5/29/08 FCST: SD/NE/KS/IA/MN

[Paul Knightley]

Trends in the 12Z runs, to my eyes, seem to edge a little south. I quite like the Red Cloud, NE, area at the moment, or perhaps south towards Lebanon, KS. The latter is pretty much en route to the former from Salina, so either seems reasonable at the moment. We are really looking for a picturesque discrete cell today, as that's something which has so far eluded us this trip.

 

[Tony Laubach]

We are really looking for a picturesque discrete cell today, as that's something which has so far eluded us this trip.

I'm definitely with you on that today, but I'm afraid a lack of a decent cap is going to make that a difficult thing today. I imagine a similar scenario to last week where numerous cells go up early and tornado in the sweet spot yet to be determined. What I wouldn't give for a bit stronger of a cap just to supress things enough to keep cells a bit more discrete, but I hunch there will be a nightmarish situation ongoing as of 2100z with a multitude of tornatic cells across central and eastern Nebraska and northern Kansas.

 

[Mark Farnik]

I am currently grabbing my chase gear and will be departing for my initial target of Kearney, NE in the next half hour. I can make it to Kearney from where I live in 3 1/2 hours, so I should be there before 2 p.m. CDT, with time to spare to make last minute target adjustments. With the cap not as strong as I would like, I hope we can avoid the situation we had last week in western KS, where pretty much every cell was tornadic at near or the same time. If that is going to be the case, I pray they maintain classic structure and don't morph into HP beasts with rain wrapped wedges straightaway... had enough of that last week to last me a lifetime, thank you.
But at any rate, if this pans out anywhere near the way the models depict it, eastern NE and western IA will be in for an extremely rough evening and night...

 

[Paul Knightley]

I'm definitely with you on that today, but I'm afraid a lack of a decent cap is going to make that a difficult thing today. I imagine a similar scenario to last week where numerous cells go up early and tornado in the sweet spot yet to be determined. What I wouldn't give for a bit stronger of a cap just to supress things enough to keep cells a bit more discrete, but I hunch there will be a nightmarish situation ongoing as of 2100z with a multitude of tornatic cells across central and eastern Nebraska and northern Kansas.

Yes, very true, Tony. The higher res WRF models seem to show a transition to lines quite quickly too. Even so, I think we may be OK to play a bit further south from the higher risk area.

 

[Michael O'Keeffe]

I agree Paul. My earlier forecast hasn't changed from the KS/NE border. I am praying that we can make it in time. I hate when we have a delayed departure, but we can't get out the door till 3-4pm! It sucks really bad, but I think based on the RUC and NAM we should be fine. Both models are showing an isolated supercell right on the border at 00z the RUC really protrays that picture and the new 12z NAM that was showing a nice supercell track in SC Nebraska this morning and yesterday is now showing it in NC Kansas which could be a place to keep an eye on. As for the 4km WRF model, it has been absolutely horrid this year. It broke out nothing during last weeks system and if it did they weren't supercells that's for sure. Another thing is that the shear is still condusive for at the least semi-discrete supercells.

Well that's my 2 cents worth, I think it could be a long afternoon/evening for areas mainly along the I80 corridor south US36 and points along and east of US281. Good luck to everyone and stay safe.

 

[Scott Weberpal]

The 15z RUC solidifies my target SW of Grand Island. Should have no problem getting a vigorous isolated supercell with 50 miles or so of the KS/NE border around the 21z timeframe. Forecast hodographs, and instability should yield at least a few strong tornadoes. I'm very leary about the northern target. LL jet should remain slightly more backed closer to the KS border, and appears to intensify well before dark. Currently looking at the area near Alma for the tornadofest to begin.

 

[Fritz Kruse]

Not an Easy Tornado Forecast

Not an easy slam dunk tornado forecast imo. Very warm H7 temps spreading into west Nebraska. CIN may become an issue from the western portion of the Mod Risk into western Nebraska and even into parts of central Nebraska, and especially south into northern KS. Also mixing out of dewpoints from Dodge and north with maybe a 90/57 towards Hill City by 00z would be not very good for tornados. WRF shows a warm front up near Lexington with backed sfc winds but RUC showing farther north. So where can the sfc winds become backed on the edge of the warm h7 cap and where the temp/dewpoint spread is minimized is....???

 

[David Draun]

Currently at the Super 8 in York, NE. It's friggin cold out here right now, but very humid. 70/68. Mesoanalysis starting to show some good CAPE values in NC KS/SC NE. EHI values are high too. The team will likely head to Grand Island, NE shortly. I would like to see less cloud cover and warmer temperatures before this all gets started. Ditto on the discrete cell complaints. I've been on HP atom-bombs all week! Though anvil-level winds tend to be a bit stronger farther north, which may get some nice classic sups spinning up. Good luck to all, and stay safe!

 

[HAltschule]

I was reviweing the posts and notice Jeff Snyder's post and concerns about dew points reaching 70f. Kansas as of 3pm EDT has DP's as high as 68-69f. GFS Lamp data has DP's up to 69 degrees into NE and IA later today. It seems reasonable to expect 68-70 dewpoints this afternoon but 70+ dewpoints seems like a slight stretch. We should be seeing some pretty intense thermodynamic conditions nonetheless.

Be safe everyone and lets hope that no one does anything stupid.

 

[Andrew Stoller]

There's a fair amount of CINH now and through the early afternoon. 700 mb temps are 12-14 degrees already across southwest Nebraska, and cool to about 10 degrees C by 3Z.

CINH goes from about -350 to almost nothing by 00Z.

If anything, from my barely trained eye, I'd say that's pretty decent for holding things down a bit longer and keeping things a bit more discrete and explosive.

As of right now, per RUC analysis, there's two CAPE bulls eyes - one right around North Platte, and the other around Phillipsburg, KS. RUC breaks out two discrete cells in the Red Cloud to Grand Island corridor.

Visible Satellite shows cumulous developing around Goodland - once that gets going into the above mentioned corridor, things should be good.

I'd be parked in Kearney sippin lemonade if I had a genie in a bottle. There's another CAPE bullseye further west northwest with developing cumulus - might need to keep an eye on that.

:edit: I'd head further soutwest towards the McCook to Curtis corrider - just talked to Mark Farnik and he sees the huge towers around Goodland - says they are exploding. He's headed south on 83 out of North Platte

 

[Mike Johnston]

I was reviweing the posts and notice Jeff Snyder's post and concerns about dew points reaching 70f. Kansas as of 3pm EDT has DP's as high as 68-69f. GFS Lamp data has DP's up to 69 degrees into NE and IA later today. It seems reasonable to expect 68-70 dewpoints this afternoon but 70+ dewpoints seems like a slight stretch. We should be seeing some pretty intense thermodynamic conditions nonetheless.

Be safe everyone and lets hope that no one does anything stupid.

Surface obs have been tracking very close to the way the RUC is forecasting the build in dewpoints today. Check out the latest hourly td observations (2:00pm CDT):

Concordia 71
Hebron 72
Hastings 69
Kearney 70
York 70
Grand Island 69

Lee surface low deepending in E Central CO now. At the current hour, I like a target from Smith Center, KS to Red Cloud, NE -perhaps setting up somewhere along U.S. 281 in that general vicinity.

Good luck to all chasing. If anyone needs any nowcast help today, I'll be available; just PM me.