nj2va Posted December 15, 2020 Share Posted December 15, 2020 I’d lean mesoscale models for thermals at this point. I hope Canadian is right for the cities/close in burbs but I wouldn’t put my stock, if any, in the temp depictions. Someone smarter than me can weigh in though... 2 Link to comment Share on other sites More sharing options...
NorthArlington101 Posted December 15, 2020 Share Posted December 15, 2020 1 minute ago, PivotPoint said: I feel like the Gem is always colder. Canadians are like “ayy, what’s a couple degrees, jee golly” yeah, it takes DCA down to 24 tonight. I'd be skeptical. That said, quite the difference in guidance. I know I'd lean towards being hurt. Link to comment Share on other sites More sharing options...
psuhoffman Posted December 15, 2020 Share Posted December 15, 2020 2 minutes ago, DDweatherman said: Looking at SV maps, which are posted here above it looks like. Surface temps are also chilly. GFS thermals are like 5-7 degrees warmer. Yea but those precip plots are “previous 6 hours” and the temps are at the end of the period as temps crash on the back. Need to see the temps at 48hrs to know if it’s better or your seeing it AFTER the warm surge. Would imply at least some snow on the back but how much hard to say without that info. Link to comment Share on other sites More sharing options...
WEATHER53 Posted December 15, 2020 Share Posted December 15, 2020 1 hour ago, Ji said: whats going on here lol The high at this point is doing what it can, below zero at Canadian border. Back to snow 6-7pm Link to comment Share on other sites More sharing options...
Warm Nose Posted December 15, 2020 Share Posted December 15, 2020 5 minutes ago, ers-wxman1 said: Changes likely by morning. Understood, from your earlier statements I figured that was a foregone conclusion. Link to comment Share on other sites More sharing options...
PivotPoint Posted December 15, 2020 Share Posted December 15, 2020 For what. It’s worth hrdps starts out hot and heavy, but most area loses 540 off the bat Link to comment Share on other sites More sharing options...
ers-wxman1 Posted December 15, 2020 Share Posted December 15, 2020 1 minute ago, Warm Nose said: Understood, from your earlier statements I figured that was a foregone conclusion. Not my office anymore, but gut feeling is they’ll be coming down. Link to comment Share on other sites More sharing options...
pazzo83 Posted December 15, 2020 Share Posted December 15, 2020 2 minutes ago, NorthArlington101 said: yeah, it takes DCA down to 24 tonight. I'd be skeptical. That said, quite the difference in guidance. I know I'd lean towards being hurt. yeah our temp hasn't budged basically since sundown (39/40). Link to comment Share on other sites More sharing options...
PivotPoint Posted December 15, 2020 Share Posted December 15, 2020 Next panels even better but we might start mixing here... Link to comment Share on other sites More sharing options...
NorthArlington101 Posted December 15, 2020 Share Posted December 15, 2020 I suppose it's not shocking that the HDRPS is cold on the surface. Unlike the CMC though, the HDRPS only drops DCA to 27/28 tonight (the actual forecasted low). Keeps DCA below zero till the end of its run (48) tomorrow though. Link to comment Share on other sites More sharing options...
baltosquid Posted December 15, 2020 Share Posted December 15, 2020 Totals actually are worse on the 00z Canadian despite what's going on with the surface temps. Low gets into the Chesapeake and 850's get too warm Wednesday evening, heaviest snow is lost for I95. Link to comment Share on other sites More sharing options...
ers-wxman1 Posted December 15, 2020 Share Posted December 15, 2020 8 minutes ago, clskinsfan said: Can a met or someone smarter than me explain what the hell happened during this 6 hour period? 48 54 This is the 500 low and lift depiction. Noted this in a post earlier. Ideal for us would be a deepening 500 low closing off just to our south and phasing. Above is a progressive low, good forcing but strung out and best lift to our north. Not ideal for a good column. 3 Link to comment Share on other sites More sharing options...
clskinsfan Posted December 15, 2020 Share Posted December 15, 2020 3 minutes ago, ers-wxman1 said: This is the 500 low and lift depiction. Noted this in a post earlier. Ideal for us would be a deepening 500 low closing off just to our south and phasing. Above is a progressive low, good forcing but strung out and best lift to our north. Not ideal for a good column. Thank you! 1 Link to comment Share on other sites More sharing options...
PivotPoint Posted December 15, 2020 Share Posted December 15, 2020 Hrdps stops here but nice deform band, possible follow-up on the back side for dc area. Maybe not a lot but decent run. Still a lot more to come for norther folks after this, obviously More to come for northerns, perhaps wrap around or trailing follow-up 1 Link to comment Share on other sites More sharing options...
Warm Nose Posted December 15, 2020 Share Posted December 15, 2020 @ers-wxman1 Your earlier comments about the relative strength of the cold airmass make sense to me. This just doesn't seem to have the strength of arctic cold that we need for this close a track to hold for any length of time. Link to comment Share on other sites More sharing options...
PivotPoint Posted December 15, 2020 Share Posted December 15, 2020 CMC wasn’t a great run but models are kinda jumpy right now. I still feel like there’s some wiggle room with temps. Tonight lows and any cloud cover tomorrow to keep temps low would help. Won’t help mid levels but will help possibly keep a little more frozen action longer Link to comment Share on other sites More sharing options...
ers-wxman1 Posted December 15, 2020 Share Posted December 15, 2020 6 minutes ago, Warm Nose said: @ers-wxman1 Your earlier comments about the relative strength of the cold airmass make sense to me. This just doesn't seem to have the strength of arctic cold that we need for this close a track to hold for any length of time. Very marginal airmass, shallow, and it retreats quickly. So the maps might show the wedge all the way into Georgia, but knife deep, not much reinforcing cold to the north. Nothing aloft to reinforce the cold. heavy precipitation also has latent heat release which warms the column as well. 2 Link to comment Share on other sites More sharing options...
psuhoffman Posted December 15, 2020 Share Posted December 15, 2020 5 minutes ago, PivotPoint said: Hrdps stops here but nice deform band, possible follow-up on the back side for dc area. Maybe not a lot but decent run. Still a lot more to come for norther folks after this, obviously More to come for northerns, perhaps wrap around or trailing follow-up Gem products shifted west and warmer this cycle. That’s all I’m taking away. Link to comment Share on other sites More sharing options...
Snowchaser Posted December 15, 2020 Share Posted December 15, 2020 Seems solid. Most of us are inside 6”+ Link to comment Share on other sites More sharing options...
fujiwara79 Posted December 15, 2020 Share Posted December 15, 2020 this also isn't a classic miller B. it's closer to a miller A, if anything. And miller A's tend to have more warm air with them. Link to comment Share on other sites More sharing options...
ers-wxman1 Posted December 15, 2020 Share Posted December 15, 2020 3 minutes ago, WxWatcher007 said: What specifically in the guidance should we be looking for to determine the depth and reinforcing potential from a Canadian high? Source region of the cold airmass, extent of the cold air, depth of freezing layer, are we drawing from a true arctic airmass, wind direction...how long we hold onto the airmass etc. if we are filtering air from single digit temps with dry dews then cold air hangs in longer etc. this air mass starts around 30, not much room. 2 Link to comment Share on other sites More sharing options...
BTRWx's Thanks Giving Posted December 15, 2020 Share Posted December 15, 2020 From Mike Thomas: " For what it's worth, long range HRRR gets about 80% of the storm now and has heavy snow to sleet in DC and not full transition to rain. 0z GFS was a mix/rain dud for DC though. NWS did not change much. " Link to comment Share on other sites More sharing options...
jayyy Posted December 15, 2020 Share Posted December 15, 2020 Any shot that high stays anchored in bit longer (Better CAD than depicted) and pushes this baby south/southeast 30-40-50 miles? Or is everything too progressive at 500 mb for that to be a possibility? Link to comment Share on other sites More sharing options...
high risk Posted December 15, 2020 Share Posted December 15, 2020 4 minutes ago, BTRWx's Thanks Giving said: From Mike Thomas: " For what it's worth, long range HRRR gets about 80% of the storm now and has heavy snow to sleet in DC and not full transition to rain. 0z GFS was a mix/rain dud for DC though. NWS did not change much. " Ok, but the HRRR has been running stupidly cold for winter precip events at longer ranges. For today's cold rain, a couple of the longer range runs had 4-6" through the DC area. 2 Link to comment Share on other sites More sharing options...
Negnao Posted December 15, 2020 Share Posted December 15, 2020 Just now, high risk said: Ok, but the HRRR has been running stupidly cold for winter precip events at longer ranges. For today's cold rain, a couple of the longer range runs had 4-6" through the DC area. This is entertaining 2 Link to comment Share on other sites More sharing options...
PivotPoint Posted December 15, 2020 Share Posted December 15, 2020 19 minutes ago, psuhoffman said: Gem products shifted west and warmer this cycle. That’s all I’m taking away. LP track did shift a bit west. But I feel like the thermal profiles didn’t really shift west with it like I thought. Making me feel like the slight track shift is having a marginal effect. Maybe the fact the system is becoming more progressive means less warm air is advected at 850/925 with no rapid deepening like earlier runs? Link to comment Share on other sites More sharing options...
PivotPoint Posted December 15, 2020 Share Posted December 15, 2020 15 minutes ago, Snowchaser said: Seems solid. Most of us are inside 6”+ I wouldn’t go so far as to say “most”, ugh 3 Link to comment Share on other sites More sharing options...
Amped Posted December 15, 2020 Share Posted December 15, 2020 29 minutes ago, baltosquid said: Totals actually are worse on the 00z Canadian despite what's going on with the surface temps. Low gets into the Chesapeake and 850's get too warm Wednesday evening, heaviest snow is lost for I95. If CMC is correct this has all the makings of a bust From DC to PHI and Burbs. NYC will get a good thump but even there they will have sleet and a dryslot and struggle to make the low end of whatever ridiculously high range the NWS gives.. This looks exactly like most Non-megalopolis storms. Death band State College to Scranton to Albany to Concord. 1 Link to comment Share on other sites More sharing options...
Snowchaser Posted December 15, 2020 Share Posted December 15, 2020 TWC has a large area of 6”+. D.C 1-4” Link to comment Share on other sites More sharing options...
40westwx Posted December 15, 2020 Share Posted December 15, 2020 1 hour ago, DDweatherman said: The Canadian is a total beatdown W of 95 for a lot of folks. Track is actually W of GFS (questionable double barrel look), but much better thermal profiles. LOL at the GFS vs the Canadian for upstate New York... they hundreds of miles apart... I feel like the GFS is wrong in general Link to comment Share on other sites More sharing options...
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