State of the Chase Season: 2019

[Ethan Schisler]

00z NAM tonight shows the most favorable outcome so far I've seen (not saying I buy it) for Wednesday. A 70 knot jet streak at 500mb is passing through the KS/NE region around 00z Wednesday evening and CAMs show initiation taking place between 21-00z and storms up and down the dry line toward evening. The same model only shows a very narrow corridor where CIN is low enough to maintain a surface based storm, which is highly suspect. If we can get storm imitation anywhere the CIN isn't particularly high, co-alligning with the best surface convegence, especially near the triple point, I definitely think there could be a tornado threat. Highly conditional, but its April, so best keep our eyes peeled. I'll wait for another day to create a thread or if someone beats me to it

 

[Marshall Stoner]

It looks like a cap bust on the plains. Then the storm is filling when the warm sector finally reaches Illinois/Indiana, so isallobaric compenent isn't favorable for sufficiently backed low levels there, plus weak instability. NAM has the warm front getting into Michigan but every NWS discussion thinks its full of shit. lol Was really hoping for an Illinois / Indiana chase. Maybe the next system will be better. Who knows.

 

[Warren Faidley]

For the sake of the chase season, I hope the models are wrong.

 

[Quincy Vagell]

That is pretty remarkable that the CFS is so tame, even out into mid-May. Sure, it doesn't have much usefulness past 2-3 weeks, in my experience, but it's actually trending away from climatology in the long range. I'm not sure I can explain that, but regardless, you will have better verification going with climatology than the CFS in the 4-6 week range.

 

[JamesCaruso]

I was feeling nervous about having such a late chase vacation this year (starting 5/24), but I feel better about it after seeing that CFS.

5/24 will be the very next column that appears on the model today...

 

[Marc R. O'Leary]

I'm taking my first official chase vacation this year. The wife and I are going to go wander around the plains and see what happens. No specific destinations, no crazy chasing. Just off we go to see what we see. Weather, great! Roadside attractions, great! Good restaurants, great!

I think this will be fun. From a chasing standpoint, I'm a homer, sticking to CO and nearby areas of neighboring states. My wife is just starting to get interested in what I do when I wander off into nowhere for an entire day, then text her pictures of the crazy weather I'm seeing. This will be a mellow stand-off chase-cation as I have no interest in getting up close into the crowds, and my wife, sure as shit, doesn't want to do that.

In any case, last week of May. Hopefully I'll see some of you fellow crazy people out there.

 

[Andy Wehrle]

I have taken my chasecations in the late season (late May-sometime in June) based on climatology every year since I've had a full-time job to take a chasecation from (2014) and been burned every year other than the first when my vacation coincided perfectly with the Pilger-Coleridge days yet I still missed both. 2016 hurt the most as I had booked the week AFTER DDC/Chapman which ended up being almost historically dull for that timeframe.

Unfortunately I don't have the financial luxury to wander from one end of the Plains to the other after marginal setups, so in the other years my "chasecation" has turned into a "staycation."

 

[JamesCaruso]

I have taken my chasecations in the late season (late May-sometime in June) based on climatology every year since I've had a full-time job to take a chasecation from (2014) and been burned every year other than the first when my vacation coincided perfectly with the Pilger-Coleridge days yet I still missed both. 2016 hurt the most as I had booked the week AFTER DDC/Chapman which ended up being almost historically dull for that timeframe.

Unfortunately I don't have the financial luxury to wander from one end of the Plains to the other after marginal setups, so in the other years my "chasecation" has turned into a "staycation."

If it’s any consolation, those were all pretty lean years, except for the few isolated events you mentioned, of which I was only there for one, DDC (wasn’t chasing during Pilger/Coleridge, and missed Chapman due to post-DDC complacency). You can’t go wrong going with climatology, even though you got burned doing so it was only because every one of those seasons as a whole was pretty bad.

Climatology aside, this year it looks like IF it’s going to be more active, it’s going to be later in the season.

 

[Jeff House]

I strongly recommend flexible days. That is hard flying and with certain jobs. Need a manager who understand and FF miles to blow last minute. Otherwise, a long drive with audio books is not bad. Radio has too many ads. Even satellite radio or your own playlist can't pass 12 hours. Audio books on the other hand make the drive easy.

Tropical forcing has favored Dixie Alley early. Some years that translates into the Plains later. However we have a secondary crap pattern mixed in every 4-6 weeks. Thankfully it only lasts a couple weeks. However mid-May would be just devastating. I still favor May 15-31 over early June. Later has some classics, but May is easier to forecast. Therefore, odds are greater in May.

 

[Warren Faidley]

Just received the latest ENSO El Niño Advisory...........

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf

 

[Marshall Stoner]

What do you guys think about the system showing on the 17th? It looks similar to the one last Wednesday/Thursday, but farther north and better moisture... perhaps eventually. I think the problem with the big system last week was it bombed out while still over the rockies and was basically just spinning itself out by the time it got east enough to potentially draw gulf moisture. Some warm dry southwesterlies is normally a good thing, but not when they're so strong they shunt away and/or mix out all the MT air. Maybe there was also a problem with incipient dry northerlies over the Gulf. I don't know. You wouldn't think a deepening plains system would have as much trouble picking up 60 degree dewpoints by now though. Not after the current rainfall.

 

[Jeff House]

Weekend system had two basic problems on Saturday. First winds from 850-500 did not turn enough. Second, the lowest level CAPE/instability was not enough to overcome that issue. Waste of low level shear (up to 1-2 km) or blessing for people down there? Moisture did not really mix out; in fact, it was deep and contributed to HP mode. Saturday is why it takes more than parameters.

Midweek has some differences, including coming out farther north. Timing will be everything; but, here's what it looks like as of Sunday evening. Wednesday is borderline, mostly east of I-35 and into the Ozarks. Could fire farther west, but too early to fcst. Thursday is progged from Indiana to Alabama. Compared to the Delta, IN/TN/AL is more favored by climo. However a Gulf Coast MCS would end the party. Too early to tell now.

Looking farther ahead, 6-10 day forecasts keep delaying the relatively quieter period. State of the season is not bad.

 

[Marshall Stoner]

Weekend system had two basic problems on Saturday. First winds from 850-500 did not turn enough. Second, the lowest level CAPE/instability was not enough to overcome that issue. Waste of low level shear (up to 1-2 km) or blessing for people down there? Moisture did not really mix out; in fact, it was deep and contributed to HP mode. Saturday is why it takes more than parameters.

I was talking about the big plains snowstorm bomb system before that. I'm way up in Michigan so I have trouble getting excited about stuff happening in the deep south. I'd say it was scary enough for the people that actually live there though. I seem to recall the day of the 2011 Joplin tornado didn't have perfect looking hodographs. There was extreme instability in that case though.

Midweek has some differences, including coming out farther north. Timing will be everything; but, here's what it looks like as of Sunday evening. Wednesday is borderline, mostly east of I-35 and into the Ozarks. Could fire farther west, but too early to fcst. Thursday is progged from Indiana to Alabama. Compared to the Delta, IN/TN/AL is more favored by climo. However a Gulf Coast MCS would end the party. Too early to tell now.

Yea. Lingering stratiform rain and debris will probably ruin instability north of the Ohio river on Thursday. I don't know exactly what it takes for that not to happen though. Just seeing a nice supercell structure in the southern Great Lakes / northern Ohio Valley would make me happy. It's rare to get good instability that far north in April, but I'm scared that the synoptic pattern will be pathetic by late May. I don't know what was wrong with last year but there was just no shear or synoptic forcing at all from late spring through summer. It was like the tropics extending into the northern US. I worry that maybe it's global warming. When western Canada is so damn warm so early and there's no shear to be seen anywhere its hard to even get a decent MCS to survive east of the Mississippi by June.

Looking farther ahead, 6-10 day forecasts keep delaying the relatively quieter period. State of the season is not bad.

The southern plains and central Mississippi valley will definitely get something. I don't know that the season will have anything close enough for me to chase though. Just seeing a nice supercell would make me happy though. Not being anywhere near the plains I don't really care that much about tornadoes.

 

[chrisbray]

We had some good discussion about MJO on the discord server today. Essentially, models are currently suggestive of phase 1/2 in May at some point, and Phase 2 has a significant correlation to March/April/May tornado outbreaks. The cited paper is: https://journals.ametsoc.org/doi/10.1175/MWR-D-12-00173.1

Essentially we are in a pretty good match in terms of 500mb Heights compared to patterns suggestive of a favorable phase of MJO coming up in a couple weeks. Seems to be good reasons to remain optimistic about May

 

[Jeff House]

While the IO is flaring up as expected, convection in the West Pac muddies the waters. I expect characteristics of both. Still a chase day pickers market. I don't see a great pattern the next 15-20 days. Hopefully it'll light up right at peak season May 15-31. Please, no VBV junk.