6/4/2010 FCST: IA/IL/MI/MO

[Robert Dewey]

Not a good looking setup this morning... Clouds coming in, rain right behind them. Back to the "embedded EF0 and no chase" mode for now.

Fortunately, the eastern side of the state is still looking good in terms of sunshine. VIS satellite shows only thin cirrus, which is breaking up across the western side of the state. Mid-upper 60's Tds are also present just south of the border. However; even with mostly sunny skies, we've only managed to make it to 71F so far. We'll need to climb another 8-10F... and I'm not sure if that's possible.

 

[Tim Balassie]

Well, OK. Uncle …

Looking at WRF, GFS and RUC this morning can’t see anything to get excited about for IL. Again, upper level support way east by 0z. Altho T and Td look good (I wonder if the RUC is overdoing the Td) winds look unidirectional up to 85h. Winds look a little weak above, and the Ts are kind of high.

The one glimmer I saw was WC IL mid-afternoon. There the surface convergence extends from NE MO NEWD into IL, so I like Collin’s, Andrew’s and Randall’s target on this. If we can get a little more CAPE and perhaps Andrew’s OFB there may be a photographable storm in the mix.

It’ll be interesting to see how this evolves.

Tim
KC9JIB

 

[Rob Wadsworth]

Please correct my forecast skills at will - noob here...

With little shear, little/no surface heating, and few other components going for the IL discussion, it looks to be linear storms producing a fair amount of rain, some small hail, and lightning. Good for the crops but not for a chase. Right or wrong?

However, the SPC is giving the SE NE/SW IA I-29 corridor the thumbs up for some decent hail. Maybe if a little more shear could kick in before the 21z hour - maybe even an isolated tornado or two - perhaps?
>hopes<

TWC has given a tor/con rating of 5 for IL and 2 for the IA/NE/KS/MO corner. It seems that all forecasts from TWC and the SPC have been off for a few days.

One more thing. I cannot understand why the SPC hasn't given any indication of the NE CO/NW KS/SW NE region. if that low pressure pulls in tight - it looks like a quasi-classic dryline setup - IMO. 300mb westerly flow is in place, and 850mb are from the south at present. CAPE and dewpoints, as well as some shear and helicity are already present in the RUC and may organize there as well. Thoughts?

 

[ericjkelly]

Sitting in Fort Wayne trying to make a decision on which way to go! My initial thoughts were SW Michigan but doesn't seem like enough instability to get things going. We have had clear sky's here all morning, so I am hoping things may pop a little closer to home. CAPE still looks pretty weak, so it may be a bust day.

 

[Matt Hunt]

I won't be traveling this far, but I'd have to agree with Andrew's target of Ottumwa, IA. Clouds are clearing in that area, and as far as I've seen with the models, this is the consistent area of good CAPE and sufficient shear. I'm a noob like Rob, however, so take my opinion for what it's worth, lol! My hopes are that something fires here in Central Indiana and I can get a quick local chase in. Can't afford the gas for my gas guzzling truck to go very far! Tomorrow looks better around here, but I'll be babysitting my niece all day.

 

[rdale]

Sitting in Fort Wayne trying to make a decision on which way to go! My initial thoughts were SW Michigan

No way... Enjoy the clear skies more to your south and east. Less tor potential, but better storm potential.

 

[Robert Dewey]

Typical MI trade-off. If the warm-front comes through, we'll bump up instability at the cost of sfc winds veering to the S/SW (lower helicities). Satellite shows a Cu field developing over SE MI, which is a good sign.

 

[Jason Persoff]

So...yesterday was supposed to be my last day out and today a travel day. Due to sold out motels throughout NC NE, I ended up exhausted in Kearney, NE, planning on cruising I-80 back to DEN for my flight back to JAX tomorrow night. As has been a very recurrent theme this season, when I wake up the synoptic scale has changed considerably and it's as if nothing I assumed the day before is still valid. Fine by me .

So it appears I'm back in chase mode and I'm delighted.

Current mesoanalysis shows the sfc winds to be a bit of mess with wind barbs showing about 100 degrees of change from the NW to the SW along I-80. That said, pooling of exceptionally high (65+) Tds along all of C NE and C KS, but T/Td spreads also remain large (which still could lead to some gorgeous strux). SAT shows nothing but clear skies and occasional thin cirrus. Insolation is pretty incredible with exceptionally warm H7 temps, and CIN is likewise very high. Underneath it all, though, is exceptional CAPE exceeding 4000 J/kg on the KS/NE border.

H5 winds out of the WSW are around 40kt along I-80. While 850mb winds are currently out of the SW, RUC suggests the LLJ will gradually shift winds out of the SSW over most of the region by 00z.

SRH looks to remain best N of I-80 whereas the best instability will be south of there. Balancing it all presents a potential target for me...well...right here in Kearney, NE, and maybe drifting depending on SAT changes as the day unfolds.

 

[Andrew Pritchard]

Still liking the odds of a supercell possibly producing a couple tornadoes in NW Illinois this afternoon. Currently sitting in Monmouth eating lunch, under a pretty thick cloud cover. However, to the west skies are clear in southeast and eastern Iowa with a cu field starting to fill in already. Sbcape values are already AOA 3000 j/kg in this area just ahead of the approaching boundary and shortwave. This setup might not grab your eyes as much as a traditional SW flow scenario, but I think this region bares close attention thru the evening. I expect severe thunderstorms to develop from around the Quad Cities southwest into southern Iowa by late afternoon. My attention will be on the north and east portion of this cluster, as I think the chances of a supercell latching this boundary and slowly riding it southeastward, modifying it's surrounding environment and producing a couple tornadoes seem quite decent.

I'll likely sit here in Monmouth for now, as I've got 67 for a N-S option, and 34 as an E-W. My main concern is getting on storms early, as a transition to HP mode seems a good bet, as well as the eventual consolidation into a larger storm cluster / MCS.

 

[Robert Dewey]

The threat is looking pretty weak across MI. Tds haven't really bumped up into the mid-60's as advertised, although temps are approaching 80F in the south. SPC mesoanalysis does show sfc-based instability advecting northward. I'm also noticing some cells popping up over NE IL and Lake MI, along a ribbon of moisture at 700mb and some weak sfc moisture convergence.

I wouldn't totally discount the threat across MI, but it certainly isn't all that great.

 

[John Vandehei]

I've been getting pessimistic about anything happening in Michigan, with the warm front taking its time getting up here. It appears that the warm front is right along or maybe just north of I-80 right now. So there might be some hope for the southern tier of counties, mainly south of I-94. I have to drive to Milwaukee this evening, so maybe I'll catch some the activity that's firing up over Illinois. Of course, driving through the Chicago Metro area is not exactly ideal for storm chasing.

 

[Ryan McGinnis]

Oddly enough, the HRRR keeps wanting to develop something tonight in western Nebraska near North Platte:

http://bit.ly/d3K3ic

Not sure what to make of that.