07/09/09 FCST: MN/IA/WI/MI

[Jeremy Den Hartog]

Its looking like Thursday may be a decent day for chasing here in the northern plains. Forecast models are predicting dew points of higher then 70 and shear is forecast to be 60+ knots giving the potential for supercells in the area. I will be out chasing this day - hopefully things can come together

**Mods** please change the title of this thread to '07/09/09 FCST: MN/IA/WI/MI'...that will teach me to copy and paste

 

[Jeremy Den Hartog]

Thursday continues to look like a decent chase day...

The SPC is forecasting supercells in southeast MN and west central WI...and maybe Northeast Iowa. My initial target is from a Owatonna, MN to Rochester, MN line. Anyone else who happens to be out and about in this area keep in mind the closer you get to the Minnesota/Wisconsin border - the worse the chase terrain is with lots of trees and hills. This is also the case in Wisconsin as well. Personally I'm hoping to stay west of this area along Highway 14...

 

[Jeremy Den Hartog]

Of course after I made my last post, the SPC went updated things ... (sorry - I'm still learning how to forecast so I rely on the SPC for forecasts for the time being). Its looking like the Fort Dodge, IA area might be a decent play as well as they are now forecasting more action in Iowa then they initially were...obviously will have to check out things closer between now and when I head out tomorrow

 

[Jeremy Den Hartog]

SPC has pulled the severe threat back into Nebraska and western Iowa, with a small 5% tornado chance over eastern Nebraska.

Yep they sure did...oh well. There is still a slight chance of severe weather over the region I plan on targeting (northwest and north central Iowa). I'm hoping that as the day goes on they will shift the higher tornado threat a little further north and east - but maybe that is wishful thinking I suppose . I just hope this thread doesn't confuse alot of people since it still has the 'NOW' in the title instead of 'FCST'...

 

[Mike Hollingshead]

Probably end up a fairly obvious target later where this outflow boundary intersects the stalling cold front. Think the nice supercell potential is going to be quite high later near/nw of Norfolk.

0z OFK

Turn a storm right on an OFB with that and I think things happen. 5000 cape with 80 knots upstairs, say it ain't so. Strong cap with a slowing cold front may help keep things sort of isolated at initiation, at least I hope. Nice timing for the ofb too, let it bake a bit today. Just hope it's not all washed out and can be defined. Then again may not matter with models showing backed sfc winds here anyway.

 

[Jeremy Den Hartog]

I'm starting to like southwest Minnesota and southeast South Dakota more and more (dews of 70+ and clear skys right now). I'd like to target eastern Nebraska but thats to far since I'm not going to be able to leave until 1 PM local time...that gives me about an hour to set at least a general target and to watch things

 

[Chad Cowan]

I'm with H; eastern NE is the place to be today. I'm a little concerned about the LCL heights being in the 1400m neighborhood so it could turn out to be a structure day. Or, if initiation holds off until later in the day, it could be a magic-hour tornado fest as the bases lower and the low-level shear cranks up. I'm leaving for Omaha in the next hour and will likely end up around the Columbus area.

I performed some major surgery on my laptop last night and brought it back from the dead so my stream will be up today. Is it bad that I have two screws left over after putting it back together?

 

[Ryan Pfannkuch]

I'll start out by admitting that work obligations will keep me from chasing today, so maybe there could be a hint of bias in my thinking Nonetheless, I really have some doubts regarding the likelihood of eastern NE initiation, at least before dark. Current RUC-mesoanalysis places some pretty healthy 11-13C 700mb temps across this area, and this doesn't look to be improving much anytime soon. The better combination of a more breakable cap (proxied by 9-10C at 700mb), along with stronger 500mb flow (40+ kts) seems to be juxtaposed across southwest/south central MN and possibly adjacent portions of far northern IA. Of course, airmass recovery from the departing MCS is gonna take awhile. Maybe I'll end up eating my words on this one, but despite the myriad boundaries in place across eastern NE, this cap looks to be fairly formidable.

 

[Chris Hovanic]

Currently 35 miles outside of Omaha along I-29 and headed to Columbus, NE. OFB/cold front intersection should set up between Columbus and Norfolk, with a nice surface heating axis notching northward into that area as well. Weak mid-level shortwave also moves into central Nebraska around 0z, and it seems that initiation would be most probable across the aforementioned areas. Warm mid-level temperatures are a concern as always this time of year, but large MLCAPE values and substantial deep-layer shear should support well-organized supercells, provided thunderstorms do indeed develop. Very large hail would seem to be the main threat, but perhaps an isolated tornado or two, especially for storms that can interact with eastern sections of the OFB, in closer proximity to 25-30 kt LLJ axis and associated stronger low-level shear.