6/5/06 FCST: MN / SD / IA / NE / KS / OK

SW rounding the longwave ridge will move southeastward through portions of eastern NE and eastern KS, down the Missouri River valley. MesoETA is forecasting the presence of low level instabilities and moderate 3 km SRH. Investigating profiles around GRI, HSI, and OFK shows the presence of a capping inversion out to 00z, nevertheless the MesoETA model breaks out convection along a line extending from south central NE on up into northeast NE. GFS has convection breaking out in SE SD and moving southeastward.

Just opening this for discussion ... maybe some hope for the season. Awaiting thoughts from SPC at 1730z.
 
The 12z NAM this morning is a big surprise to me. I am likely going to be hitting the road to KS this afternoon.

Target attm: Colby or a bit NE of Colby, maybe scratching into NE.

The parameters look pretty impressive with nearly all components decent for an interesting day. Td's in 60's (E of Colby, but backing sfc winds are progged to continue to 06z, and SW storm motion would have storms riding the front with ever-better fuel after initiation), CAPE 2-3000, 0-3km helicity 100-150-ish @ 00z, and dramatically increasing to 06z, good convergence, LLJ...

Upper level support could be a tad better, especially @ 700mb, but it's there. 700 temps a bit warm, too, but not terrible.

Bob
 
Looking like maybe a big nw flow day in NE tomorrow. Just glancing at the prog's makes me see several flying eagles on radar dropping across the state. Jinx.

http://www.wxcaster.com/modelskewt.php3?mo...&STATIONID=khsi

The cap looks to be gone by 21z through most of central NE. This would be the same time a 40-50 knot mid-level jet is over the whole warm sector. Like nearly every chase this year poor moisture might be a concern, but it certainly looks better than it has been. I would expect at least low 60s for the region on this one. They don't have that far to go. It'd be nice to get some pooling and squeeze out a few mid-60s for this. Low level flow doesn't look terribly strong but at least there is some there.

I have a feeling I'm going to hate figuring out a target on this one. Will probably target Grand Island early and go from there. I'd certainly want to error to the south...and be on a good east west option.

Good luck to everyone. Maybe this will mark the turning point.
 
well, i suppose it's all relative in this miserable season, but im a little surprised by the strong wording in the day2 outlook. looks like another blah msc to me. The only thing weaker than the winds (the one flag in NE sits over a whole lot of nothin) are the weak pressure falls. hope im wrong tho.
 
Though sfc winds may be a bit weak, you haven't forgotten that if storm motion is S or SSW, the storm relative inflow will be somewhat enhanced, right?

Have you guys seen this?:

http://weather.cod.edu/forecast/ETA/SP/etaSP_700_vvel_42.gif

Are you sure about NE as a target? Is the NAM nuts?

Bob
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Hi Bob: well yeah the NAM IS nuts, but i wouldn't let its VV field from its model-produced mcs influence a chase decision. dont get me wrong tho--id chase if i were off from work!
As for the storm relative flow, well yeah im sure the mcs will have ok storm relative flow, although weak+weak still = weak.
 
This mornings NAM looked a lot like last weeks event across Nebraska with strong 700mb VV from north to south likely to favor a linear convective mode once again. This week, however, looks a bit more promising over extreme northern Kansas and south central Nebraska, where better moisture, slightly stronger cap, less forcing and strong shear should promote discrete storms. Best shear looks to be juxtaposed with left front quadrant of 50knt upper jet with NAM 6km shear vectors in this region, extending from Central City, NE to Smith Center, KS forecast to be 60 to 70 knots, with CAPE values of 2500 to 4000 J/KG. Looks like my ultimate target for tomorrow will again be Smith Center, KS with a temporary data stop in Hastings. My hope is to intercept an active, SW moving, tail end charlie.
 
Talk about lucky, I came out from Denver today to retrieve my van from Topeka. I head back west tomorrow which will take me straight into tomorrow's potential action. Always nice to chase my way home for a change!

Rather surprised to see such a change in the forecast for tomorrow. Shear, instability, it all looks good tomorrow. I haven't had a chance to be specific in my target for tomorrow, but I'm eyeballing an area along I-70 north to the KS/NE border someplace between Hays and Wakeeney (northward). Will fine tune things later tonight and tomorrow to figure out what route to take home.

In any case, tomorrow's trip back west has turned to a potential chase day. Hope the van's new transmission is ready for some action.
 
I have to say that I smell a rat with the big changes in the NAM over 24 hours, and the substantial variation in the SPC forecast. However, I do like how the 00UTC NAM is consistent with the 00UTC RUC through the first 12 hours, keeps good moisture in the NC KS, SC Nebraska areas, and has adequate shear for some supercellular development.

The primary difference between tomorrow and last week's Nebraska event is that the 500 winds are stronger, and the differences in direction between lower and upper level winds are really improving the hodographs. Low level shear even looks to be good for a tor or two if we can keep the moisture from mixing out again. One thing that really worries me in this sense is that the RUC is indicating SW winds at 850 hPa at 1200 UTC Monday, bringing in much drier air from west Texas. After several non events due simply to mixing out of the moisture base, I am more than leary.

An early chase target for myself would be just west and a hair north of Grand Island for the initial development.
 
Chase target:
Chambers, NE (15 miles south of O’Neill).

Timing:
Renewed convection will take place at 4 PM CDT, with storms reaching severe limits as early as 5 PM.

Comments:
Supercell storms early in convective evolution, with storms forming a line by early evening. An isolated tornado threat will exist between 5 and 7 PM with any discrete cells.

Discussion:
UA analysis indicates a number of waves embedded within NWRLY flow while numerous MCS’s are in progress throughout the Plains and upper-Midwest. SFC and radar analysis indicates a weak, nearly stationary OFB in the wake of ongoing MCS’s between US-183 and US-281 in NERN NE, and this boundary will provide the focus for enhanced hodograph curvatures by mid-afternoon as a shortwave enters the area and convection fires along a SFC CF/trough.

Ample moisture and instability will be coupled with marginal but adequate share parameters. BL airmass will rapidly recover following clearing over the next few hours as MCS CI shield lifts to the east, and evaporation of recent rainfall allows SFC dewpoints to reach 70 degrees F. Additionally, OAX sounding indicates 150mb deep moist layer therefore both surface-based and mean-layer parcels should be extremely unstable. Despite modest mid-level lapse rates in the 7 C/km range, MLCAPE’s should exceed 4000 J/kg as renewed convection takes place. Regarding shear, 35kt WNWRLY H5 flow over 10 kt SERLY SFC winds should result in (SFC-6km) deep-layer shear to 40 kts. MWP suggests only modest hodograph curvatures, however the aforementioned OFB will result in increased SRH values in the target area, with (SFC-3km) SRH to 200m^2/s^2. A significant negative today will be the linear mode of forcing.

- bill
 
I am liking the SD setup - yeah, I know, I'm prefering the local chase - so sue me. The line is defintiely defined. Things should pop on a Huron to Mitchell line around 3-4 pm. There's ample instability, anvil level winds are 40-50 knots, dewpoints in the high 60's and low 70s according to the GFS (RUC agreeing). Hope things don't explode too quick as they come off. Even so, if it breaks into an MCS, it should make for some beautiful pictures. For some reason the COD GFS images are messed up - don't know what's going on with that. Should be a fun day - good luck for the majority taking the south option - to all the others, I'll see you some where on Highway 14 probably.
 
MODS: Please change title to include Oklahoma

Definately looks like a June 17th 2005 day. Monster MCS to develop in Kansas and truck SSE through the day. Just talked with close friend of mine at NSSL and he says MOD risk likely to be drawn southward into Oklahoma say Hennessy-Stillwater-Tulsa line. Decaying MCS's in NE and OK are resulting in abundunt insolation to raise CAPES to around 3000J/Kg. Unlike 2nd half of spring, shear is progged at 30-45kts SSE and surface winds are SSEly at around 15kts. Dews in mid 60s are hauling north at this time. All ingrediants are there for high end severe thread with damaging winds in the area of 80-100mph. Being a NW flow event, the threat for tornadoes is not particularly high but as always early in MCS infant.

Will be chasing with NEWS9 Stormtracker
Target: Woodward/Alva
 
Anyone know if there will be or has been an OUN 1800 UTC raob? It's not showing up at the COD site.

Nonethless, both DDC and LMN 18 UTC soundings show quite a stout cap. It is probably unlikely to break this during daylight hours, but I'm still watching anyway. Prepare for a raging MCS overnight in OK.
 
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