Windspeed Posted April 6, 2020 Share Posted April 6, 2020 Possible severe on Wed evening into Thurs AM? 1 Link to comment Share on other sites More sharing options...
Windspeed Posted April 6, 2020 Share Posted April 6, 2020 And of course the one we've been watching for: The trough/phase dynamics at play, leading to a potential outbreak on Easter Sunday. This might be a doozy: 1 Link to comment Share on other sites More sharing options...
jaxjagman Posted April 7, 2020 Author Share Posted April 7, 2020 2 hours ago, Windspeed said: Possible severe on Wed evening into Thurs AM? We'll see what kind of cap comes with it Link to comment Share on other sites More sharing options...
jaxjagman Posted April 7, 2020 Author Share Posted April 7, 2020 8 hours ago, Windspeed said: And of course the one we've been watching for: The trough/phase dynamics at play, leading to a potential outbreak on Easter Sunday. This might be a doozy: Big shift to the west overnight 1 Link to comment Share on other sites More sharing options...
Windspeed Posted April 7, 2020 Share Posted April 7, 2020 1 Link to comment Share on other sites More sharing options...
Windspeed Posted April 7, 2020 Share Posted April 7, 2020 Round one tomorrow evening/night.. 1 Link to comment Share on other sites More sharing options...
Runman292 Posted April 8, 2020 Share Posted April 8, 2020 This morning’s short term AFD from MRX: Moving into/through Wednesday, conditions across the TN Valley will improve as the day progresses with the aforementioned low clouds scting out to favor low cu and ample heating amongst sustained sly/swly moisture advection. With that, did keep pops mentionable albeit low during peak heating as iso/sct convection is possible once convective temps are reached (highs in the 70s to low 80s), with low confidence in placement. Meanwhile the synoptic pattern really starts to amplify as a fast moving H5 wave/trough dives out of Canada across the Northern Rockies into the Plains, resulting in surface cyclogenesis across MO/IL. This deepening surface low will propel a fast moving cold front into a very moist/unstable warm sector over the OH Valley late Monday evening with ample convection to accompany. This frontal convection will then race across the Plateau, through the Great Valley, and into the Southern Appalachians around sunrise Thursday. Profiles in the warm sector across East TN are fairly impressive ahead of the convection (despite the timing) with very steep lapse rates amidst deep dry air and unidirectional/strong sheer. As for hazards, nothing is off the table as large hail and damaging winds are certainly the primary threats, but an isolated tornado or two cannot be ruled out as some embedded rotations are likely. Instability does look to wain closer to daybreak as the line of convection moves east, mainly just on diurnal trends, therefore would expect some gradual weakening closer to the NC line. All said, SPC has upgraded areas generally west of I75 to an Enhanced Risk of severe thunderstorms, which is where instability/shear are maximized, while the remainder of the area is essentially favored in the Slight Risk Category. As for timing specifics, the CAMs seem to be in fairly good agreement with only one slower outlier. Typically these fronts outperform as far as speed/timing thus leaned away from the slower outlier thereby favoring a fast fropa between midnight and 5-6AM eastern time. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted April 8, 2020 Share Posted April 8, 2020 This Easter Sunday outbreak looks like it could be ugly to me on the Euro. I don't know very much about severe parameters or exactly how ugly, but as Webb's cyclone map that Windspeed posted says, one look at that is all I need. I am not a fan of storms moving SW -> NE with a strong upper low moving over the bootheel of Missouri, since that can send them right up the river valleys in East TN with a lot of shear. Most damaging storms I can remember have that motion. Looking at Pivotal soundings, still looks like most of the worst is S and SE of east TN, but all I'm going on is the "threat box" if that is what it is called, where it tells you the possible wx threats. Most soundings over middle E TN give a "Marginal Severe" result, with "Marginal Tornado" nearer Nashville, but near Chatt it is giving a tornado result, with storms moving up the TN river valley near the mts. Euro suggests that there could be a bigger line/ clusters of cells moving through first, and then more with a secondary line of discrete cells as the front moves through. What do y'all who know a lot more about severe weather think? Link to comment Share on other sites More sharing options...
McMinnWx Posted April 8, 2020 Share Posted April 8, 2020 By the Grace of God, my family and friends survived the last few tornadoes that came through McMinn County, including the monster back in 2010 (or 2011; whichever was first, because there were two consecutive years of tornadoes hitting us). I do not like when the term "outbreak" starts getting thrown around, as I'm sure many others do not. 1 1 Link to comment Share on other sites More sharing options...
Calderon Posted April 8, 2020 Share Posted April 8, 2020 This Easter Sunday outbreak looks like it could be ugly to me on the Euro. I don't know very much about severe parameters or exactly how ugly, but as Webb's cyclone map that Windspeed posted says, one look at that is all I need. I am not a fan of storms moving SW -> NE with a strong upper low moving over the bootheel of Missouri, since that can send them right up the river valleys in East TN with a lot of shear. Most damaging storms I can remember have that motion. Looking at Pivotal soundings, still looks like most of the worst is S and SE of east TN, but all I'm going on is the "threat box" if that is what it is called, where it tells you the possible wx threats. Most soundings over middle E TN give a "Marginal Severe" result, with "Marginal Tornado" nearer Nashville, but near Chatt it is giving a tornado result, with storms moving up the TN river valley near the mts. Euro suggests that there could be a bigger line/ clusters of cells moving through first, and then more with a secondary line of discrete cells as the front moves through. What do y'all who know a lot more about severe weather think? The overall synoptic pattern is incredible, but what will make or break is going to be in the short term, such as WF position, junk convection, etc. 27/4/2011 was really tampered back for Middle TN because of consistent rain and convection to the south keeping things much more stable. . 1 Link to comment Share on other sites More sharing options...
nrgjeff Posted April 8, 2020 Share Posted April 8, 2020 The good the bad and the ugly. Bad first: Tonight looks like an overnight event. The Good: I don't see enough turning (low or upper level) for a big tornado risk. Wind and hail yes, especially from sups. Instability could cause some gorilla hail Midsouth. Yeah we'll have some sups, but turning wind is not that bad. Helicity forecasts are up due to speed shear, but directional is meh. The Ugly: Forecasting an Outbreak Day 5 Sunday. Who knows? Maybe a Gulf Coast MCS will rescue all of us. I mean, it is Easter! Since we can't chase right now, might as well side with the Public and wish against severe. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted April 8, 2020 Share Posted April 8, 2020 Thanks Jeff and Calderon for the replies. McMinn, sorry about the outbreak word, I was probably too loose with that as far off as things are now. It is 2020 after all though, so my mind just went to worst case right away, lol. Yeah, hopefully something kills this threat Sunday AM, no one needs power outages and other major infrastructure problems right now. 2 Link to comment Share on other sites More sharing options...
McMinnWx Posted April 8, 2020 Share Posted April 8, 2020 24 minutes ago, Holston_River_Rambler said: Thanks Jeff and Calderon for the replies. McMinn, sorry about the outbreak word, I was probably too loose with that as far off as things are now. It is 2020 after all though, so my mind just went to worst case right away, lol. Yeah, hopefully something kills this threat Sunday AM, no one needs power outages and other major infrastructure problems right now. Oh, wasn't directing that at you or anyone else! No need to say sorry! I have a little PTSD from that time. 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted April 8, 2020 Share Posted April 8, 2020 The good the bad and the ugly. Bad first: Tonight looks like an overnight event. The Good: I don't see enough turning (low or upper level) for a big tornado risk. Wind and hail yes, especially from sups. Instability could cause some gorilla hail Midsouth. Yeah we'll have some sups, but turning wind is not that bad. Helicity forecasts are up due to speed shear, but directional is meh. The Ugly: Forecasting an Outbreak Day 5 Sunday. Who knows? Maybe a Gulf Coast MCS will rescue all of us. I mean, it is Easter! Since we can't chase right now, might as well side with the Public and wish against severe.Jeff... how much influence could the cluster moving out of Ohio into Virginia effect our area? I’m worried it could lay down a secondary boundary somewhere across ETn and possibly enhance the storms by adding more shear, or even causing the surface winds to back a little. Thoughts?. 1 Link to comment Share on other sites More sharing options...
Windspeed Posted April 8, 2020 Share Posted April 8, 2020 1 Link to comment Share on other sites More sharing options...
Windspeed Posted April 8, 2020 Share Posted April 8, 2020 Link to comment Share on other sites More sharing options...
Windspeed Posted April 8, 2020 Share Posted April 8, 2020 Link to comment Share on other sites More sharing options...
Windspeed Posted April 8, 2020 Share Posted April 8, 2020 Quick discussion about a possible secondary boundary setting up SW of the current MCS complex (currently moving through EKY->SWVA->TriCities) over portions of ETN Valley later tonight when the main event rolls through. Could that add to the dynamics in play for some brief QLCS spinups? 1 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted April 8, 2020 Share Posted April 8, 2020 Quick discussion about a possible secondary boundary setting up SW of the current MCS complex (currently moving through EKY->SWVA->TriCities) over portions of ETN Valley later tonight when the main event rolls through. Could that add to the dynamics in play for some brief QLCS spinups? I think this is possible. Kinda depends on where the boundary gets laid down at. . Link to comment Share on other sites More sharing options...
Runman292 Posted April 9, 2020 Share Posted April 9, 2020 In the latest update from the SPC, the 5% Tornado probability has expanded into the Eastern Valley. Link to comment Share on other sites More sharing options...
McMinnWx Posted April 9, 2020 Share Posted April 9, 2020 9 minutes ago, Runman292 said: In the latest update from the SPC, the 5% Tornado probability has expanded into the Eastern Valley. Can you link? Link to comment Share on other sites More sharing options...
PowellVolz Posted April 9, 2020 Share Posted April 9, 2020 Can you link?. 1 Link to comment Share on other sites More sharing options...
jaxjagman Posted April 9, 2020 Author Share Posted April 9, 2020 I think the HRRR missed the boat,talk about bad ,can't say much for the other models either.Models are not doing a very good job lately Link to comment Share on other sites More sharing options...
John1122 Posted April 9, 2020 Share Posted April 9, 2020 Got extremely windy here but the storm itself never managed to connect with the line in Kentucky like SPC thought, so it didn't even rain here with the line passing. Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted April 9, 2020 Share Posted April 9, 2020 Yeah same here. Lucked out with some heavy rain to knock the pollen down though. Link to comment Share on other sites More sharing options...
jaxjagman Posted April 9, 2020 Author Share Posted April 9, 2020 1 hour ago, Holston_River_Rambler said: Yeah same here. Lucked out with some heavy rain to knock the pollen down though. I agree with the pollen,its been brutal Link to comment Share on other sites More sharing options...
McMinnWx Posted April 9, 2020 Share Posted April 9, 2020 Reed Timmer’s latest tweet is terrifying. Link to comment Share on other sites More sharing options...
Bob's Burgers Posted April 9, 2020 Share Posted April 9, 2020 Posted this in the SE thread, but if this forecast holds, high risk would seem probable if not expected. Link to comment Share on other sites More sharing options...
nrgjeff Posted April 9, 2020 Share Posted April 9, 2020 Wednesday night southwest flow apparently washed out any boundary. The veered off onslaught saved us from spinners. 19 hours ago, PowellVolz said: Jeff... how much influence could the cluster moving out of Ohio into Virginia effect our area? I’m worried it could lay down a secondary boundary somewhere across ETn and possibly enhance the storms by adding more shear, or even causing the surface winds to back a little. Thoughts? Then the 5% East Tenn. Wow it was obvious back around midday Wednesday that's not necessary. 11 hours ago, jaxjagman said: I think the HRRR missed the boat,talk about bad ,can't say much for the other models either.Models are not doing a very good job lately Might explain SPC. With all due respect, they've been way too model dependent the last couple seasons. Especially the amped up HRRR. 2 Link to comment Share on other sites More sharing options...
jaxjagman Posted April 13, 2020 Author Share Posted April 13, 2020 MJO is now headed into some favorable phases,when it gets into the eastern IO seems some uncertainty afterwards,CFS seems to want to show the GWO going -ve but still into the COD,but even so the East Asia seems like its going to get active once again.Depending on the teleconnections their could be a system in the long range as as a trough went through the Yellow Sea into S/Korea yesterday,possibly the end of next weekend we might see something.As well you should look at the ENSO,after the MJO, Kelvin and a WWB on going, region 4 might not be the hot spot but east of the IDL might be,and could excite once again the S/Jet even more down the road Link to comment Share on other sites More sharing options...
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