5/23/08 FCST: NE, KS

[Bill Schintler]

Chase Target for Friday, May 23

Chase target:
Utica, KS (39 miles northeast of Garden City).

Timing and storm mode:
Storms should initiate at 4 PM CDT. A full spectrum of severe weather, including tornadoes, is likely.

Synopsis:
The WRN CONUS ULVL low will continue to expand slowly while retrograding slightly over the next 48 hours. This in turn will maintain a SRLY flow over the high-plains at all levels along with a continuing moisture feed and unsettled WX as disturbances rotate along the ERN periphery of the low. The WRF, GFS, and UKMET are over forecasting SFC moisture by a few degrees, with obvious QPF implications. Latest MDLs also shift optimum parameters further S, probably in response to both a delay in the EWRD advance of the ULVL system, we well as outflow from ongoing convection.

Discussion:
Another day of active WX is in store, with a synoptic setup similar to that of today in that the DL will again be active late in the period; however the best combination of shear, instability, and LCLs will again exist along and N of the WF. Storm motion will again be towards the N or even slightly to the NW at 40kts and nearly perpendicular to the orientation of the WF. ST cloud cover will be prevalent over most of KS and NEB during the morning, with clearing taking place S and W of Colby, KS 18-20Z and expanding to the N while allowing for differential heating across the WF. A DL will mix E during the afternoon, reaching a Goodland/Colby/Dodge City line by 20Z. Meanwhile, the WF will remain largely stationary along I-70 throughout the period, with a slight NWRD retreat noted in WRN KS in response to slow NEWRD movement of the low in NERN CO. Convection should initiate near the triple point in a zone of up sloping LLVL flow, with convective development further SWRD along the DL into SRN KS not occurring until after 01Z when stronger assent overspreads the area while the mid-levels cool.

Moderate subsidence should persist within the right exit region of a 125kt H25 speed max, which should serve to hold off convection until later in the day as well as limiting SWRD storm development along the DL until early evening. Associated with this will be a compact 60kt H7 streak, resulting in enhanced shear in KS N of I-70 through 02Z. Large directional shear in the lowest 3km AGL will exist N of the WF as a SRLY 40kt LLJ surges over 20kt strongly backed SFC flow. A wedge of strong instability with MLCAPEs to 3000J/kg will nose from NWRN NEB E of the DL. This will taper to a narrow axis near the target as the DL overtakes the WF, however sufficient instability will exist NE of the WF for storms crossing that boundary to continue to enjoy ingestion of nearly SFC-based parcels in an environment characterized by large SRHs.

- bill
10:40 PM CDT, 05/22/08

 

[Mark Farnik]

It looks very probable that this afternoon and evening will bear witness to a prolific tornado outbreak across the central High Plains. The 1300 UTC SPC Day 1 has a Moderate Risk area over southwestern NE/northwestern KS/extreme northeastern CO, with a hatched tornado area depicted from extreme southeastern WY through the NE Panhandle/far northeastern CO and into southwestern NE and northwestern KS. The outlook mentions a potential upgrade to High Risk once the fine mesocale details in regards to this morning's convection, the resultant outflow boundaries and the capping inversion are resolved.
This morning's Denver, Goodland and North Platte AFD's are extremely strongly worded, in particular highlighting and underscoring the possibility of strong, long track tornadoes across parts of their CWA's this afternoon and evening as the surface low intensifies over eastern Colorado and the triple point noses into the NE/KS/CO border area.
Today looks to potentially be an even bigger day than yesterday, and storm motions are going to be 5-10 mph slower ( 35 to 45 mph as opposed to 45 to 55 mph) and in a much more favorable north/northeasterly direction. With any luck, supercellular mode should be classic (I think it would be fair to say everybody will tear their hair out in copious amounts if we have another day of HP beasts with rain wrapped tornadoes like we did yesterday...)
This morning's widespread convection across northwestern KS and southwestern NE and the resultant cloud cover they will leave in their wake could be the fly in the otherwise amazing ointment, but the SPC, as well as the local WFO's, seem confident that the activity will move out of the area later this morning and the resulting cloud cover will burn off by late morning to early afternoon and we will see more than adequate surface heating to reach convective temperatures. At the moment, myself, Jared Farrer, Terrence Cook and Derek Weston are holed up at the Budget Host in WaKeeney (which sustained a direct hit from an
EF-1 tornado last night about a half hour before we checked in, ironically enough) and probably aren't going anywhere anytime soon, seeing as that we are smack in the middle of the Moderate Risk area. Later this morning or early this afternoon we will probably make a move north and west, likely towards the Colby/Oberlin area in preparation to play storms firing off the dryline and near the triple point.
Good luck to everyone today, and be safe.

 

[Tim Marshall]

TARGET: OAKLEY, KS TIME OF DEPARTURE FROM SALINA, KS: 10:30 AM - Round 2 of tornadofest should occur today. Since not much as changed in the upper air from yesterday, I expect more race chasing today -but perhaps a tad bit farther west near the KS/CO border. Overnight convection has strengthened the backed surface winds across I-70, but has left a cool boundary in its wake. Still, I feel that storms will re-fire in western KS later today near GCK and race northward into SW NE spinning like crazy when they sample those easterly winds. Hopefully, the rain last night has dampened those dusty (but well graded) country back roads in KS. TM

 

[Matthew Fischer]

Good morning chaser fans, we (Adam Lucio and I) are currently heading to McCook, Ne. We belive that is would be a good area to sit and wait for this crapvection to die down and maybe let the sun praise us and give us the convective temperatures and nice classic supercells and not the HPs that every one chased yesterday. I'm glad i went with my gut feeling saying this was going to a moderate, with now wording for a high risk. Great way to start my 2 week vacation! We are still 3 to 4 hours from McCook. Not to sure yet. Damn crapvection and trucks slowing us down. Basically thinking is the upslope along with shortwave coming through. Plus the 50 degree dews help too. Basically going to play the waiting game and see what happens. Now everyone be safe and watch out for the fellow chaser drooling at the tornado and not really paying attention till the large hail stone hits his windshield!

 

[Eric Treece]

Currently sitting in McCook.........awoke to hail beating on the windows of the motel. First thing that entered my mind was "oh boy........crapvection going to screw up the day." However looking at the latest satellite image, Eastern CO looks pretty clear...........hopefully the garbage here will move out and let the clearing skies come east and warm things up. With all the rain in yesterdays storms I would be careful on those good old back roads. Back to the forecast..........I love the dew pt bulge, very similar to yesterday as well on the 00 NAM. Also, the Davies tornado mask is insane in NE/CO/KS border for 00Z. Also want to give a kudos to Bill Schintler for nailing the Hoxie target yesterday. Caught 2 tornados within 5 Miles of Hoxie. I think we are going to stay put in McCook here for a little while and reposition when I can fine tune things a little later.

 

[J.B. Dixon]

Currently in North Platte this morning, anticipating heading south and east towards an area bounded by Colby to McCook to Phillipsburg to Wakeeney back to Colby. We should get surface heating starting by early afternoon, priming the pump once again. When in doubt, find a boundary today.

Reminder.....those dusty back roads yesterday are SOUP today. Choose your routes wisely!! Delorme is notorious for making dogs--t roads look great on a map.

Good luck!! Stay safe!!

 

[Michael O'Keeffe]

Taking a look at the RUC and current spc mesoanaylsis I think just south of I70 will once again be a better play with everything moving north with time. Current temps south of I70 are in the low-middle 70s with 2000-3000j/kg present already with clearing skies. If the RUC is correct bringing in a whopping 5000-6000j/kg and 70+F tds (GBD td 68F as of 9:45am) we could see some nasty cells south of I70, also north of I70 the RUC is showing temps barely reaching the 70s which is concerning, but I think that may be underdone, but based on what I've seen the convection on-going in Nebraska will supress the WF from moving much north of I70. We may head down towards Scott City-Ness City line by early afternoon.

Check out those CAPE values.

 

[Jeff Snyder]

I expect a high risk to be issued on the 1630z, as today looks about as good as it gets for violent tornadoes in the Plains. Both the 12z RUC and 12z NAM indicate that extreme instability will develop east of the dryline this afternoon as rich Gulf moisture has spread farther W and N than it had yesterday (e.g. 66F Td in GCK, 66F TD in Slapout OK, 66F Td in Perryton TX, etc). It also looks like the 500mb jet axis be a tad farther eastward as well, with 50-70kt deep-layer shear progged across and east of the dryline by 00z. ESE to SE sfc winds veer to SSW at 500mb and increase nicely, with the 12z RUC forecast >250 m2/s2 0-1km SRH across western KS and norhwestern OK. In all honesty, I can't really find anything to dislike about this setup (minus the desire for storm motion to be a bit more easterly, and a bit slower). The dryline SHOULD be much more productive today than it was yesterday (we all but busted in SW KS yesterday -- couldn't make it farther N to the warm front in time). Anywhere E of the dryline between I40 and I70 looks primed, IMO. We're currently in GBD after spending the night, with thoughts last night being to play the "rinse and repeat" setup in NW KS. However, the elevation convection that keeps developing N of I70 may lead to a more significant theta-e boundary (i.e. not-gonna-budge cold pool) N of I70. If the stratus don't break up and insolation doesn't increase there, I'm not sure how confident I am in seeing a repeat of yesterday for areas more than a county or two N of I70.

 

[Brett Adair]

MCD issued conerning the expansion NW of the MDT risk already. They are obviously thinking that RUC data is being underdone. I personally think that today will be a repeat maybe *Slightly* east of the areas hit yesterday by a county or so given the current indications. Dryline retrogression overnight will put the same areas under the gun today with a more favorable H3 pattern overhead for more persistent/long lived tornadoes today, IMO. The Theta-E axis that intersects with the dryline/warm front will likely be the breeding ground for a very strong tornado this afernoon. Ness City looks to be a good spot with the parameters coming together. 20z will almost certainly go high risk.

 

[Mike Hollingshead]

If the wf doesn't wind up with too much rain cooled air along it, I don't think today will be much different than yesterday(btw, north of I70/wf won hands down yesterday...imo...not that I saw any of it).

Once again the nam wants to veer 500s a little more than is likely to happen. I think they'll be 100% southerly once again. I'd expect the dl to initiate the storms like yesterday, then again they go nuts just north of the wf. The one thing that makes me wonder a little more about south of the wf is the better dews today to the dl. The storms were rather wound up south of the front, but their bases were just too high(mostly).

Yesterday killed me by not being more willing to play north of the front. It'd be annoying to lose today by playing north of it. Going to be a hard choice for me, if the bl is a little cooler north of it(it may not be) and the juice is a little better against the dl.

I'm probably leaning towards 55% odds of closer to the dl staying south of the warm front and 45% catching storms north of the wf.

Good luck to all.

 

[Mikey Gribble]

My thinking is pretty close to Michael's. I like the idea of getting on storms that fire in the DDC area and riding them North to I70 and a little North of there. If possible I will stair step down the storms again like we did yesterday, abandoning them after they get a county north of I70. Of course we missed a wedge doing that yesterday, so maybe it wasn't so smart lol.
It is the same game as yesterday and the compromise between CAPE and shear has to be made. The better quality tornadoes yesterday were in the higher SRH lower CAPE areas, but I still can't bring myself to target that area. The extreme instability being shown by the RUC reaching up to I70 looks good to me. I basically think the DDC to Hays area will get raked today, if storms can stay discrete. I think a lot of the tornado potential was lost yesterday because of the convective mode. It was pretty sloppy out there, but I think today may be a bit better. I also really like the KS-OK border area, but I think this area further north has a slight edge, so that is what I will go with. 10km SR winds are slightly better today so hopefully storms will tend more towards the classic variety instead of the HP beasts we dealt with yesterday.
FYI I am still just now getting started on my forecasting so I may tweak it one way or another.

 

[Mike Peregrine]

I will also be opting for south of I-70 later this afternoon, anywhere from Ness City to Wakeeney. While my confidence remains high of severity north of I-70 and even north of the Nebraska line, I just want to get started well south of any rain-cooled air like I'm seeing out there right now. Hopefully that mess gets pushed out quick so more instability can develop to the north. I'm actually working this morning and can't leave until after lunch, so it's anybody's guess if I can actually make it past Hays before the action gets started. I'll be streaming all afternoon/evening.

 

[Paul Knightley]

Ness City to Dighton may well be our starting point - don't want to get on the early dryline stuff too quickly (if of course it fires) - I like the idea of storms forming on the dryline a bit further east by 5-6pm CDT, and then following them to the front. We'll remain in Hays for the time being, keeping an eye on everything.

 

[Van DeWald]

One thing to think of, since storms may be firing in a similar area, many of the side roads are already trashed from the heavy rains yesterday. I know some of the dirt roads I was on yesterday were absolutely horrible and a couple I ultimately regretted going through, although no choice once you're in it.

 

[Jonathan Whitehead]

Well Im a bit surprised SPC didnt go HIGH. Im a very conservative guy when it comes to MDT and High risks. But everything ive seen points to it. Just take one look at sfc dews, visible satellite, and the NM VAD wind profilers, they are insane with shear. I think the reason for the MDT risk is due to the isolated nature of convection. The area that I speak of is the southern end of the MDT risk, basically along 400 in Southern KS. I think thats the best place to be, specifically somewhere say around Greensburg.
Might suggest reading ICT morning AFD update, really well done and good explanation of how things will play out, specifically about the dryline making more of an eastward push today.
Well good luck to all those chasing. Wish I could go out today but have to be in the office, but sure things will get interesting around here come 4-5. Will have binoculars ready here in Wichita.