andyhb

About to have a problem moving into Overland Park. Damage reported in Eudora.

TDS on it too.

Slight risk today.

Tornado confirmed on the storm near the SD/ND border north of Buffalo: https://twitter.com/Wx_Dan/status/616056420618768384

Looks like a localized tornado outbreak ongoing over E ND and W MN right now.

Yeah that whole idea fell apart fast. Looks as if we'll go all of Spring and June without a high risk or PDS watch at this juncture.

Just a few thoughts about the 00z guidance (focusing on the operationals): There are two camps in this set of model runs. One, consisting of the Euro and GGEM, is more progressive with the closed low that breaks off the main northern jet branch in the NW in a couple days (this is mainly due to it not retrograding west as far) and eventually leads to a rather messy, disjointed troughing across the N tier of the CONUS late next week since the aforementioned low does not phase very well with the incoming southern stream that undercuts the Aleutian ridging. The other, potentially more volatile scenario is shown by the GFS and likely an extrapolated UK. These two model retrograde the closed low far enough so that it is not picked up by the northern stream for a slightly longer period of time (both in a similar position at 144 hours). It then (on the GFS) is picked up by the northern stream afterwards and phases with the southern branch more effectively, eventually leading to a very potent shortwave trough ejecting across the Northern Plains around D8-9 with some extremely impressive wind fields for June (and likely higher end severe potential as it seems a large reservoir of seasonably high instability will be in place for whatever does come down the chute then). In conclusion, while it seems all guidance would indicate at least some severe possibilities late next week (as they have for several days now), it's going to be crucial to monitor the evolution of this closed low off the West Coast over the next few days as it could have major implications downstream for the northern CONUS. Should also add that the northern stream shortwaves that eventually lead to the closed low being picked up are also highly important. Overall, a lot of moving parts and it should be awhile before anything is settled on.

Some of these longer range GFS/ensemble runs as of late have really fallen into the "holy crap" category.

Man 18z GFS has a trough with a 90 kt 500 mb and 120+ kt 300 mb speed max moving across the Northern Plains next week, that would be seriously impressive.

What I seem to be seeing on the recent ensemble guidance is a tendency to shift high latitude ridging eastward over central Canada past the first week of June. Should this happen, it would likely open up an opportunity for the Aleutian low to slide east and allow a relatively open path for its associated jet to the West Coast (with an accordingly active pattern downstream).

-EPO block is going to be a problem through the next week at least, need that to break down/slide east a bit so the jet from the Aleutian low can advance east. Until then, might be more nickel and dime setups vs. bigger events.

We still haven't had that bigger event/outbreak to accent the season yet. There will likely be moisture in spades, just a question on whether the Pacific cooperates. A northern shift will help with the EML situation, with more favorable 700 mb trajectories.

June 1957 and June 1958 also had some bigger events in the N Plains and Upper Midwest (F5 in Fargo on 6/10/57 and F5 in Colfax, WI on 6/4/58).

Late May-June 2004 showing up a ton in the CPC 8-14 day analogs today.

Not sure about the Euro weeklies, but the monthly forecast from the CFSv2 for June looks pretty favorable currently. Strong northern stream on the 200 mb U-wind anomalies plowing into the Pacific NW with net troughing in the Gulf of Alaska, cool temp anomalies across the western/central CONUS and warm in the east.

Pretty spectacular sounding from AMA @ 00z Wed from the 12z NAM (with supercells in the area as well). Will start a thread on this later if some consistency is shown.

W TX setup on Tuesday looks to hold some potential with any decent amount of destabilization.

I'll send him an NARR loop of late May 04 if it helps.

Mark can you hack Ian's computer?

Might want to mention that there is a very nice W TX/E NM setup showing up next week (5/19) on the 12z GFS.

Gonna need a pretty deep eastern trough to have any appreciable affect on the Plains this time of year.

12z GFS certainly appears to show a fairly healthy EML being advected over the warm sector Friday night looking at 700 mb RH. Significant increases in instability through the day Saturday as opposed to previous runs (18z/00z/06z) despite some early convection still being there. Also appears to show stronger wind fields.

Well, the 00z Euro looks pretty similar to 12z at first glance through most of the fields. H85 temps/winds in particular are almost identical to the 12z run at 00z 5/17. Will get a look at the morning convection/EML situation a bit later. The 12z run did have widespread favorable thermodynamic profiles across a large chunk of the warm sector at 18z, 00z was partially contaminated by convection (not from the morning).

Will probably start a dedicated thread to this tonight, but yeah the 18z/00z GFS runs would certainly not have too high of a ceiling. The 12z Euro would be very volatile though, whether that goes towards the GFS tonight is the question. The 00z UK is in, although I can't see any of the wind fields on it for that timeframe so that's a bit of a mystery of what everything actually looks like. I'll also add that the hits seem to keep on coming with repeated western troughing on most ensemble guidance/etc. I'd have to think that something bad (or good, for chasers) is going to happen (in spite of the 5 fatalities over the weekend) one of these times if this type of pattern continues. That's not to mention all of the flooding.

Would be best to wait until we get better sampling. The upgraded GFS hasn't necessarily been stellar recently, nor has the Euro at times. I agree that the 12z Euro would have some pretty nasty potential, if we see a consolidation towards its solution, people in the Plains (over a large area) better be paying attention.