La Nina Forecast 2018

[Mark Blue]

good ET during the heart of chase season.

I’ve learned through the years that one cannot underestimate the role ET plays in creating a humid environment in the lowest levels that persists and strengthens as each day passes in conjunction with Spring rains and the northward transport of moisture via the LLJ.

 

[Andy Berrington]

This drought onset during winter certainly doesn't have me very rosy for the upcoming Plains chasing season, nor do some of the mentions of 2014 similarities that have been floating around (with merit). That was not a fruitful spring season for a multitude of reasons, but the main ones being Plains drought (moisture repeatedly underperforming) and repeated eastern troughing/cold shots/northwest flow throughout March-May (and everything had lifted north by June).

The May 11th event in S NE, despite producing tornadoes of significance, ended up turning into a mess quickly (and was mostly dangerous anyway due to poor visibility) because of an anafront in close proximity to the warm sector, partly due to the remnant cold air mass to the north that lingered deep into spring. This generally caused a lot of problems with RFD character, since the main supercell(s) of the day generally tracked on or parallel to this boundary.

This is a very specific case/example, but it kind of had everything that turned 2014 into a mess all in one setup (the drought detrimentally affected areas further S/W along the dryline).

 

[JeremyS]

I took a look back at my chase logs from 2014 and it was one of my busiest years for me. It looks like the reason why was because there were a lot of local chases up here in Nebraska and Iowa. Lots of moderate risks in May and June with decent tornado chances, but as you mentioned there were a lot of HP messes so I didn't see a lot of tornadoes that year.
It's been mentioned that the drought could push things east or even north, which would make sense looking back at 2014 at least.
However, there was one event that made the year for those that saw it: Pilger!
Being a bit biased based on my location, I would definitely like a 2014 repeat. I actually think I've chased more in Oklahoma/Texas the last couple of years versus my home state of Nebraska, it's been so quiet up here lately.

This drought onset during winter certainly doesn't have me very rosy for the upcoming Plains chasing season, nor do some of the mentions of 2014 similarities that have been floating around (with merit). That was not a fruitful spring season for a multitude of reasons, but the main ones being Plains drought (moisture repeatedly underperforming) and repeated eastern troughing/cold shots/northwest flow throughout March-May (and everything had lifted north by June).

The May 11th event in S NE, despite producing tornadoes of significance, ended up turning into a mess quickly (and was mostly dangerous anyway due to poor visibility) because of an anafront in close proximity to the warm sector, partly due to the remnant cold air mass to the north that lingered deep into spring. This generally caused a lot of problems with RFD character, since the main supercell(s) of the day generally tracked on or parallel to this boundary.

This is a very specific case/example, but it kind of had everything that turned 2014 into a mess all in one setup (the drought detrimentally affected areas further S/W along the dryline).

 

[Royce Sheibal]

So call me crazy, but I'm wondering if the long term drought conditions brought on by La Nina in the S / High Plains vs the short term heavy early spring rainfalls that often accompany La Nina in the central plains (as happened in 2014) can significantly modify regional scale climates enough that standard fronts / lows in the NE/IA central plains area become dryline-like enhanced boundaries more so than in typical years. Areas south and west are drier and Td's stay low, areas north and east have increased evapotranspiration, with the end result being both stronger CAPE in the warm sector and a stronger trigger method once the boundary leaves the drought zone.

 

[Jeff House]

Tough to put a silver lining on it. Tendency is Td mix-out issues even north, undercutting cold, and the like. Also might face some east of I-35 messes. However, it only takes one good sequence to make a chaser's year.

 

[Jonathan Beeson]

I'm becoming cautiously optimistic for rainfall prospects over the next several weeks. We're beginning to see the western ridge slowly breakdown as well as the southeast ridge beginning to pump up. This may mean good chances for some rainfall across the Front Range and S Plains, as well as perhaps an uptick in activity across Dixie for those of us like me based in that area of the country.

 

[Mark Blue]

I like what I see with a trough in the West today vs the ever-present ridge we’ve been seeing. Hopefully it’s a good sign, but I’m also cautiously optimistic.