State of the Chase Season: 2019

[Jay Goldberg]

Some of my best chase years have been El Nino years ... 2015 and 2016 for example I saw over 50 tornadoes with a couple big event days. I expect the impact to be very positive this year as well though those years had a STRONG El Nino.

Already a big start of the year this past week.

 

[Jesse Risley]

I happened to see this posted today: https://www.nzpchasers.com/blog/dat...pD0yJ71D6fckTmkb5nlRJBV1qKnlSTxQ_TeXRyCmbJQ0s

Make of it what you will, but something add to the repertoire of speculation about the forthcoming spring.

 

[chrisbray]

Most of the rest of March seems to look empty, but there are some signs that at least the Gulf will open back up around the end of the month.

 

[Andy Berrington]

New March ECMWF seasonal forecast for AMJ looks very promising for chase season. It also did quite well with last year. Here are the ensemble mean 2 m temperature and precipitation anomalies.




Here's the AMJ 2018 forecast and verification using the US Climate Division monthly composites (click the thumbnails for larger).

 

[Warren Faidley]

The CFS is still struggling with the next 30 days. I think the season is still in flux and could go either way. The latest ENSO forecast is showing weak El Niño conditions though summer, so you can add that to the equation. "Weak El Nino conditions are likely to continue through the Northern Hemisphere spring 2019 (~80% chance) and summer (~60% chance). The current event bears some similarities to the 2015 spring El Niño that went on to become a strong event by winter. However, it's too soon to tell whether this event will follow the same path."

 

[James Gustina]

Looks like a brief window of opportunity may crop up towards the middle of next week but other than that, March is unsurprisingly looking dead for chase prospects. Hoping we start seeing those sweeping cold fronts from the north start washing out before reaching the Gulf with a little more frequency as we head into April.

 

[Jeff House]

I remain optimistic for the season despite a 7-10 day blah window. They happen often in March and even April. I do not believe this is one of those early hope, crash and burn seasons.

Winter pattern was active in the central Plains. Heartland got plenty of snow as low press cut through the Mid Mississippi Valley. Some weeks were northwest flow; but, many were southwest flow. When KC does well in snow, it did, places farther southwest can get active in spring.

Always a risk of a sharp pattern change, but more than half the time winter pattern cycles make it into spring. So we are in a down period now, like dry NW flow in winter. I expect it t come back around in April, even if delayed until after the first week of April.

Cooler than normal SSTs are noted off Baja and also off parts of the West Coast. Latter anomaly has faded last couple weeks, but may fluctuate with the ups and downs of the West Coast storm track. Makes the PDO hard to forecast. At any rate those regions cool with Atlantic SSTs warmer than normal favor southwest flow (all else equal). Last part is always the problem in meteorology, lol.

There is a risk the West Coast SSTs revert back (warm up) from this currently favorable state. Baja might have more holding power, which would help. Fighting El Nino is also a risk. However on the broadest scale, the Pacific basin SSTs have characteristics of both attm. Probably explains the lack of textbook EN behavior all winter. South had its rain. However the West had cold.

Bottom line: We want to see more of the West trough again. I believe it will happen and I don't mind waiting. If limited duration, better to do it closer to May than to waste it on fickle early April. Of course early and often would build more confidence.

 

[Jeff Duda]

I never want to see an active March. I can't think of too many seasons in the last 20 years featuring *both* an active March *and* an active May-June. I don't believe the synoptic scale pattern ever maintains itself long enough to be active from March all the way through June.

It's too early to speculate about the overall quality of the season. Surely by mid-April we will start to see how the early part of the main season will go.

 

[Dan Robinson]

A big factor in the upcoming season is that eastern Nebraska is going to be essentially out of play despite any quality setups there. I know chasing is trivial compared to what those residents are going through.

 

[Paul Knightley]

There is a reasonable amount of model support for an active sub-tropical jet this spring, with some other forms of guidance hinting at this too. This could result in a rather active pattern through this spring. Of course, given the last couple of years, even a moderately active one would seem 'active' by comparison!

 

[JamesCaruso]

I never want to see an active March. I can't think of too many seasons in the last 20 years featuring *both* an active March *and* an active May-June. I don't believe the synoptic scale pattern ever maintains itself long enough to be active from March all the way through June.

It's too early to speculate about the overall quality of the season. Surely by mid-April we will start to see how the early part of the main season will go.

I remember you commenting on this last year Jeff; in somewhat of a post-mortem on the season you noted how many troughs there had been in March (maybe April too, I can’t remember). My takeaway, in crude terms, was that the atmosphere had sort of “used up” its allotment of troughs by the time the heat and moisture of spring arrived.

Anecdotally, any year that I saw a lot of early activity I always worried that I was going to miss out on the action by the time I got out there in mid to late May. So I, too, am relieved to see an inactive March, but how do you view April? Is it that you like to see the same low activity in early April as in March, but then want to see an active late April? Or do you look for the month of April overall to be a Goldilocks month, when the ideal is not too much and not too little?

 

[Jeff Duda]

Anecdotally, any year that I saw a lot of early activity I always worried that I was going to miss out on the action by the time I got out there in mid to late May. So I, too, am relieved to see an inactive March, but how do you view April? Is it that you like to see the same low activity in early April as in March, but then want to see an active late April? Or do you look for the month of April overall to be a Goldilocks month, when the ideal is not too much and not too little?

I think there are some potential signals for an analogy to 2015. Weak El Nino going in. A tendency for a wetter period to begin (although there was still widespread severe drought across the southern Plains leading into the 2015 chase season, but it ended up being OKC's wettest May ever). Active subtropical jet.

April 2015 was pretty active, and I chased a lot, although I missed all of the tornadoes in that month. May was where it was at, but it was grungy for sure.

Provided we don't continue to see the TPV persist well into April (it is currently persisting in the NE CONUS and across the Hudson Bay area) throwing cold surges clear down to the Gulf, I think there's a pretty good chance of an active April.

 

[Andy Wehrle]

I think there are some potential signals for an analogy to 2015. Weak El Nino going in. A tendency for a wetter period to begin (although there was still widespread severe drought across the southern Plains leading into the 2015 chase season, but it ended up being OKC's wettest May ever). Active subtropical jet.

April 2015 was pretty active, and I chased a lot, although I missed all of the tornadoes in that month. May was where it was at, but it was grungy for sure.

Provided we don't continue to see the TPV persist well into April (it is currently persisting in the NE CONUS and across the Hudson Bay area) throwing cold surges clear down to the Gulf, I think there's a pretty good chance of an active April.

Yeah, I would have thought we'd be done with the polar vortex problems by now since we did not have a late winter SSWE like last year (whew) and we had our mid-March thaw on time here in the Upper Midwest, which of course had led to all the flooding problems.

 

[Andy Wehrle]

Anyone have any updated thoughts? I've heard rumblings April might not be as hot as originally thought earlier in March. GFS has been all over the place in the medium to long range as usual. At times it teases some good looking western troughs/systems at 240+ hours and even keeps them for a few consecutive runs, but so far they've all deteriorated as they've gotten closer.

The good news is, even the fantasy end of the GFS still only reaches out to mid-April, and barring something crazy and unforeseen it doesn't look like we will be faced with anything like the extreme delayed spring of last year.

 

[Dan Robinson]

IMO nothing on the horizon yet. The Gulf is finally showing some signs of life (widespread 70s DPs) in a week or so, but not much of it making its way north. Add to that at least one Gulf-scouring front hinted at after one of next week's waves. GEFS ensembles show an active southern stream jet, but too far south for any Plains action. That will also help prevent Gulf moisture return to chaseable latitudes. There are some narrow ribbons of moisture that poke north of I-40 now and then, but only good for lightning/hail and some high-based supercells. Maybe some Dixie ops with the active jet down there, but not much in the Plains and Midwest.