rdale
EF5
2016 is forecast to be below normal in tornado alley... http://www.climatecentral.org/news/el-nino-tornado-season-19910
Upcoming 2016 Storm Chasing Season
- Thread starter Andy Berrington
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calvinkaskey
Guest
- Joined
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http://www.climatecentral.org/news/el-nino-tornado-season-19910
That article is very vague in locations covered in the prediction, along with what years they used for the average, [mean] for last year's above average numbers. Also if those are the chances of >25% below or above and this is the same measure from last year they would have been wrong because 7% above is way below >25%
. ..."127 tornadoes from Nebraska to Texas", are they actually including Nebraska in south central United States?
That article is very vague in locations covered in the prediction, along with what years they used for the average, [mean] for last year's above average numbers. Also if those are the chances of >25% below or above and this is the same measure from last year they would have been wrong because 7% above is way below >25%
. ..."127 tornadoes from Nebraska to Texas", are they actually including Nebraska in south central United States?
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Brett Roberts
EF5
List of spring severe weather seasons during waning El Nino events since 2000:
2003
2005
2007
2010
2015
Would any Plains chaser really object to next spring representing some combination of the above? I mean, 2005 and 2015 weren't necessarily seasons everyone can agree on being wonderful, but even they weren't "bad." The others were pretty much undeniably good.
A common theme: a lot of good chase setups in the Plains, even with generally pedestrian annual CONUS tornado counts. The climatecentral forecast for below average activity in "Tornado Alley," if they mean "Texas to Nebraska" as they define it in the article, does not seem well-founded solely on the basis of ENSO. If anything, it's areas farther north and east which are less likely to see active tornado seasons during Nino, on average.
I probably sound like a broken record on this topic, but chasers who focus on the "traditional" Alley from TX to SD should not be worried about El Nino equating to a bad season -- particularly one that is waning as we head into spring.
2003
2005
2007
2010
2015
Would any Plains chaser really object to next spring representing some combination of the above? I mean, 2005 and 2015 weren't necessarily seasons everyone can agree on being wonderful, but even they weren't "bad." The others were pretty much undeniably good.
A common theme: a lot of good chase setups in the Plains, even with generally pedestrian annual CONUS tornado counts. The climatecentral forecast for below average activity in "Tornado Alley," if they mean "Texas to Nebraska" as they define it in the article, does not seem well-founded solely on the basis of ENSO. If anything, it's areas farther north and east which are less likely to see active tornado seasons during Nino, on average.
I probably sound like a broken record on this topic, but chasers who focus on the "traditional" Alley from TX to SD should not be worried about El Nino equating to a bad season -- particularly one that is waning as we head into spring.
Andy Berrington
EF2
Going back to the 90s, 1992, 1995 (especially) and 1998 all had their fair share of setups that would probably be teaming with chasers now. It's not until you go back into the 80s where you start seeing some really ugly Nino springs showing up (of course not saying that won't happen). I mentioned before that the Northern Plains have been seeing at least one really red letter event in many of the recent mod/strong Nino decays.
I made this graph awhile back based on UCAR ENSO data of the number of violent (via Grazulis and a couple other sources) tornadoes per state in springs following winters of specific ENSO phase (green being neutral, red being El Nino and blue being La Nina) from 1900 through 2014. Has been normalized by dividing the totals by the number of the given ENSO years since neutral is more common than the other two.
Long story short, it seems the Plain states are just as likely, if not more, to get violent tornadoes in +ENSO or neutral years as -ENSO. Could probably broaden this to include EF/F2 or above, but I don't have Grazulis' book with me to work on that.
Brett Roberts
EF5
Now that is an awesome reference. Thanks for sharing! That graph is largely in line with the ENSO-related findings of my "chase season scoring system" (which emphasizes the number of tornado days first, and the number of tornadoes second):
ENSO has virtually no effect on southern Plains chase seasons
La Nina is somewhat preferred for northern Plains chase seasons
The regional discrepancies in your graph are particularly striking, though. It strongly supports the idea that La Nina really is preferred in a lot of the more eastern sections of the tornado-prone CONUS, explaining why it is often associated with higher annual tornado counts (since it doesn't really "hurt" most sections of the Plains either). But if you focus on the southern and central Plains alone, El Nino might actually be preferable. Obviously EF4-5s only is a limited sample size, but the signal for La Nina being a much bigger deal east of the Plains is unmistakable in your graph. (Caveat: 1974 and 2011 probably have a rather overwhelming effect for states like AL and TN -- but then again, they count!)
Andy Berrington
EF2
Thanks! I have others I'll probably post in here (based on the same violent tornado data) when the situation arises.
As for the caveat you mentioned, what this may simply suggest is that these areas are more prone to very large outbreaks with multiple violent tornadoes during La Nina, which certainly appears reasonable looking back over historical data particularly east of the Mississippi Valley with events like 4/11/65, 4/3/74 and 4/27/11 (likely due to the prevailing storm track, stronger polar jet during La Nina winter/early spring and SE ridging that sometimes shifts to a Bermuda ridge, among other things). There's also the whole +TNI correlation, which I may bring up another time.
chrisbray
EF4
Thanks for the sweet graphics Andy. Looks like I will likely have to make long hauls out of Illinois to OK/KS/NE for some good setups this year!
Jason Boggs
EF5
Robert Forry
EF3
That makes two of us @chrisbray but I never count out IL/IN during the spring - those damn warm fronts...
James Gustina
Supporter
At the very least, the arctic blasts in the near-term look pretty unlikely for the southern Plains even with the repeated lows moving across the central Plains. Pattern also looks to stay pretty progressive over the length of the CONUS so it could be worse, all things considered. Not too long until March.
Welp, a pretty typical winterlike pattern has setup over the CONUS over the past three weeks now, immediately after I optimistically predicted a continued active winter pattern. So much for persistence forecasting.
Looks very boring coming up the next few weeks if you're living between the Rockies and Appalachians, and especially the southern Plains. Hardly a drop of rain in the forecast, as the big troughs are coming so rapidly there isn't enough time for moisture to recover sufficiently between trough passages. At least it won't be terribly cold.
Looks very boring coming up the next few weeks if you're living between the Rockies and Appalachians, and especially the southern Plains. Hardly a drop of rain in the forecast, as the big troughs are coming so rapidly there isn't enough time for moisture to recover sufficiently between trough passages. At least it won't be terribly cold.
chrisbray
EF4
Models have been consistent on a large trough coming in Feb 1 and forming a big low on Groundhogs Day. Whether it is a rainer or a blizzard cannot yet be answered
James Gustina
Supporter
Other than that monster trough swinging through in the next 3-4 days, doesn't look like moisture makes it past Texarkana any time soon. Just like Jeff said though, at least the Plains aren't going right back into the freezer.
Sent from my XT1080 using Stormtrack mobile app
Sent from my XT1080 using Stormtrack mobile app
Michael Snyder
EF3
I need to get back to work and run the numbers for all ENSO temps and tornado by state correlations.
NOT just El Nino vs La Nino and Neutral years, but much a much more detailed look at it spread out where the ENSO temps are broken down in tenths of a degree.
I would then like to incorporate the PDO and NAO numbers in as well.
I have a full Excel spread sheet that took me months to create that now has everything in place so its just a matter of plugging in the tornado numbers from the plain states into that data set to see if I could find some , any patterns at all. The ENSO temps can give quite a different picture when you look at strong, moderate and weak el ninos, vs positive neutral, negative neutral years, Weak, Moderate Strong La Ninas.
Some interesting deviations can show up.
I've seen a couple papers on the NAO and ENSO regarding tornadoes, but Ill have to re-read those papers to remember many details.
So like its been said many times in here, its probably only worth discussing during the dog days of winter, and even then it would only ever be good as a general guideline, but its still interesting to look at if you are a hard core WX geek.
NOT just El Nino vs La Nino and Neutral years, but much a much more detailed look at it spread out where the ENSO temps are broken down in tenths of a degree.
I would then like to incorporate the PDO and NAO numbers in as well.
I have a full Excel spread sheet that took me months to create that now has everything in place so its just a matter of plugging in the tornado numbers from the plain states into that data set to see if I could find some , any patterns at all. The ENSO temps can give quite a different picture when you look at strong, moderate and weak el ninos, vs positive neutral, negative neutral years, Weak, Moderate Strong La Ninas.
Some interesting deviations can show up.
I've seen a couple papers on the NAO and ENSO regarding tornadoes, but Ill have to re-read those papers to remember many details.
So like its been said many times in here, its probably only worth discussing during the dog days of winter, and even then it would only ever be good as a general guideline, but its still interesting to look at if you are a hard core WX geek.
Robert Forry
EF3
Curious to see how the short range models deal with this system ejecting out into the southern Plains/MS Valley next week. I'd love to make my first trip down I-55 since may 2013.
