chase_stormz Posted April 25, 2012 Share Posted April 25, 2012 From Earls site. This is I believe is the old STP commonly referred to as the fixed layer STP I think. and this what I think is commonly referred to as the effective layer STP, although I'm not 100% sure about that. Could the SPC boys and gals go to 30% ???? Just a question, but I think it could be close, they may stick with the 15% chance and ramp it up with the early morning update...the pro mets here what do you think? Well, the outlook at 1am will have the actual percentages for tornadoes, wind, and hail, so there will be no general 30% area. Link to comment Share on other sites More sharing options...
cyclone77 Posted April 25, 2012 Share Posted April 25, 2012 For tornado probs I'm guessing they'll go with a larger 2% risk with a smaller 5% risk over central Illinois. If things go well I could see a 10% bubble show up somewhere in there later tomorrow. Link to comment Share on other sites More sharing options...
Minnesota Meso Posted April 25, 2012 Share Posted April 25, 2012 ok thanks for the answer's storm 19 and cyclone 77. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2012 Share Posted April 25, 2012 ok thanks for the answer's storm 19 and cyclone 77. no problem. either of you gonna take a chase chance? prolly not you minnesota lol, but maybe cyclone?? Link to comment Share on other sites More sharing options...
cyclone77 Posted April 25, 2012 Share Posted April 25, 2012 no problem. either of you gonna take a chase chance? prolly not you minnesota lol, but maybe cyclone?? Yeah I really want to, but I have committed myself to a landscaping project after work several days this week. If things really look good when I get off tomorrow afternoon I may have to break my obligation, but I really would hate to do that lol. Timing issues continue to kill me this season. Luckily it's only April. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 25, 2012 Share Posted April 25, 2012 For tornado probs I'm guessing they'll go with a larger 2% risk with a smaller 5% risk over central Illinois. If things go well I could see a 10% bubble show up somewhere in there later tomorrow. Just browsing some NAM/GFS soundings, it will probably be a narrow zone of elevated tornado probabilities if they go in that direction. Cap issues just appear too great as you move farther away on the south side of the warm front. And even then the moisture return will greatly impact just much the cap interferes near the warm front itself. That said, big CAPE between -10o to -30o C, so any elevated storm will still have the possibly drop some significant hail. Link to comment Share on other sites More sharing options...
Hoosier Posted April 25, 2012 Share Posted April 25, 2012 For tornado probs I'm guessing they'll go with a larger 2% risk with a smaller 5% risk over central Illinois. If things go well I could see a 10% bubble show up somewhere in there later tomorrow. I think I agree with a max 5% for now but could see it covering a larger area. Just too much uncertainty about surface based activity to go any higher at this point. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 25, 2012 Share Posted April 25, 2012 I need to start diving into the forecast for my CWA, but I will probably mess around with some soundings later and post them if I come up with anything interesting. Link to comment Share on other sites More sharing options...
cyclone77 Posted April 25, 2012 Share Posted April 25, 2012 Just browsing some NAM/GFS soundings, it will probably be a narrow zone of elevated tornado probabilities if they go in that direction. Cap issues just appear too great as you move farther away on the south side of the warm front. And even then the moisture return will greatly impact just much the cap interferes near the warm front itself. That said, big CAPE between -10o to -30o C, so any elevated storm will still have the possibly drop some significant hail. Yeah it looks like a fairly isolated/focused event. It may come down to one or two large sups feeding along the warm front/differential heating zone. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2012 Share Posted April 25, 2012 Yeah I really want to, but I have committed myself to a landscaping project after work several days this week. If things really look good when I get off tomorrow afternoon I may have to break my obligation, but I really would hate to do that lol. Timing issues continue to kill me this season. Luckily it's only April. Yea that tends to happen to me a lot too. I've chased 3 times this year (not including local) and only come up with a couple funnel clouds in the dark in arkansas. Busted on March 3rd in Kentucky, played to far south.. like other chasers did. And busted in Western, KS a 2 weeks ago this thurs.. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2012 Share Posted April 25, 2012 Yeah it looks like a fairly isolated/focused event. It may come down to one or two large sups feeding along the warm front/differential heating zone. Yea and that's what we are looking for. Trust me, those are fun events lol! Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 25, 2012 Author Share Posted April 25, 2012 Currently have no plans to chase this event. Will re-evaluate tomorrow though. Link to comment Share on other sites More sharing options...
OceanStWx Posted April 25, 2012 Share Posted April 25, 2012 Yeah it looks like a fairly isolated/focused event. It may come down to one or two large sups feeding along the warm front/differential heating zone. These northwest flow types of events it only takes one. I'm reminded of the 9/12/10 Dubuque supercell that hit the ASOS with 80 mph wind gusts, despite nearly uniform westerlies throughout the column. Just a concentrated area of moisture convergence was enough to get things going for one storm of the day. Link to comment Share on other sites More sharing options...
cyclone77 Posted April 25, 2012 Share Posted April 25, 2012 These northwest flow types of events it only takes one. I'm reminded of the 9/12/10 Dubuque supercell that hit the ASOS with 80 mph wind gusts, despite nearly uniform westerlies throughout the column. Just a concentrated area of moisture convergence was enough to get things going for one storm of the day. Yep. Yeah the 1-2 tornado producing sup days can be quite nice. From a chasing aspect it can make things a little less complicated lol. The new LSX WRF seems to follow this logic as well. Looks like one or two dominant southeastward moving sups over central Illinois... Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2012 Share Posted April 25, 2012 These northwest flow types of events it only takes one. I'm reminded of the 9/12/10 Dubuque supercell that hit the ASOS with 80 mph wind gusts, despite nearly uniform westerlies throughout the column. Just a concentrated area of moisture convergence was enough to get things going for one storm of the day. i remember that, extremely isolated event Link to comment Share on other sites More sharing options...
Minnesota Meso Posted April 25, 2012 Share Posted April 25, 2012 no problem. either of you gonna take a chase chance? prolly not you minnesota lol, but maybe cyclone?? No I don't think this set up is worth a chase....best guess is that the biggest threat would be very near or after dark. I would only chase within a 2 hr drive of the TC metro as a rule. Call me just a weather geek and not a chaser, although I am a spotter registered with the NWS... Living in MN let me give some advice....do not chase in the counties of far se MN say se of Rochester...bluff country, bad deal, east-west-north-south roads are not existent, all roads follow the bluffs, you will take your life into your own hands if you go there. On the other hand anything West of Rochester is a chaser's dream, good roads and you can see forever. Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2012 Share Posted April 25, 2012 No I don't think this set up is worth a chase....best guess is that the biggest threat would be very near or after dark. I would only chase within a 2 hr drive of the TC metro as a rule. Call me just a weather geek and not a chaser, although I am a spotter registered with the NWS... Living in MN let me give some advice....do not chase in the counties of far se MN say se of Rochester...bluff country, bad deal, east-west-north-south roads are not existent, all roads follow the bluffs, you will take your life into your own hands if you go there. On the other hand anything West of Rochester is a chaser's dream, good roads and you can see forever. it's only worth it for local residents to take a chance at this one. and oh i've chased arkansas and mississippi a few times.. so yea.. lol Link to comment Share on other sites More sharing options...
andyhb Posted April 25, 2012 Share Posted April 25, 2012 5% tornado probs across Central IL in the new Day 1. ...MIDWEST/OH VALLEY REGION...AS THE AFOREMENTIONED SURFACE LOW SHIFTS SEWD ACROSS IA DURING THE DAY AND REACHES THE MS RIVER...A SWLY LOW-LEVEL JET IS FORECAST TO DEVELOP -- NOSING NEWD TOWARD/ACROSS THE SURFACE WARM FRONT. AS THE MOISTENING BOUNDARY LAYER DESTABILIZES THROUGH THE AFTERNOON...EXPECT STORM INITIATION TO OCCUR -- LIKELY NEAR AND TO THE COOL SIDE OF THE FRONT AS WARM SECTOR CAPPING IS LIKELY TO LARGELY INHIBIT CONVECTIVE DEVELOPMENT. INITIAL DEVELOPMENT SHOULD OCCUR INVOF ERN IA/NWRN IL...AND WITH STEEP LAPSE RATES/MODERATE CAPE FUELING THE CONVECTION...INCREASING STORM COVERAGE -- AND EVENTUALLY UPSCALE GROWTH INTO A BOWING LINE OF STORMS -- APPEARS POSSIBLE. INITIAL STORM MODE IS LIKELY TO BE SUPERCELLULAR...WITH LOW-LEVEL FLOW VEERING RAPIDLY AND INCREASING TO 40 KT FROM THE NW. THESE STORMS WILL LIKELY BE ACCOMPANIED BY LARGE HAIL...WITH LOCALLY DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. PRESUMING UPSCALE LINEAR GROWTH DOES OCCUR...THREAT FOR WIND WOULD INCREASE -- AIDED BY MID-LEVEL NWLYS ALOFT INCREASING A BIT TO 40 TO 50 KT DRIVING A FAST-MOVING MCS ACROSS THE OH VALLEY ROUGHLY ALONG THE WARM FRONTAL ZONE. SOME SEVERE THREAT MAY LINGER WELL INTO THE OVERNIGHT HOURS -- PARTICULARLY IF THE LINEAR/BOWING MCS CAN DEVELOP. Link to comment Share on other sites More sharing options...
Minnesota Meso Posted April 25, 2012 Share Posted April 25, 2012 Best guess is that the SPC stays at 15% chance overall, with the tornado risk being about 5% and the hail being around 30%, I don't think at this time they will go to 30% percent severe overall chances, but I think it will be close, they may even in their discussion mention that later outlooks may have to reconsider the potential. Link to comment Share on other sites More sharing options...
Hoosier Posted April 25, 2012 Share Posted April 25, 2012 5% tornado squeaks into western IN also hatched hail Link to comment Share on other sites More sharing options...
andyhb Posted April 25, 2012 Share Posted April 25, 2012 Best guess is that the SPC stays at 15% chance overall, with the tornado risk being about 5% and the hail being around 30%, I don't think at this time they will go to 30% percent severe overall chances, but I think it will be close, they may even in their discussion mention that later outlooks may have to reconsider the potential. There is no such thing as 15% and 30% overall probabilities on Day 1 outlooks, they are split into separate categories for tornadoes, hail and wind. Both the 15% and 30% probabilities in Day 2/3 outlooks fall under the "Slight" categorical outlook. Link to comment Share on other sites More sharing options...
tornadotony Posted April 25, 2012 Share Posted April 25, 2012 Boy, that is tempting...quite tempting...also if that squeezes any farther NE then south suburbs could have at least a substantial hail threat tomorrow, if not the chance of a tornado. Link to comment Share on other sites More sharing options...
Minnesota Meso Posted April 25, 2012 Share Posted April 25, 2012 There is no such thing as 15% and 30% overall probabilities on Day 1 outlooks, they are split into separate categories for tornadoes, hail and wind. Both the 15% and 30% probabilities in Day 2/3 outlooks fall under the "Slight" categorical outlook. Andy sorry, I forgot that the SPC puts slights risk and moderate risks overall. me bad. I know better, still 30% hatched hail chance is impressive IMO, sorry dude, again my bad Link to comment Share on other sites More sharing options...
andyhb Posted April 25, 2012 Share Posted April 25, 2012 No problem, although the details on the outlooks can be found on the SPC website in their FAQ and also on the Wikipedia page. http://en.wikipedia.org/wiki/Storm_Prediction_Center Link to comment Share on other sites More sharing options...
RCNYILWX Posted April 25, 2012 Share Posted April 25, 2012 http://www.nssl.noaa.gov/wrf/uhmx16_loop.html 1-6km hourly max updraft helicity on the 4km NSSL WRF is interesting for I-80 and south in Illinois and northwest Indiana tomorrow early evening. Curious to see what the 00z SPC-WRF NMM shows, if it comes out. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 25, 2012 Share Posted April 25, 2012 00z ECMWF is quite a bit farther N with the surface low/initiation. Link to comment Share on other sites More sharing options...
Minnesota Meso Posted April 25, 2012 Share Posted April 25, 2012 No problem, although the details on the outlooks can be found on the SPC website in their FAQ and also on the Wikipedia page. http://en.wikipedia....ediction_Center Thanks Andy I know what the day 1,2 and day 3 outlooks mean, I just scr***ed up is all. Thanks for your patience it's appreciated Link to comment Share on other sites More sharing options...
cyclone77 Posted April 25, 2012 Share Posted April 25, 2012 00z ECMWF is quite a bit farther N with the surface low/initiation. Euro looks like it would favor a QC/La Salle/ Peoria triangle early evening. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 25, 2012 Share Posted April 25, 2012 Euro looks like it would favor a QC/La Salle/ Peoria triangle early evening. Are you chasing tomorrow? Link to comment Share on other sites More sharing options...
chase_stormz Posted April 25, 2012 Share Posted April 25, 2012 Are you chasing tomorrow? i am. where does initiation occur and what time on the euro? i don't have access to it.. Link to comment Share on other sites More sharing options...
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