6/15/08 FCST: KS/MO

[Michael O'Keeffe]

Tomorrow looks like a classic mid/late June NW flow event for E Kansas and W Missouri. Though tornadoes don't look like a threat we could see a monsterous hail and significant wind damage event. Shear and instability look favorable for supercells at first with a significant hail threat, but I expect a fairly quick transition to a powerful MCS or derecho with mainly a damaging wind threat. Anyway since it looks close to home and its the weekend we may head out tomorrow and try to get on the storms from the start and maybe get some good structure and/or some big hail!

 

[Bill Schintler]

Chase Target for Sunday, June 15

Chase Target:
Fairview, KS (40 miles W of St. Joseph, MO)

Timing and storm mode:
Elevated convection will approach the area from the NW, and become surface-based through 12 noon. Supercells with tornadoes will be likely early in storm evolution, with a transition into a fast moving, forward propagating MCS by late afternoon. This MCS will race southeast and then south through MO and eastern KS, with the primary severe threat becoming severe winds.

Synopsis:
The Great Lakes ULVL trough will deepen through the period with increasingly NWRLY flow aloft over the upper Midwest. A couple pieces of energy will rotate to the SE within this flow, with a potent 50-60kt H7 S/WV FCST to dive into NWRN MO during the afternoon. At the SFC, a CF will extend from NRN WI SWWRD to low pressure near near DDC by 18Z.

Discussion:
Tonight, an MCS will develop in ERN SD into SWRN MN, and this will track ESE into NERN IA while weakening during the morning hours. A second elevated area of convection should be ongoing in SERN NEB into SWRN IA early in the period at the nose of a veering 40kt LLJ. By early afternoon, instability will rapidly increase with SFC dewpoints rising into the mid-70s as the LLJ advects 16-18C H85 dewpoints over the area. Contributing to the instability will be mid-level lapse rates of nearly 8C/km, with MLCAPEs rising to nearly 5000J/kg. Storms will become SFC-based, with a cold pool becoming established early on. Deep layer shear AOB 60 kts will be coincident with sizable hodograph curvatures, which will support storm organization and rotating updrafts. Later in the period, the forward propagating MCS will turn to the S into the highest H85 theta-E air and into a strengthening SWRLY LLJ and coincident moisture transport bulls-eye.

- bill
9:00 CDT, 06/14/08

 

[Mike Hollingshead]

Jeez, talk about some sick instability tomorrow. Guess that is what mid-70 dews under -12c at 500mb gets a person.

Just south of KC at 21z

6000 uncapped SFC based Cape 1pm Falls City Nebraska


This is quite the precip signal, lol:
http://www.wxcaster2.com/CENTRAL_ETA_1000-500_SLPPRPTHK_24HR.gif
http://www.wxcaster2.com/CENTRAL_ETA_1000-500_SLPPRPTHK_30HR.gif

To me this seems like one of those setups that might be worth it just for the monsterous haboob structure that could happen. May 27, 2001 in eastern KS this time?

NAM doesn't do much with precip in eastern or se NE till at least late morning tomorrow: http://www.rap.ucar.edu/weather/model/eta15hr_sfc_prcp.gif If it can be that way and not get too crazy, I'd sure as hell want to be on initiation, which would appear to be quite early. Hmmm, to skip father's day or not to. Michael, you have it easy! This is going to be too close with too much "ugly storm" potential for me to skip I'm thinking.

 

[Mike Peregrine]

6700 j/kg is going to be interesting alright. Looks like storm motions out of the northwest. Initiation between 12-18z near NE/IA/MO/KS intersection, moving south over Kansas City. We'll definitely be getting some wildness by mid to late afternoon down here. I'm guessing around 5-7:00 pm for KC. This will be the day for a special shot I've been dreaming of. Not thinking of tornadoes really, but there are going to be some mean-looking, scary skies tomorrow. Sounds like fun -

 

[Jason Harris]

Think that IN and MI should be added to this thread. Storms are already moving through IL. Also, a severe thunderstorm watch is expected shortly for N. IN and SW MI. Aside from that, there is already 200 helicity in SW MI and sufficient bulk sheer (up to 50 currently for 0-6km and 60 up to 8km)--effective bulk sheer will continue to improve as those west winds continue, with increasing speeds over the vertical. With plenty of sunshine still expected, CAPE will also be sufficient. Although, the moderate risk from SPC is largely for wind from bowing segments the bulk shear suggests the possibility of long-liveds supercells if any are able to develop. RUC indicates though that the best helicity might be coming in prematurely (now), though there will be some more around 15Z. The lack of widespread favorable helicity suggests there won't be many tornadoes, but an event like last Sunday, which produced two, doesn't seem out of the question at all with imbedded supercells in bowing segments.

Speed shear will clearly be in place with potent upper level jets coming in as the afternoon progresses, but will there be backing winds? Thoughts?

Update: There is now a severe t-storm watch.