mappy Posted March 4, 2013 Share Posted March 4, 2013 Is elevation gonna play a role at all? I mean, obviously the areas in VA that have a bit more elevation are going to cash it, that much is practically a lock... but what about other areas? I'm assuming it is going to start as rain then mix before a full changover, so with that said, I'd expect areas that have a little more elevation to change over quicker. Or am I totally off base? Link to comment Share on other sites More sharing options...
vinylfreak89 Posted March 4, 2013 Share Posted March 4, 2013 Maybe dtk could answer this but I've noticed for a while on the sref that the arw members are always way too amped. We're talking nam on steroids. They throw off the whole sref mean. I ignore them and just look at the other 14 members but why hasn't ncep done something about this? this isn't new. I remember the ARW being amped in 2010 as well. One thing I've noticed from the high res maps is they have a lot of spin ups... likely convection isn't paramaterized too well in that model Link to comment Share on other sites More sharing options...
Bob Chill Posted March 4, 2013 Share Posted March 4, 2013 i hate to focus on it but high temps today and tomorrow will be what I will also watch. I know i will be told it won't matter much what happens the day before but seeing a stronger amount of cold air in place before it starts can only help speed up any flip from mix to snow. Luckily "warmth" will be shallow and the air mass is dry. 45 degrees won't mean much with low dews and below freezing just a few thousand feet up. Link to comment Share on other sites More sharing options...
psuhoffman Posted March 4, 2013 Share Posted March 4, 2013 fwiw, 6Z RGEM looked to be in the north camp, but it only goes out 48 hrs http://www.weatheroffice.gc.ca/data/model_forecast/colour_images/06_054_R1_north@america_I_QPFTYPES_t6_048.png http://www.weatheroffice.gc.ca/data/model_forecast/3285_100.gif Hard to tell. All the models look north at that point but then gfs/nam redevelop further north and move ene. Ggem uk and ec all continue the se momentum through redevelopment and shunt the precip shield more southeastward. We need the next frame to tell which way rgem goes. We will know at 12z. Link to comment Share on other sites More sharing options...
WxUSAF Posted March 4, 2013 Share Posted March 4, 2013 i hate to focus on it but high temps today and tomorrow will be what I will also watch. I know i will be told it won't matter much what happens the day before but seeing a stronger amount of cold air in place before it starts can only help speed up any flip from mix to snow. It's probably unscientific, but I'll be impressed if high temps stay in the low 40s today where LWX says they will. A full-sun day in March with temps 8-10F below climo suggests a respectable airmass. Is elevation gonna play a role at all? I mean, obviously the areas in VA that have a bit more elevation are going to cash it, that much is practically a lock... but what about other areas? I'm assuming it is going to start as rain then mix before a full changover, so with that said, I'd expect areas that have a little more elevation to change over quicker. Or am I totally off base? I think elevation always helps. In those rarer and rarer cases where everyone is in the low-mid 20s for a big snowstorm, then it doesn't matter too much, but in this situation with surface temps hanging in the 31-35F range, it probably will help. I could see a pretty wildly variable looking accumulation map coming out of this storm, especially if we get some convective banding in the deform zone. Link to comment Share on other sites More sharing options...
mitchnick Posted March 4, 2013 Share Posted March 4, 2013 Maybe not-- and of course I see it otherwise. The Euro is about that lattitude and the GGEM is pretty cold on the backside, like it's ramping up pretty quickly. The EC pretty much runs due east 20 miles south of the VA border. 7H RH map on the bottom left shows high RH ready to rotate into DCA/BWI area, which is similar to NAM and GFS I don't really know what it does to your area, but it definitely looks decent up here Link to comment Share on other sites More sharing options...
Bob Chill Posted March 4, 2013 Share Posted March 4, 2013 Here's the sounding for 1pm tomorrow. Mid 40's at the surface but very dry and cold enough just overhead. I don't think temps busting high tomorrow afternoon will have much of an impact tbh. Link to comment Share on other sites More sharing options...
mappy Posted March 4, 2013 Share Posted March 4, 2013 I think elevation always helps. In those rarer and rarer cases where everyone is in the low-mid 20s for a big snowstorm, then it doesn't matter too much, but in this situation with surface temps hanging in the 31-35F range, it probably will help. I could see a pretty wildly variable looking accumulation map coming out of this storm, especially if we get some convective banding in the deform zone. Thanks. I figured every bit helps. Definitely a cold morning today, but like you said it will be interesting to see how warm it actually gets today/tomorrow. Like H2O said, many of us will be watching temps tomorrow Link to comment Share on other sites More sharing options...
Huffwx Posted March 4, 2013 Share Posted March 4, 2013 7H RH map on the bottom left shows high RH ready to rotate into DCA/BWI area, which is similar to NAM and GFS I don't really know what it does to your area, but it definitely looks decent up here But, the Ec has an inch of QPF, it's not like it won't show good RH, My take-- it's chaning to snow quickly on the backside-- that's a more amped solution earlier, ala the euro. Maybe that's a wish cast. Link to comment Share on other sites More sharing options...
tmagan Posted March 4, 2013 Share Posted March 4, 2013 fwiw, 6Z RGEM looked to be in the north camp, but it only goes out 48 hrs http://www.weatheroffice.gc.ca/data/model_forecast/colour_images/06_054_R1_north@america_I_QPFTYPES_t6_048.png http://www.weatheroffice.gc.ca/data/model_forecast/3285_100.gif 06Z RGEM, MSLP, three-hour dominant p-type valid at hour 54. Link to comment Share on other sites More sharing options...
PhineasC Posted March 4, 2013 Share Posted March 4, 2013 Isn't the RGEM at 54HR really just the GGEM or is it some kind of extrapolated DGEX thing? Link to comment Share on other sites More sharing options...
tmagan Posted March 4, 2013 Share Posted March 4, 2013 Isn't the RGEM at 54HR really just the GGEM or is it some kind of extrapolated DGEX thing? 06Z/18Z RGEM goes out to 54 hours. Link to comment Share on other sites More sharing options...
needbiggerboat Posted March 4, 2013 Share Posted March 4, 2013 Thanks. I figured every bit helps. Definitely a cold morning today, but like you said it will be interesting to see how warm it actually gets today/tomorrow. Like H2O said, many of us will be watching temps tomorrow Somewhat of an apples and oranges exercise to compare the 1940's to today's world, but in the four days prior to DCA's max March snowfall of 11.5 on 3/29/42, the high temps were 61, 60, 58 and 46 Link to comment Share on other sites More sharing options...
clskinsfan Posted March 4, 2013 Share Posted March 4, 2013 6z GFS is another Winchester bullseye. Euro is not bad out here either. It looks like The Northern Shenandoah Valley is getting a foot of snow regardless of which solution verifies. Odd that 2 totally different solutions still hammer this area so hard. Link to comment Share on other sites More sharing options...
mappy Posted March 4, 2013 Share Posted March 4, 2013 LWX morning discussion is pretty decent for those who haven't read it http://forecast.weather.gov/product.php?site=NWS&issuedby=LWX&product=AFD&format=CI&version=1&glossary=1&highlight=off Link to comment Share on other sites More sharing options...
SNO Posted March 4, 2013 Share Posted March 4, 2013 6z GFS is another Winchester bullseye. Euro is not bad out here either. It looks like The Northern Shenandoah Valley is getting a foot of snow regardless of which solution verifies. Odd that 2 totally different solutions still hammer this area so hard. Agreed. I would say I-81 from Woodstock to Martinsburg and east to Paris Mountain and south to Front Royal on Chester Gap will be hammered. 12+ is very likely. Link to comment Share on other sites More sharing options...
clskinsfan Posted March 4, 2013 Share Posted March 4, 2013 HI res NAM is gorgeous: Link to comment Share on other sites More sharing options...
stormtracker Posted March 4, 2013 Author Share Posted March 4, 2013 Well, so far, NAM is a little south of 6z at the current panel. Link to comment Share on other sites More sharing options...
usedtobe Posted March 4, 2013 Share Posted March 4, 2013 12Z NAM starts soon, plus we get the 09Z SREFs. North shift maybe? Based on the 30 hr NAM, looks to me like it is shifting south again. Hope I'm wrong. Link to comment Share on other sites More sharing options...
Huffwx Posted March 4, 2013 Share Posted March 4, 2013 Well, so far, NAM is a little south of 6z at the current panel. It's actually a tad south of the Euro for the same time frame last night-- Link to comment Share on other sites More sharing options...
BTRWx Posted March 4, 2013 Share Posted March 4, 2013 Based on the 30 hr NAM, looks to me like it is shifting south again. Hope I'm wrong. yet hr 36 has the darker precip slightly north. Link to comment Share on other sites More sharing options...
stormtracker Posted March 4, 2013 Author Share Posted March 4, 2013 Definitely wetter Link to comment Share on other sites More sharing options...
dtk Posted March 4, 2013 Share Posted March 4, 2013 Maybe dtk could answer this but I've noticed for a while on the sref that the arw members are always way too amped. We're talking nam on steroids. They throw off the whole sref mean. I ignore them and just look at the other 14 members but why hasn't ncep done something about this? We've been dissecting and discussing the SREF membership over and over again in our model evaluation group meetings. The real issue seems to be related to the (unperturbed/base) initial conditions used within the SREF membership....i.e., all of the ARW members use one set, the NMM use another, and the NMMB a third (where the ICs are the RAP, GFS, and NAM ICs, IIRC). I know that the complaints have been noted and folks are working on a better solution, but the membership as currently constructed does seem quite problematic as it results in extreme clustering. Link to comment Share on other sites More sharing options...
psuhoffman Posted March 4, 2013 Share Posted March 4, 2013 06Z/18Z RGEM goes out to 54 hours. yea, no denying what camp that is in. Link to comment Share on other sites More sharing options...
Buddy1987 Posted March 4, 2013 Share Posted March 4, 2013 Blocking is looking stronger in New England Link to comment Share on other sites More sharing options...
stormtracker Posted March 4, 2013 Author Share Posted March 4, 2013 Weird...surface low looks to be in the same place. Precip gets in here earlier. Link to comment Share on other sites More sharing options...
mitchnick Posted March 4, 2013 Share Posted March 4, 2013 much wetter than 6z Link to comment Share on other sites More sharing options...
usedtobe Posted March 4, 2013 Share Posted March 4, 2013 yet hr 36 has the darker precip slightly north. 36hr looks like it would be a big hit. Link to comment Share on other sites More sharing options...
stormtracker Posted March 4, 2013 Author Share Posted March 4, 2013 36hr looks like it would be a big hit. That's what I was thinking. I think wetter compensates for a slight jog south? Link to comment Share on other sites More sharing options...
Ian Posted March 4, 2013 Share Posted March 4, 2013 March snow in Washington, D.C.: A precedent for ending winter with a bang http://www.washingtonpost.com/blogs/capital-weather-gang/post/march-snow-in-washington-dc-benchmarks-for-snowquester-potentially-similar-seasons/2013/03/04/e72f52b6-848b-11e2-9d71-f0feafdd1394_blog.html Link to comment Share on other sites More sharing options...
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