Hoosier Posted July 12, 2017 Author Share Posted July 12, 2017 IMO, based on the current situation and the short range models, if a training situation sets up later tonight, perhaps it may tend to favor areas closer to the I-80 corridor. Link to comment Share on other sites More sharing options...
Jim Martin Posted July 12, 2017 Share Posted July 12, 2017 AFD from the NWS in Wilmington OH tidbit... .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... What looked like a relatively painless forecast through the rest of the afternoon and evening has shifted into something a little more challenging, as a result of a complicated convective scenario upstream of the ILN CWA. Of first concern is the complex of thunderstorms over central Indiana, which requires a discussion of sounding conditions over the middle Ohio Valley region. The 12Z KILN sounding indicated a respectable cap at around 875mb, with a surface dewpoint at ob time of around 71 degrees. Rather than slightly decrease during afternoon mixing as might sometimes be expected, the persistent southwesterly flow has resulted in a net dewpoint rise of several degrees across the ILN CWA (especially in the southwestern quadrant). That has turned a strong cap over ILN to a weak cap, and a weak cap further west into little to no cap at all. The region to the west (central Indiana) has a significant gradient in CAPE, per SPC mesoanalysis, and all indications are that net propagation for this storm complex will eventually trend southward. Nonetheless, there was enough uncertainty (combined with some showers popping up over central Kentucky) to add a 20-PoP for the western / southwestern edge of the forecast area this afternoon and evening. To say the least, the HRRR has been off its rocker all day today -- not only failing to capture this southern extent of convection, but continually insisting on a strengthening of the storms over southern Michigan (which did not occur). Link to comment Share on other sites More sharing options...
Hoosier Posted July 12, 2017 Author Share Posted July 12, 2017 Big SBCAPE gradient currently across IL. 5000 J/kg central areas to very little around Chicago. Link to comment Share on other sites More sharing options...
Jim Martin Posted July 12, 2017 Share Posted July 12, 2017 The NWS in Wilmington (OH) just shared this graphic. Incredible. Link to comment Share on other sites More sharing options...
homedis Posted July 12, 2017 Share Posted July 12, 2017 13 minutes ago, Hoosier said: Big SBCAPE gradient currently across IL. 5000 J/kg central areas to very little around Chicago. Sun's almost out, clearing happened very fast. I think we can recover pretty quickly. Link to comment Share on other sites More sharing options...
Paulie21 Posted July 12, 2017 Share Posted July 12, 2017 12 minutes ago, Hoosier said: Big SBCAPE gradient currently across IL. 5000 J/kg central areas to very little around Chicago. That's pretty obvious though..steep low level lapse rates due to heating in C IL and inversion due to rain in N IL, lifting a parcel from sfc won't give accurate representation of instability whatsoever. Mid level lapse rates are more impressive up here. Link to comment Share on other sites More sharing options...
Hoosier Posted July 12, 2017 Author Share Posted July 12, 2017 7 minutes ago, homedis said: Sun's almost out, clearing happened very fast. I think we can recover pretty quickly. We'll see. Won't be anything like it could've been but as mentioned by Paulie, mid level lapse rates are steeper in northern IL. Link to comment Share on other sites More sharing options...
homedis Posted July 12, 2017 Share Posted July 12, 2017 We're already at 1.1k J/kg MLCAPE here in far NE IL with the sun out Link to comment Share on other sites More sharing options...
Stebo Posted July 12, 2017 Share Posted July 12, 2017 High clouds are thinning pretty rapidly here, already up to 81/72, rose 6 degrees since 3:20. Link to comment Share on other sites More sharing options...
IWXwx Posted July 12, 2017 Share Posted July 12, 2017 2 hours ago, Chicago Storm said: 8-10" rainfall estimates widespread in NE. IL/SE. WI. More storms rolling through those areas now. I'll bet everyone in that area is congregating on Mt. Geos. It seems that every few days for several months now, someone in the subforum is getting ark builders. Link to comment Share on other sites More sharing options...
Jim Martin Posted July 12, 2017 Share Posted July 12, 2017 Link to comment Share on other sites More sharing options...
Hoosier Posted July 12, 2017 Author Share Posted July 12, 2017 9 minutes ago, homedis said: We're already at 1.1k J/kg MLCAPE here in far NE IL with the sun out I keep refreshing for the LOT afd lol Link to comment Share on other sites More sharing options...
homedis Posted July 12, 2017 Share Posted July 12, 2017 Just now, Hoosier said: I keep refreshing for the LOT afd lol hahaha same Link to comment Share on other sites More sharing options...
Harry Perry Posted July 12, 2017 Share Posted July 12, 2017 GRR throws in the towel for severe chances this evening and into the overnight. Clearing off to the west but just not enough time left to warm it up here. South of the state looks excellent for some good convection. Link to comment Share on other sites More sharing options...
homedis Posted July 12, 2017 Share Posted July 12, 2017 Updated AFD from LOT... Quote Turn attention to expected additional development later this evening into the overnight hours. Area to watch for this later development will be across eastern Iowa and southwest Wisconsin where surface low and surface cold front are situated. Upstream mid level energy progressing through the Central Plains will interact with these surface features supporting quickly developing thunderstorms across this area. As this front and surface low shift east with time this evening, will continue to see additional development along/ahead of it. This will occur as most guidance in decent agreement of strong instability axis shifting back overhead, and as effective shear supportive of organized development is in place. Time window of this returning precip will likely be around the 2-3z time window across northern Illinois, with this development then progressing east southeast with time through the overnight hours. Sufficient instability with this synoptic forcing will support a severe threat, once again hail and wind. However, a close eye will be needed with likely heavy rainfall and possible flash flooding. Link to comment Share on other sites More sharing options...
Torchageddon Posted July 12, 2017 Share Posted July 12, 2017 EC issued a SVR t-storm warning for southern Grey county at 3:50 pm and I'm not kidding, there was nothing approaching! They canned it around the same time but the convection to the.north got re-warned. Link to comment Share on other sites More sharing options...
Hoosier Posted July 12, 2017 Author Share Posted July 12, 2017 20 minutes ago, homedis said: Updated AFD from LOT... Sounds good. My concern is how much instability is surface based at that time. This daytime mess of clouds/precip means we won't necessarily have a classic diurnal curve with temps. Maybe temps are steady/slowly rising for the next several hours? Link to comment Share on other sites More sharing options...
Indystorm Posted July 12, 2017 Share Posted July 12, 2017 I'm not so much concerned with the svr threat for northern IL tonight as I am worried about training torrential rainfall once again. Link to comment Share on other sites More sharing options...
cyclone77 Posted July 12, 2017 Share Posted July 12, 2017 Picked up 0.20" from a few passing showers today. Heard a little thunder this morning. Link to comment Share on other sites More sharing options...
cyclone77 Posted July 12, 2017 Share Posted July 12, 2017 Yesterday's scenic Conroy IA tor was rated EF-1 today by DVN. Link to comment Share on other sites More sharing options...
homedis Posted July 12, 2017 Share Posted July 12, 2017 Lake Cook Road in Northbrook just closed as well. Impacts from earlier flooding are still significant, worried for tonight as well. Link to comment Share on other sites More sharing options...
Indystorm Posted July 12, 2017 Share Posted July 12, 2017 19 minutes ago, homedis said: Lake Cook Road in Northbrook just closed as well. Impacts from earlier flooding are still significant, worried for tonight as well. I have a cousin in Deerfield just north of Lake/Cook road with a leaky glass solarium as part of her home. Link to comment Share on other sites More sharing options...
Jim Martin Posted July 12, 2017 Share Posted July 12, 2017 Link to comment Share on other sites More sharing options...
Indystorm Posted July 12, 2017 Share Posted July 12, 2017 With those higher dew points pooling along the Ohio turnpike the I-80 corridor along IL/IN/OH might be the sweet spot tonight. Link to comment Share on other sites More sharing options...
Hoosier Posted July 13, 2017 Author Share Posted July 13, 2017 00z LOT TAF sounded pessimistic. Link to comment Share on other sites More sharing options...
Hoosier Posted July 13, 2017 Author Share Posted July 13, 2017 MI peeps will love the 01z outlook. Link to comment Share on other sites More sharing options...
hawkeye_wx Posted July 13, 2017 Share Posted July 13, 2017 I was afraid Sunday night would be our only rain of this active period, but this evening I lucked out when the one storm cluster in the area passed right over CR. I picked up a quick 0.83", boosting my 3-day total to 2.05". I'm satisfied with that. A personal station just a half mile to my nw has picked up 3 inches during that period. Link to comment Share on other sites More sharing options...
Jim Martin Posted July 13, 2017 Share Posted July 13, 2017 Before the rain comes tonight to Northwest Ohio... Link to comment Share on other sites More sharing options...
Chinook Posted July 13, 2017 Share Posted July 13, 2017 For what it's worth, the DMX radar is picking up a lot of radar anomalies, and some rain showers. It may be hard to tell the difference if you just take a quick look. Link to comment Share on other sites More sharing options...
tmagan Posted July 13, 2017 Share Posted July 13, 2017 3 minutes ago, Chinook said: For what it's worth, the DMX radar is picking up a lot of radar anomalies, and some rain showers. It may be hard to tell the difference if you just take a quick look. My rule of thumb: When you see echos remaining stationary for a few volume scans, disregard, happens every night south of Long Island in the warm weather months with warm air over the cooler water. Link to comment Share on other sites More sharing options...
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