5/13/09 FCST: IA/IL/MO/OK

[John Farley]

Very thorough discussion from the St. Louis NWS:

http://kamala.cod.edu/mo/latest.fxus63.KLSX.html

This backs up the concept of trying to get on any strong storm near initiation. Easier said than done sometimes, of course. (NOTE: The above link is time-sensitive.)

 

[Adam Lucio]

That 4km really threw me for a loop. I dont think I will nail down a target till I can take a peak at the RUC tomorrow morning. Ill narrow it down to the western half of the state as of now.

I think the precip models are going so linear so soon because theyre having trouble picking up any boundaries...there isnt a really sharp warm front and obviously and outflow boundaries wont be visable till tomorrow afternoon.

Im keeping an eye on the cluster of junk thats in Iowa right now. If that is said morning crapvection than it looks like it would be out of here by 10am and that could gives us a really nice window to destabilize as long as nothing new goes up.

Preliminary target is probably around Springfield, I dont want to commit going too far north or south yet so I will probably stop just shy of there as not to get caught up in metro traffic.

Either way Im looking forward to at least SOME sort of significant severe weather. If it happens to be a raging squall line with big hail and 80+ MPH winds...ill take it but i see a real potential for some monster HP sups should things come together right.

 

[Mike Hollingshead]

Morning convection will likely be related to the stuff in western NE now and more that fires later....behind what is in IA now. 18z NAM showed this pretty well, almost seeming like it would track along the IA/MO border, possibly leaving an OFB e-w through the Hannibal MO area. My best guess is placing me at Hannibal tomorrow early. Any cap is rapidly going bye bye between 1-4pm.

 

[Jim Zandonai]

The main IF is if it can clear out and heat up in time..Especially north. We seem to always have that issue with warm fronts not moving far enough east/north. IF it can it should be fun. There will probably be a few key areas to target in this set up too. I'll be off at 1pm. and we'll see what it look like then. Here in RFD I am probably too far north so more then likely I'll head south along I-39. I-39( if it isnt under construction somehwere) is an excellent main road to use along with 88 and 80. I have a feeling there will be one or more hooks early on ..Good luck.

 

[Tom Shotwell]

It seems that there will be multiple locations for tomorrow. I will still need information tomorrow morning, but I do want to get away from the jet stream. For all of you north, it will be quick, so be ready. I will start out in southeast Mo. and track south.
Good luck to all and be safe.

Tom

 

[Angie Norris]

Based on this morning's WRF, I'm seeing good shear across OK, winds veer quite nicely with a 90 degree differential from the surface (south) to 500mb (west) and nice CAPE across central OK by 0Z in the >3000J/kg range. There is a quite pronounced dryline bulge in the Frederick area at 0Z. On the negative side, it looks like the cap may be an issue again, along with dewpoint depression progged at about 20 degrees so high LCLs.
I'm not calling a specific target right now, but Lawton is a distinct possibility for a starting point. I'll know a bit better after I check things out in the morning.

 

[Jacob Ferden]

I tend to think the only area with true outbreak potential is in central and west central Illinois. All of the parameters seem to be in order, with the sole exception being a less than stout cap. The farther south you move, the less ideal the conditions become, and I can't see anything other than an MCS event south of St. Louis, with the possible exception of a "tail end" sup or two along the I-44 corridor in OK. But I definitely am not very bullish on those prospects.

 

[Mark Sefried]

I think that Mike H. has hit the forecast on the bullseye for tomorrow per tonights 0z NAM with an ofb setting up across eastern Mo into South Central IL. It will be interesting to see what the GFS shows here in a few hours. Looks like mainly an I-70 corridor event shaping up from near Columbia, MO East to Effingham, IL anytime from the early afternoon hours on if you trust the NAM. It looks to be one of those days where it will be very tough to pinpoint an actual target based mainly on the previous nights model runs. It would be very wise to closely look at the mornings data and then adjust accordingly based on the current trends. I will be off work chasing tomorrow so hopefully something happens..

 

[jamesmseitz]

I am getting set for the I-70 play as well. I hope the NAM is right about the morning Convection getting out of the way in time. Tomorrow mornings data will be key but it should at worst be a ok day..... just thinking and looking for the big day. It is all there if everything can Clear out, and then stay from the MCS mode for a few hours

 

[Steven Yezek]

Current thinking for a target area will be Burlington Ia. I have a feeling there will be a mess further north near the triple point with the mess eroding further south. Also thinking that the storms should fire in south eastern Iowa into Mo with them being more supercellular before becoming linear. Once they move into IL, I'm almost wondering if they could become more of a derecho event as they move east into eastern IL and IN?.

Be safe and courteous to everyone out there. Good luck

 

[Andrew Pritchard]

Hope the new NAM is just a one run glitch, or else we're hosed. Blows up a massive mcs / bow echo across the entire "would be" moderate risk area in the early afternoon. This is pretty terrible timing. Earlier in the morning would be fine, and would aid in boundary development but if this thing is sticking around into the afternoon I'd give very little chance at any recovery and decent instability north of Interstate 70.

 

[J West]

Due to other obligations in the AM tomorrow, I am forced to stay north and play the triple point or thereabouts. The good news is I can get south to Rockford, IL area quickly in the afternoon. My concerns mimic everyone's about the northern end either staying dormant or filling in with crapvection early on and shutting the area down completely.

Right now the target area is a 50 mile radius of Rockford, since the road network is good and I can get any direction quickly. GFS seems to favor the cap staying in place until late afternoon, but with days like this up here either nothing happens or it goes all the way. The MKX discussion makes note of an OFB setting up from the morning convection in an east-west line around the IL/WI border, which could be the extra kick needed when the triple point moves into the vicinity.

Storm mode will hopefully start discreet, but like usual the storms will probably congeal within an hour or two of initiation.

 

[Jeff Duda]

My guess is it's a hiccup...or at least I'm hoping so

Granted, I may have to adjust my guess when I see the 00Z GFS run and the 00Z hi-res NMM and ARW runs.

 

[Jesse Risley]

Hope the new NAM is just a one run glitch, or else we're hosed. Blows up a massive mcs / bow echo across the entire "would be" moderate risk area in the early afternoon. This is pretty terrible timing. Earlier in the morning would be fine, and would aid in boundary development but if this thing is sticking around into the afternoon I'd give very little chance at any recovery and decent instability north of Interstate 70.

The one reason to believe that there might be a glitch is a quick review of the simulated radar and SBCAPE parameters between 21z and 00z. The simulated radar reflectivity at 21Z was showing a broad area of precipitation over the western part of the state, but despite the presence of this precipitation, SBCAPE increases to nearly 2000 J/KG in far WC IL by 00Z. I'm not sure how well this will verify if the area experiences any convective activity three hours earlier, which makes me think the simulated reflectivity might be a bit superfluous.

 

[Chris Allington]

If the trend of the 00z NAM continues the Oklahoma target will certainly become the better play. Keep in mind its about 7 hours to each area for me so I am not really geographically biased. Both the 00z NAM and 18z GFS forecast AOA 4,000 j/kg of instability... with mid-upper 60s dews and mid 80s surface temperatures. The mid levels are lacking a bit in OK but surface winds are backed nicely across most of C and N'rn OK and there are some pretty nice looping hodo's in the area W and NW of OKC. If this MCS across IL disappears on the 00z GFS I may open back up to consider a Ern MO and Wrn IL target, but if it continues I would definately prefer a Wrn OK target. Say somewhere around the Kingfisher area for now.