Active Severe Weather Pattern Beginning Next Week

[Ian]

I definitely think it's too early to call that. Any subtle shortwave trough and amplification of the flow fields in the following days and there's likely going to be some pretty nuclear updrafts with the amount of instability that's going to be in place there.

2016ing and 2015ing and 2014ing and etc etc is getting to people. Also too many model runs and subsequent micro analysis of all of them. With so many potential wave ejections one or two has to get something done. If not it might be time to declare the end of tornadoes.

[Ian]

6 tor was an outbreak when we had much lesser sensing capabilities via Doppler and chasing and general eyes. Might still classify it as a regional tornado event but you'd have like 30-40 outbreaks a year on avg if that was your base metric. Kinda dumb there is no accepted definition tho.

[andyhb]

2016ing and 2015ing and 2014ing and etc etc is getting to people. Also too many model runs and subsequent micro analysis of all of them.

 

Well it's kind of understandable considering we still have this mega +PDO (among other things) in place.

[thewxmann]

I've said this before, but it's late May, there's SW flow aloft, boundary layer moisture is outstanding, EML looks manageable. It's not an outbreak scenario but there will be opportunities for things to happen in the coming week and what else could you hope for as a chasecationer.

 

(Obviously, if I'm wrong, I'll stop myself from saying anything good about tornado setups ever again.)

[Ian]

Well it's kind of understandable considering we still have this mega +PDO (among other things) in place.

I'm the last person that would argue that the past few years have been good for tornadoes but I still don't know if it's sound forecasting to assume an at least somewhat favorable stretch will fail because other events did.

[Ian]

I've said this before, but it's late May, there's SW flow aloft, boundary layer moisture is outstanding, EML looks manageable. It's not an outbreak scenario but there will be opportunities for things to happen in the coming week and what else could you hope for as a chasecationer.

(Obviously, if I'm wrong, I'll stop myself from saying anything good about tornado setups ever again.)

Not sure I'd say it's not an outbreak scenario either. There have been runs with an ejection that would probably cause an outbreak if they were right. The lack of any sort of significant continuity on days etc perhaps means sky high is unlikely but outbreak isn't 50+ just like it's not 6.

[andyhb]

I'm the last person that would argue that the past few years have been good for tornadoes but I still don't know if it's sound forecasting to assume an at least somewhat favorable stretch will fail because other events did.

 

It isn't. The thing I don't like is the tendency for height rises following next Monday that has been showing up recently and the lack of defined shortwave ejections through mid-week (not so much any sort of anecdotal 2016/2015/whatever, although I understand where some are coming from with that). Granted these are small scale features that will exhibit high variability over a dprog/dt analysis, but I would like to see a bit more energetic support from guidance.

 

I'm hoping Sunday doesn't shift too far E so that I'm completely out of the game, since I am flying into Denver in the afternoon and I have some things to take care of before the 3 hour drive to Colby.

[thewxmann]

Not sure I'd say it's not an outbreak scenario either. There have been runs with an ejection that would probably cause an outbreak if they were right. The lack of any sort of significant continuity on days etc perhaps means sky high is unlikely but outbreak isn't 50+ just like it's not 6.

 

Maybe I should put it this way: it's not a large-scale synoptically-evident outbreak scenario. A regional event/localized outbreak would be in the realm of possibilities if the cards line up.

[andyhb]

Maybe I should put it this way: it's not a large-scale synoptically-evident outbreak scenario.

 

I should probably add that the near total lack of these since 4/14/12 in the Plains doesn't help a lot of people's optimism.

[thewxmann]

It isn't. The thing I don't like is the tendency for height rises following next Monday that has been showing up recently and the lack of defined shortwave ejections through mid-week (not so much any sort of anecdotal 2016/2015/whatever, although I understand where some are coming from with that). Granted these are small scale features that will exhibit high variability over a dprog/dt analysis, but I would like to see a bit more energetic support from guidance.

 

I'm hoping Sunday doesn't shift too far E so that I'm completely out of the game, since I am flying into Denver in the afternoon and I have some things to take care of before the 3 hour drive to Colby.

 

The funny thing is that our still-juiced STJ might actually help us in this aspect, but yeah, this is a fair point. Sunday is trying to trend a bit west, hopefully we can get that dryline as far west as GLD.

[Ian]

It isn't. The thing I don't like is the tendency for height rises following next Monday that has been showing up recently and the lack of defined shortwave ejections through mid-week (not so much any sort of anecdotal 2016/2015/whatever, although I understand where some are coming from with that). Granted these are small scale features that will exhibit high variability over a dprog/dt analysis, but I would like to see a bit more energetic support from guidance.

I'm hoping Sunday doesn't shift too far E so that I'm completely out of the game, since I am flying into Denver in the afternoon and I have some things to take care of before the 3 hour drive to Colby.

Current modeling is less emphatic than it was for sure. But we have generally seen moderate run to run changes when it comes to details at least. Tornado peak season has been kinda whack since I started chasing so perhaps I need to quit.

[Ian]

I should probably add that the near total lack of these since 4/14/12 in the Plains doesn't help a lot of people's optimism.

But that was a top end event at least numberwise and we had an unusually large number of those in the decade or so preceding it. Not sure we should really be expecting that as often as we were seeing it during that stretch. Not to mention the likely overall detrimental impacts of climate change.

[andyhb]

But that was a top end event at least numberwise and we had an unusually large number of those in the decade or so preceding it. Not sure we should really be expecting that as often as we were seeing it during that stretch. Not to mention the likely overall detrimental impacts of climate change.

 

To see a couple of bigger, synoptically evident Plains (or more like just spring in general) events over a 5 year stretch isn't exactly asking for 2003-2011 though.

 

I laugh at some of the characters who say CC will lead to increased tornadic activity when it's supposed to weaken the jet. Shear > CAPE.

[Ian]

To see a couple of bigger, synoptically evident Plains (or more like just spring in general) events over a 5 year stretch isn't exactly asking for 2003-2011 though.

I laugh at some of the characters who say CC will lead to increased tornadic activity when it's supposed to weaken the jet. Shear > CAPE.

Yeah the past few years have been pretty sad overall. And yes seems maybe something to increased winter activity but that doesn't make up for the negative effects during peak season IMO.

[jojo762]

Latest 00Z GFS seems to prefer later in the week for a bigger more obvious severe threat--in the Thursday-Saturday (5/26-28) time frame for somewhere across KS/OK/TX. Verbatim it actually looks pretty great for each of those days compared to any day earlier in the week (Sunday-Wednesday), will have to see if this becomes a trend...

[bjc3395]

Latest 00Z GFS seems to prefer later in the week for a bigger more obvious severe threat--in the Thursday-Saturday (5/26-28) time frame for somewhere across KS/OK/TX. Verbatim it actually looks pretty great for each of those days compared to any day earlier in the week (Sunday-Wednesday), will have to see if this becomes a trend...

Precisely. Both the euro and gfs have shown this feature consistently.... but this was the first time it ejected with the strength being maintained. Other recent runs basically killed the flow as it ejected. 0z guidance actually ejects a strong lead wave, allowing a sequence of severe days.

As you said, and as I've been watching for a while now.... this IMO holds potential for a rather robust event over the southern and central plains. This run was particularly interesting because it actually strengthened the system compared to prior runs. This run also slows the progression of the trough such that it's Thursday through Saturday... if this becomes a trend, I will hardly be able to contain my excitement (especially on the heels of this week's early "stuff"). I will wait for better consistency though so that I don't suffer from severe disappointment; I've had plenty of that the last year or so of chasing.

So much to watch throughout the week..

[jojo762]

Precisely. Both the euro and gfs have shown this feature consistently.... but this was the first time it ejected with the strength being maintained. Other recent runs basically killed the flow as it ejected. 0z guidance actually ejects a strong lead wave, allowing a sequence of severe days.

As you said, and as I've been watching for a while now.... this IMO holds potential for a rather robust event over the southern and central plains. This run was particularly interesting because it actually strengthened the system compared to prior runs. This run also slows the progression of the trough such that it's Thursday through Saturday... if this becomes a trend, I will hardly be able to contain my excitement (especially on the heels of this week's early "stuff"). I will wait for better consistency though so that I don't suffer from severe disappointment; I've had plenty of that the last year or so of chasing.

So much to watch throughout the week..

this run in addition to the impressive flow now shown on both Thursday/Friday... also lessened the meridonial component considerably for the final S/W, the one in which has the best potential in my mind. About a week out... So TONS will change for better or worse. Just will need to be watched given all the other things that will already be in place-- extremely moist BL, impressive LRs, solid EML, etc.

[bjc3395]

this run in addition to the impressive flow now shown on both Thursday/Friday... also lessened the meridonial component considerably for the final S/W, the one in which has the best potential in my mind. About a week out... So TONS will change for better or worse. Just will need to be watched given all the other things that will already be in place-- extremely moist BL, impressive LRs, solid EML, etc.

just looking synoptically.... 0z euro is very impressive with a pretty strong negative tilt trough ejecting over SE CO/TX PH with 60 knots max nosing into west OK...

Pretty impressive.

[thewxmann]

Yeah the past few years have been pretty sad overall. And yes seems maybe something to increased winter activity but that doesn't make up for the negative effects during peak season IMO.

 

Here in CA it's causing drier winters so that's a double-edged sword for me. Climate change is starting to really suck from my perspective, weather events just aren't as good as they used to be...

[andyhb]

Certainly can't complain about either the 00z GFS or Euro compared to previous runs. Looks like good potential on 3-4 days next week on both of them. GFS seems to favour later in the week, with the Euro looking interesting on Tuesday and Thursday (not to mention continuing to show a more favorable setup on Sunday with the dryline further W and a stronger LLJ than the other guidance by 00z).

[nrgjeff]

Next week is good for a travel chase trip, even if no one day stands out. On a travel chase one plays the law of averages, more chances the better. One big day is great if one lives in the Plains; go for the single day odds. Several subtle days are ideal for a travel chase trip.

 

Sunday is nice with two targets to spread weekend crowds. Monday and Tuesday target selection will probably be morning or even midday calls. Both mornings may feature ongoing rain. In late May it is a plus, laying down outflow boundaries. Atmo has plenty of time to recover. One would target, follow, and chase boundary intersections. When hi-res models shift cells, look for the reason; models are probably shifting the boundaries. Also follow desired boundary intersection on surface and visible satellite.

 

Rising heights may offer a rest day midweek. Late week models are struggling with another wave coming out. I doubt it comes together as a big outbreak finale, but another chase day sounds reasonable. Good luck, especially to those on vacation, and everybody chase safely.

[bjc3395]

Next week is good for a travel chase trip, even if no one day stands out. On a travel chase one plays the law of averages, more chances the better. One big day is great if one lives in the Plains; go for the single day odds. Several subtle days are ideal for a travel chase trip.

Sunday is nice with two targets to spread weekend crowds. Monday and Tuesday target selection will probably be morning or even midday calls. Both mornings may feature ongoing rain. In late May it is a plus, laying down outflow boundaries. Atmo has plenty of time to recover. One would target, follow, and chase boundary intersections. When hi-res models shift cells, look for the reason; models are probably shifting the boundaries. Also follow desired boundary intersection on surface and visible satellite.

Rising heights may offer a rest day midweek. Late week models are struggling with another wave coming out. I doubt it comes together as a big outbreak finale, but another chase day sounds reasonable. Good luck, especially to those on vacation, and everybody chase safely.

I mean we're a full week out, a little early to call it either way.

I'm glad I live in Norman. One of these days will pan out nicely.

[brettjrob]

The chasecationers will be begging for a down day by next weekend if the 12z GFS verifies. Literally a week straight of high CAPE dryline action starting Sunday! Last night's Euro wasn't as enthusiastic with the late week period, but we have several setups to get through before worrying too much about that.

[Ian]

I'll take the gfs for sure. Already sad I have two days of nothing.

[Thundersnow12]

12z god model EMC SPC WRF with 3 possible areas tomorrow...north of Denver, southeast CO, and the TX PH

[pbrussell]

GFS sure is pumping out some fat cape values for next week. 

[andyhb]

GFS sure is pumping out some fat cape values for next week. 

 

Models have indicated very large CAPE for at least a week now in this timeframe. It's just a matter of strengthening the flow aloft. I can't recall seeing such explosive instability in May for a long stretch like this since 2013 (might have to go back further than that).

[JoMo]

Well, I'm definitely hoping the GFS is too far east with the dryline. It usually is from this range, isn't it?

[andyhb]

Well, I'm definitely hoping the GFS is too far east with the dryline. It usually is from this range, isn't it?

 

Yes, it has been all year.

[Chinook]

I was messing around and looking up some past severe weather outbreaks. I noticed that the 500mb forecast for Monday is actually quite similar to June 22, 2003, the day of the 7" Aurora hailstone and a regional outbreak of tornadoes near the KS/NE border. I don't know if this analog is going to be very helpful for anybody, I just wanted to point it out.

 

http://www.spc.noaa.gov/obswx/maps/500_030623_00.gif