Active season for the Northern Plains and Upper Midwest?

[Derek Heide]

The pattern is ramping up for the Central and Southern Plains right now. A good event has come and gone, albeit the best of the action was East of the Plains. Another trough will roam the Plains and points East later this week. So far, we've seen the centre (yes, I'm Canadian) of low pressure drift toward the North Dakota/Saskatchewan/Manitoba border a couple of times already this spring. I remember this happening in 2005 and 2007, both summers (June-August) were quite active across the Dakotas/Minnesota and up into Manitoba and Saskatchewan.

The last two years have been rather quiet in the aforementioned regions and, from what I see, June and July could have some potential. There is some support in the past with fading El Ninos and Neutral cycles for an active Northern tier come Summer.

Thoughts?

 

[Scott Olson]

During El Nino years the northern plains (especially the Dakotas) tend to be overly active. I think there is a ton of uncertainity as to how this year is going to play out though. In an El Nino year the Dakotas have nearly twice as much tornado activity.

However, I must say the pattern is looking very active for the first twelve days of May. I mean, it looks really great on the latest GFS. If it turns out to be a really active May, then I think we risk a ridge/blocking pattern in June. I hate these things but a single pattern featuring west coast trough after west coast trough cannot last indefinitely.

 

[Chris Carter]

Well i have been hearing that temps in the Pacific are beginning to fall, a sure sign that La Nina may be on the horizon for the summer and fall. Though the effects of La Nina won't be felt for a good 3 months, it could impact the severe weather season towards the end of the chase season.

 

[Matthew K. Hartman]

I will say that while I haven't perused extended models or spaghetti plots, we definitely have the soil moisture up here, at least in the Red River Valley of North Dakota to favor storm development this summer. It's been a very conducive spring for early planting of fields and ET has a very big influence up here. It's, in fact, been subject to research for tornadic events before:

http://www.crh.noaa.gov/images/fgf/casestudy/BarnesF4_20040718.pdf

It's valid material to consider and not only in North Dakota, but even in portions of South Dakota.

I'm anxious to see what the chase season brings to us up here. I have, at least, one other co-worker that agrees with me, that when we see severe weather in North Dakota, it's the best chasing in the country.

Maybe we're biased.

 

[MatthewCarman]

I would say 2008 was far from a quite year. Most of the winter for 2008 had tornado outbreaks and the Spring was very active including May.

 

[Matthew K. Hartman]

Matthew, I think we are talking about the Northern Plains... Of which, has been quiet the past couple of years, with the lone exception of a few days here and there. In 2008, we had a two week period in early July, but that was it. Two weeks... out the 3-4 months of chasing we get here in ND. That's not much.

I'm hoping for a much more active pattern than that this summer!

 

[Justin Turcotte]

One thing this year the Dakotas has in common with 2005 is it follows a cold summer with few storms the previous year. Despite the crappy summers of 2004 and 2009 there were still a few storms to chase including the Barnes County F4 in '04, the June 26th eastern ND weak tornado "outbreak" last year as well as Dickinson EF3 tornado. I've lived in Grand Forks the last six years and IMO the "best" chase pattern for the area is that of a death ridge in the central plains with the edge of it sitting in northern ND or southern Manitoba. Weak impulses will ride along the periphery of the ridge and interact with a quasistationary front. This pattern is most likely from mid June through mid August. The ridge can be relatively fixed for an extended period resulting in severe storms and potential tornadoes several days in a row. I have my passport ready should the need arise to chase in MB.

I am not a long range forecaster but Matt is correct about soil conditions in North Dakota. A wet fall and winter put lots of moisture in the ground. A very warm and dry April allowed farmers to get their crop in several weeks earlier than average and well over a month from last year's non-spring. Evapo-transpiration is a key player here as the area is often too far north for advection of true GoMex moisture. One would be inclined to believe the chase season would begin early given the crop situation but it seems like storms are a couple weeks late hitting areas further south this year. Time will tell which trend wins. I figure we can only improve on the anemic storm season and summer weather in general from last year. The local NWS graphed the number severe reports from the last decade and 2009 was lowest on the chart.

 

[Derek Heide]

I've lived in Grand Forks the last six years and IMO the "best" chase pattern for the area is that of a death ridge in the central plains with the edge of it sitting in northern ND or southern Manitoba. Weak impulses will ride along the periphery of the ridge and interact with a quasistationary front. This pattern is most likely from mid June through mid August. The ridge can be relatively fixed for an extended period resulting in severe storms and potential tornadoes several days in a row.

This part, especially, grabbed my attention. I agree with it 100%. This exact type of set up produced the Elie tornado in 2007. From June 22-25, there was severe weather each and every day.

I'd like to discuss 2005 a bit more. That was the year I, personally, became uber interested in severe weather. There were numerous great setups in my area and for the Dakotas, as well. June and July were exceptional months but, as opposed to 2007 with a stalled front, '05 I remember being very progressive. I think the flow was rather zonal but there were periods of deep SW flow and things really got active quick. It would be nice to get a good Bermuda high pattern this summer...

 

[Scott Olson]

I personally had a fairly decent year in 2005. My northern plains perspective:

May 6th - Severe storms (winds) in western and eastern South Dakota.
May 8th- Tornado warned storm Lac Qui Parle County.
May 10th- Tornadic Supercell in Harrison County, IA. (This was the day many of you were near Grand Island on a similar intense supercell.) Though, I didn't see the tornado with this particular storm.

May 20th- Several tornadic supercells in North Dakota. Several tornadoes off two seperate cyclonic supercells. Some sort of landspout tornado as well. (I know you saw that Justin).

May 23rd- Colorado chase day, high based supercells.
May 24th- Several supercells in Colorado, tornadoes near Ft. Morgan.
June 4th- (HIGH RISK) Supercell near Waverly, NE.
June 7th- Common tell me you don't remember that badlands beauty, you were all there, right? Sculpted LP-Supercell. Weakly tornadic at one point.
June 20th- Tornado warned supercell near Watertown in early afternoon, followed by several waves of pulse storms into the evening. What a wonderful world!
June 23rd- Several tornadoes in NE South Dakota. Everyone was there.
June 28th- Moderate Risk in W SD. Beautiful sculted LP Supercell persisted for hours. Virtually unrecgnoizeable on radar but stunningly sculpted. I love the high plains!
September 18th- Tornado warned storm near Norfolk
September 24th- Twilight supercell near dusk near Laretto, NE.

All in all, 2005 was a pretty fun year for chasing. 5-20 was one of the more interesting days I can remember.

After busting the previous day in Kansas, I headed back home. An wave was moving towards Montana and SPC was highlighting the Montana/NW SD area with a 5% tornado risk. I wasn’t going to drive that far, so I took a look at Eastern ND. What I saw looked pretty decent, a warm front was present across ND with 1500-200 j/kg SBCAPE expected by mid-afternoon. Storm Releative helicity was 150-200 m2/s2 in the 0-3km layer. Most importantly, the low level winds were backed to the SE near the front, leading to good low level shear. Usually in these situations the area remains capped, since the upper support is farther away, however in this instance both the RUC and ETA forecasted intiation by mid-afternoon. As of the morning outlook, SPC had no tornado risk for this area.

 

[MatthewCarman]

Matthew, I am assuming you mean the Dakota's, Minnesota, Iowa, Wisconsin and Illinois as the northern plains or do you just mean the "plain" states? If so they were active in 2008. January started off with an outbreak in Wisconsin and Illinois with an EF3 tornado knocking a train off it's tracks. Sure March and April were quite for the northern plains with the exception of 1-2 days in April but there was 3-4 big days in may including the Parkersburg EF4 on the 25 and on the 29 numerous tornadoes in southern Iowa. I am sure there was a day with Numerous tornadoes in NW Iowa in May aswell. June and July were both very active for the northern plains. There was multiple tornado outbreaks including the Hubbard County, Minnesota tornado that destroyed homes and there was numerous days with large hail and destructive winds including a wind gust measured at 115 MPH near Grant, South Dakota on one of those days. If you are referring to just days with numerous tornadoes then yes over all the northern plains was not very active with the exception of Iowa but there was many days with less than 10 tornadoes reported.

When I think of an area being inactive I guess I just don't look for days with tornadoes. If you include all forms of severe weather the plains was pretty active. When I think of 2008 for the northern plains I think of the EF5 monster in Iowa. I just can't picture 2008 as an inactive year but that's just me.

How active does an area have to be to be considered active? If I added up all of the reported tornadoes for the northern plains I would probably get over 200 tornado reports just from all of the dates I looked at. What does the northern plains average a year? Tornado Alley is mostly south of the northern plains so maybe 2008 was average or above average in the northern plains. Maybe it wasn't. These are just things to think about. Thanks for the discusion.

 

[Derek Heide]

Scott,

Thanks for the recap of 2005. It was a fun year and very active up here in Manitoba. This video was captured by Dave Carlsen of a beautiful multi-vortex tornado near Pilot Mound, MB on July 2 of '05

http://www.youtube.com/watch?v=b7u0MsbRJPc

Back on the topic of this season, much of the Northern Plains and Southern Canada have been dealing with cold anomalies the past couple of weeks. By the end of this upcoming week, a large ridge of high pressure is being advertised. We could be baking in well above normal temperatures in, maybe a week or two.

Looking West, there is a trough that will just be waiting to explode through the ridge complex. This week will be a show in the Central and Southern Plains but I get the feeling that the jetstream may "jump" up North some time around the May Long Weekend.

I sense that this season will be quite active for the Northern Tier of the US and into Southern Canada. As mentioned earlier in this thread, most crops have been planted and, with the ridge expected to build in after a relatively wet period, evapotranspiration may become a player quite early this year.