The last two runs of the NAM on College of DuPage aren’t working properly and that has drug out my forecasting longer than I hoped. COD is my go to page for forecasting. I look at quite a few other sights, but COD is where I spend the most time looking at model data so the NAM not working properly on there tonight just killed me. I had to take that shit over to Twisterdata and go off the nation wide view, which sucks. That’s the kind of thing you can list under first world problems lol.
Anyway, I didn’t spend much time forecasting because I just can’t get into it when I’m not excited about a setup. I am leaning towards chasing tomorrow. Not because I like the tornado potential (the tornado threat tomorrow is weak sister), but because I wouldn’t mind giving the equipment one more test run now that it’s hopefully fixed and because I like helping with coverage for KWCH. Not a chance in hell I’m going all the way up into Nebraska for a setup like this so take that option off the table and what you’re left with is two areas of potential action (plus I think convection in Nebraska along the cold front will go linear rather quickly). The first and better setup will likely be north central Kansas. I’m not sure exactly where the triple point will be (thanks in part to the wide-ass view Twisterdata feels the need to give you), but it should be some place over north central Kansas or south central Nebraska. The initiating boundary will be a NE-SW cold front pushing southeast over Nebraska and a dryline that runs north-south from the triple point. The NAM wants to break out a line of storms along the cold front across Nebraska down into north central Kansas and it also breaks out some isolated convection over southwest/south central Kansas along the dryline. I’m not going to get into much detail because I just don’t care that much, but below is a map showing a few quick thoughts on each portion of the threat area for severe weather tomorrow. Please excuse the tacky colors and childish map I threw together. I’m actually getting ready to start using powerpoint to generate my maps. They look a lot better (already created my templates). Just too lazy to get on the other computer tonight.
A few of those notes are based off the 12Z NAM since that’s all I could get off COD. I did look at the 00Z on Twister data and it made me question the lower dewpoint depression near the triple point compared to the dryline in southern Kansas in addition to surface winds backing more near the triple point, but I can’t see shit for definition on Twisterdata so I’ll stick to it until I can see the NAM on COD or the HRRR in the morning. I’ll update tomorrow morning anyway so I’m not worried about botching a few details tonight on this low profile of a setup.
I think you can basically break the threat area down into three distinct areas/setups tomorrow. You have the cold front in Nebraska where storms will likely go linear quickly keeping the tornado threat to a minimum, but that area will also likely pose the greatest severe weather threat (certainly as far as coverage is concerned). Next you have the near triple point environment over north central into NW Kansas. The models hint that there will be a tail end to the linear convection along the cold front in that area or you may have a more broken line with more discrete cells that can have less impeded inflow than the squall line along the cold front. The better chance for more favorable convective evolution in this area in addition to the idea that surface winds may back a bit more in this area make me think it probably has the best shot at a weak tornado tomorrow. Finally you have the dryline storms. Much more likely to get discrete cells along the dryline tomorrow, but despite the more favorable convective evolution along the dryline I think larger dewpoint depressions and being farther away from the stronger mid level winds up north may mitigate any advantage convective evolution gives it keeping the tornado probabilities lower here than near the triple point. At least that’s my thinking for the moment. I’m going to check model data in the morning and may change my mind then since I haven’t forecasted much for this setup. I pray to god COD is working properly by then. I just don’t feel right when I can’t use that site for forecasting. I would rather not chase a setup like tomorrow’s, but since it’s in Kansas and I need to give the equipment a good test run anyway I’m leaning towards heading out. I’ll make that call in the morning. Right now I’m thinking some place along I70 in north central Kansas would be a good starting point.
Beyond tomorrow’s setup attention turns to Thursday. I didn’t look at it hardly at all since the NAM is F’ed on COD, so I’ll hold off on getting into that until tomorrow. My general principles for Thursday still stand with the best potential being near the triple point in central Oklahoma. I’m leaning towards chasing Thursday and I do think the tornado potential will likely be better than it will be tomorrow.
I will hold off on getting into the setups for Sunday-Monday too. The GFS has been jumping around quite a bit and slowed down/changed the evolution of the upper air pattern so there may be a whole lot of nothing on Sunday. We’ll get into that tomorrow though.
I’ll try to post tomorrow morning some time so check back then for an update.