Indystorm Posted December 23, 2015 Share Posted December 23, 2015 Sim reflectivity has a broken line of cells near the IL/IN border at 3z before crossing into Indiana. Add to that a 130-150 knot 300mb jet from Effingham to north central IN and we've got trouble. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted December 23, 2015 Author Share Posted December 23, 2015 The non 4K NAM is really picked up down south in the Afternoon, has even worse PDS Tornado sigs. Link to comment Share on other sites More sharing options...
chase_stormz Posted December 23, 2015 Share Posted December 23, 2015 Where is that? The non 4K NAM is really picked up down south in the Afternoon, has even worse PDS Tornado sigs. Link to comment Share on other sites More sharing options...
Hoosier Posted December 23, 2015 Share Posted December 23, 2015 Any thoughts on locally? The morning/early afternoon stuff looks to be lacking surface based instability and I'm not too thrilled about it, though it looks like there's enough elevated CAPE to support at least a modest severe threat. My main focus is what happens later in the day but I'm wondering about convective coverage with that round. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted December 23, 2015 Author Share Posted December 23, 2015 Where is that? North Central Mississippi Link to comment Share on other sites More sharing options...
cyclone77 Posted December 23, 2015 Share Posted December 23, 2015 New 4km is fairly ominous for the QCA. Slightly slower timing allows the broken line of low-topped sups to develop in eastern IA and then impact the MS river region. 12km NAM forecast sounding showing around 750j/kg cape at 00z just ahead of that near QC. Not the most impressive cape, but as many have pointed out that should be enough given all the other available ingredients. Guessing the slight will be pulled northwest to include more of the DVN area if model trends continue. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted December 23, 2015 Author Share Posted December 23, 2015 More Soundings: IMBY at 30 hours (06Z Thur) West Central Indiana is borderline PDS: Link to comment Share on other sites More sharing options...
Hoosier Posted December 23, 2015 Share Posted December 23, 2015 Link to comment Share on other sites More sharing options...
Stebo Posted December 23, 2015 Share Posted December 23, 2015 This is December right? Link to comment Share on other sites More sharing options...
RCNYILWX Posted December 23, 2015 Share Posted December 23, 2015 The 12km NAM distinctly resolves a supercell track in the QPF field from about PIA right across Chicago between 00z and 06z tomorrow evening. The 00z NAMs definitely further upped the ante locally for tomorrow. Sent from my SM-G900V using Tapatalk Link to comment Share on other sites More sharing options...
Quincy Posted December 23, 2015 Share Posted December 23, 2015 Some pretty solid mid-level lapse rates up into Illinois. Looks like a function of height falls and mid/upper level cooling. The NAM tries to develop a little something near the Quad Cities and surrounding areas. Otherwise, most of the environment is blown out to the north, keeping the best instability/shear overlap well to the south, across the Gulf Coast states and Tennessee. 00z 4km NAM: Link to comment Share on other sites More sharing options...
Superstorm93 Posted December 23, 2015 Share Posted December 23, 2015 0-3km SRH values are pretty ominous. Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted December 23, 2015 Share Posted December 23, 2015 This is December right? I took a walk around the neighborhood today... t-shirt, shorts as it was 60 degrees, sunny. I found myself asking the same thing. Link to comment Share on other sites More sharing options...
IllinoisWedges Posted December 23, 2015 Share Posted December 23, 2015 Quick question for y'all, do you use the RAP model? Reason I'm asking is it's showing the airmass recovering a lot better than some other models.. *cough* 4k. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted December 23, 2015 Author Share Posted December 23, 2015 Some pretty solid mid-level lapse rates up into Illinois. Looks like a function of height falls and mid/upper level cooling. The NAM tries to develop a little something near the Quad Cities and surrounding areas. Otherwise, most of the environment is blown out to the north, keeping the best instability/shear overlap well to the south, across the Gulf Coast states and Tennessee. 00z 4km NAM: nam4kmSGP_con_1kmehi_021.gif the Non 4K NAM has good lapse rates further north. Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 23, 2015 Share Posted December 23, 2015 Any thoughts on locally? The morning/early afternoon stuff looks to be lacking surface based instability and I'm not too thrilled about it, though it looks like there's enough elevated CAPE to support at least a modest severe threat. My main focus is what happens later in the day but I'm wondering about convective coverage with that round. I agree that the early day activity could pose some severe threat, especially in the WAA regime with increasing elevated CAPE and DP's. Probably would be limited to a hail threat obviously. As for the afternoon, I'm still on the fence. One thing I can say, is even though DP's in the 50's will be easily enough, I hate seeing that early convection sort of push the higher DP's (60F+) that are feeding northward off to the east during the afternoon. Luckily sun won't be needed either, since there might not be a ton of clearing. If all goes well I'm on board for a broken line of cells developing near the Mississippi River in IL, then racing NE...with a continued threat into the night into IN/MI, and possibly OH. I do think there will be a gap in coverage too for the second round, with the line north and then activity farther down south. Obviously it all hinges on the early day activity, as that's really the only deal breaker I could see right now. I cleared tomorrow out, so I'll be chasing if it looks warranted. Right now a good starting point might be out near Macomb/Galesburg area, though I'm not sure I'd actually head that far west. Link to comment Share on other sites More sharing options...
Quincy Posted December 23, 2015 Share Posted December 23, 2015 Is there any reason to favor 12km NAM over 4km NAM, aside from the fact that it's less of a buzzkill to the north? Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 23, 2015 Share Posted December 23, 2015 Is there any reason to favor 12km NAM over 4km NAM, aside from the fact that it's less of a buzzkill to the north? 0z 4KM NAM is the first and only piece of guidance I've seen to show that solution. Wouldn't throw it out, but doesn't have a ton of support...yet. Link to comment Share on other sites More sharing options...
Superstorm93 Posted December 23, 2015 Share Posted December 23, 2015 Quick question for y'all, do you use the RAP model? Reason I'm asking is it's showing the airmass recovering a lot better than some other models.. *cough* 4k. Because at this point the RAP is pretty much obsolete. Its lower resolution and I cant even recall the last upgrade it had. The HRRR was its replacement once it became operational Link to comment Share on other sites More sharing options...
bdgwx Posted December 23, 2015 Share Posted December 23, 2015 I will say on the 11/16 event the NAM definitely overestimated 0-3km CAPE. I remember seeing sounding after sounding with 300 j/kg in MO. But, the SPC mesoanalysis that day never got above 150 j/kg. That's a huge difference and it definitely had a detrimental effect on the storms in MO...a la the single tornado in the state that day. I realize equilibrium levels are much higher in this event so the low level CAPE probably won't matter as much. But, the 200 j/kg in many of the soundings for this event could be a bit high. And the SREF means are still well below 1000 j/kg for many of the Ohio Valley sites. So if it weren't for the fact that the Euro was also showing those pockets of higher CAPE I'd be whacking a good chunk right off the top of the NAM instability estimates. With that said I agree with everyone that the GFS is probably low balling the instability on this event and the NAM isn't unrealistic. Yipes...on the 80+ kts of 6km shear and 115+ kts of 8km shear! I really wish IND was an upper air station. Link to comment Share on other sites More sharing options...
Hoosier Posted December 23, 2015 Share Posted December 23, 2015 4km goes to town...979 mb Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 23, 2015 Share Posted December 23, 2015 Because at this point the RAP is pretty much obsolete. Its lower resolution and I cant even recall the last upgrade it had. The HRRR was its replacement once it became operational The RAP was the RUC replacement. V2 was implemented in early 2015, and V3 is set for early 2016. The HRRR is of higher resolution. Link to comment Share on other sites More sharing options...
PGM Posted December 23, 2015 Share Posted December 23, 2015 Any thoughts on what the SPC risk level will be on the Day 1 outlook? Sent from my XT1563 Link to comment Share on other sites More sharing options...
Quincy Posted December 23, 2015 Share Posted December 23, 2015 Any thoughts on what the SPC risk level will be on the Day 1 outlook? Sent from my XT1563 They may go moderate for a small area from NW MS into Middle Tennessee, but I don't expect any drastic changes. By 1300, once convective evolution and mesoscale details are more certain, then some things could change. Link to comment Share on other sites More sharing options...
Superstorm93 Posted December 23, 2015 Share Posted December 23, 2015 South West of Nashville on the 12km NAM Link to comment Share on other sites More sharing options...
Hoosier Posted December 23, 2015 Share Posted December 23, 2015 4km goes to town...979 mb nam4km_ref_ncus_8.png RGEM too...essentially same location/strength. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted December 23, 2015 Author Share Posted December 23, 2015 Any thoughts on what the SPC risk level will be on the Day 1 outlook? Sent from my XT1563 Probably expanding the slight north and the enhanced north, if the rest of the 0Z Suite comes in juiced maybe a Moderate. Link to comment Share on other sites More sharing options...
PGM Posted December 23, 2015 Share Posted December 23, 2015 They may go moderate for a small area from NW MS into Middle Tennessee, but I don't expect any drastic changes. By 1300, once convective evolution and mesoscale details are more certain, then some things could change.Alright, thanksSent from my XT1563 using Tapatalk Link to comment Share on other sites More sharing options...
bdgwx Posted December 23, 2015 Share Posted December 23, 2015 Speaking of the HRRR...the experimental v2, which runs out to 24 hours, is showing a thin ribbon of 1000 j/kg of SBCAPE at 00Z in IL. There isn't any convective activity under that more juicy spot though. The CIN is a little high and it does appear to be increasing after Sunset, but it's not insurmountable so I'd take the lack of convective activity with a grain of salt. Link to comment Share on other sites More sharing options...
bdgwx Posted December 23, 2015 Share Posted December 23, 2015 The RAP was the RUC replacement. V2 was implemented in early 2015, and V3 is set for early 2016. The HRRR is of higher resolution. HRRR v2 goes live in 2016 as well. It's probably important to note that the RAP is used to initialize the HRRR. Link to comment Share on other sites More sharing options...
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