6/10/04 FCST: Plains

  • Thread starter Kevin Scharfenberg
  • Start date

Kevin Scharfenberg

12Z/07th eta model output suggests the first in a string of severe weather days for the plains may be Thursday the 10th.

A 35-40 kt 500 mb jet is progged to emerge onto the plains over the dryline, where 70+ dewpoints and a strong elevated mixed layer should be in place. If the system were to slow down by 12 hours or so we might have to wait til the 11th.

Forecast discussions for the 10th go right...about...

Hrmm...cursory look at the 12z ETA was enough to really peak my curiosity...

fairly deep negative tilt to the western US trof by 00z 11 June...35-40 kt 500 mb flow and 40+ kt flow at 850...impressive for this time in June across SW KS....Low level flow progged by the ETA to be fairly backed east of the dryline across W and C Kansas SWWD into W OK and TX, leading to 0-3km SREH's above 200 m^2/s^2.

of course, its so hard to resolve any features except the general synoptic-scale flow this far out...but the potential for a fairly deep maritime airmass and subsequent moderate instability, coupled with pretty good deep layer shear, certainly bears watching.

will have to watch the progression of this system but it certainly looks interesting. could very well be my last chase in the plains before moving east to grad school (and I thought 29 May was the last...but i'll take another :lol: )
After checking out the latest 12Z ETA guidance for 00 UTC FRI., I'm definitely impressed with the dynamics forecast to set up by Thursday afternoon-evening. Elongated low east of the Rockies advects warm, very moist air staright up into the Dakotas, with winds backing across the entire area. Negatively tilted trough brings outbreak to mind, and LLJ advecting tons of steam (30-40 kts) right up to the dry line will make for better Temp/Dewpoint (Td) spreads to prevent cold-pooling. While this setup is definitely promising, the one area that grabs my attention is around Garden City, in SW KS. 850s progged to back out of the SE @ around 35 kts right at the dry line over that area (nicely maximizing low-level directional shear), and a nice 80 deg. Theta-E axis stretches all the way back there as well. Dry line also appears sharpest & most well-defined over SW, W-central KS, so the way things are looking now would definitely head towards the Garden City area on Thursday.
Just hope I can get off work that day :roll:
This may be a pretty simple comment for a forecast thread, but the 0z eta just spit out something quite similar to May 22. Anyplace from along the wf in NE down the dryline will probably have tornadic supercells on it. Beings it looks a good deal like May 22 I'd probably play west of North Platte early. The shear along the wf with the 850 jet crossing it further east would be quite tempting as well(ala the Thayer county beast). Looks rather big to me right now.

I've heard some good stuff about this thursday's severe weather event, unfortunately I havent seen much in the HWOs and forecast discussions from local NWS offices in the plains. Maybe this afternoon things will be updated to reflect the possibility of an outbreak. Upgrade to at least modereate risk is likely on thursday. Hope this is just the first of many good chase days this week and next week
12z ETA run still hinting at an interesting setup for Thu.....strongest 500 mb flow over SW KS/OK Panhandle, with a 991mb sfc low in far SW NE....SPC 3 Day made a mention of the high T/Td spreads just ahead of the dryline...will be interesting to see how much moisture ends up mixing out before initiation. How far will storms that fire along the dryline need to travel before tapping the deeper moisture? Situation very similar thermodynamically, at least in this respect, to 29 May.

still like SW KS/NW OK for dryline action, but best stuff may end up being in S NE/N KS along the warm front.....sounds awful familiar.
Originally posted by Chad Ringley

still like SW KS/NW OK for dryline action, but best stuff may end up being in S NE/N KS along the warm front.....sounds awful familiar.

I agree... Looking at the 12z ETA run, the best combination of instability and shear appears to be along the wf in northern KS and southern NE. With the best low-level shear farther north, OK may be left in the dust... Flow still sufficient in norhtwestern OK and southern KS, but the mixing out higher dewpoints may kill tornado chances for the 'southern targets'. I don't know if I want to trek up to southern NE again, since I have school the next morning at 8am... And if Friday looks like a possible chase day too east of I35 in OK and KS, who knows...

Oh yeah, the ETA has had a tendency this year to overmix the boundary layer and thus overdry the dewpoints. Just something to keep in mind...
SPC's new Day 2 outlook for the 10th has a MOD RISK across most of Western and Central Nebraska, as well as southern parts of S. Dakota and northern sections of Kansas. This just out as of 20 minutes ago (yes, I am still up).

A bit too tired to glance over models right now, as I am more concerned with potential in NE Colorado Wednesday, but I would say that North Platte looks to be a good starting point for me for Thursday's run. Maybe will end my chasing tomorrow in/near Julesburg, Colorado and will crash overnight up there.

More later..
North Central Nebraska

Virtual Chase Target: Naper Nebraska, or 30 nnw of O'Neill abt 7 pm Thursday

I really like this favorable deep layer shear profile and the backed forecast surface
winds near the warm front, in the theta-e nose, near the 700mb cap and shortwave
trough, and lower Temp/Td spreads. Question is the 700 temps maybe too cool
that far north and have alot of storms going up at once. So maybe a tail end Charlie
storm just south of there, around O'Neill, in the better cap.

I have to work the Evening Shift at Dodge City, so I will be only virtually chasing.

Mitchel SD has an interesting forecast sounding.





I think O'Neill and west might be a good start. Sucks there is no digital once you get west of Neligh for the most part. I would expect an outflow boundary up there somewhere.


Not good for the locals in se NE that is for sure.
Sitting here at the Flying J in Salina on my way to North Platte for the night. Still looking like a few good chase days ahead! This cloud deck/precip grunge sure is stubborn - thought I would be out of it a long time ago. Been in the rain and overcast since 7AM east of St. Louis! Hoping a similar deck doesn't spoil things tomorrow.
Good morning from Ogallala.. yes, it's 6am, but sleeping in your car doesn't allow for a real easy time sleeping in. A nap may be in order as I have very little distance to go to put me in my target zone..

Today's target, the southern end of the MOD RISK, initially targeting North Platte (a whopping 50 miles away), then playing things off from there. My best data access is right here, so I may elect to hang in this area and see how things progress, either that or blast a bit further east into Elm Creek near Kearney where I also get full WiFi access. That's 130 miles away and I think puts me just a hair bit further east than I'd rather be. I'll see how things play out in the next few hours and make that choice.

The southern end of the risk looks better for the better isolation of cells longer as opposed to things north of here. SPC's talks make mention of things going linear in the northern areas much faster than in the south. I'm going to play the area close to I-80 initially and see how storms go before jumping north/south by large amounts. The RUC has cape values in the 2500/3000 range in the 9 hour prog in southern Nebraska with a 4000+ bulls-eye just north and east of me in the 12 hour forecast.

I'm going to take a more detailed look after some breakfast (and maybe a couple hours more sleep) before pinning down final target areas. Right now, I am content to stick close to where I am now.
No longer looking to chase today. I'd spend my last $20 on a May 29, but today isn't one of those (at least not where I'd have to chase).

Shoulda looked at models before posting, my bad.
Decided it's a "no go" for me today as far as the Nebraska/NW Kansas target is concerned. The latest guidance suggests low-level shear and helicity will be marginal along and south of I-80, and to the north the cap is weak and forcing is strong which may force an MCS early. Plus, I'm limited to a day chase from Norman, so that would be 15-16+ hours driving to and from the target alone. I still wouldn't be surprised to see a few nice supercells east through northeast of GLD.

I wouldn't write off the TX Panhandle up into far SW KS. I will be monitoring this region for a possible noon departure. I like the strongly backed winds along the caprock progged by the 09Z RUC, and there should be a strong and sharp dryline there. The cap will be an issue, but the DDC and AMA 12Z soundings suggest temperatures around 90F would be sufficient with the strong dryline circulation to break the cap locally.

Good luck to all chasing today!
I didn't intend to end up this far west yesterday, but it turns out Colby might not be a bad starting point for today. Still a lot of stratus here, but the sat loop shows it quickly clearing out. I'm hesitant to go too far north where a big MCSfest looks likely - but I'm also a little worried about KS and points south, as the cap might be a spoiler - and RUC doesn't break out much if any sustained precip down there either.

Like Tony, I have great data access here in Colby and therefore don't want to go too far now...will wait a couple hours and see how things are panning out.

Hope everyone who is out today is successful!