OSUmetstud Posted December 28, 2015 Share Posted December 28, 2015 8 to as much as 15 cm for toronto and peel areas. Quick transition through zr and ip to plain rain and drizzle. 20 to 30 cm for Ottawa/Renfrew/Algonquin Any decent icing is relegated to Guelph-east imo. Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 28, 2015 Share Posted December 28, 2015 edit: mean Guelph-west. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 8 to as much as 15 cm for toronto and peel areas. Quick transition through zr and ip to plain rain and drizzle. 20 to 30 cm for Ottawa/Renfrew/Algonquin Any decent icing is relegated to Guelph-east imo. lol this is new (to me at least). Flatrock, NL? I never even heard of it. I do know it's a long wayz away from BUF. Thanks for your input Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 28, 2015 Share Posted December 28, 2015 lol this is new. Flatrock, NL? I never even heard of it. I do know it's a long wayz away from BUF. Thanks for your input About 15 km north of St. John's. I had to forecast for those areas today. We forecast for a bunch of Ontario Municipalities. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 About 15 km north of St. John's. I had to forecast for those areas today. We forecast for a bunch of Ontario Municipalities. Cool. Glad to have a red tagger chime in. You work for EC or private sector? Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 28, 2015 Share Posted December 28, 2015 Cool. Glad to have a red tagger chime in. You work for EC or private sector? Amec Foster Wheeler...combo of contract stuff with terrestrial companies/govt and offshore drilling rigs. Closest EC weather office would be Gander, NL. There's none in St. John's. Although, I have to say...EC...blah. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 Amec Foster Wheeler...combo of contract stuff with terrestrial companies/govt and offshore drilling rigs. Closest EC weather office would be Gander, NL. There's none in St. John's. Although, I have to say...EC...blah. Agreed with the bolded. Back to the storm...RGEM is really beefed up with the QPF shows widespread 30-40mm across S Ontario. For Toronto, the breakdown is 5-10mm as snow, <5mm as rain, and 15-20mm as ice pellets. I could live with 5-10cm of snow and 5-10cm of ice pellets. Probably too wet though. Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 28, 2015 Share Posted December 28, 2015 Agreed with the bolded. Back to the storm...RGEM is really beefed up with the QPF shows widespread 30-40mm across S Ontario. For Toronto, the breakdown is 5-10mm as snow, <5mm as rain, and 15-20mm as ice pellets. I could live with 5-10cm of snow and 5-10cm of ice pellets. Probably too wet though. Id be surprised to see that much as ice pellets honestly. These tend to thump snow on the edge of the cold dome with strong lift...The high is sliding east with temp nothing to keep the surface from warming aside from in situ. Link to comment Share on other sites More sharing options...
harrisale Posted December 28, 2015 Share Posted December 28, 2015 Thinking I'll be in for a decent amount of freezing rain in addition to the snow and pellets. Tricky forecast in play, no doubt. Thinking areas west of Toronto will see heaviest accumulations of Freezing Rain (Kitchener-Waterloo, London, Goderich and especially Stratford). I suspect those areas will have more than 0.15" of ZR accretion. Ran BUFKIT for CYKF and the latest NAM shows 4 hours of IP followed by 6 hours of ZR. No snow at all. Ice would be equivalent to over 10-15mm (about a half inch) of precip which would be pretty substantial given the 35kt momentum transfer. I've always found these 4 p-type events kind of cool. There's always a surprise or two in store. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 Id be surprised to see that much as ice pellets honestly. These tend to thump snow on the edge of the cold dome with strong lift...The high is sliding east with temp nothing to keep the surface from warming aside from in situ. Hope so. NAM is indicating all PL, but the thermal profile (per soundings) initially is pretty marginal and could easily be snow. As the WAA strengthens then the depth of the warm layer increases to the point where PL is more likely. Models don't seem to do well at discerning when multiple p-types will be falling at a given location. At least that's the impression I get when looking at p-type maps. Everything's compartmentalized into discrete categories. Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 28, 2015 Share Posted December 28, 2015 Hope so. NAM is indicating all PL, but the thermal profile (per soundings) initially is pretty marginal and could easily be snow. As the WAA strengthens then the depth of the warm layer increases to the point where PL is more likely. Models don't seem to do well at discerning when multiple p-types will be falling at a given location. At least that's the impression I get when looking at p-type maps. Everything's compartmentalized into discrete categories. No youre right ptype stuff is hard. Both because its not always obvious and because of model error when small changes result in big impact outcomes ie zr vs. Ip. It happened it ottawa this morning. Yesterdays soundings were clearly sleet but warm nose under modeled...and you get zr. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 GFS continues to be our best friend. Seems to evaporatively/dynamically cool us to a predominantly snow event east of the escarpment. Have been a few sneaky, under-forecasted front-end thumps in the past. February 8, 2001 and March 1, 2007 come to mind. Nothing much in the last 7-8 years though from my recollection. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 Thinking I'll be in for a decent amount of freezing rain in addition to the snow and pellets. Tricky forecast in play, no doubt. Thinking areas west of Toronto will see heaviest accumulations of Freezing Rain (Kitchener-Waterloo, London, Goderich and especially Stratford). I suspect those areas will have more than 0.15" of ZR accretion. Ran BUFKIT for CYKF and the latest NAM shows 4 hours of IP followed by 6 hours of ZR. No snow at all. Ice would be equivalent to over 10-15mm (about a half inch) of precip which would be pretty substantial given the 35kt momentum transfer. I've always found these 4 p-type events kind of cool. There's always a surprise or two in store. I agree. Adds a layer of excitement to the whole thing (looking at upsteam obs, checking highway cams to find the transition line, constantly going outside to see if you can hear pinging). Link to comment Share on other sites More sharing options...
blizzardof96 Posted December 28, 2015 Share Posted December 28, 2015 When taken verbatim, the 0z NAM has little in the way of snow for the GTA. The 700-800mb warm layer looks weak at first but is pretty significant once the main band moves through. 850-700mb thicknesses are warm enough to fully melt the precip in the column as sfc temps are flirting with the freezing mark(just above). The saving grace is the cold BL which is probably why p-type algorithms have it as PL before 12z tuesday, instead of RN/ZR. Link to comment Share on other sites More sharing options...
blizzardof96 Posted December 28, 2015 Share Posted December 28, 2015 The 0z RGEM has a similar look with 850-700mb thicknesses >155(supportive of RN/ZR) yet 100-850mb are <129(support PL reformation). The 850-700mb WAA looks too aggressive for any significant snow. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 WSW dropped for the GTA. I don't think it's that bad of a call. If this is mostly a PL storm total amounts are going to be underwhelming. 5-10cm seems like a good call assuming a couple of hours of SN to start. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 HRRR showing snow to start.... Link to comment Share on other sites More sharing options...
blizzardof96 Posted December 28, 2015 Share Posted December 28, 2015 Just scanned over hrrr BUFKIT data. The warm layer at ~800mb is >0c at the onslaught of precip and then cools to a snow sounding after a couple of hours. The weird thing is that the t/d spread at 795 mb is 0.6/-31c when light precip starts and becomes 1.3/-10 once the heavy precip moves in. Seems a bit weird. If H8 dew points are that cold(-30c), then it shouldn't be too tough to bulb down to +SN for a while. Link to comment Share on other sites More sharing options...
blizzardof96 Posted December 28, 2015 Share Posted December 28, 2015 12z sounding OBS at BUF seem to confirm the initial dry layer between 850-500mb. Huge t/td spreads. Link to comment Share on other sites More sharing options...
Sub_Zero Posted December 28, 2015 Share Posted December 28, 2015 Looking good Link to comment Share on other sites More sharing options...
harrisale Posted December 28, 2015 Share Posted December 28, 2015 Parents house in Oakville already getting some light (albeit extrememly light) snow falling, lending credence to that lake band on the models. East flow off the lake could help saturate and eat through some of that dry air. Link to comment Share on other sites More sharing options...
mississaugasnow Posted December 28, 2015 Share Posted December 28, 2015 Parents house in Oakville already getting some light (albeit extrememly light) snow falling, lending credence to that lake band on the models. East flow off the lake could help saturate and eat through some of that dry air. Same thing here in south Mississauga. Just some extremely light snow falling for the last 20 minutes or so. Link to comment Share on other sites More sharing options...
Sub_Zero Posted December 28, 2015 Share Posted December 28, 2015 Jackpot from Petawawa to Montreal Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 Just took a look at the 19z RAP soundings. Its p-type algorithm is indicating the brunt of the precip in Toronto is going to be in the form of pellets. But when you look at the sounding it has the entire column below freezing up until 4z, when 0.60" of liquid equivalent has fallen. Link to comment Share on other sites More sharing options...
dan123 Posted December 28, 2015 Share Posted December 28, 2015 Just took a look at the 19z RAP soundings. Its p-type algorithm is indicating the brunt of the precip in Toronto is going to be in the form of pellets. But when you look at the sounding it has the entire column below freezing up until 4z, when 0.60" of liquid equivalent has fallen. Means more snow? Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 Means more snow? You'd think. HRRR has a better handle on the p-type, with SN to PL then back to +SN during heavier precip before 4z, then PL exclusively until we turn to -RA/DZ around 9z. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 The dirty fantasy with this storm lies in the fact that it's so juicy. All the models are showing around 1" qpf with the front-end thump. So if we can somehow, someway stay predominately snow this has 20cm+ potential. That's not my forecast obviously but it's what the weenie in all of us should be rooting for. uvvs of -20 ubars/s and some elevated CAPE as well. Maybe a rumble of thunder? Link to comment Share on other sites More sharing options...
dan123 Posted December 28, 2015 Share Posted December 28, 2015 The dirty fantasy with this storm lies in the fact that it's so juicy. All the models are showing around 1" qpf with the front-end thump. So if we can somehow, someway stay predominately snow this has 20cm+ potential. That's not my forecast obviously but it's what the weenie in all of us should be rooting for. uvvs of -20 ubars/s and some elevated CAPE as well. Maybe a rumble of thunder? Too bad this isn't all snow for us. Areas to the north are going to cash in nicely. Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 28, 2015 Share Posted December 28, 2015 The dirty fantasy with this storm lies in the fact that it's so juicy. All the models are showing around 1" qpf with the front-end thump. So if we can somehow, someway stay predominately snow this has 20cm+ potential. That's not my forecast obviously but it's what the weenie in all of us should be rooting for. uvvs of -20 ubars/s and some elevated CAPE as well. Maybe a rumble of thunder? Still think 9 to 12 cm for Peel south to north before changeover. Not much ip/zr in my estimation. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 28, 2015 Share Posted December 28, 2015 Still think 9 to 12 cm for Peel south to north before changeover. Not much ip/zr in my estimation. So you think 9-12 then a change over basically to rain (brief zr/ip interlude)? That's definitely going against the models, which are showing IP being a dominant p-type form. Mad props if you're right. Link to comment Share on other sites More sharing options...
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