Future of the season - 2013 edition

[Dan Robinson]

I can't remember a season that stayed as cold (throughout all levels) as late as this one. Can anyone think of good analogs to this year? I'm inclined to think that the late retreat of colder air (at the surface and aloft) may help things come mid to late April, increasing baroclinicity (stronger surface lows) and mid/low level lapse rates, at a time when high sun angles and longer days finally get the low levels where we want them. It's almost like having March upper patterns with April instability. Then again, I also wonder if this situation we're in will lead to the lack of a proportional EML to keep things in check. Thoughts?

 

[Bob Hartig]

I've been thinking exactly the same thing. Just speculation, but it makes sense to me that when this season finally pops, we could see setups with strong instability in tandem with robust shear. Once April insolation finally flexes its muscles beneath March-like cold upper levels, we could have some wicked scenarios.

I hadn't thought about the EML, but I can't imagine it'll be a problem. Steep lapse rates could enhance the influence of even a slightly warmer elevated layer. That's my guess. Even apart from that rationale, speaking more viscerally, I just can't picture Great Plains systems without some capping.

 

[Robert Edmonds]

I don't mind a delayed start. This year I'm working on a second masters in addition to a PhD, so I would be annoyed if there were a ton of great setups. May would be a perfect time for the season to get going Last year though by May I was heading up to MN, ND, way too soon. Wouldn't mind the cool temps help establish the jet stream further south and chase in say Texas.

 

[Logan Karsten]

Something I have been thinking about is well is the potential positive impacts of colder air hanging around longer and drought conditions across the plains. Last year, things warmed up so quickly, combined with the lack of snow across the Northern US, set things up for the drought to really intensify into the summer. Early warmth probably helped the soils to dry out quickly by the time April rolled around. Yes, there is still a long-term drought across the Plains, but at least temperatures are below normal, and there has been some snow across the Central U.S., and there is a fairly decent snow pack across the Northern U.S. This has been facilitating some soil moisture recharge across regions, without serious ET due to above normal temperatures. That was one of my fears going into this year was that we would have a repeat of above normal temperatures early in the season, leading to high ET over already dry soils, leading to a total lack of moisture across the region.

 

[Jacob Ferden]

What makes long range prognosticating about the future of a given season so difficult is that it is virtually impossible to forsee the little elements that go into any given chase day. The last year that things were notably moisture starved (i.e. dewpoints, ongoing drought notwithstanding) in the southern plains going into April was 2009. Looking at that year...later in April, a system came through and produced two days (the 25th and 26th) that certainly *looked* impressive each respective morning, but for many chasers under-produced, though there were tornadoes on each day (Enid on the 25th, Roll on the 26th). Several days prior to that, there was a localized tornado outbreak in the Texas panhandle (can't recall the exact date) that I believe resulted from an outflow boundary or something. Then as we moved into May, there was a localized event in north central Oklahoma and of course the event at Kirksville, Missouri...after that, we all know what happened: a ridge that pretty well killed off the second half of May. The point of all this rambling is that this far out you just don't know what you're going to get...could get a dismal year, could get two months of insanity...just know way to forecast it with high confidence right now.

Having said all of that, I am encouraged by the fact that the series of winter storms which has affected the central and southern plains has made significant progress in improving, but not eliminating, the drought conditions which have been plaguing the area. I also like the reasonably consistent appearance of fairly robust systems past 100 hrs. on the GFS. The next three of four days in Oklahoma and Texas all hold some slim potential, but with zonal to NW flow aloft and sub-60 F dewpoints the ceiling is not particularly high.

My hope is that as we move towards mid-April improved instability will coincide with a series of systems to produce an uptick in chasing possiblities.

My concern is that all of these systems which have been coming through and scouring out the moisture will give way to a period of tranquil conditions aloft, extending the season's slow start.

Time will tell.

 

[Jeff Duda]

Obtained from 1950-2012 tornado counts from SPC sources:

Statistically, the number of tornadoes in March has no bearing on the number of tornadoes throughout the rest of the spring season. In fact, there's essentially no correlation between the tornado numbers in any one particular month or between sets of months. (Not shown) The correlation between tornadoes in March and tornadoes in April-June is 0.075 (i.e., no relationship).

 

[Jesse Risley]

Personally, I don't worry too much in advance that present patters are going to indicate how well (or not) the season is going to evolve. I remember looking at some point back in February, and Gulf of Mexico SSTs were running at or above climatological levels of normalcy.

As others have noted, it is encouraging to see some improvement in drought conditions as well, as it seems that was a factor in some EML issues last season. With the long-range ECMWF hinting at a ridge building across the west-central CONUS in the next 10 days or so, it is looking like April might get off to a slower start. Nonetheless, even if we don't see a repeat of 2004 or 2011, for example, I have no doubt there will be good chase days before the 'traditional' season starts to wind down in June. It's still pretty early in the spring season, but as we transition more to meridional flow and moisture begins to creep northward, I'm betting we'll have at least something more than a marginal chase day in the next 2-3 weeks.

 

[Paul Knightley]

I think a pattern shift is going to take place around the N Hemisphere within 2 weeks - the incessant high latitude blocking, which has just brought the UK its coldest March since 1962, will break down, and the westerly flow will pick up a bit. This should bring to an end the long run of cold weather we've had here, and potentially start to kick in some troughs into the western USA. Longer range ECMWF EPS output shows a western US trough in the mean for days 10-15.

 

[JamesCaruso]

I don't think there is much value in trying to predict the long-term, but I certainly understand the desire to try; I obsess over it myself every year. It's like sports fans debating an upcoming baseball or football season, or political junkies trying to forecast election results. Despite the lack of scientific validity, I admit to becoming agitated when I see a lot going on in the early spring; my anxiety builds as I worry that the best will be over before my arrival on the Plains sometime during the last two weeks of May. So again, scientifically valid or not, this year I am happy to see that nothing is happening yet! But I don't want the season to end up being too much later than normal either, as this year I am going to need to complete my trip by May 31 as opposed to having the first week of June available like in years past.

 

[Damien49]

If it makes you feel better, in France, now is exactly the same problem. Snow and cold conditions in West-Europe and planned until mid-April, never seen.

 

[Paul Knightley]

I don't think there is much value in trying to predict the long-term, but I certainly understand the desire to try; I obsess over it myself every year. It's like sports fans debating an upcoming baseball or football season, or political junkies trying to forecast election results. Despite the lack of scientific validity, I admit to becoming agitated when I see a lot going on in the early spring; my anxiety builds as I worry that the best will be over before my arrival on the Plains sometime during the last two weeks of May. So again, scientifically valid or not, this year I am happy to see that nothing is happening yet! But I don't want the season to end up being too much later than normal either, as this year I am going to need to complete my trip by May 31 as opposed to having the first week of June available like in years past.

There is certainly value if you can predict it! However, I agree with your sentiments that currently there is not much value in many long-range products.

 

[Chris Wilburn]

Early next week is beginning to look interesting. A nice 500mb trough has been showing up for several runs now centered around the first part of next week. The ECMWF is in agreement with this trough. It's still 5-6 days out, but Monday the 8th is beginning to look very nice with plenty of moisture and instability. This may very well be our first real chase opportunity of the year. Something to keep an eye on for sure.

 

[Stan Rose]

Yes, ive been watching this closely the last few days, and despite the big swings in the evolution of the trough, the GFS and EC have both consistently been pegging parts of OK/TX with some good instability and excellent shear. The Sunday through Tuesday period all has potential, but yeah im liking Monday the best, seems to be the best chance for the action to shift from the Red River closer to the TX panhandle--giving me a shot on my day off!

 

[Rob Wadsworth]

I don't think there is much value in trying to predict the long-term, but I certainly understand the desire to try; I obsess over it myself every year. It's like sports fans debating an upcoming baseball or football season, or political junkies trying to forecast election results. Despite the lack of scientific validity, I admit to becoming agitated when I see a lot going on in the early spring; my anxiety builds as I worry that the best will be over before my arrival on the Plains sometime during the last two weeks of May. So again, scientifically valid or not, this year I am happy to see that nothing is happening yet! But I don't want the season to end up being too much later than normal either, as this year I am going to need to complete my trip by May 31 as opposed to having the first week of June available like in years past.

I can tell you as a Iowa farmer, we do labor over the 3 month weather estimates.

I agree with those that see the late winter pattern as a precursor for instability this year. My first year of chasing was '08, and there was not a few great storm setups that came around late May due to a powerful sub-polar low that became available. I will be waiting and watching with my gear ready.

 

[Paul Knightley]

I think a pattern shift is going to take place around the N Hemisphere within 2 weeks - the incessant high latitude blocking, which has just brought the UK its coldest March since 1962, will break down, and the westerly flow will pick up a bit. This should bring to an end the long run of cold weather we've had here, and potentially start to kick in some troughs into the western USA. Longer range ECMWF EPS output shows a western US trough in the mean for days 10-15.

The 10-15 day ECMWF EPS did rather well with this pattern change. Output for this timescale has certainly got better in recent years.