BaltimoreWxGuy Posted February 19, 2019 Share Posted February 19, 2019 2 minutes ago, Fozz said: How good are the WRF models (ARW and NMM)? The 0z runs all show a good hit for MD. Maybe someone can correct if I’m wrong but I think they’re usually too amped and wet. Link to comment Share on other sites More sharing options...
MillvilleWx Posted February 19, 2019 Share Posted February 19, 2019 Maybe someone can correct if I’m wrong but I think they’re usually too amped and wet. ARW has a known wet bias and NMM actually can run dry. They are used in ensemble packages and are better utilized for convective purposes. . 1 Link to comment Share on other sites More sharing options...
high risk Posted February 19, 2019 Share Posted February 19, 2019 34 minutes ago, psuhoffman said: It's really hard to use the GFS in these situations because its lack of resolution really forces you to assume a lot about the details. But the GFS blasts our area with some heavy precip between 11am and 3pm. At 18z the column is still cold enough for snow across northern MD...barely. By 0z its toast. But how long it can hold on with mixing of the warm layer with those heavy rates would determine our fate. If we can hold on an extra hour or two during that band (not a crazy idea given the typical mixing and dynamic cooling in such bands) the GFS implies a really good thump up here. we CAN see the in-between hours for the GFS on the mag.ncep.noaa.gov site which has the full hourly output. You'll see that the changeover is well before 00z, but as has been noted, the GFS is well-known for being way too fast in breaking down inversions and warming the low levels Link to comment Share on other sites More sharing options...
Snowchaser Posted February 19, 2019 Share Posted February 19, 2019 Weather channel is bullish 1 Link to comment Share on other sites More sharing options...
SnowGoose69 Posted February 19, 2019 Share Posted February 19, 2019 Looks like UKMET didn’t come in today or is delayed. At least on the meteocentre site Link to comment Share on other sites More sharing options...
yoda Posted February 19, 2019 Share Posted February 19, 2019 12z HRDPS is crushing DC metro at 12z WED with 8mm/hr 5 Link to comment Share on other sites More sharing options...
MN Transplant Posted February 19, 2019 Share Posted February 19, 2019 3 minutes ago, yoda said: 12z HRDPS is crushing DC metro at 12z WED with 8mm/hr 3”/hr. Totally checks out. 1 Link to comment Share on other sites More sharing options...
BaltimoreWxGuy Posted February 19, 2019 Share Posted February 19, 2019 LWX updated their snow maps. Doesn’t look to be much of a change. If I get 5” I’ll be very happy Link to comment Share on other sites More sharing options...
SnowGolfBro Posted February 19, 2019 Share Posted February 19, 2019 10 minutes ago, yoda said: 12z HRDPS is crushing DC metro at 12z WED with 8mm/hr 4mm/hr would be a crushing. 8mm/hr would be epic Link to comment Share on other sites More sharing options...
notvirga! Posted February 19, 2019 Share Posted February 19, 2019 Just now, BaltimoreWxGuy said: LWX updated their snow maps. Doesn’t look to be much of a change. If I get 5” I’ll be very happy They went from 4-6 to 6-8 in my area and moved the heavier snow north Link to comment Share on other sites More sharing options...
yoda Posted February 19, 2019 Share Posted February 19, 2019 12z HRDPS 0.35 to 0.40 QPF all snow for DCA through 14z WED Link to comment Share on other sites More sharing options...
Scraff Posted February 19, 2019 Share Posted February 19, 2019 11 minutes ago, yoda said: 12z HRDPS is crushing DC metro at 12z WED with 8mm/hr Well it’s definitely been consistent with the beat downs on the last few runs. Hope it’s right! Link to comment Share on other sites More sharing options...
yoda Posted February 19, 2019 Share Posted February 19, 2019 12z HRPDS brings a "squall line" I guess through 18z to 21z... I95 corridor and to the N and W are still below freezing at 22z Link to comment Share on other sites More sharing options...
SomeguyfromTakomaPark Posted February 19, 2019 Share Posted February 19, 2019 8 minutes ago, yoda said: 12z HRPDS brings a "squall line" I guess through 18z to 21z... I95 corridor and to the N and W are still below freezing at 22z It’s still a beatdown in DC metro. 6+ for the whole area. I hope this time tomorrow we’re singing “oh Canada”. 1 3 Link to comment Share on other sites More sharing options...
winterymix Posted February 19, 2019 Share Posted February 19, 2019 1 hour ago, psuhoffman said: It's really hard to use the GFS in these situations because its lack of resolution really forces you to assume a lot about the details. But the GFS blasts our area with some heavy precip between 11am and 3pm. At 18z the column is still cold enough for snow across northern MD...barely. By 0z its toast. But how long it can hold on with mixing of the warm layer with those heavy rates would determine our fate. If we can hold on an extra hour or two during that band (not a crazy idea given the typical mixing and dynamic cooling in such bands) the GFS implies a really good thump up here. @HighStakes It totally depends on the banding. Think of the similar events to this...Feb 2007 (NOT the VD storm the second one), December 2013, Feb 2015 had some similarities too... the area's that get under the heavy bands will hold the column longer. The VV's and heavy precip will help to mix out the mid level warm layer from WAA for a time. If we get under that banding we will get thumped. If we don't...the mid level warmth will race north and its congrats PA. We know the drill. I have no idea where that banding will set up. No one does. We can all make educated guesses. But the idea of a duel max is gaining some traction imo today. Even the guidance that hits our area pretty good "sees" the banding associated with the jet streak up over PA its just not killing the STJ WAA moisture plume into our area as much and is hitting that band up there less. Figuring out those kind of details are above my pay grade though. So my goalposts from 2 days ago are still in the same place LOL... Notice even the guidance that thumps us still has some enhancement up in central PA associated with the jet streak? Its just the NAM is going nuts with that and killing the WAA/STJ moisture feed south of it. The other guidance has more of a duel max idea hinted at between those two areas. That is a much better result for us. Good and detailed analysis. Personally, I'm taking the prerogative of using the model that gives me the most snow in my backyard. For now, with my limited analysis, that shall be the GFS. The dominant precipitation type gives mby snow from hour 24 to hour 33. The QPF is about 0.7... with heavy wet snow and ratio of 8:1 (YAG) I'm hoping for 5" to 6". Link to comment Share on other sites More sharing options...
Interstate Posted February 19, 2019 Share Posted February 19, 2019 31 minutes ago, yoda said: 12z HRDPS is crushing DC metro at 12z WED with 8mm/hr What is the verification score on the HRDPS? Link to comment Share on other sites More sharing options...
snowdude Posted February 19, 2019 Share Posted February 19, 2019 Interesting observation from Mount Holly. Maybe models underdoing the initial banding lifting north, especially eastern edge? Or maybe it means nothing. ...930 AM Update: No changes made yet to the forecast for this period, as we are waiting to see more of the 12Z guidance. However, it is interesting to note that the current precipitation shield extends further east (across the Carolinas) than what the models had depicted. I am not sure this will result in any significant changes for our area as models already had the precip extending across our region by late tomorrow. We will have a complete update on this system with the 4 PM update. 2 Link to comment Share on other sites More sharing options...
yoda Posted February 19, 2019 Share Posted February 19, 2019 1 minute ago, snowdude said: Interesting observation from Mount Holly. Maybe models underdoing the initial banding lifting north, especially eastern edge? Or maybe it means nothing. ...930 AM Update: No changes made yet to the forecast for this period, as we are waiting to see more of the 12Z guidance. However, it is interesting to note that the current precipitation shield extends further east (across the Carolinas) than what the models had depicted. I am not sure this will result in any significant changes for our area as models already had the precip extending across our region by late tomorrow. We will have a complete update on this system with the 4 PM update. Would this mean an earlier start or heavier precip at the start due to increased banding? If it meant something? Link to comment Share on other sites More sharing options...
WEATHER53 Posted February 19, 2019 Share Posted February 19, 2019 4 minutes ago, snowdude said: Interesting observation from Mount Holly. Maybe models underdoing the initial banding lifting north, especially eastern edge? Or maybe it means nothing. ...930 AM Update: No changes made yet to the forecast for this period, as we are waiting to see more of the 12Z guidance. However, it is interesting to note that the current precipitation shield extends further east (across the Carolinas) than what the models had depicted. I am not sure this will result in any significant changes for our area as models already had the precip extending across our region by late tomorrow. We will have a complete update on this system with the 4 PM update. Yes there is a decided eastern move but looks like lifting north is starting. 1040 still west of us and that’s a good sign for cold not substantially being east of us come crunch time and then see what effect it has on changeover Link to comment Share on other sites More sharing options...
Snowchaser Posted February 19, 2019 Share Posted February 19, 2019 Updated Maps! 1 1 Link to comment Share on other sites More sharing options...
snowdude Posted February 19, 2019 Share Posted February 19, 2019 3 minutes ago, yoda said: Would this mean an earlier start or heavier precip at the start due to increased banding? If it meant something? I believe they’re hinting at an earlier start. But I can also see a more organized system meaning more precip. But again we’ll see. 1 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted February 19, 2019 Share Posted February 19, 2019 As of 1pm, the cirrus function on GOES-16 shows a thicker cloud deck streaming into the area from the west...our EOC wx station shows the solar energy dropping off from 300 watts at 11am to just 40 now. That should really cut down on temperatures across the area for the rest of the day. Link to comment Share on other sites More sharing options...
LP08 Posted February 19, 2019 Share Posted February 19, 2019 12z Euro looks like it will be a better thump than 0Z through 24. 5 Link to comment Share on other sites More sharing options...
ers-wxman1 Posted February 19, 2019 Share Posted February 19, 2019 35/12 at IAD and 39/8 at DCA...midday readings. CAD setting up. That’s some dry air and clouds starting to stream in. 2 Link to comment Share on other sites More sharing options...
Deck Pic Posted February 19, 2019 Share Posted February 19, 2019 Euro is meh for me. 1 3 Link to comment Share on other sites More sharing options...
feloniousq Posted February 19, 2019 Share Posted February 19, 2019 We have this discussion a fair amount, but the expected/low/high graphics packages just make no sense. Leesburg's "expected" is 6-8 but the "high end" (10%) is 7? 2 1 Link to comment Share on other sites More sharing options...
Kleimax Posted February 19, 2019 Share Posted February 19, 2019 Just now, feloniousq said: We have this discussion a fair amount, but the expected/low/high graphics packages just make no sense. Leesburg's "expected" is 6-8 but the "high end" (10%) is 7? Right! Was just about to say that. Makes 0 sense Link to comment Share on other sites More sharing options...
jaydreb Posted February 19, 2019 Share Posted February 19, 2019 1 minute ago, feloniousq said: We have this discussion a fair amount, but the expected/low/high graphics packages just make no sense. Leesburg's "expected" is 6-8 but the "high end" (10%) is 7? Expected is 6-8. Only a 10% chance of more than 7. So I guess they are keying in on 6-7”? 1 Link to comment Share on other sites More sharing options...
LP08 Posted February 19, 2019 Share Posted February 19, 2019 Better than 0z, slightly drier than 6z. Still a general 2-4 before flip. 1 1 Link to comment Share on other sites More sharing options...
SomeguyfromTakomaPark Posted February 19, 2019 Share Posted February 19, 2019 Just now, LP08 said: Better than 0z, slightly drier than 6z. Still a general 2-4 before flip. I think the goal posts are set. Tossing the Canadian crew we have a general 2-4 for DC and immediate burbs. Link to comment Share on other sites More sharing options...
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