05/21/05: TALK: KS/NE/IA

This is probably my last chase day on the Plains this May, so hopefully it will send me off with another smile on my face. NAM is bringing some really good prospects for SAT, especially across NE KS/SE NE. We'll have rocking instability with >4500J/KG SBCAPE, with very strong vertical shear that will be very sufficiant for supercells and tornadoes...

It's still 36HRS out, but decided to make a TALK thread...
As of right now I'm targeting NE Kansas. The cap can be a chaser's best friend and worst enemy. I like the cap in Kansas because it will keep storms isolated if they develop, but it could also break a good kansas day. With the weaker cap further north we could see too many storms develop. NE Kansas is my best bet. Head there early in the day and see what happens. :)
Well...looks like many things are pointing twoards NERN KS or SERN NE on saturday. But, just as you guys mentioned the extent of capping across Kansas is yet unknown...with many people thinking that the cap will not break farther south than the NE/KS border...hopefully we can get a little more moisture up here with DP's now hovering in the mid 50's. The OAX AFD mentions that DP's may even approach 70 with CAPEs going over 3000 across much of the area. And bulk shear values around 50 kts.
My only concern is that things will go to lines fairly early...but we will see...

I am by no means a good forcaster...lol

Preliminary Target- West of Lincoln, NE
We have so many things in place, but I myself am worried about the CAP. NAM doesn't show the CAP breaking until 0Z, which means tomorrow could be May 10th II, which is fine with me... Just as long as it does BREAK!
I took a quick look at some of the forecast models this morning, and thought I'd offer my 2 cents on what I see based solely on model guidance. Consensus is for an MCS to track from the Dakotas down the Mo. River valley overnight - and die out late morning around the vicinity of southern IA. Strong shortwave ridging during the day will reinforce the capping inversion across the northern plains - and potentially widespread cloudiness across much of eastern NE during the day. By late evening, convection redevelops over northeast KS on the nose of the LLJ and tracks southward across eastern KS. Wind fields are relatively modest - but show considerable veering with height - which might be tolerable given the expected degre of instability. Deep layer shear looks great - as is often true for northwest flow events. But - with the expected strength of the capping inversion and apparent lack of strong convergence - it might be extremely difficult to get convection during daylight hours. The front is held up well north of where evening convection initiates - but low-level wind fields near the front look horrible. Really need for convection to develop well to the southeast - ala residual outflow boundary if it can press down into this region. NAM provides little evidence of this happening - but chasers should rejoice if a strong MCS is indeed ongoing in se NE -sw IA tomorrow morning. Since it is imposible to know if or where this boundary will set up - I'd probably target the optimal place for it to end up - around Topeka KS.

Well... I'm going to give this talk a shot...

A lot of people are liking the capped areas of KS/NE and parts of southern IA. This is because the skies will be clear, instability high, but the cap will also be tough to break. But, if it does like any other severe outbreak, it will break hard! So, current thinking for those liking the southern option should target an area around KS/NE border.. Storms may not break until nightfall there though, so it is a difficult decision.

As for myself, I won't be chasing anyway due to graduation... But, the northern option will include the areas of NE/IA that should see the first initiation of convection in the afternoon as the front begins to move through. Right now, the target area in this area is going to be the Storm Lake or Carroll/Denison areas. These should be on the front at peak hours, making them good choices.

Right now that models are looking a little off on front positioning... GFS is faster at moving the front though, they have it past the nw IA area by 00z, while the NAM has it right on the SD/MN/IA/NE corners by this time. If the NAM verifies it will turn out better for many chasers in the northern option becuase this gives the air plenty of time to destabilize with capes in the 2500 j/kg range. Looking at Carroll skew-t for 00z, shows great shear (EHI at 2.9/SRH nearly 300), cape at 2000 j/kg, cinh is negative, and LCL height is at a great 690 meters...
Looking at the 12Z NAM run, I'm pretty much stuck with the same target -- perhaps a bit north, to just north of the KS/NE border in SE Nebraska. I could probably just hang around in Lincoln and wait for them to pop. ;) If the NAM is to be believed, the cap erodes at some time just after 21Z or so with big, sloppy bucketfuls of CAPE. (Check out the Skew-Ts for KLNK). LCLs still a bit high as someone else mentioned, but I don't care because I want to chase some storms! :lol: Winds look like they back a bit in this area too on the 850 at the 0Z.

Storm motion should be SE at around 20 to 25kts Saturday. I think I might try to get south and west a bit of Lincoln since this is NW flow. I'm not a big fan of core punching. Man, here's hoping for a nice front-lit tornado at golden hour. ;)
I decided to target Grand Island hours ago. I would like isolated supercells in eastern Kansas but the cap looks to hold strong. With a cape bullseye of more than 5000 over eastern Nebraska and some decent helicities and supercell potential of 90% I think there'll be a chaserfest in eastern Nebraska tommorw. Here's to what might very well be the best day of 2005 so far :D
Well... weve had a few more hours of updates now... moisture is supposed to be arriving tonight with DP's up to as high as 70 mentioned... CAPE is expected to be around 4000 j/kg and fairly decent directional shear looks to be in place... my concerns are that the better upper level support will be farther S in KS... and still everything going into a squall too quickly... it is a coldfront after all...

good luck to all....
What is my biggest concern? Time of initation... But, I guess I'm feeling a bit more confident that the CAP will break by evening (likely BEFORE dusk)...
As of now I would target good ol' Beatrice, NE for initiation and look to drop down to KS/NE border where with the SE traveling storms will encounter better Helecity values. 1km helicity, per eta, looks rather weak except for extreme NE KS and SE NE. 3km helicity looks nice througout the target area. Tomorrow could be good we will see how it unfolds, unfortunatley I will chairborne chasing this one from VA. If anyone needs a nowcaster feel free to PM me and I will give ya my cell number.
my concerns are that the better upper level support will be farther S in KS... and still everything going into a squall too quickly... it is a coldfront after all...

Quite often there are boundaries ahead of a cold front that can and do make the day worthwhile. With overnight convection and a sfc low in the region I imagine we'll have a good boundary to work with. Plus the southern portion of that front doesn't look to be very cold with temps in the upper 80s behind it.



Upper level flow is certainly better the more north you get.

I would expect an almost due south storm movement tomorrow. I hope the sfc winds do not back more than due south as I don't care for too much turning. Something say 150 degrees or less will make me happy.
I'll be leaving Denver for I-80 between Grand Island and York, Nebraska at 6am MDT tomorrow. Will refine my target as the evening and morning progresses; still awaiting final word on the Colorado Crew to see whom will be caravaning out on this marathon chase! Looks good tomorrow!
I will also be leaving tomorrow morning for a target area of Grand Island, Nebraska. Free Wi-Fi at the Bosselman's Travel Center at I-80 and US-281. Activity will develop in Nebraska before it does in Kansas, and the chasing terrain near Grand Island is absolutely wonderful, would love to chase the area again! Grand Island has been good to be 2 Saturday's ago, and hopefully it will do a good job again!
hopefully you guys get a repeat of the crazy stack of plates that many had photographed recently near Grand Island. Good luck to all and I hope to see some of you out there!
Depending on the next NAM run, we might position ourselves near or around Nebraska City AGAIN. To shoot in any direction needed. Great WIFI at truckstop there FYI. Just need to stay out of KC metro area mess. Let's hope things are west of the river and not in atchison and doniphan counties, due to their poor road networks.
As of current data my target is Manhattan, KS. Everything I like is there - instability, moisture, lift. And the added bonus is the perfect cap. We might be waiting til 7pm for initiation, but it will happen (if current data verifies). I can say with confidence this has been the easiest forecast of the year for me thus far.
I am not sure than Kansas has enough of a "sure thing" going for it to chase there. Discrete cells possible? Yeah... but I think that storms will stay fairly discrete further north as well. You will also have access to better instability and lower LCLs, which is always good.
I would say that SW of Omaha just a little bit would be a nice place to start... maybe near Lincoln. It would be nice for the big storms to form a bit closer to Iowa so they can be under lower LCLs and higher shear, but I think it should turn out at least fairly decent in eastern Nebraska.
I am going to hold off until tomorrow morning to decide where to go. I am sure if I named a city now it would change anyways. I am leaning towards setting up near the Kansas/Nebraska border. I will stop in Salina or Topeka for data and pick a target from there. I am thinking it will be better to be too far South than too far North given storm motion. Good luck to everyone tomorrow.
I have shifted my target east to the triangle of the Omaha/Lincoln/Nebraska City areas. Best combination of 0-3km helicity, lower LCL's, SBCAPE/MLCAPE, weaker CAP, and earliest storm initiation make the area prime for severe storm development.

Looks like Holly and I will see some of you over at the Sapp Bros. truck stop over off of I-29.