State of the Chase Season: 2017 Edition

[James Gustina]

A little late getting this off the ground this season but it's about time to transition over seeing as we've already had several setups with a potentially busy week coming up. This thread can be used to talk about distant pattern shifts, how your season is going so far, climatology or anything else related to the 2017 chase season you can think of.

 

[chrisbray]

Seems like there will be at least a few slight risk type setups next week, maybe an enhanced in there somewhere. The nice thing is there are no real bad drought conditions over tornado alley right now, and we have had good EMLs so far this year. I haven't seen anything in the long term pattern that looks as though it will completely kill potential over the next week+. Best we can hope for is an active pattern continuing, as the moisture is in place and the Gulf is warm.

 

[Andy Wehrle]

Agreed. The two biggest May killers are an early death ridge (which drought will promote) or a return to a winterlike pattern with cool, stable air dominating east of the Rockies. Not seeing anything to favor that either so am cautiously optimistic about this season. The rest of April also looks to hold some promise as Chris alluded to, exactly how much remains to be seen.

 

[JamesCaruso]

All anecdotal but late March and April seem to be relatively active so far (including the balance of this week). Anyone aware of any correlations between that and the remainder of the season? If it's active early does that tend to mean the season will also shut down earlier? Or does it bode well for an active chasing season throughout? I've been chasing a long time but have never really tried to quantify or analyze this...

The reason I am asking is because I am trying to figure out whether to leave for my chase vacation on 5/15 or 5/26. The earlier period would generally be favored but this year that is less convenient for me and my chase partner, and would also have to be a shorter (9 or 10 day) trip. Whereas the 26th is later than I would ordinarily like to go, but works better with our professional and personal schedules and would be a full two weeks. I am especially worried about a later trip when it is active early in the season, I always fear it's also going to shut down early too...


Sent from my iPad using Tapatalk

 

[GPhillips]

All anecdotal but late March and April seem to be relatively active so far (including the balance of this week). Anyone aware of any correlations between that and the remainder of the season? If it's active early does that tend to mean the season will also shut down earlier? Or does it bode well for an active chasing season throughout? I've been chasing a long time but have never really tried to quantify or analyze this...

This graphic shows a running total of tornado LSRs for this year overlaid on the same type of reports for the previous 12 years. Not sure how much you can glean from it but it's something. That graphic is from the SPC WCM page. http://www.spc.noaa.gov/wcm/

 

[JamesCaruso]

This graphic shows a running total of tornado LSRs for this year overlaid on the same type of reports for the previous 12 years. Not sure how much you can glean from it but it's something. That graphic is from the SPC WCM page. http://www.spc.noaa.gov/wcm/

Thanks for posting this. Looks like this year is in fact running relatively high, it's not just anecdotal. Maybe my confirmation bias is at work because I am looking for support for a later trip, but it does look as if the years with a similar or greater tally to this point flatlined a little in early to mid May, before climbing again in late May and continuing in early June.


Sent from my iPad using Tapatalk

 

[Dan Robinson]

It's been relatively active in terms of a progressive upper pattern and many western US troughs, but so far none of this has translated to predictable quality chase setups. Right now, I don't see any way to make an informed call between mid-May and late May - other than climatology, which would favor the latter. If I had to make a call right now, I'd choose the late May timeframe - but if there is any way to hold off the decision until the first week of May or beyond, you'll at least have the benefit of the mid-May period being in the window of some long-range guidance.

 

[Paul Knightley]

This post relates to a potential uptick in severe weather potential in the next 10 days - I think we're almost within range of Target Area posts for individual days, but I will leave others to start those up as/when it becomes a bit more obvious where the higher threat levels are. For several days now, ensemble output (e.g. the ECMWF ENS) has been depicting that a powerful Pacific jet stream early next week will 'collapse' into a substantial western USA trough by mid-late week, the latter also propagating into the central CONUS. Ahead of this, a cold front may get as far south as 'just north' of the Yucatan Peninsula by Monday.

However, as a zonal flow develops Mon/Tue, return flow should commence, and even the fairly conservative ECMWF model depicts ~high 60s dewpoints into OK by Weds evening, and also across the mid-MO valley area. The variability then kicks in, dependent on the exact evolution of the trough, and shortwaves rotating around its southern flank. Pattern-matching and climatology would favour at least one major severe weather episode between ~ Weds and Monday (26th April-1st May), but pinning down higher risk days is not possible at this stage. Even so, the SPC has already delineated an area for Day 8.

 

[Brett Roberts]

After some recent convective complexes, it's now looking almost certain that evapotranspiration will be in full effect across the southern Plains as we head into May. Here are radar-derived rainfall estimates for the past 30 days (courtesy of the NWS River Forecast Center):



Barring a major pattern shift that keeps us bone dry for weeks on end starting next week, this should be sufficient for green-up and associated lower T/Td spreads across areas like W OK, C/W KS, and the Panhandles as we head into mid-late May and early June -- much like last year. In other words, this is about the best signal one can hope for at this range if they're planning a chasecation (or otherwise planning to chase a lot) during the peak season/late season in this region.

The usual caveat: ET simply helps setups when the synoptic-scale pattern is supportive of severe weather ingredients. The worst Plains chase season on record was 1988, and it was actually relatively wet (it certainly wasn't plagued by severe drought like some of our recent bad seasons), but the synoptic pattern was dominated by eastern troughing through much of the season. With that said, odds are good any given year that we'll at least see periods of SW flow with sufficient shear for good chase days, given ET-aided low-level moisture.

 

[Ethan Schisler]

I'm becoming more interested in next week as time draws closer. Hopefully someone or myself will start a "target area" thread for one of these upcoming events. I'm trying not to get too excited given the string of underwhelming setups we had around this time period last year (4/24-30), all of which I chased and came home with a total of 1 tornado in the jungle south of OKC (lol). Anyway, it seems like most years you can bank on something at the end of April and then again at the end of May. So the end of May is when we will be taking our annual "chasecation" or whatever you want to call it for a week. For me though, it doesn't matter too much, because I'm on a much shorter leash this year financially and time wise than I was at this point in 2016, so I say bring it on!

 

[Todd Lemery]

I'm eyeballing heading down to the plains mid next week for the first time this year. GFS has been showing the moisture getting there, but I'm not totally convinced yet. It's showing cape at 2500 plus starting Wednesday through Saturday. I'm not seeing the winds pulling the Gulf moisture up very strongly until later Thursday though making me question the depth of the moisture available. The mid level winds look like they'll be working harder though. I'll feel a lot better when it gets in NAM's range and verifies the moisture return. I'm thinking it's about 80-85 percent a go right now .

 

[Dan Robinson]

I'm cautiously optimistic about next week, but still we're talking about just a single day looking good, and one where the GFS has been waffling on the spatial extent of the good parameters. The 12z and 06z runs have trended downward with the setup's size and placement, and with it still being 6 days out, this one could easily be gone in 48 hours. I'll get excited if yesterday's output shows up again starting on Tuesday.

 

[JeremyS]

The 18Z GFS took the first system moving through on Tuesday and Wednesday and pushed the really great moisture much further south towards the Texas coast thus not allowing as high of dew points to return in time on Thursday. Something to watch for sure.


Sent from my iPhone using Stormtrack

 

[Jeff Duda]

I really, really, really do not like the look of the cold fronty looking setups coming next week. I see at least two FROPAs with wind barbs friggin perpendicular to the surface isobars, which is a sign of the power of the cold air mass behind those fronts. Such fronts will absolutely undercut storms, shove events further south, and clear the CONUS and portions of the Gulf of moisture, none of which are favorable for widespread organized severe events. I suspect at least one of the "potential" events this upcoming week will go the way of Friday - largely uneventful. Ugh, it's looking like April is going to be a rather significant disappointment for 2017.

Here's to hoping May makes up for a largely inactive April.

 

[Ethan Schisler]

Well its nice to see the latest model guidance shooting next week down the crapper lol. I see maybe a play on Tuesday and potentially Wednesday given the speed of the system. However given the models being so inconsistent, I'm not betting on anything yet. However I shouldn't be entirely too surprised, given its been 5 years since we had a large scale outbreak in the plains in April. Bring on May I suppose......