Predict/Guess the Number of Tornadoes and the First High Risk of 2016

[thewxmann]

After seeing the evolution of everything so far this year (which has not been acting like a strong Nino at all, and the PDO will remain at extremely + levels) I'm changing my prediction.

 

900 tornadoes, first and only high risk on 6/10.

[brettjrob]

Yeah - yet again, most signs that can be interpreted this early (for whatever they're worth) are red flags. Short-term drought already looming for the Plains, especially judging by the medium-range guidance to close out this month. Rinse and repeat.

[Stebo]

After seeing the evolution of everything so far this year (which has not been acting like a strong Nino at all, and the PDO will remain at extremely + levels) I'm changing my prediction.

 

900 tornadoes, first and only high risk on 6/10.

The PDO spike was to be expected with the Nino, so I am not sure why this is a surprise to anyone. If it continues to rise in spring then there is necessary concern needed. I don't think it will with the Nino expected to break down. The only place that this hasn't been acting like a strong Nino is California. everywhere is it has been textbook strong Nino, so you might want to widen your scope a bit.

[andyhb]

After seeing the evolution of everything so far this year (which has not been acting like a strong Nino at all, and the PDO will remain at extremely + levels) I'm changing my prediction.

 

900 tornadoes, first and only high risk on 6/10.

 

What?

 

Aside from California (and a few other regions), this has been behaving like a lot of the strong Nino composites suggested for Dec/Jan/Feb. Retrogression of the Aleutian low was expected later in the winter.

[Stebo]

Yeah - yet again, most signs that can be interpreted this early (for whatever they're worth) are red flags. Short-term drought already looming for the Plains, especially judging by the medium-range guidance to close out this month. Rinse and repeat.

Short-term drought that could easily be erased with one good system, plus there is no long term drought like you had to deal with for years, that was completely evaporated starting last spring.

 

Edit: what short term drought are you talking about...

 

 

The long term is equally as good

 

[thewxmann]

The PDO spike was to be expected with the Nino, so I am not sure why this is a surprise to anyone. If it continues to rise in spring then there is necessary concern needed. I don't think it will with the Nino expected to break down. The only place that this hasn't been acting like a strong Nino is California. everywhere is it has been textbook strong Nino, so you might want to widen your scope a bit.

 

If the West Coast ridge continues to assert itself, the PDO will spike in spring...

 

And I'm not just talking about California. Pacific NW has been wetter than normal (not Nino-like). TX has been near-average as well (not Nino-like). Southern Hemisphere Pacific TC activity has been below normal until recently (not Nino-like).

 

My point is, if El Nino is not asserting itself in the CONUS weather pattern, why should we expect it to influence the tornado season later on in spring? And if not, why should we expect it to be different than the past few years, given the sky-high PDO?

[Stebo]

If the West Coast ridge continues to assert itself, the PDO will spike in spring...

 

And I'm not just talking about California. Pacific NW has been wetter than normal (not Nino-like). TX has been near-average as well (not Nino-like). Southern Hemisphere Pacific TC activity has been below normal until recently (not Nino-like).

What if it doesn't, we don't know if we will remain in a +PNA pattern for long, plus I'd rather we burn a +PNA pattern now vs April-June. We both know a +PNA isn't going to remain going forward 4 months that would be unheard of, so when it flips down goes the PDO. Case in point the Euro weeklies that just came out, the mean flips the pattern in 15 days, even if you throw in some lag and push it to 20 days, you are talking the majority of March with a mean trough in the West. Just because a pattern shows one thing right now, doesn't mean it is locking in forever.

[andyhb]

If the West Coast ridge continues to assert itself, the PDO will spike in spring...

 

And I'm not just talking about California. Pacific NW has been wetter than normal (not Nino-like). TX has been near-average as well (not Nino-like). Southern Hemisphere Pacific TC activity has been below normal until recently (not Nino-like).

 

My point is, if El Nino is not asserting itself in the CONUS weather pattern, why should we expect it to influence the tornado season later on in spring? And if not, why should we expect it to be different than the past few years, given the sky-high PDO?

 

Um, not sure how to put this nicely, but did you even look at the precip composites in the link that you yourself linked on Twitter? There are clearly some strong El Ninos there that contain some of these anomalies.

[thewxmann]

What if it doesn't, we don't know if we will remain in a +PNA pattern for long, plus I'd rather we burn a +PNA pattern now vs April-June. We both know a +PNA isn't going to remain going forward 4 months that would be unheard of, so when it flips down goes the PDO.

 

The PNA was positive in winter 1987-88 and actually became more positive through the spring and summer. There is precedent. 

[thewxmann]

Um, not sure how to put this nicely, but did you even look at the precip composites in the link that you yourself linked on Twitter? There are clearly some strong El Ninos there that contain some of these anomalies.

 

Fair enough, but regardless, if it remains this dry in both CA and TX for an extended period of time, you'll see some anomalies that are unlike anything in those set of maps... there has to be something that is neutralizing the Nino effect.

[andyhb]

The PNA was positive in winter 1987-88 and actually became more positive through the spring and summer. There is precedent. 

 

Actually it didn't.

 

1988 0.93 1.24 1.42 0.94 1.20 0.74 0.64 0.19 -0.37 -0.10 -0.02 -0.43

[Stebo]

The PNA was positive in winter 1987-88 and actually became more positive through the spring and summer. There is precedent. 

One year, and the one year this Nino isn't following. If we are cherry picking years then, I am sure you saw the stuff HM posted on twitter, the NAO/AO is following 1953 and 1998 so far this winter. Soooooo it is fun to cherry pick things to fit the narrative we are trying to post.

[Stebo]

Actually it didn't.

 

1988 0.93 1.24 1.42 0.94 1.20 0.74 0.64 0.19 -0.37 -0.10 -0.02 -0.43

 

I guess going up in May = spring and summer

[thewxmann]

One year, and the one year this Nino isn't following. If we are cherry picking years then, I am sure you saw the stuff HM posted on twitter, the NAO/AO is following 1953 and 1998 so far this winter. Soooooo it is fun to cherry pick things to fit the narrative we are trying to post.

 

I'm not cherry-picking, I was arguing against your point.

 

I'm encouraged about the NAO/AO information, I was under the impression that those factors were worse off than they actually are.

[thewxmann]

Actually it didn't.

 

1988 0.93 1.24 1.42 0.94 1.20 0.74 0.64 0.19 -0.37 -0.10 -0.02 -0.43

 

Are we looking at the same dataset?  

ftp://ftp.cpc.ncep.noaa.gov/wd52dg/data/indices/pna_index.tim

[andyhb]

It's also of the utmost importance to consider what type of +PDO orientation we're looking at right now compared to back in 2014/etc. Right now we have a lot of cool water over the NW and N Central Pacific with relatively warm water over the NE Pacific/W Coast. Back then, we had a huge warm pool over the Gulf of Alaska and down the West Coast i.e. the blob, along with generally average SSTAs over the N Central and NW Pacific. That should tell you something about where the forcing is primarily arising for the recent rise in the PDO.

[andyhb]

Are we looking at the same dataset?  

ftp://ftp.cpc.ncep.noaa.gov/wd52dg/data/indices/pna_index.tim

 

To link to something as generally variable as the PNA, which is something that is often forced by the larger scale when we're talking about long range forecasting, that doesn't really work. Notice that there are rather large fluctuations in between months there. That's why I linked the PDO since it is generally smoother in trend (and has direct impacts on the PNA)

 

If we're talking about it rising through spring and summer, why is it dropping from Feb to March, April to May and July to August?

[Stebo]

I'm not cherry-picking, I was arguing against your point.

 

I'm encouraged about the NAO/AO information, I was under the impression that those factors were worse off than they actually are.

Arguing my point would be better if you used more data than one year. Furthermore there were other complications with 87-88 like the start of a massive drought across a large portion of the country. I don't see that happening going into spring.

[thewxmann]

Arguing my point would be better if you used more data than one year. Furthermore there were other complications with 87-88 like the start of a massive drought across a large portion of the country. I don't see that happening going into spring.

 

You said there was no precedent. I said there was. That's it. 

 

That's all beside the point anyway. Jist of my revised prediction was, well El Nino is not doing as much as expected, let's revert to persistence. Would have been a good call for CA this winter.

[thewxmann]

To link to something as generally variable as the PNA, which is something that is often forced by the larger scale when we're talking about long range forecasting, that doesn't really work. Notice that there are rather large fluctuations in between months there. That's why I linked the PDO since it is generally smoother in trend (and has direct impacts on the PNA)

 

If we're talking about it rising through spring and summer, why is it dropping from Feb to March, April to May and July to August?

 

We were talking about PNA, why post numbers about PDO? They may be linked but they're not the same thing.

 

The general trend was rising, which is what I was referring to, since, as you stated, the PNA can be quite variable month-to-month.

[andyhb]

You said there was no precedent. I said there was. That's it. 

 

That's all beside the point anyway. Jist of my revised prediction was, well El Nino is not doing as much as expected, let's revert to persistence. Would have been a good call for CA this winter.

 

On this front, there were >1150 tornadoes last year per SPC.

 

We were talking about PNA, why post numbers about PDO? They may be linked but they're not the same thing.

 

The general trend was rising, which is what I was referring to, since, as you stated, the PNA can be quite variable month-to-month.

 

But what about this is really relevant in forecasting for a whole season then?

[Stebo]

You said there was no precedent. I said there was. That's it. 

 

That's all beside the point anyway. Jist of my revised prediction was, well El Nino is not doing as much as expected, let's revert to persistence. Would have been a good call for CA this winter.

And a bad call for most of the east/midwest/south.

[thewxmann]

On this front, there were >1150 tornadoes last year per SPC.

 

But <1000 in each of the three years before.

 

 

But what about this is really relevant in forecasting for a whole season then?

 

Not much really. I made a quick statement that if if the PNA stayed positive then the PDO would rise. I was countered with "there's no precedent for [the PNA staying positive so long]," which I refuted.

[thewxmann]

And a bad call for most of the east/midwest/south.

 

Given the East has been fairly cold the last few years, with a few big snowstorms here and there, forecasting at least one big snowstorm and at least one big cold shot this winter wouldn't have been a totally wrong proposition.

[andyhb]

But <1000 in each of the three years before.

 

You can toss 2012 from that pool since it was so completely backwards from what we have now.

 

Fluctuations in Nino influence or not, 2013 and 2014 had nowhere near the type of tropical forcing that this year or even 2015 had (remember the flooding in the S Plains via the enhanced ST jet).

[Chinook]

The year-to-date rainfall has been quite low in Texas and Oklahoma so far, but I think the soil moisture is not too low yet. October to December rainfall was high in the Plains. So, don't call it a drought quite yet. Lack of rain in Jan-Feb may be an indicator of a weaker severe weather season to come, but not the only predictor.

[Stebo]

Given the East has been fairly cold the last few years, with a few big snowstorms here and there, forecasting at least one big snowstorm and at least one big cold shot this winter wouldn't have been a totally wrong proposition.

That wasn't what was forecast, and a few big snowstorms, you do realize many locations have set snowfall records in the last 2 years both in the midwest and the east? I am sorry but you don't seem well verse on the topic and you are just trying to find something to fit your narrative of less tornadoes because.... ....reasons? If you didn't do this every year I wouldn't have an issue but man every year going back for about 8 now you have always been on the side of less tornadoes for events, for the year as a whole. It is like broken clock meteorology.

[thewxmann]

That wasn't what was forecast, and a few big snowstorms, you do realize many locations have set snowfall records in the last 2 years both in the midwest and the east? I am sorry but you don't seem well verse on the topic and you are just trying to find something to fit your narrative of less tornadoes because.... ....reasons? If you didn't do this every year I wouldn't have an issue but man every year going back for about 8 now you have always been on the side of less tornadoes for events, for the year as a whole. It is like broken clock meteorology.

 

Wait... that's my point I said a big snowstorm this year would've been a good call precisely because the East has been doing well in snow past few years.

 

I don't get it... I'm not even trying to nitpick reasons to support my point right now, I'm actually just responding to your responses.

 

And of course I'm always on the conservative side for tornadoes, I like to set low expectations and see the atmosphere (and you guys) prove me wrong.

 

Plus this is a guess thread anyway.

[Stebo]

Wait... that's my point I said a big snowstorm this year would've been a good call precisely because the East has been doing well in snow past few years.

 

I don't get it... I'm not even trying to nitpick reasons to support my point right now, I'm actually just responding to your responses.

 

And of course I'm always on the conservative side for tornadoes, I like to set low expectations and see the atmosphere (and you guys) prove me wrong.

 

Plus this is a guess thread anyway.

I'm sorry if I came on hard but, I just see what you say on twitter and on here and it gets irksome. You don't always have to be conservative especially when things are looking up. The problem is, you always use the worst case scenario for a negative outcome, just like bringing up 87-88, that isn't even like the current year. I mean it just doesn't make sense to constantly have a negative or conservative theme on everything.

[brettjrob]

Short-term drought that could easily be erased with one good system, plus there is no long term drought like you had to deal with for years, that was completely evaporated starting last spring.

 

Edit: what short term drought are you talking about...

 

Precipitation over the S Plains has been almost nil since Christmastime, and you can see a few splotches of D0 showing up over TX/OK on the drought monitor. It certainly isn't a major concern yet, but it means we have less leeway over the next 30-45 days. If for some reason we remain fairly dry through mid-late March, then I would expect the usual over-mixing issues over the S Plains to commence during storm season until/unless a couple big, wet systems come to the rescue (which they did last year, after a dry winter).

 

I'm not worried at all yet. Persistent west coast ridging during mid-late winter isn't what I'd like to see if I had the choice, but until March it's not all that relevant (other than starting to run up a short-term precip deficit). It looks like we'll average a slightly -AO for DJF, which in my chase season rankings is a bearish indicator for Plains spring activity, as is the +PDO. These aren't particularly strong correlations, of course.

 

One minor quibble: I would argue 1988 is a decent analog, as painful as it is to admit. There are probably 4-5 others that are equally strong or better, but still.