MacintoshPro Posted February 16, 2015 Share Posted February 16, 2015 I'm really not worried here yet. Seems storm is verifying well west and well on the north side. Gotta play with the edge sometimes. No reason to be worried if you are in DC or south. 5"+ depicted on every model besides the RGEM. Link to comment Share on other sites More sharing options...
mitchnick Posted February 16, 2015 Share Posted February 16, 2015 I'm really not worried here yet. Seems storm is verifying well west and well on the north side. Gotta play with the edge sometimes. bingo! they've had light or mod snow in Cincinnati since 5AM, and they are the same lat as me Link to comment Share on other sites More sharing options...
nj2va Posted February 16, 2015 Share Posted February 16, 2015 Certainly the trends today are nudging this a bit south, at least on the models, but I think DC is good for 4-6"+. I'm definitely overly parsing every little movement and should just sit back and nowcast. I say that every time but I still look at the models until the very end. Link to comment Share on other sites More sharing options...
WxMan1 Posted February 16, 2015 Share Posted February 16, 2015 12z RGEM as was mentioned is pretty dry....maybe 0.25 - 0.3 for DC ...and around .15" for BWI. As mentioned yesterday, this "squeeze play" with the QPF gradient -- i.e. drier on the dry side and wetter on the wet side -- fits right into the strength of the w-e frontogenesis we're dealing with here. I had a feeling that the gradient on both ends was gonna tighten, that's what they do in highly frontogenetic cases like these, which is why the means (sref mean particularly) should be ignored. Still, ratios north of D.C. will be better, likely averaging somewhere 15-18 to 1 for this event. Even with .25 QPF, that's still 4-4.5". Link to comment Share on other sites More sharing options...
mitchnick Posted February 16, 2015 Share Posted February 16, 2015 somebody mentioned the RAP didn't look great.....looks fine to me as of the 14Z run Link to comment Share on other sites More sharing options...
BristowWx Posted February 16, 2015 Share Posted February 16, 2015 I have to remind myself that if we didn't have that arctic wall pushing down on this it might be a cutter...without blocking I am not sure what would stop it so we would end up mixing...the current scenario isn't perfect for everyone but better than most of us imagined 3 days ago Link to comment Share on other sites More sharing options...
wkd Posted February 16, 2015 Share Posted February 16, 2015 High pressure loves DC Link to comment Share on other sites More sharing options...
Ian Posted February 16, 2015 Share Posted February 16, 2015 somebody mentioned the RAP didn't look great.....looks fine to me as of the 14Z run Don't look at the HRRR. Silly GFS upgrade wildcard. Maybe it's actually good at everything now. Link to comment Share on other sites More sharing options...
BristowWx Posted February 16, 2015 Share Posted February 16, 2015 somebody mentioned the RAP didn't look great.....looks fine to me as of the 14Z run cool. I remember seeing a post on how it was bad...dry Link to comment Share on other sites More sharing options...
Deck Pic Posted February 16, 2015 Share Posted February 16, 2015 ...and around .15" for BWI. As mentioned yesterday, this "squeeze play" with the QPF gradient -- i.e. drier on the dry side and wetter on the wet side -- fits right into the strength of the w-e frontogenesis we're dealing with here. I had a feeling that the gradient on both ends was gonna tighten, that's what they do in highly frontogenetic cases like these, which is why the means (sref mean particularly) should be ignored. Still, ratios north of D.C. will be better, likely averaging somewhere 15-18 to 1 for this event. Even with .25 QPF, that's still 4-4.5". thanks...it could still be too far south even despite the configuration making sense (I hope) Link to comment Share on other sites More sharing options...
mitchnick Posted February 16, 2015 Share Posted February 16, 2015 Don't look at the HRRR. Silly GFS upgrade wildcard. Maybe it's actually good at everything now. it's OK if I end up getting screwed on this I get NAM'ed with .20" qpf Wednesday night with the PV Link to comment Share on other sites More sharing options...
usedtobe Posted February 16, 2015 Share Posted February 16, 2015 thanks...it could still be too far south even despite the configuration making sense (I hope) My guess is that the RGEM has things too suppressed. It seems to be on the low side of the cluster, possible but I'd go witht he NAM before the RGEM and would go witht eh euro either of them. Plus I think there is potential for some goofy band to set up farther north than where the models have their max QPF. Link to comment Share on other sites More sharing options...
wawarriors4 Posted February 16, 2015 Share Posted February 16, 2015 Feeling pretty good down near EZF......feels odd to say that, but I think about 8 -10 around Spotsylvania.....maybe we can squeeze out 12? Link to comment Share on other sites More sharing options...
BristowWx Posted February 16, 2015 Share Posted February 16, 2015 My guess is that the RGEM has things too suppressed. It seems to be on the low side of the cluster, possible but I'd go witht he NAM before the RGEM and would go witht eh euro either of them. Plus I think there is potential for some goofy band to set up farther north than where the models have their max QPF. Quantico/Dale City/Aquia area perhaps. That would make Jeb happy. Link to comment Share on other sites More sharing options...
mitchnick Posted February 16, 2015 Share Posted February 16, 2015 Feeling pretty good down near EZF......feels odd to say that, but I think about 8 -10 around Spotsylvania.....maybe we can squeeze out 12? you will do well....good luck just look out for this crazy dude walkin' up and down I95 singing and dancing when it's snowing the hardest Link to comment Share on other sites More sharing options...
clskinsfan Posted February 16, 2015 Share Posted February 16, 2015 My guess is that the RGEM has things too suppressed. It seems to be on the low side of the cluster, possible but I'd go witht he NAM before the RGEM and would go witht eh euro either of them. Plus I think there is potential for some goofy band to set up farther north than where the models have their max QPF. This should help talk some of us off the ledge. The one concern is the RGEM has handled the Boston storms very well this year. But the Ukie has been very good as well. Link to comment Share on other sites More sharing options...
Inverted_Trough Posted February 16, 2015 Share Posted February 16, 2015 what's the causing the dry nose in the Shenandoah? It's been modeled this way for several runs. Is it because the low seems to "jump" a bit, from the GA/SC border to 100 miles off VA Beach, within 6 hours? Link to comment Share on other sites More sharing options...
wawarriors4 Posted February 16, 2015 Share Posted February 16, 2015 you will do well....good luck just look out for this crazy dude walkin' up and down I95 singing and dancing when it's snowing the hardest Haha, oh Jeb........16 degrees right now, loving that we aren't flirting with the R/S line Link to comment Share on other sites More sharing options...
BTRWx Posted February 16, 2015 Share Posted February 16, 2015 I rarely post my amateur discussions here from my Facebook page, but this one seems relevant. Feel free to move to banter if needed. Overnight models shifted largely in favor for a little more snowfall in and around D.C., but the latest GFS does have a very slight shift to the south. The NWS forecast was bumped up from 4-8" to 6-10" this morning that I very much agree with. Because temperatures are expected to be so cold, our liquid to snow ratios may be higher than we typically see. This means that an inch of liquid precipitation would produce greater than the typical 10" of snowfall. Now we probably will not see a full inch of liquid precipitation this far north, but with the modeled .5"-.7" give or take of liquid equivalent precipitation, the ratio conversions could give anywhere from snowfall values of between 12X to as much as up to 20X the liquid values at times during the snowfall.Temperatures will greatly affect how much snow we get because of these factors. More liquid equivalent precipitation is good, because there's more moisture to fall as snow. A slight shift to the south would indicate a colder atmosphere and higher ratios, which if cold enough can also increase our snowfall.My overall view is the following. If the atmosphere has higher moisture content, then the .7" liquid multiplied by about an average of ratio multiplier of 12-13 would be about 8" to 9" in in the District. If on the other hand the the storm shifts more to the south, temperatures would be slightly colder giving higher ratio multipliers of 13-15 leading to between 6.5"-8.5".This is almost a win-win for the D.C. area, but if both the storm track is more to the south AND temperatures are closer to the freezing point with lower liquid to snow ratios, less snow would fall. This scenario is less likely, but not impossible. Link to comment Share on other sites More sharing options...
Ji Posted February 16, 2015 Share Posted February 16, 2015 so every storm runs north except for this ha Link to comment Share on other sites More sharing options...
hosj III Posted February 16, 2015 Share Posted February 16, 2015 Link to comment Share on other sites More sharing options...
gymengineer Posted February 16, 2015 Share Posted February 16, 2015 This should help talk some of us off the ledge. The one concern is the RGEM has handled the Boston storms very well this year. But the Ukie has been very good as well. Some.. not all. It was showing MD getting more snow on Saturday than much of southern New England up until the very end. Link to comment Share on other sites More sharing options...
Random Chaos Posted February 16, 2015 Share Posted February 16, 2015 I'm sitting at 12.6F here in Annapolis and still have a light wind from the WNW. Thermal profiles are cold. Soundings from 7am were in line with GFS, maybe a degree colder at 700mb. Waiting for the 18z sounding...hope the launch one from IAD. The snow ratio is going to be the killer here, much more impactful than the 0.1 QPF changes we are fighting over - a 2 degree change at 700mb could be the difference between a 12:1 and a 15:1 ratio or a 15:1 and an 18:1 ratio. With 0.5" QPF, 12:1 is 6" while 18:1 is 9". We're right on the warm edge of the best dendritic growth zone. The temperature profile is going to be key. Link to comment Share on other sites More sharing options...
ers-wxman1 Posted February 16, 2015 Share Posted February 16, 2015 It will be a battle between the dry arctic airmass pushing down and the precip. I'm concerned with drying...at least to start. wish the best forcing was further north which would more easily overcome dry air. I'm most nervous for NOVA and points north. Link to comment Share on other sites More sharing options...
lsukev Posted February 16, 2015 Share Posted February 16, 2015 Judging by how the short range models have been overblowing the cold lately, even within 12 hours and less, I am a little optimistic that they may be too suppressed. Just thinking of how the HRRR had DCA at 0 Sunday morning and we verified at 11 degrees. Link to comment Share on other sites More sharing options...
BTRWx Posted February 16, 2015 Share Posted February 16, 2015 It will be a battle between the dry arctic airmass pushing down and the precip. I'm concerned with drying...at least to start. wish the best forcing was further north which would more easily overcome dry air. I'm most nervous for NOVA and points north. Wouldn't dry air initially allow temperatures to fall more until precipitation arrives? eta: assuming precip starts around sundown Link to comment Share on other sites More sharing options...
psuhoffman Posted February 16, 2015 Share Posted February 16, 2015 I always hate these last minute slices....just feeds on the paranoia for future events the models are just sampling reality better. Model runs don't spook me the reality of how hard it is to get big snows does. I'm always looking for what the most likely fail is because 9/10 times a threat will fail. This one the progressive flow was our problem. Had the tues night storm been the big player cutting probably was the threat. It's going to snow I just doubt the 6" totals get much north of dc. The pattern looks better the foreseeable future. Just hope we get lucky and it's not a year where storms seem to deflect north or south of us. Link to comment Share on other sites More sharing options...
BristowWx Posted February 16, 2015 Share Posted February 16, 2015 It will be a battle between the dry arctic airmass pushing down and the precip. I'm concerned with drying...at least to start. wish the best forcing was further north which would more easily overcome dry air. I'm most nervous for NOVA and points north. where would you place the most worry in NOVA? North of 50? 66? route 7? just curious Link to comment Share on other sites More sharing options...
wawarriors4 Posted February 16, 2015 Share Posted February 16, 2015 It will be a battle between the dry arctic airmass pushing down and the precip. I'm concerned with drying...at least to start. wish the best forcing was further north which would more easily overcome dry air. I'm most nervous for NOVA and points north. What are your thoughts down here around EZF in terms of dynamics and such? Link to comment Share on other sites More sharing options...
ers-wxman1 Posted February 16, 2015 Share Posted February 16, 2015 Wouldn't dry air initially allow temperatures to fall more until precipitation arrives? eta: assuming precip starts around sundown Cold temperatures are not the issue...moistening the column and keeping it saturated is. We need good lift/forcing and not weak lift. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.