cyclone77 Posted May 16, 2019 Share Posted May 16, 2019 Yeah that LLJ should feed tonight's MCS all through the morning tomorrow, so it'll likely go on for quite awhile. HRRR/3km doesn't break out new convection until around, or just after 00z. Good chance it actually happens a bit later than that. Strong capping will be in place just south of the boundary, and with the nocturnal inversion starting to settle in just as the convection finally takes off it makes you wonder just how robust any surface-based convection can get. Good chance tomorrow evening's biggest threat will come from torrential rains from the storms that may have a tendency to train over the same areas as storm motion vectors parallel the nearly stationary boundary. Link to comment Share on other sites More sharing options...
Jim Martin Posted May 16, 2019 Share Posted May 16, 2019 Link to comment Share on other sites More sharing options...
King James Posted May 16, 2019 Share Posted May 16, 2019 She looks like she's starting to bow in WI Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted May 16, 2019 Share Posted May 16, 2019 Tor warning for south central DKB county Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted May 16, 2019 Share Posted May 16, 2019 Had a good burst of hail with the storm as well, quarter size. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted May 16, 2019 Share Posted May 16, 2019 1 minute ago, SchaumburgStormer said: Tor warning for south central DKB county Law enforcement reported poss tornado on the ground N of Shabbona at 1137 Link to comment Share on other sites More sharing options...
Hoosier Posted May 16, 2019 Share Posted May 16, 2019 From latest outlook ...Midwest... Considered increasing tornado probabilities and adding significant hail but low confidence exists in whether supercells can be sustained in the warm sector across IL/IN. A slowly decaying MCS is ongoing near the IL/WI border within a warm advection regime. Morning CAM guidance has poorly handled with most struggling to maintain any semblance of convection beyond initialization. The stratiform region across Lake MI should have an impact on downstream destabilization in Lower MI given that richer boundary-layer moisture characterized by low to mid 60s surface dew points is currently confined from IL west. It is possible that the MCS may not entirely dissipate as warm advection persists through the period. Renewed development on the upshear side would seemingly be most likely along trailing convective outflow. Along the eastern extent of the Great Plains elevated mixed layer at peak heating, robust upstream diabatic heating should result in large buoyancy with MLCAPE of 2000-3000 J/kg. Veering of the wind profile with height on the periphery of moderate mid-level northwesterlies will favor supercell structures. An evolution to another MCS with wind/hail risks appears probable tonight towards the OH Valley. Link to comment Share on other sites More sharing options...
snowlover2 Posted May 16, 2019 Author Share Posted May 16, 2019 2 minutes ago, Hoosier said: From latest outlook ...Midwest... Considered increasing tornado probabilities and adding significant hail but low confidence exists in whether supercells can be sustained in the warm sector across IL/IN. A slowly decaying MCS is ongoing near the IL/WI border within a warm advection regime. Morning CAM guidance has poorly handled with most struggling to maintain any semblance of convection beyond initialization. The stratiform region across Lake MI should have an impact on downstream destabilization in Lower MI given that richer boundary-layer moisture characterized by low to mid 60s surface dew points is currently confined from IL west. It is possible that the MCS may not entirely dissipate as warm advection persists through the period. Renewed development on the upshear side would seemingly be most likely along trailing convective outflow. Along the eastern extent of the Great Plains elevated mixed layer at peak heating, robust upstream diabatic heating should result in large buoyancy with MLCAPE of 2000-3000 J/kg. Veering of the wind profile with height on the periphery of moderate mid-level northwesterlies will favor supercell structures. An evolution to another MCS with wind/hail risks appears probable tonight towards the OH Valley. Beat me to it. Link to comment Share on other sites More sharing options...
Chinook Posted May 16, 2019 Share Posted May 16, 2019 14 minutes ago, SchaumburgStormer said: Law enforcement reported poss tornado on the ground N of Shabbona at 1137 Based on storm relative velocity, I think rotation was weak-moderate north of Leland (south of Shabbona) 11:44 AM. Link to comment Share on other sites More sharing options...
Indystorm Posted May 16, 2019 Share Posted May 16, 2019 Mesoscale Discussion 0638 NWS Storm Prediction Center Norman OK 1209 PM CDT Thu May 16 2019 Areas affected...Parts of northern and central Illinois and Indiana Concerning...Severe potential...Watch possible Valid 161709Z - 161815Z Probability of Watch Issuance...40 percent SUMMARY...Vigorous thunderstorm development is currently being maintained near a southward advancing cold pool, to the southwest of the Chicago area. It is not certain how long this will persist this afternoon, but there is at least some potential for further intensification and organization which could require a severe weather watch. DISCUSSION...Warm and capping elevated mixed-layer air is in the process of advecting across the mid/lower Missouri Valley, toward portions of the Upper Midwest, around the northern periphery of amplified ridging within the mid-latitude westerlies. Along the leading edge of this air mass, a zone of enhanced lower/mid tropospheric warm advection is maintaining vigorous thunderstorm development, which may be also increasingly forced by lift above an associated surface cold pool. This appears to be occurring in the presence of modest (30+ kt) west-northwesterly deep layer mean flow. The influence of a 30-40 kt west-southwesterly 850 mb speed maximum nosing east of the Mississippi River may contribute to more of a southward propagation near and west of the Illinois/Indiana state border area through 18-20Z. While this track will be increasingly into weak mid-level height rises, mid/upper ridging and weaker flow aloft, the boundary layer ahead of the southwestern flank of the outflow continues to gradually moisten across much of central Illinois. Additional boundary layer warming and moistening may contribute to weakening inhibition for boundary layer parcels with CAPE increasing in excess of 2000 J/kg. Thus, while it remains unclear if synoptic forcing for ascent will maintain ongoing convection this afternoon, it appears at least possible that mesoscale processes will, with subsequent further intensification and organization possible. This probably would be accompanied by increasing potential for strong winds at least approaching severe limits along a strengthening gust front. ..Kerr/Grams.. 05/16/2019 Link to comment Share on other sites More sharing options...
Indystorm Posted May 16, 2019 Share Posted May 16, 2019 LaSalle county EMA reported a tornado near Sheridan IL. Link to comment Share on other sites More sharing options...
Jackstraw Posted May 16, 2019 Share Posted May 16, 2019 URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 168 NWS Storm Prediction Center Norman OK 1250 PM CDT Thu May 16 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of East-central and northeast Illinois West-central and northwest Indiana * Effective this Thursday afternoon and evening from 1250 PM until 600 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...A small linear bowing cluster may continue southeast along the Illinois and Indiana border region this afternoon. Damaging wind gusts and severe hail are the primary hazards, although a brief tornado or two is also possible. The severe thunderstorm watch area is approximately along and 65 statute miles east and west of a line from 35 miles west northwest of Valparaiso IN to 30 miles south southeast of Danville IL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). Link to comment Share on other sites More sharing options...
Chicago Storm Posted May 16, 2019 Share Posted May 16, 2019 This MCS that has regenerated this morning and early afternoon looks likely to push SE/SSE alight the instability gradient in place, which runs down along the IL/IN border area. It has featured embedded areas of rotation at times in the SW/S metro, with a few wall cloud reports. Overall severe reports have been surprising low though, given wind and hail sigs on radar. Re-development of quality surface based activity later this afternoon and evening in a very nice environment ahead of the cold front and near the OFB across Iowa, S. WI/N. IL looks questionable...With slightly rising heights, subsidence in the wake of the current S/W, no formidable wave close upstream and a cap in place. Link to comment Share on other sites More sharing options...
Harry Perry Posted May 16, 2019 Share Posted May 16, 2019 Several short range runs showing explosive development around 00z tonight.. fortunately the MCS has weakened to the point where the atmosphere should remain untapped over this way, but later on I’m trying to find what the models are seeing that’s driving explosive development along the boundary other than the LLJ. Link to comment Share on other sites More sharing options...
hlcater Posted May 16, 2019 Share Posted May 16, 2019 That MCS threw down an OFB that is favorably oriented to storm motion vector. If it gets time to cook, could get interesting(in W IL) late this afternoon should redevelopment occur. Link to comment Share on other sites More sharing options...
Chicago WX Posted May 16, 2019 Share Posted May 16, 2019 Pea sized hail here. Lightning strikes are impressive. Winds are meh. Rain is unbelievable. So tired of it... 2 Link to comment Share on other sites More sharing options...
UMB WX Posted May 16, 2019 Share Posted May 16, 2019 Just had about 15 seconds of hail drop out of nowhere. Few of them larger than pea. Link to comment Share on other sites More sharing options...
Indystorm Posted May 16, 2019 Share Posted May 16, 2019 Svr watch issued till 9 eastern time to the south and east of the earlier watch. Link to comment Share on other sites More sharing options...
snowlover2 Posted May 16, 2019 Author Share Posted May 16, 2019 Tornado warning near Danville IL. Link to comment Share on other sites More sharing options...
snowlover2 Posted May 16, 2019 Author Share Posted May 16, 2019 4 minutes ago, snowlover2 said: Tornado warning near Danville IL. https://www.wcia.com/live-stream1 Says there is a debris sig. Link to comment Share on other sites More sharing options...
Jackstraw Posted May 16, 2019 Share Posted May 16, 2019 That same cell is N of Terre Haute now and warned again with numerous reports of a wall cloud. It's pretty much on its own now. Link to comment Share on other sites More sharing options...
Indystorm Posted May 17, 2019 Share Posted May 17, 2019 Look what is forming this evening from northern IN westward across northern IL into IA. Maybe those mesoscale models that predicted training west to east t storms overnight are going to be correct in spite of the MCS that rolled through the area earlier today. Link to comment Share on other sites More sharing options...
NTXYankee Posted May 17, 2019 Share Posted May 17, 2019 4 minutes ago, Indystorm said: Look what is forming this evening from northern IN westward across northern IL into IA. Maybe those mesoscale models that predicted training west to east t storms overnight are going to be correct in spite of the MCS that rolled through the area earlier today. Saw that, seemed to start popping up pretty quick. HRRR says Columbus around 5z so we’ll see out this way. Link to comment Share on other sites More sharing options...
Tim from Springfield (IL) Posted May 17, 2019 Share Posted May 17, 2019 I don't usually like to start a severe thread, and don't mean to be late to the party on today's event either, but I started a new catch-all thread starting with today/tonight's action (including another MD in IA/N IL), going to early Wednesday: Link to comment Share on other sites More sharing options...
IWXwx Posted May 22, 2019 Share Posted May 22, 2019 Head's up western/northern IL and Chicagoland. SPC has the slight risk all the way up to ORD and the CAMs look like there could be some golf balls and a tornado threat in the late evening. Trust me, those golf-to-tennis balls can inflict some serious damage. 1 Link to comment Share on other sites More sharing options...
King James Posted May 22, 2019 Share Posted May 22, 2019 Head's up western/northern IL and Chicagoland. SPC has the slight risk all the way up to ORD and the CAMs look like there could be some golf balls and a tornado threat in the late evening. Trust me, those golf-to-tennis balls can inflict some serious damage.For tonight? Link to comment Share on other sites More sharing options...
IWXwx Posted May 22, 2019 Share Posted May 22, 2019 13 minutes ago, King James said: For tonight? Yes sir. Link to comment Share on other sites More sharing options...
King James Posted May 22, 2019 Share Posted May 22, 2019 6 minutes ago, IWXwx said: Yes sir. Dang, busy day. Completely missed this. Thanks for the heads up. Link to comment Share on other sites More sharing options...
janetjanet998 Posted May 22, 2019 Share Posted May 22, 2019 TOR watch for me and SW looks like there is a mini dew point front moving north....where dew points are 68-69 south versus 59-61north....CU field in MO developing on the leading edge models start backing winds more SSE. around 23-0z as a mini low forms I-72 baby (you can never go wrong) Link to comment Share on other sites More sharing options...
yoda Posted May 22, 2019 Share Posted May 22, 2019 Tornado Warning in NE MO for Marion and Shelby counties Link to comment Share on other sites More sharing options...
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