snowstormcanuck Posted January 31, 2015 Share Posted January 31, 2015 In 2007-08 we saw two storms at or above 30cm. The Dec 15-17th one and the early February storm. I noticed SSC didn't include that in his list. The most recent one is the Feb, 2013 storm. The Feb 2014 storm was a close one. Dec 2007, was 30cm+ downtown, but not at YYZ. Feb 2008 was 30cm+ at YYZ, but not downtown. When tabulating Toronto snowstorms, I always use the downtown data because of the measuring issues at YYZ. But I'm not going to throw a YYZ storm into the list because it's favourable. It unduly inflates the list. Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 The GFS coming in slightly further N than the 12z. Link to comment Share on other sites More sharing options...
Ottawa Blizzard Posted January 31, 2015 Share Posted January 31, 2015 I'm guessing about 4-6" for my area of the city. Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 Yeah, it's about 15:1. Another tick to the north would help in getting those better dynamics near the sfc to help with dendrite production. Here's the sounding: yyzbufkit.jpg Yellow line represents the DGZ, grey line is the uvvs (the more to the left the line goes, the better the lift). Not quite intersecting. Nice appreciate it. Wouldn't be surprised if we saw some deformation bands esp. if the storm can track just 50 or so miles further north. Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 Dec 2007, was 30cm+ downtown, but not at YYZ. Feb 2008 was 30cm+ at YYZ, but not downtown. When tabulating Toronto snowstorms, I always use the downtown data because of the measuring issues at YYZ. But I'm not going to throw a YYZ storm into the list because it's favourable. It unduly inflates the list. Oh i see your point. The Dec 2007 storm was underestimated at YYZ as was the March 08 blizzard. Had they not been, I'm confident it would have been the snowiest Winter on record. We just needed 15cm i believe. Oh well. Compared to DTW, we do see bigger storms overall. Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 18z GFS consistent with the 18z Nam. Shows 15-20cm for Toronto proper with the 25cm line just hugging the Western regions. Link to comment Share on other sites More sharing options...
WestCoaster Posted January 31, 2015 Share Posted January 31, 2015 Wow amazing. 15-20cm would be a repeat of that Dec 11th storm which i wouldn't mind at all. What ratios are we looking at? 15:1 sounds reasonable. Something I learned in my met classes was that snow ratios are super tricky to pinpoint (since they aren't constant during an entire event) but the best way to identify it is to look at sounding (Tephigram, Skew-T, pick your poison) and look at the pressure levels displaying near saturation. If there are multiple points of saturation, take the point with the highest temperature. Then use that temperature to estimate your ratio. -16C --> 25:1 -14C --> 23:1 -12C --> 17:1 -10C --> 12:1 -8C --> 10:1 -6C --> 9:1 Based on the GFS it seems like we hover around -12C at the max saturation pressure levels (850-700 mb) for the juicy part of the precip, with some -14C rates at the onset of precip. I'd say 16:1 is probably a better ratio off the 12Z GFS only. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted January 31, 2015 Share Posted January 31, 2015 18z GFS looks very similar to the 12z run. Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 Something I learned in my met classes was that snow ratios are super tricky to pinpoint (since they aren't constant during an entire event) but the best way to identify it is to look at sounding (Tephigram, Skew-T, pick your poison) and look at the pressure levels displaying near saturation. If there are multiple points of saturation, take the point with the highest temperature. Then use that temperature to estimate your ratio. -16C --> 25:1 -14C --> 23:1 -12C --> 17:1 -10C --> 12:1 -8C --> 10:1 -6C --> 9:1 Based on the GFS it seems like we hover around -12C at the max saturation pressure levels (850-700 mb) for the juicy part of the precip, with some -14C rates at the onset of precip. I'd say 16:1 is probably a better ratio off the 12Z GFS only. Wow nice man. It would be great if you could do these kinds of analyses more often. Temperatures at 850mb look to be around -15 to -17C and -11C to -13C at the surface during the heaviest rates. Alot of moisture feed going into this storm with a strong jet streak in the upper atmosphere (300mb). A slight shift northward could mean huge differences in amounts so hoping for that. Link to comment Share on other sites More sharing options...
WestCoaster Posted January 31, 2015 Share Posted January 31, 2015 If I've learned anything about these south-sliders, it's to not discount areas along the 401. Time after time I've seen models show a steady gradient loss north of the city with systems like these, only to see a juicy deformation band hug the 401 the entire event. I hate to say it, but I kind of like the uncertainty with this thing. I only wish it were hitting at a different time of day... it looks like this is going to be at its peak during the overnight hours on Sunday night/Monday morning. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted January 31, 2015 Share Posted January 31, 2015 Oh i see your point. The Dec 2007 storm was underestimated at YYZ as was the March 08 blizzard. Had they not been, I'm confident it would have been the snowiest Winter on record. We just needed 15cm i believe. Oh well. Compared to DTW, we do see bigger storms overall. Dec 2007 was fine at Pearson. I only measured 22cm in my backyard. They were similar. Downtown racked up 30cm+ because of enhancement off Lk. Ontario. Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 Got an Accounting Test on Monday and I know it won't be enough to cancel classes, but if so, I'd be happy, lol. Link to comment Share on other sites More sharing options...
WestCoaster Posted January 31, 2015 Share Posted January 31, 2015 11" line looks to get very close to the GTA on the 18Z GFS Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 Dec 2007 was fine at Pearson. I only measured 22cm in my backyard. They were similar. Downtown racked up 30cm+ because of enhancement off Lk. Ontario. If i remember correctly i recorded 24cm. That March blizzard was amazing. I recorded 32cm with that. Link to comment Share on other sites More sharing options...
blizzardof96 Posted January 31, 2015 Share Posted January 31, 2015 18z GFS looks very similar to the 12z run. Similar but even juicier with the defo band. QPF will match the NAM pretty closely. Link to comment Share on other sites More sharing options...
Ottawa Blizzard Posted January 31, 2015 Share Posted January 31, 2015 6" would be amazing when you consider that we weren't even expecting to get impacted by this a few days ago. Link to comment Share on other sites More sharing options...
blizzardof96 Posted January 31, 2015 Share Posted January 31, 2015 18z QPF Zoomed in Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 18z QPF Zoomed in gfs_tprecip_toronto_11.png Right on the edge. If we can get a nice defo band to set-up, it could easily increase our amounts locally. Link to comment Share on other sites More sharing options...
blizzardof96 Posted January 31, 2015 Share Posted January 31, 2015 Going to bump my call to 5-8". Link to comment Share on other sites More sharing options...
WestCoaster Posted January 31, 2015 Share Posted January 31, 2015 Going to bump my call to 5-8". My call has been 6-8" which I feel very nervous about in both directions. Crazy. Link to comment Share on other sites More sharing options...
blizzardof96 Posted January 31, 2015 Share Posted January 31, 2015 My call has been 6-8" which I feel very nervous about in both directions. Crazy. Tis the winter for huge last minute changes. You're absolutely on point. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted January 31, 2015 Share Posted January 31, 2015 Yeah, I'm going to go with the consensus and bump amounts to about 6". + 1/2" along Lk Ontario, -1/2" along Steeles/Highway 7. Final call until we get this to within nowcasting time and can start analyzing trends. Link to comment Share on other sites More sharing options...
Snowstorms Posted January 31, 2015 Share Posted January 31, 2015 18z RGEM Link to comment Share on other sites More sharing options...
snowstormcanuck Posted January 31, 2015 Share Posted January 31, 2015 Chris Scott: Chris Scott @ChrisScottWx 6m6 minutes ago Increasing confidence that #Toronto itself will get slammed by #onstorm Sun night-Mon morn. WON'T be a case where the downtown escapes 0 replies 9 retweets 4 favorites I dunno about "slammed". Very unlikely we get the type of foot plus amounts that may occur in Hamilton/Niagara, but at least he's raising awareness about this storm more than EC is with their bury their head up their ass approach to forecasting. Link to comment Share on other sites More sharing options...
Ottawa Blizzard Posted January 31, 2015 Share Posted January 31, 2015 Going to bump my call to 5-8". You thinking 5" is possible for the McCowan and Steeles area? Link to comment Share on other sites More sharing options...
Ottawa Blizzard Posted January 31, 2015 Share Posted January 31, 2015 Chris Scott: Chris Scott @ChrisScottWx 6m6 minutes ago Increasing confidence that #Toronto itself will get slammed by #onstorm Sun night-Mon morn. WON'T be a case where the downtown escapes 0 replies 9 retweets 4 favorites I dunno about "slammed". Very unlikely we get the type of foot plus amounts that may occur in Hamilton/Niagara, but at least he's raising awareness about this storm more than EC is with their bury their head up their ass approach to forecasting. This. It seems to be a running theme with EC. Link to comment Share on other sites More sharing options...
WestCoaster Posted January 31, 2015 Share Posted January 31, 2015 I think there is too much to fight to the north for this thing to clobber the GTA. 10-15 cm will be disappointing if everyone else scores big. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted January 31, 2015 Share Posted January 31, 2015 I think there is too much to fight to the north for this thing to clobber the GTA. 10-15 cm will be disappointing if everyone else scores big. I don't think I'll feel the same way. Dec 2014 storm dropped a nice 20-25cm over us, no one else saw a flake. Feb 2013, 30-40cm for us, virtually no one else in this subforum saw anything more than a few inches. It happens. I'm glad we're getting sloppy seconds rather than nothing at all. Link to comment Share on other sites More sharing options...
WestCoaster Posted January 31, 2015 Share Posted January 31, 2015 Liking the northern precip field development, particularly in southern Minnesota: http://radar.weather.gov/Conus/full_loop.php Link to comment Share on other sites More sharing options...
dan123 Posted January 31, 2015 Share Posted January 31, 2015 Good for chris Scott. He really knows his stuff. Too bad he isn't an on-air meteorologist at TWN anymore. Link to comment Share on other sites More sharing options...
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