-ish. Not really a hurricane signal.

By the new standards a season in the high teens would be normal. I haven't done the comps past the analog year, but my guess would the low teens.

[gigabite]

One of the drawbacks of this methodology is that it has no way to detect annual shear, when the sub aphelion new moon falls between two previous sub points equidistant apart the only difference is left or right movement for the season. It is not that I think El Niño is as good as it's most recient definition. It is that I think that it should be sectioned latitudinally.

[HurricaneRyan]

All I know is that this upcoming season if my favorite name list, lol.

Hopefully it's an active season with INTERESTING storms.

[CrazyC83]

The 2013 names:

Andrea - Barry - Chantal - Dorian - Erin - Fernand - Gabrielle - Humberto - Ingrid - Jerry - Karen - Lorenzo - Melissa - Nestor - Olga - Pablo - Rebekah - Sebastian - Tanya - Van - Wendy

[MGC]

No way we have another season with hardly any MDR storms unless there is a strong El Nino. It will all depend on ENSO phase come ASO. Doubt we get two May systems in 2013......MGC

[ROCK]

cant make a prediction until the Spring poll but I will say the long range EURO is showing higher pressures in the carib and MDR come summer. Saw that map in another thread. Though I hug the EURO I dont think it will verify. It didnt verify last year so I dont put to much stock into it. I DO think we are in for an active year and significantly more landfalls ie FL......sorry FL folks but your time is up....

[cycloneye]

I think vertical instability is key and I don't understand what drives it, why it's been unusually low for the last few seasons, or if it's going to change. It's one of those things I didn't pay attention too until storms started to struggle. IMO it's key for strength but not overall numbers, similar to your thinking.

I'm a big believer in that make believe law of averages, so I think el nino is a real possibility for next year. It's been a while.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Almost two months have passed since you posted that and if you look at the ENSO thread,El Nino continues to hide. I agree 100% with the vertical Instability factor as being very important to see how the season evolves in terms of quantity vs quality.