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> Long Range Spring 2017 Outlooks and Discussion, Share thoughts, forecasts, trends, excitement, anxiety here.
ClicheVortex2014
post Dec 28 2016, 05:46 PM
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Third straight Spring thread in a row created by yours truly biggrin.gif

My thoughts...

We probably have a better shot at an early spring (warm February) this year more than any year in the past due to the La Nina. What has me worried is people talking about a cold March.

Regardless, the west has seen troughiness and the east has seen ridging predominately since October. Since the start of December, we've been in a strong -PNA regime. Due to occasional -EPO/-WPO, there's been CPF that pools up cold air in the PacNW/Western Canada and eventually bleeds and moderates eastward. The dominant storm track so far has largely been GLC; the SE ridge pushes the system to the northeast, but the abundance of cold air behind the front allows the front to suppress the SE ridge and get cold air into most of the east US. The airmass has failed to make it to the Gulf coast, however. The SE ridge only gets suppressed and has remained along the Gulf. As such, the SE US is much warmer than average for the month of December.

After that system/trough/airmass is gone, a robust SE ridge builds northward and pushes the cold back to PacNW/Western Canada.

This has left Canada VERY cold for the entire month of December. They're running somewhere between 15 to 20 degrees below average for the month. Seasonal computer models and Meteorologists are catching on to this pattern (warm SE/very cold NW) for at least the first half of January.

If the -PNA regime continues, as it's proven to be a multi-monthly oscillation in the past and strongly associated with ENSO, it would set us up for an active spring. It does 3 things

1) SE ridge encourages GLC's: favorable storm track for the Midwest, Ohio Valley, and Mississippi river valley.
2) The cold PacNW/Western Canada is a reservoir for cold air: cold air available, but not disruptively close to the Plains/MW
3) The inability for the Arctic airmasses to penetrate far beyond the Gulf coast keeps the Gulf warm, which enhances the moisture available (moisture pooling is your friend)

In summary...

Pros:
La Nina (weak, transitioning to neutral)
Possibly +TNI (has been negative since June 2012)
Definitive SE/Southern ridge in the first half of winter (-PNA)
PDO(?)

Cons:
Strong tendency for -AO/-NAO since October
PDO(?)

That's all I can think of right now. PDO is in pros and cons because I don't know how it's gonna evolve. November reversed a weakening +PDO trend, but I think December is going to move closer to neutral in December but still may be strongly positive. I'd imagine the cold PacNW/west coast will encourage the water along the coast to cool... and the cold blob south of Alaska looks to be intruding on the west coast. So I still think the PDO has the potential to become closer to neutral or maybe even flip to a weak -PDO. In which case, the PDO will become a "Pro" and not a "Con".




This post has been edited by ClicheVortex2014: Dec 28 2016, 05:51 PM


--------------------
Meteorology undergrad at Ohio University

Historic weather events in the Ohio Valley:
- The 1974 Super Outbreak (read more)
- The 2012 "Super" Derecho
- The Great Blizzard of 1978
- ILN Severe Weather Climatology

2017 Weather for Cincinnati

Days >90: 11 (Last: 9/24/17)
Marginal risks: 18 (Last: 8/11/17)
Slight risks: 14 (Last: 8/22/17)
Enhanced risks: 7 (Last: 11/5/17)
Moderate risks: 0 (Last: 6/22/16)
High risks: 0 (Last: 11/17/13)

Realtime Weather on Campus: http://www.phy.ohiou.edu/~scalia/state_street/upload.png
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stuffradio
post Dec 28 2016, 06:14 PM
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Not going to lie, I've been waiting for this thread to be created! I will try and see if I can contribute to this thread, but I'm still learning in many areas, so I don't know that I can contribute much.
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snowsux
post Dec 28 2016, 06:47 PM
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QUOTE(ClicheVortex2014 @ Dec 28 2016, 05:46 PM) *
My thoughts...

We probably have a better shot at an early spring (warm February) this year more than any year in the past due to the La Nina. What has me worried is people talking about a cold March.


They say it's gonna be a cold March just about every year.
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alczervik
post Dec 29 2016, 07:50 AM
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March is such a wild card in regards to spring, especially in the Northern 1/3 of the country. I hope spring is quick and we march right into summer.
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MotownWX
post Dec 29 2016, 09:03 AM
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Good stuff, Cliche.

Regarding March: I tend to view St Patrick's Day as the turning point into spring and raise a cold pint. Sure, you'll get another cold snap (or two) and some snow thereafter, but it's usually short lived, accumulating snow melts in a couple days, and the longer daylight gets much more noticeable.

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ClicheVortex2014
post Dec 30 2016, 12:29 AM
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QUOTE(MotownWX @ Dec 29 2016, 09:03 AM) *
Good stuff, Cliche.

Regarding March: I tend to view St Patrick's Day as the turning point into spring and raise a cold pint. Sure, you'll get another cold snap (or two) and some snow thereafter, but it's usually short lived, accumulating snow melts in a couple days, and the longer daylight gets much more noticeable.

Thanks.

March is indeed a weird month. Probably the weirdest month of them all, weather-wise. It can easily be an extension of winter or an early start to the tornado season.

I just don't know what to think. With a La Nina, you expect an active severe season... but I don't know about this one. This La Nina was never that strong, and it's definitely falling apart at this point. If this was a multi-winter Nina, I'd feel more confident in the SE ridge remaining through spring, but this is clearly not.

On the other hand, despite the strength of the Nina, the OLR is much more positive than I'd expect... which has caused the -PNA to be quite strong for the entire month of December.

But will this really maintain for 4-6 more months as we move into La Nada? I really don't know

But I can use a paper already published about the TNI (Trans-Nino Index) that looks for a correlation between a decaying/persisting ENSO phase and an active tornado season. The severe weather/tornado season is generally what I'm most interested in with these threads, but of course an active tornado seasons generally come with warm weather for most of us. So I guess that's how a common person can interpret my ramblings.

Here's a list of the top 10 most extreme tornado years. It lists what the ENSO transition was, and the corresponding TNI value. 7 are highlighted red, as they were +TNI years. 3 of those are potential "analogs" for this coming spring. The 3 are split into 2 groups, depending what is going to happen with the ENSO for 2017-18. Either we're gonna transition to an El Nino like 1957 and 1965, or the La Nina is just gonna die like 2008.

Attached File  tnitornadoactivity.png ( 170.57K ) Number of downloads: 1


What's out of the question is the Nina persisting, and obviously since we're not in an El Nino transitioning to a La Nina, that's also out.

Out of the 7 years, 5 started with a La Nina. 1 or 2 of which may share some similar ENSO characteristics.

The TNI value for November was -0.101, increased from -0.508 in October. The TNI briefly barely went positive last summer, but other than that, it's been strongly negative since July 2012.

Granted, if the TNI goes positive this spring, I don't expect it to go very positive like some of those years. But even a +TNI would probably be favorable for an interesting spring.

This kinda shines a light on what we might be able to expect with the general pattern going forward, knowing at least 3 notable years started with a La Nina and became either an El Nino or La Nada. It tells us that the ENSO forcing can stay through the spring. It has in the past, but no year is the same.

Will this be the year to break the 4 year streak of relatively boring severe seasons?

BTW, I've been excited for this spring for about a year and a half. I have a record of talking about it going back to July 2015. I'm less excited than I was because this Nina turned out to be much weaker than I thought it'd be. Regardless, it's something other than El Nino or La Nada, so a change of pace is always nice.

QUOTE(ClicheVortex2014 @ Jul 8 2015, 09:59 PM) *
QUOTE(grace @ Jul 8 2015, 10:31 PM) *
I have no idea what this is based on but it's on the CPC website:

DEC, JAN, FEB

JAN,FEB,MAR

FEB,MAR,APR

LINKY: http://www.cpc.ncep.noaa.gov/products/pred...ead=8&var=t

Looks like that's just the CPC's outlook


Disco:
http://www.cpc.ncep.noaa.gov/products/pred...day/fxus05.html

One bit:
QUOTE
ONE ISSUE THAT SHOULD BE CONSIDERED IN FUTURE FORECAST CYCLES IS THE
TENDENCY TO TRANSITION FROM STRONG EL NINO EVENTS TO LA NINA EVENTS. THIS
EMPIRICAL RELATIONSHIP COULD BE USED IN FORECASTS FOR SUMMER 2016 AND BEYOND.


Is it too early to start hyping the 2017 tornado season? laugh.gif


Afterthought disclaimer: just because we start off the year with a La Nina doesn't guarantee the TNI will go positive.

This post has been edited by ClicheVortex2014: Dec 30 2016, 12:34 AM


--------------------
Meteorology undergrad at Ohio University

Historic weather events in the Ohio Valley:
- The 1974 Super Outbreak (read more)
- The 2012 "Super" Derecho
- The Great Blizzard of 1978
- ILN Severe Weather Climatology

2017 Weather for Cincinnati

Days >90: 11 (Last: 9/24/17)
Marginal risks: 18 (Last: 8/11/17)
Slight risks: 14 (Last: 8/22/17)
Enhanced risks: 7 (Last: 11/5/17)
Moderate risks: 0 (Last: 6/22/16)
High risks: 0 (Last: 11/17/13)

Realtime Weather on Campus: http://www.phy.ohiou.edu/~scalia/state_street/upload.png
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stuffradio
post Jan 3 2017, 12:43 AM
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Latest models are out from CanSIPS.

Attached File  cansips_apcpna_multimonth_us_3.png ( 73.41K ) Number of downloads: 3

Attached File  cansips_T2maMean_month_us_3.png ( 78.39K ) Number of downloads: 2

Attached File  cansips_T850aMean_month_us_3.png ( 77.92K ) Number of downloads: 2


This post has been edited by stuffradio: Jan 3 2017, 12:44 AM
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ClicheVortex2014
post Jan 12 2017, 08:46 PM
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New JAMSTEC has a -PDO forming for spring. Would be the first spring -PDO in half a decade.





This post has been edited by ClicheVortex2014: Jan 12 2017, 08:47 PM


--------------------
Meteorology undergrad at Ohio University

Historic weather events in the Ohio Valley:
- The 1974 Super Outbreak (read more)
- The 2012 "Super" Derecho
- The Great Blizzard of 1978
- ILN Severe Weather Climatology

2017 Weather for Cincinnati

Days >90: 11 (Last: 9/24/17)
Marginal risks: 18 (Last: 8/11/17)
Slight risks: 14 (Last: 8/22/17)
Enhanced risks: 7 (Last: 11/5/17)
Moderate risks: 0 (Last: 6/22/16)
High risks: 0 (Last: 11/17/13)

Realtime Weather on Campus: http://www.phy.ohiou.edu/~scalia/state_street/upload.png
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NorEaster07
post Jan 13 2017, 06:35 AM
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As we approach mid way point of winter, thoughts of spring arise.

6 weeks away. Averages and records start climbing higher and higher as well as the sun angle

Graph is for Bridgeport, CT at the coast. 84 record early March 1990. 11 Early March 1949.



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ILStormwatcher
post Jan 18 2017, 09:49 PM
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Looks like an early not late start to Spring is in store that will quickly transition to a hot summer around May that lasts into September. April looks like the best shot at widespread severe storms mainly in the plains and perhaps the southeast. Seems like the patterns ring of 2012 which was in or coming out of a nina and a -PNA pattern with a favoring towards neutral to positive NAO/AO.
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NorEaster07
post Jan 20 2017, 12:15 PM
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Actual temp departures for each Spring since 2011.

I hate using 3 month averages because it doesn't show a true result of what happens with ups and downs or extremes ect or even a majority of what was happening..


Anyway -- Temp Departures.


Source:






Precip Departures. Ohio Valley and Northeast hasn't really had a good wet spring since 2011.


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OSNW3
post Jan 20 2017, 12:58 PM
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I will bet on a severe weather outbreak early April. The event will recur late May. Consider it the signature correlation phase "abrupt atmospheric change" that should be noted.
Attached File  spring_stuff_1.png ( 123.22K ) Number of downloads: 2


I will bet that DLH sees accumulating snow early May.
Attached File  1617mbDLH_image048.gif ( 28.5K ) Number of downloads: 1


I will bet that I am wearing a winter hat during the daytime mid June.*
Attached File  spring_stuff_2.png ( 124.93K ) Number of downloads: 1

* The transition from winter to spring to early summer I often find my self sporting a tuque until daily high temperatures surpass 60F for several consecutive days.




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ClicheVortex2014
post Jan 22 2017, 10:18 PM
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Well... we just broke a 996 day streak of no high risk days in the US. Last high risk was June 3, 2014. The only other January high risk with January 21, 1999.

Tornadic activity is off to a very quick start this year. Not really surprising if you look at the pattern we've been in so far. 79 tornadoes so far... pales in comparison to 2008's 128 tornadoes. I say that year was just too anomalous to be fair.



Unfortunately, we've already had at least 3 killer tornadoes. We're up to at least 20 tornado fatalities after today. That's already more fatalities than we saw in the entire year of 2016.

This post has been edited by ClicheVortex2014: Jan 22 2017, 10:22 PM


--------------------
Meteorology undergrad at Ohio University

Historic weather events in the Ohio Valley:
- The 1974 Super Outbreak (read more)
- The 2012 "Super" Derecho
- The Great Blizzard of 1978
- ILN Severe Weather Climatology

2017 Weather for Cincinnati

Days >90: 11 (Last: 9/24/17)
Marginal risks: 18 (Last: 8/11/17)
Slight risks: 14 (Last: 8/22/17)
Enhanced risks: 7 (Last: 11/5/17)
Moderate risks: 0 (Last: 6/22/16)
High risks: 0 (Last: 11/17/13)

Realtime Weather on Campus: http://www.phy.ohiou.edu/~scalia/state_street/upload.png
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WeatherMonger
post Jan 29 2017, 06:32 PM
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Truthfully, can't wait for this thread to pick up. Not that it ever gets as active as the winter threads, but the more I keep replaying the weather set ups the past few months the more optimistic I get for some decent storms IMBY.

There's a few set ups out there that if they reoccur could be quite alarming.I'm, not talking IMBY in particular, wherever they set up
Wish we had a few more long range forecasts out there like we get for winter.

Bass and panfish will be spawning before we know it, mushrooms will be coming up and the disappointment of winter will soon be fading from memory.

This post has been edited by WeatherMonger: Jan 29 2017, 06:33 PM
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ILStormwatcher
post Jan 29 2017, 06:40 PM
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CFS is trending toward a cooler and wet March. Dixie Alley looks to get pounded off and on through April before shifting into the Mississippi River Valley late April into early June.

Two tornado hot spots I'm looking at are Alabama/Georgia/Mississippi area as well as Arkansas, Missouri into Illinois and Indiana. The traditional tornado alley might be a bit lackluster then usual, but they're still be some action of course. Some long range guidance and models have been hinting at a solid season though with an overall good set up pattern here and there, but nothing concrete. This year should be busier by a long shot compared to previous years however.
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ClicheVortex2014
post Jan 29 2017, 06:51 PM
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QUOTE(ILStormwatcher @ Jan 29 2017, 06:40 PM) *
CFS is trending toward a cooler and wet March. Dixie Alley looks to get pounded off and on through April before shifting into the Mississippi River Valley late April into early June.

Two tornado hot spots I'm looking at are Alabama/Georgia/Mississippi area as well as Arkansas, Missouri into Illinois and Indiana. The traditional tornado alley might be a bit lackluster then usual, but they're still be some action of course. Some long range guidance and models have been hinting at a solid season though with an overall good set up pattern here and there, but nothing concrete. This year should be busier by a long shot compared to previous years however.

CFS can't decide the forecast for February, so I wouldn't pay any attention to the March forecast until the end of February.


--------------------
Meteorology undergrad at Ohio University

Historic weather events in the Ohio Valley:
- The 1974 Super Outbreak (read more)
- The 2012 "Super" Derecho
- The Great Blizzard of 1978
- ILN Severe Weather Climatology

2017 Weather for Cincinnati

Days >90: 11 (Last: 9/24/17)
Marginal risks: 18 (Last: 8/11/17)
Slight risks: 14 (Last: 8/22/17)
Enhanced risks: 7 (Last: 11/5/17)
Moderate risks: 0 (Last: 6/22/16)
High risks: 0 (Last: 11/17/13)

Realtime Weather on Campus: http://www.phy.ohiou.edu/~scalia/state_street/upload.png
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WeatherMonger
post Jan 31 2017, 10:17 AM
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Done in Wimter threads for the season, but hoping the 2nd storm system in Feb. can cut far enough north to bring me the first rumbles of thunder this year. Can't remember the last time I actually heard thunder, have had lightning within the region but never IMBY the past few months.
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ClicheVortex2014
post Feb 10 2017, 05:55 PM
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QUOTE(StL weatherjunkie @ Feb 10 2017, 05:04 PM) *
Great paper published in Nature Geoscience discussing the El Nino - La Nina relationship to severe hail / tornadoes http://www.nature.com/ngeo/journal/v8/n4/pdf/ngeo2385.pdf

Doubt anyone will want to pay for it, but maybe others with good library resources may decide to go look it up or just read the abstract below (numbers embedded in here are hyperlinks to other relevant literature if you follow the link above).
More or less, the take-away for this point in the season is 'you get what you see'. So far this season it's been across the southeast, particularly along the Gulf coast, so that's a good place to expect it for this month anyways. The threat zones will ooze north with time given climatology. However, there's no doubt in my mind this will be the most active severe thunderstorm/ tornado season since at least 2011. I remember harping on this back in late December ~10-15 days in advance of the first outbreak of 2017.

Not surprised by their findings.

This has indeed been a very active winter for severe weather. We're at the second most tornado count in the past 12 years. Only year beating us right now is 2008, which I argue isn't fair because that year was ridiculous.



A word of caution though. 2012 and 2013 both started out very active with tornadoes, but both years ended below average... with 2013 ending well below average.

However, where 2012 dropped off in tornadoes it picked up in wind/hail reports.

One thing I remember pointing out consistently through the winter is the inability for Arctic fronts to push into the Gulf, which has kept the moisture pooled relatively close to the US. This is blatantly obvious when you look at the temp anomalies to-date.




--------------------
Meteorology undergrad at Ohio University

Historic weather events in the Ohio Valley:
- The 1974 Super Outbreak (read more)
- The 2012 "Super" Derecho
- The Great Blizzard of 1978
- ILN Severe Weather Climatology

2017 Weather for Cincinnati

Days >90: 11 (Last: 9/24/17)
Marginal risks: 18 (Last: 8/11/17)
Slight risks: 14 (Last: 8/22/17)
Enhanced risks: 7 (Last: 11/5/17)
Moderate risks: 0 (Last: 6/22/16)
High risks: 0 (Last: 11/17/13)

Realtime Weather on Campus: http://www.phy.ohiou.edu/~scalia/state_street/upload.png
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StL weatherjunki...
post Feb 10 2017, 06:40 PM
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QUOTE(ClicheVortex2014 @ Feb 10 2017, 06:55 PM) *
Not surprised by their findings.

This has indeed been a very active winter for severe weather. We're at the second most tornado count in the past 12 years. Only year beating us right now is 2008, which I argue isn't fair because that year was ridiculous.

A word of caution though. 2012 and 2013 both started out very active with tornadoes, but both years ended below average... with 2013 ending well below average.

However, where 2012 dropped off in tornadoes it picked up in wind/hail reports.

One thing I remember pointing out consistently through the winter is the inability for Arctic fronts to push into the Gulf, which has kept the moisture pooled relatively close to the US. This is blatantly obvious when you look at the temp anomalies to-date.

The main justification I have for a much above normal tornado season is the transition from El Nino to La Nina. Even though the La Nina was not particularly strong and is already nearly dead already, I believe it has already put it's fingerprints on the the atmosphere.

Since Oct/Nov I have been comparing this winter to the 98/99 winter, which was also quite active w.r.t. severe thunderstorms. Both 1999 and 2008 had impressive spring tornado outbreaks and the atmosphere is now a couple years richer in accumulated heat and moisture from anthropogenic and natural (major El Nino) sources relative to those years. Therefore, I don't think it's unreasonable to make early claims that this spring will be very active.

While differences in the mean atmospheric conditions leading up to today exist, I would argue that the similarities are more substantial.

1999 500 mb height anomalies between Jan 1 - Feb 9
Attached File  500_mb_early_1999.gif ( 16.45K ) Number of downloads: 0


2008 500 mb height anomalies between Jan 1 - Feb 9
Attached File  500_mb_early_2008.gif ( 15.76K ) Number of downloads: 0


2017 500 mb height anomalies between Jan 1 - Feb 9
Attached File  500_mb_early_2017.gif ( 15.92K ) Number of downloads: 0


This post has been edited by StL weatherjunkie: Feb 10 2017, 06:41 PM


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All model guidance is just that, guidance. It is the responsibility of the forecaster to take that information, make it better, and to appropriately communicate the forecast to the users.

Fervent supporter of the idea to make GFS output beyond hour 168 proprietary! Anyone wanting to post/share/tweet/etc GFS output beyond day 7 should have 1) a limited set of graphics available with the option to 2) contribute a nominal fee to get a full suite of products while improving future GFS output. #EURObusinessfor-the-win
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ClicheVortex2014
post Feb 10 2017, 07:14 PM
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QUOTE(StL weatherjunkie @ Feb 10 2017, 06:40 PM) *
The main justification I have for a much above normal tornado season is the transition from El Nino to La Nina. Even though the La Nina was not particularly strong and is already nearly dead already, I believe it has already put it's fingerprints on the the atmosphere.

Since Oct/Nov I have been comparing this winter to the 98/99 winter, which was also quite active w.r.t. severe thunderstorms. Both 1999 and 2008 had impressive spring tornado outbreaks and the atmosphere is now a couple years richer in accumulated heat and moisture from anthropogenic and natural (major El Nino) sources relative to those years. Therefore, I don't think it's unreasonable to make early claims that this spring will be very active.

While differences in the mean atmospheric conditions leading up to today exist, I would argue that the similarities are more substantial.

1999 500 mb height anomalies between Jan 1 - Feb 9
Attached File  500_mb_early_1999.gif ( 16.45K ) Number of downloads: 0


2008 500 mb height anomalies between Jan 1 - Feb 9
Attached File  500_mb_early_2008.gif ( 15.76K ) Number of downloads: 0


2017 500 mb height anomalies between Jan 1 - Feb 9
Attached File  500_mb_early_2017.gif ( 15.92K ) Number of downloads: 0

No argument here. Regarding the point you made about the transition from La Nina to El Nino, refer back to my post on page 1

At the time of the post, the TNI was still negative but not by much. Now a month and a half later, we're due for another update of the index any day now... but the last trimonthly value was +0.324. Strongest positive number since June 2012... aside from a brief period of +TNI last summer, it's the first time the index has been positive since June 2012.

With the current ENSO configuration, I don't see any reason why the next update won't be even more positive

https://www.esrl.noaa.gov/psd/gcos_wgsp/Tim...a/tni.long.data

For reference, April 2011 was +1.271. April 1974 was +1.728. The first half of 2008 was ridiculously high; from +1.6 to +2.6.

This post has been edited by ClicheVortex2014: Feb 10 2017, 07:15 PM


--------------------
Meteorology undergrad at Ohio University

Historic weather events in the Ohio Valley:
- The 1974 Super Outbreak (read more)
- The 2012 "Super" Derecho
- The Great Blizzard of 1978
- ILN Severe Weather Climatology

2017 Weather for Cincinnati

Days >90: 11 (Last: 9/24/17)
Marginal risks: 18 (Last: 8/11/17)
Slight risks: 14 (Last: 8/22/17)
Enhanced risks: 7 (Last: 11/5/17)
Moderate risks: 0 (Last: 6/22/16)
High risks: 0 (Last: 11/17/13)

Realtime Weather on Campus: http://www.phy.ohiou.edu/~scalia/state_street/upload.png
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