Thoughts about the upcoming 2015 chase season

[Royce Sheibal]

Here in Nebraska, we've got green grass and people mowing their lawns in the middle of January. This happened a couple of years ago in 2012 and that year was a dud for chasing in Nebrsaka. It was a weak la-nina event that spring which has a mild correlation to low tornado counts. Last year it was typical cold and blah until early May, at which point summer hit and boom tornadoes like weeds. It was neither el-nino or la-nina, which typically means a higher count season around here.

The long term enso forecast this year shows early spring weak la-nina, most likely with the RRR over cali, meaning another down early season, but perhaps it will settle before the ridge of death hits in June.

I understand the scepticism about using computer models and weak correlations etc, but a weak correlation is better than assuming total randomness. And when all else fails, forecast the same thing that happened last time we had the same inputs.

 

[Ben Holcomb]

Interestingly, I see more and more chasers traveling into the eastern regions of TA to either luck out and find a bald spot in the woods and/or lurk behind and feed off disasters. I'm hoping this is not a new trend as "chasing" becomes harder and the glory of arriving in ground zero for media coverage and personal glory takes center stage.

This is exactly what chasers are doing, and sadly, these are the events that actually sell to the media. I hate chasing out east, but was glad I did so last year as it ended up being my only real tornadoes.

 

[Nate Weikal]

Since it's January, chase season is just around the corner. I'll be honest, I'm not sure what to think about 2015. As far as moisture, we haven't really had that much around the TX Panhandle area. I know it's just speculation talking about the upcoming season right now, but what are your thoughts or concerns going into the chase season?

Depends on how long the cold sticks around, which I don't think will be as prevalant as last year. And a lack of ground moisture doesn't neccessarily mean we won't have any decent outbreaks. The southern plains drought was worse in 2013 and we still had some really significant severe weather outbreaks that year (El Reno, Moore, Granbury).

 

[Brett Roberts]

Depends on how long the cold sticks around, which I don't think will be as prevalant as last year. And a lack of ground moisture doesn't neccessarily mean we won't have any decent outbreaks. The southern plains drought was worse in 2013 and we still had some really significant severe weather outbreaks that year (El Reno, Moore, Granbury).

The short-term drought, i.e. soil moisture, was worse in 2014 than 2013 for most of this region. Of course, even in 2013 which featured decent springtime precipitation, most of the significant storms were in undesirable terrain along I-35 (see the events you listed).

As is rightly pointed out every time threads like this start up in mid-winter, predictability is negligible at this timescale for features as specific as favorable chase systems. But as I said around this time last year, I believe the Southwest and southern Plains drought is one factor which can be monitored and provide some skill in predicting the ceiling for the season over a portion of Chase Alley. Specifically, if the drought does not improve substantially by April, then southwestern portions of the Alley (W TX/Panhandles, NM, W OK, W KS) are less likely to see numerous good chase days until or unless the drought improves during the season. For areas farther east and north, trying to call the quality of the season from this lead time really is almost pointless, though.

It should be noted that this is the first winter since 2009-10 in which the ONI (Nino 3.4 SST anomaly) averaged +0.5°C or higher during the Sep-Dec period; before that, the previous case was 2006-07. Obviously, both of the following springs (2007 and 2010) were pretty good for the southern High Plains. However, this cold season, the duration of the warm anomaly was shorter and the magnitude smaller than both those cases. And so far, the +PNA pattern with incessant eastern troughing has dominated this cold season yet again, which the medium range guidance strongly suggests will continue through the end of the month at least. But as Jeff mentioned, it only takes a few weeks of anomalous precipitation to impact the short-term drought meaningfully, so there's still plenty of hope -- see Feb-Mar 2007 for an impressive example. Let's see where the drought situation stands at the beginning of March before starting to get concerned.

 

[Nate Weikal]

The short-term drought, i.e. soil moisture, was worse in 2014 than 2013 for most of this region. Of course, even in 2013 which featured decent springtime precipitation, most of the significant storms were in undesirable terrain along I-35 (see the events you listed).

As is rightly pointed out every time threads like this start up in mid-winter, predictability is negligible at this timescale for features as specific as favorable chase systems. But as I said around this time last year, I believe the Southwest and southern Plains drought is one factor which can be monitored and provide some skill in predicting the ceiling for the season over a portion of Chase Alley. Specifically, if the drought does not improve substantially by April, then southwestern portions of the Alley (W TX/Panhandles, NM, W OK, W KS) are less likely to see numerous good chase days until or unless the drought improves during the season. For areas farther east and north, trying to call the quality of the season from this lead time really is almost pointless, though.

It should be noted that this is the first winter since 2009-10 in which the ONI (Nino 3.4 SST anomaly) averaged +0.5°C or higher during the Sep-Dec period; before that, the previous case was 2006-07. Obviously, both of the following springs (2007 and 2010) were pretty good for the southern High Plains. However, this cold season, the duration of the warm anomaly was shorter and the magnitude smaller than both those cases. And so far, the +PNA pattern with incessant eastern troughing has dominated this cold season yet again, which the medium range guidance strongly suggests will continue through the end of the month at least. But as Jeff mentioned, it only takes a few weeks of anomalous precipitation to impact the short-term drought meaningfully, so there's still plenty of hope -- see Feb-Mar 2007 for an impressive example. Let's see where the drought situation stands at the beginning of March before starting to get concerned.

Those were just a few of the events. That year, I also chased some decent storms in central TX and the panhandle (where the drought was worse that year). But I agree with the difficulty of figuring out just how the weather will behave this spring.

 

[James Gustina]

Its still a ways out and the season is still a ways off but damn is this discouraging:

 

[Caleb Grunzke]

It's winter. This type of blocking pattern can be expected. If it's the middle of March and we're still looking like this then I'll be worried. But enough with the negative vibes.

 

[James Gustina]

It's winter. This type of blocking pattern can be expected. If it's the middle of March and we're still looking like this then I'll be worried. But enough with the negative vibes.

True enough. I've just got the usual jitters and so far haven't been thinking logically about how insignificant this all is until we're right up on March.

 

[JamesCaruso]

My understanding is that there is no correlation between global patterns (such as ENSO) and tornado activity, and I believe Dr. Greg Forbes shared findings along these lines at ChaserCon 2014. Regardless, it is fun to debate what the season may hold, much as many of us may also enjoy predicting what will happen in upcoming sports seasons.

On a personal note, after enjoying a few years of flexibility in which I was able to time a two-week chase trip to a favorable period within a three or even four week window of opportunity to take time off from work, I am now faced with scheduling constraints that are going to require a computer algorithm to solve. My CPA firm has merged into a large national firm, and the timing of their firm-wide events couldn't be worse: I must attend a national training conference the first week of May, and a national partner meeting the first week of June. Although there are still some weeks of the season that remain available, I have to be aware of being away from the office and from the family for too many weeks in a row, if the business events and chasing were to be in consecutive weeks. Unfortunately, this is likely to be a problem every year from now on But this year is even worse because even the period in between the business commitments are filled with first communions and confirmations.

So if anyone wants to add to this thread with some commiserating about difficulties making it out onto the Plains this year, please do... As the saying goes, misery loves company!

I am also curious as to others' thoughts: if you were in my shoes, and if travel costs were not an issue, would you go for one week in May (in between the business commitments) and then another week in June (after the last business trip)? OR would you go for two consecutive weeks in June (assuming two consecutive weeks in May won't fit in)? The first option includes a week in peak season, but going for just one week always runs the risk of hitting a bad pattern, whereas two weeks smooths out the probabilities... Plus I enjoy and prefer immersing myself into the rhythm of chasing for two weeks straight. But I fear that waiting until June I might miss all the best stuff, even though in some years the best events have held off until then (see Pilger!)

Jim

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[JamesCaruso]

Are there any eastern US chasers, ie from Ohio se to North Carolina and ne of there? What are your thoughts on those areas?

I live in southeast PA (Philadelphia area). I head out to the Plains every year but don't do any local chasing here where I live. Sure, I keep tabs on the weather and get excited when we are under the gun. But chasing around here just isn't worth it - trees, hills, buildings, traffic, low clouds and haze... Not to mention that nothing much ends up happening most of the time. Primary severe mode is squall lines. I definitely don't spend any time on long range prognosticating for the local area, I just try to enjoy what I can if it's coming through my neighborhood. I won't drive any distances to position.


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[Caleb Grunzke]

I know last year was an exception but 20-31 of May always seem to be the most active. I would probably stick with climatology if you're having to pick now which weeks you want to chase. It seems like the safe choice.

 

[Shane Adams]

True enough. I've just got the usual jitters and so far haven't been thinking logically about how insignificant this all is until we're right up on March.

You're thinking like a met student. They pretty much teach you guys everything that can go wrong with a setup LOL.

 

[Caleb Grunzke]

You're thinking like a met student. They pretty much teach you guys everything that can go wrong with a setup LOL.

Which is why I'm always so pessimistic about setups... lol

 

[James Gustina]

Guilty haha. Caleb slapped a little bit of sense back into me, I'm still very bitter about 2014 and its showing.

 

[Robert Forry]

After my job change last April (yeah, yeah... mini violins playing) I'm just happy to be getting back out to the Plains this season. Picking early to mid June this year to try something different and to avoid some of the chaser hordes, but will chase all the major set ups regardless. Most of the stuff around Michigan tends to hit in May/June anyway, so at least we'll be around for most of that (if they do occur). Yes, I said that because one can only hope in the Great Lake state..