wxdude64 Posted February 18, 2019 Share Posted February 18, 2019 40 minutes ago, WxMan1 said: NAM3 sfc temps at 00Z Thurs. Certainly not ideal for appreciable ice accretion, especially with higher rates (which more runoff). But, light fzra or fzdz at 32°F is certainly more efficient, especially on elevated surfaces, as we saw with the recent event in/near Mt. Airy. You just have to love CAD and our mountains! Look at the spread between Blacksburg (27) and Bristol (57) on that map. If the models are off just a bit and we hang on to the CAD several hours longer I can see a potential for .25/.5 of freezing rain in western VA areas. 1 Link to comment Share on other sites More sharing options...
AmericanWxFreak Posted February 18, 2019 Share Posted February 18, 2019 Link to comment Share on other sites More sharing options...
LP08 Posted February 18, 2019 Share Posted February 18, 2019 GFS is still hitting south of dc with the intense snow for Wednesday until about 1-3 pm. Link to comment Share on other sites More sharing options...
snjókoma Posted February 18, 2019 Share Posted February 18, 2019 The GFS has functionally shown the same thing for the past five runs. Pretty impressive consistency on putting the heaviest band just south of DC. Could be consistently wrong. 1 Link to comment Share on other sites More sharing options...
snowfan Posted February 18, 2019 Share Posted February 18, 2019 By 18Z Wed, the GFS has DC barely holding onto the column. Probs some heavy riming. You can see the affect of the heavier precip south of DC.....the column is cooler south of DC near Fredericksburg.....heavy snow. Link to comment Share on other sites More sharing options...
snowfan Posted February 18, 2019 Share Posted February 18, 2019 By 0Z Wed, DC and Bmore lose the entire column. At that point, there's an inch of precip for BWI and 1.25" for DC. Link to comment Share on other sites More sharing options...
stormtracker Posted February 18, 2019 Author Share Posted February 18, 2019 I actually feel better being in the middle of the GFS and NAM band. It's like the ICON if you average it out. I just kinda wonder why the GFS likes just south of the area while others don't. 2 Link to comment Share on other sites More sharing options...
SomeguyfromTakomaPark Posted February 18, 2019 Share Posted February 18, 2019 3 minutes ago, snowfan said: By 18Z Wed, the GFS has DC barely holding onto the column. Probs some heavy riming. You can see the affect of the heavier precip south of DC.....the column is cooler south of DC near Fredericksburg.....heavy snow. Yessir, whereever that heavy band sets up is gonna be fun. Link to comment Share on other sites More sharing options...
ers-wxman1 Posted February 18, 2019 Share Posted February 18, 2019 Keep in mind Global solutions like the GFS, CMC, and Euro won’t clue into the short range as effective with a setup like this. CAD may be underdone and eroded too quickly. 2 Link to comment Share on other sites More sharing options...
wxdude64 Posted February 18, 2019 Share Posted February 18, 2019 1 minute ago, stormtracker said: I actually feel better being in the middle of the GFS and NAM band. It's like the ICON if you average it out. I just kinda wonder why the GFS likes just south of the area while others don't. I'll be honest, I haven't looked at models yet, but maybe the GFS has a slightly stronger H to the north of us (wall)? Link to comment Share on other sites More sharing options...
snowfan Posted February 18, 2019 Share Posted February 18, 2019 GFS basically discounts icing as a concern in the metro area, but we know it's struggles w/CAD. As for snow, it's a general 3-6" snowfall with more in higher spots south and southwest. Link to comment Share on other sites More sharing options...
DDweatherman Posted February 18, 2019 Share Posted February 18, 2019 The RGEM 12z at h48 was setting up to do some crushing, heavy snows moving SW to NE up through CVA. That's about the ideal precip orientation and movement. 1 Link to comment Share on other sites More sharing options...
jaydreb Posted February 18, 2019 Share Posted February 18, 2019 Just now, ers-wxman1 said: Keep in mind Global solutions like the GFS, CMC, and Euro won’t clue into the short range with a setup like this. CAD may be underdone and eroded too quickly. Is the main issue the extent of the CAD or the trajectory of the storm and placement of the heaviest banding? I suppose it’s both. Link to comment Share on other sites More sharing options...
high risk Posted February 18, 2019 Share Posted February 18, 2019 22 minutes ago, WxUSAF said: I thought they were essentially abandoned years ago. I think the NAM has a planned sunset as well? @dtk? There won't be any further upgrades to the NAM, although it's not clear when it can be turned off. As long as the GFS struggles in cold air damming events and with instability in general, the NAMs will stay. The NAM3 sometimes runs a bit cold in damming events and can be too wet, but it's far superior to the GFS in overall handling of this type of event. We saw that very clearly with the November storm. 3 1 Link to comment Share on other sites More sharing options...
Hyphnx Posted February 18, 2019 Share Posted February 18, 2019 RGEM showing heavy snow in CVA at h46. Still snowing at h48 with the ice coming in around h50. 1 Link to comment Share on other sites More sharing options...
psuhoffman Posted February 18, 2019 Share Posted February 18, 2019 35 minutes ago, WxUSAF said: All setups. 3k NAM certainly has value as does the Canadian mesos IMO. The rgem looked good at 48 imo. It seemed in the “south” camp with the initial fronto banding. 15 minutes ago, snjókoma said: The GFS has functionally shown the same thing for the past five runs. Pretty impressive consistency on putting the heaviest band just south of DC. Could be consistently wrong. 8 minutes ago, stormtracker said: I actually feel better being in the middle of the GFS and NAM band. It's like the ICON if you average it out. I just kinda wonder why the GFS likes just south of the area while others don't. This!!!! Being in between two major model camps (gfs/rgem v euro NAM) isn’t a bad place to be as usually some kind of compromise ends up reality. 3 Link to comment Share on other sites More sharing options...
psuhoffman Posted February 18, 2019 Share Posted February 18, 2019 4 minutes ago, high risk said: There won't be any further upgrades to the NAM, although it's not clear when it can be turned off. As long as the GFS struggles in cold air damming events and with instability in general, the NAMs will stay. The NAM3 sometimes runs a bit cold in damming events and can be too wet, but it's far superior to the GFS in overall handling of this type of event. We saw that very clearly with the November storm. Thanks. Do you or @dtk know of any future plans to improve the short range high resolution guidance? The sref was a great idea (a short range high res ensemble could be useful) but the members just suck and have extreme biases. Link to comment Share on other sites More sharing options...
clskinsfan Posted February 18, 2019 Share Posted February 18, 2019 This event is a lock at this point IMO. General 3-6 for just about everyone followed by some sleet/ice. Obviously still details on who jacks with the snow. But we are all gonna get hit. 5 Link to comment Share on other sites More sharing options...
WinterWxLuvr Posted February 18, 2019 Share Posted February 18, 2019 Wow the fv3 is super wet. If that all falls as frozen, gonna be fun no matter what the type. Link to comment Share on other sites More sharing options...
SnowGolfBro Posted February 18, 2019 Share Posted February 18, 2019 5 minutes ago, clskinsfan said: This event is a lock at this point IMO. General 3-6 for just about everyone followed by some sleet/ice. Obviously still details on who jacks with the snow. But we are all gonna get hit. I tend to agree with you. We have a well timed cold High. Their is abundant gulf tapped moisture barreling toward us. The question is who gets 10+ inches and who gets 2-4. And that just can’t be worked out until gametime 1 Link to comment Share on other sites More sharing options...
high risk Posted February 18, 2019 Share Posted February 18, 2019 9 minutes ago, psuhoffman said: Thanks. Do you or @dtk know of any future plans to improve the short range high resolution guidance? The sref was a great idea (a short range high res ensemble could be useful) but the members just suck and have extreme biases. I certainly won't defend the SREF, but it's not a hi-res ensemble (members are 16 km). The HREF is an excellent way to view existing hi-res guidance in terms of means and probabilities, although more winter products are needed. Moving towards an hourly-updated hi-res ensemble around 2021 or so. 4 Link to comment Share on other sites More sharing options...
snowfan Posted February 18, 2019 Share Posted February 18, 2019 By 18Z Wed, FV3 has heavy sleet.....maybe heavily rimed snow.....in the metro area. Heavy snow from BWI north and northeast. By 0Z, the steady precip is moving out as most of us lose the column. FV3 has a 3-5" snowfall for DC and the immediate area with much more along the 70 corridor and further E/NE from Baltimore/BWI. Link to comment Share on other sites More sharing options...
snowfan Posted February 18, 2019 Share Posted February 18, 2019 Geesh....FV3 has 1.6" QPF for DC for the event. Some areas N and W in excess of 2". 1 1 Link to comment Share on other sites More sharing options...
mappy Posted February 18, 2019 Share Posted February 18, 2019 2 minutes ago, snowfan said: Geesh....FV3 has 1.6" QPF for DC for the event. Some areas N and W in excess of 2". Regardless of the p-type, its a pretty good wintry event for everyone. 8 Link to comment Share on other sites More sharing options...
PDIII Posted February 18, 2019 Share Posted February 18, 2019 34 minutes ago, stormtracker said: I actually feel better being in the middle of the GFS and NAM band. It's like the ICON if you average it out. I just kinda wonder why the GFS likes just south of the area while others don't. the run to run consistency with the GFS placement of the band is staggering. It is probably picking up on baroclinic instability between the CAD and the SE ridge. This tells me that someone will get deathbanded.. just not sure where at this lead. Link to comment Share on other sites More sharing options...
psuhoffman Posted February 18, 2019 Share Posted February 18, 2019 2 minutes ago, PDIII said: the run to run consistency with the GFS placement of the band is staggering. It is probably picking up on baroclinic instability between the CAD and the SE ridge. This tells me that someone will get deathbanded.. just not sure where at this lead. Gfs did shift north “some”. Euro ticked south “some at 6z. Perhaps were seeing convergence on that compromise. Link to comment Share on other sites More sharing options...
LP08 Posted February 18, 2019 Share Posted February 18, 2019 12z Ukie has a very similar trajectory as the euro with the best stuff through md and southern pa. Still a good run ezf north. 1 Link to comment Share on other sites More sharing options...
packfan98 Posted February 18, 2019 Share Posted February 18, 2019 About a 9" mean on the 12z GEFS for DC. More to the west. I know that counts all precip as snow, but it indicates quite a bit of frozen qpf. 9 Link to comment Share on other sites More sharing options...
LP08 Posted February 18, 2019 Share Posted February 18, 2019 Ukie total precip. Even better than I thought with a good distribution. 5 Link to comment Share on other sites More sharing options...
yoda Posted February 18, 2019 Share Posted February 18, 2019 13 minutes ago, packfan98 said: About a 9" mean on the 12z GEFS for DC. More to the west. I know that counts all precip as snow, but it indicates quite a bit of frozen qpf. Here is the image to show it 7 1 Link to comment Share on other sites More sharing options...
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