tnweathernut Posted March 7, 2017 Share Posted March 7, 2017 Going to start a thread for what might be winter's last hoorah. Modeling has decided to throw parts of our area a bone and over the last several days there has been a trend further south with the elusive rain/snow line. This is primarily in response to three things. 1. A trend to a stronger low in SE Canada/Northeast US 2. A trend for more ridging out west 3. A trend for a stronger (and perfectly timed) high pressure nosing in from the upper midwest Let's try and reel one in, before we start reeling in FISH later this month. Looking forward to the discussion. Link to comment Share on other sites More sharing options...
tnweathernut Posted March 7, 2017 Author Share Posted March 7, 2017 I will add, there are several pieces of energy, so thinking there are more changes coming is a pretty good bet. Will there be the front runner that thumps snow? Will there be a Miller A to follow? Will this be the last chance? Lots of questions. Soon we will have answers. Link to comment Share on other sites More sharing options...
Carvers Gap Posted March 7, 2017 Share Posted March 7, 2017 Let's roll...12z guidance seems to really like a weak, southern trending first wave w potential for a stronger second wave. It is March and things sometimes are stronger than modeled. Seems like models have one foot and one foot out when choosing which piece of energy to jump on....I say let's pin this to the top... Link to comment Share on other sites More sharing options...
Olhausen Posted March 7, 2017 Share Posted March 7, 2017 I'm starting to really get excited for this one. Latest euro run has me at 3-4 inches of snow but a sharp cut off south of me. 45 minute drive north of me gets 5-6 inches while 45 minutes south of me gets flurries. Just a little bit more of a south shift and I'll be one happy camper. Link to comment Share on other sites More sharing options...
weathertree4u Posted March 7, 2017 Share Posted March 7, 2017 15 minutes ago, Olhausen said: I'm starting to really get excited for this one. Latest euro run has me at 3-4 inches of snow but a sharp cut off south of me. 45 minute drive north of me gets 5-6 inches while 45 minutes south of me gets flurries. Just a little bit more of a south shift and I'll be one happy camper. Was thinking the same thing really! Link to comment Share on other sites More sharing options...
BlunderStorm Posted March 7, 2017 Share Posted March 7, 2017 The Last Hurrah! While cold is going to be in little supply for our potential snowstorm I am concentrated and worried about the weakening of the low pressure system as a whole. How does the Low look on the latest Euro? Link to comment Share on other sites More sharing options...
Carvers Gap Posted March 7, 2017 Share Posted March 7, 2017 Looks to me like we have three options... 1. First wave is THE main piece of energy. This option looks less likely. 2. Strung-out mess w a chance for snow fo northern areas of the forum area along the TN/KY border. Second piece of energy goes OTS. Time of day is important. 3. First wave weakens and the trailing energy forms a Miller A. I give option two a 40% chance. I give option three a 35% chance. I give option one a 25% chance. Link to comment Share on other sites More sharing options...
Carvers Gap Posted March 7, 2017 Share Posted March 7, 2017 MRX afternoon disco... LONG TERM...(Wednesday night through Tuesday)... A ridge of high pressure and zonal flow aloft for Wednesday night and Thursday producing dry conditions and warm afternoon conditions. For Thursday night and Friday morning, a frontal boundary will move across the Tennessee Valley and southern Appalachians. Due to the persistent ridging into the Gulf of Mexico, this boundary will be moisture starved with only light showers anticipated. However, much cooler temperatures will spill into the Region as a cold airmass moves into the Ohio/Tennessee Valleys. Main concern for the extended is the potential of wintry conditions for southern Virginia, northern third of Tennessee, and far eastern Tennessee Mountains for Saturday night and Sunday. This is still several days out, but models show a strong 300mb jet moving across the Ohio Valley/mid-Appalachian region placing our area into the favored Right Entrance of the jet. Even though we have warm air advection at 06z Sunday, models show strong cooling of the vertical column which suggest strong forcing. Looking at the vertical cross-section, strong ageostrophic vertical circulation noted over the area so good diabatic cooling anticipated. Forecast soundings over southwest Virginia look snowy, so will need to watch over the next several days for the potential of Wintry conditions for Saturday night and Sunday (especially morning). Link to comment Share on other sites More sharing options...
Carvers Gap Posted March 7, 2017 Share Posted March 7, 2017 OHX AFD... Both the GFS and ECMWF have trended colder for the Saturday/Sunday system over the mid state. By 00Z Sunday, both the GFS and ECMWF have the 0C 850mb isotherm at the KY/TN border. By 06Z, the 0C line is around the I-40 corridor. With continued CAA overnight, any remaining QPF would likely fall as frozen precipitation, however by 12Z both models do not show very much QPF over the CWA. Right now the area of concern should these model runs verify would be Saturday evening into the early morning hours Sunday north of I-40, where some frozen precip may mix in with rain. If precip lingers around much after that, it looks to be mainly snow. It will be interesting to see if the models continue the colder trend, or, decide to shift the cooler air back northward to leave a cold rain for Saturday night. Left in mention of lingering showers over the Plateau on Sunday morning, and the remainder of the day Sunday along with Monday looks to be dry. Another trough swings down from the Midwest later on Monday, but most of the precip currently looks to remain north of the TN/KY border. Kept dry mention for now on Monday, but threw in precip chances for mainly areas east of I-65 Monday night and Tuesday as the upper trough clips the eastern zones. Link to comment Share on other sites More sharing options...
Mrwolf1972 Posted March 7, 2017 Share Posted March 7, 2017 18z even further south Link to comment Share on other sites More sharing options...
John1122 Posted March 7, 2017 Share Posted March 7, 2017 18z is ever so slighty further south with the frozen line through 102. HP is a big stronger over the top. 1043 vs 1041 and slightly further sw of it's 12z position. The low off the NE coast that keeps this thing suppressed is also a little deeper at 500. Link to comment Share on other sites More sharing options...
John1122 Posted March 7, 2017 Share Posted March 7, 2017 Yeah, 18z definitely brings it. Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 00z wobbled north by 50 miles or so. We may have finally seen the southern extent of it's movement on there. The GFS track is still slightly north of the Euro and also north of the Canadian. Link to comment Share on other sites More sharing options...
Kentucky Posted March 8, 2017 Share Posted March 8, 2017 11 minutes ago, John1122 said: 00z wobbled north by 50 miles or so. We may have finally seen the southern extent of it's movement on there. The GFS track is still slightly north of the Euro and also north of the Canadian. Really hoping we can cash in on this upcoming system, hardly even a trace all winter here in Corbin. Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 It's subject to change, but you appear to be in a sweet spot on most GFS runs. The Canadian was just a bit too far south for you at 12z but I bet it comes north this run. The Euro was pretty good for your area too. Link to comment Share on other sites More sharing options...
Kentucky Posted March 8, 2017 Share Posted March 8, 2017 Usually if I get snow, you get snow. Or vice versa. We'll see what the ECMWF has to offer. Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 Canadian is a snowy miller A, heavy snow along the heart of the 40 corridor with 2-6 inches roughly from just north of Memphis/Jackson to Nashville to Knoxville. The accumulating snow area was further south in the western half of the valley this run vs 12z. Similar in the eastern areas, though it to was slightly further south with it's heaviest axis. Right now, if I had to pick a non-elevated place to be in our region, it'd probably be somewhere in Kentucky or SWVA. I think the general track is basically settled and small shifts of 50 or so miles will occur based on the strength of some upper level features when showtime actually happens. Just have to see how many of those happen and which direction they go. Link to comment Share on other sites More sharing options...
1234snow Posted March 8, 2017 Share Posted March 8, 2017 Y'all can thank me if this system pans out. I cancelled my WeatherBell subscription just a few days ago. I really thought spring was going to be kicking into full gear. I was shocked to see the local news mention it on Facebook. 0z GFS looked more like the 12z instead of the 18z. Was a little warmer across the board. 0z CMC actually trended a little south with the rain snow line. With that said totals on the CMC were cut down some and was due to lesser QPF on the front thump. It appears to me by just looking at a few runs that we are dealing entirely with 2 separate waves of energy. The second wave has the potential for a big dog for the east coast. I think we need to put our chips in the wave 1 basket. I wish I could do pbp on the Euro but oh well lol. Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 The CMC was close to a blizzard/big snow type storm, but it just missed the triple phase. March and November are our monster snow event months. They stick around longer in Dec-Feb but the 12-20 inch type storms almost always happen in November or March. Link to comment Share on other sites More sharing options...
1234snow Posted March 8, 2017 Share Posted March 8, 2017 Canadian is a snowy miller A, heavy snow along the heart of the 40 corridor with 2-6 inches roughly from just north of Memphis/Jackson to Nashville to Knoxville. The accumulating snow area was further south in the western half of the valley this run vs 12z. Similar in the eastern areas, though it to was slightly further south with it's heaviest axis. Right now, if I had to pick a non-elevated place to be in our region, it'd probably be somewhere in Kentucky or SWVA. I think the general track is basically settled and small shifts of 50 or so miles will occur based on the strength of some upper level features when showtime actually happens. Just have to see how many of those happen and which direction they go. The GFS is more amped and favors Kentucky while the CMC favors Tennessee. I would lean toward the GFS slightly right now with a little warmer solution. Both are very similar though and are good hits for parts of the forum. Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 The Euro looks absolutely great tbh. Wide spread 3-6 inches for all but the southern parts of the forum. Dyersburg 3-5 Clarksville 3-5, Nashville 3-5, Crossville 3-5, Knoxville 3-5, Tri 3-6, SEKy 3-4, SWVA 3-5. If you border AL/GA/MS you basically get shut out with that line rising as you go west. Link to comment Share on other sites More sharing options...
Kentucky Posted March 8, 2017 Share Posted March 8, 2017 32 minutes ago, John1122 said: The Euro looks absolutely great tbh. Wide spread 3-6 inches for all but the southern parts of the forum. Dyersburg 3-5 Clarksville 3-5, Nashville 3-5, Crossville 3-5, Knoxville 3-5, Tri 3-6, SEKy 3-4, SWVA 3-5. If you border AL/GA/MS you basically get shut out with that line rising as you go west. Thanks for the update, hope we get something out of this. We have missed out all winter long, snow to the north and south. Link to comment Share on other sites More sharing options...
Daniel Boone Posted March 8, 2017 Share Posted March 8, 2017 Hopefully this thing pans out. Glad you brought up the point regarding November and March being our big snow months. BTW, saw earlier posts about the March 9-10 ,1960 storm. The official total for closest to here was 20" in Pennington gap by official NWS spotter Ernest Frye. I wouldn't be surprised if it was probably a bit more as measurement criteria was different back then as they were taken after snow had ended, and sometimes that would be several hours afterward as they would measure after getting up in the morning. Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 The snow line wobbled back south on the 06z gfs. You could see that the HP in the upper midwest/southern Canada was going to be stronger. The airmass in Canada under the big high is the coldest in that region in 60 years at this time of year. The cold air is there to tap. I-40 and north corridor looks to do really well on the Euro/Canadian and the GFS at this point. Link to comment Share on other sites More sharing options...
Reb Posted March 8, 2017 Share Posted March 8, 2017 What timeframe are we looking at, John? All models look to be on board ATM Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 Generally Saturday afternoon sees snow spreading across the state between 1 and 7pm. The heaviest snow from Nashville to Knox and points north occurs between 7pm Saturday and 7 am Sunday morning. Link to comment Share on other sites More sharing options...
Mrwolf1972 Posted March 8, 2017 Share Posted March 8, 2017 Looks close to what cmc showed last. Night Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 The airmass is cold in areas north of 40 during the event. Down in the 20s. It actually ratios out a little higher than it 10:1s along the border counties, SEKY and SWVA. You get some 12-14:1 ratios over those areas at the height of the storm. Along 40 where the rain/snow line sets up you get ratios as low as 5:1. We're talking over a 20-30 mile distance. My ratio is 12:1 at hour 90 and northern Knox is 5:1 but the cold quickly crashes into the Knox area as the storm winds up to the south. Same as you head west. Nashville looks to be 10:1 while a county or so south you get 5:1 then rain quickly. Wherever the edge sets up you're liable to go from 3-5 inches of snow to just rain over a very short stretch. Some ice is still being advertised on this side of the Apps, much more so in Western NC. Link to comment Share on other sites More sharing options...
John1122 Posted March 8, 2017 Share Posted March 8, 2017 The crazy thing is, this may not even be the last gasp. A lot of cold and a parade of clippers is in the pipeline per the GFS. This event is 48-72 hours after the first event. I am not saying it's going to happen, but in March of 1960 we had big snow events 3 consecutive Wednesdays, and in-between clipper/NW flow events. Link to comment Share on other sites More sharing options...
1234snow Posted March 8, 2017 Share Posted March 8, 2017 6z was a thing of beauty. Wave one gets the Tennessee Valley and wave 2 bombs out and hits the Northeast. Everyone gets in on the action. Like John said the high pressure in the Midwest was a few mbs stronger that run. Also the wave was a little more positively titled just ever so slightly. I think that with the look at 500mb we will not see this storm trend significantly north at the last second. Yes, there will probably be some adjustments north before the storm arrives but I like where we stand. Link to comment Share on other sites More sharing options...
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