March 2-3 Disco, Part III

[winterymix]

RGEM: Snow

The RGEM is fairly useful out ahead of these systems, thanks for posting.  It signals that the American

models don't necessarily have it all figured out just yet.

 

Everybody should keep in mind that the models give signals and the signals are generated with some inherent biases.   Didn't the RGEM used to run warm with these systems?

[DDweatherman]

We can get manic-elated or profoundly depressed when the NAM fairy visits just after 9:15 pm

and we get to do it all over again with the wicked witch of the GFS around 10:40 pm.

Then when one goes south and the other comes north, the Euro will decide the battle at 12:57.

[nj2va]

18Z RGEM total snow

rgem_total_snow.jpg

 

RGEM was posted a few pages back but here it is for reference.  

[winterymix]

Then when one goes south and the other comes north, the Euro will decide the battle at 12:57.

Everyone with a membership here retains the privilege of tossing out the model

that gives the least snow.

[Bob Chill]

Nights like tonight are prime examples of why the nam should run hourly

[mitchnick]

Nights like tonight are prime examples of why the nam should run hourly

you worried yet?       

[Bob Chill]

you worried yet?

Not at all. I'm good with 4-6" and some sleet on the bottom. Whenever storms have narrow swaths I never expect to be ground zero. We're pretty close to a final solution already imo.

[Random Chaos]

GFS is borderline pure snow by 4am on Monday somewhere near Silver Spring. Northern suburbs will be solid snow by then, most likely, while there and south could be still mix for another hour or so.

 

This is almost the same as the NAM soundings.

 

I should also note that evening GFS soundings on Sunday show that transition from rain to mix will be somewhere between 7 and 10pm. That's way earlier than it was earlier today.

 

Still have a lot of questions about the storm track on this GFS run, but the temperatures are cold, colder than the NAM.

 

[nj2va]

GFS is borderline pure snow by 4am on Monday somewhere near Silver Spring. Northern suburbs will be solid snow by then, most likely, while there and south could be still mix for another hour or so.

 

This is almost the same as the NAM soundings.

 

I should also note that evening GFS soundings on Sunday show that transition from rain to mix will be somewhere between 7 and 10pm. That's way earlier than it was earlier today.

 

Still have a lot of questions about the storm track on this GFS run, but the temperatures are cold, colder than the NAM.

 

 

I'd probably suspect its colder than the 12z run because it shifted slightly south at 18z (due to the cold air mass pressing further south). 

[WxUSAF]

GFS is borderline pure snow by 4am on Monday somewhere near Silver Spring. Northern suburbs will be solid snow by then, most likely, while there and south could be still mix for another hour or so.

 

This is almost the same as the NAM soundings.

 

I should also note that evening GFS soundings on Sunday show that transition from rain to mix will be somewhere between 7 and 10pm. That's way earlier than it was earlier today.

 

Still have a lot of questions about the storm track on this GFS run, but the temperatures are cold, colder than the NAM.

 

GFS_3_2014030118_F39_39.0000N_77.0000W.png

That's a snow sounding. 

[wxmeddler]

That's a snow sounding. 

 

Rimed snow isn't any fun..

[Ian]

1-10 10 being the most sad...what level?

Sunday's Sad Digit: 6/10 - why the fuxk is Richmond stealing my snow.

[Ian]

Nights like tonight are prime examples of why the nam should run hourly

Get out of my head https://twitter.com/islivingston/status/439850413316399104

[Bob Chill]

Get out of my head https://twitter.com/islivingston/status/439850413316399104

Ha! We're very sic.

So you're thinking the south trend is going keep going I see. I'm just not worried for some weird reason. I keep thinking the precip field will end up larger than prog'd so wiggle room will grow a bit even with the maxima south of us.

I think we're done with the trend personally. We'll see what happens later.

[Deck Pic]

Not at all. I'm good with 4-6" and some sleet on the bottom. Whenever storms have narrow swaths I never expect to be ground zero. We're pretty close to a final solution already imo.

 

My guess is that starting at 0z, if the NAM/Euro/Canadian agree on general track and placement of max stripe, then we have a pretty good solution, but not a locked in one...my guess is the NAM will tick north at 0z to look like the Euro/GGEM did at 12z.  The Euro/GGEM will hold serve or tick south very slightly.  Max Precip should generally end up from CHO to 30 mi SE DC, but I think there will be decent accumulating snow up to Central Jersey.  I would definitely use the Euro for QPF tonight.  I'd guess 1-1.25" for DC and BWI. 0.8"-0.9" for M/D line.  Flip to snow for DC around 3-4am after a period of sleet with the main thump, which could arrive at the same time, so sleet may be on the brief side.  Developing story will be early onset of frozen for FDK/HGR that could come with some frontrunning push.....the "light" rain Sunday evening may end up not being so light.  This isn't going to be a 2/13 style 8 hour lull.   Ultimately I think we go into tomorrow with a good consensus forecast of 6-10" for DC/BWI, 8-12 for western/NW burbs of DC, and 5-8" for far NE MD.  I think the folks at 0.75 - 1" do fine and get into good banding.  Hi-Res NAM is already hinting at it, and we know the periphery of decent modeled QPF gets into good secondary bands.  There is never only one primary precip max.  Good banding will develop 50-75mi NW of the primary max.  Notice I didn't mention the GFS.  It is low resolution, and I don't really care much what it says if the others agree.  It has been very poor at this range for our big ticket storms this year.  

[bigjohndc]

I've only had intermittent access to Internet all day. Is this "trend" from the 18z suite or was there evidence of it earlier? I thought both the 12z GFS and Euro were huge hits. If I'm missing something please let me know. It seems the bullseye is where exactly the front ends up, which we won't fully know until game time. I'm not worried, yet.

[yoda]

My guess is that starting at 0z, if the NAM/Euro/Canadian agree on general track and placement of max stripe, then we have a pretty good solution, but not a locked in one...my guess is the NAM will tick north at 0z to look like the Euro/GGEM did at 12z.  The Euro/GGEM will hold serve or tick south very slightly.  Max Precip should generally end up from CHO to 30 mi SE DC, but I think there will be decent accumulating snow up to Central Jersey.  I would definitely use the Euro for QPF tonight.  I'd guess 1-1.25" for DC and BWI. 0.8"-0.9" for M/D line.  Flip to snow for DC around 3-4am after a period of sleet with the main thump, which could arrive at the same time, so sleet may be on the brief side.  Developing story will be early onset of frozen for FDK/HGR that could come with some frontrunning push.....the "light" rain Sunday evening may end up not being so light.  This isn't going to be a 2/13 style 8 hour lull.   Ultimately I think we go into tomorrow with a good consensus forecast of 6-10" for DC/BWI, 8-12 for western/NW burbs of DC, and 5-8" for far NE MD.  I think the folks at 0.75 - 1" do fine and get into good banding.  Hi-Res NAM is already hinting at it, and we know the periphery of decent modeled QPF gets into good secondary bands.  There is never only one primary precip max.  Good banding will develop 50-75mi NW of the primary max.  Notice I didn't mention the GFS.  It is low resolution, and I don't really care much what it says if the others agree.  It has been very poor at this range for our big ticket storms this year.  

 

Nice post and well stated Zwyts.  Hard to disagree with any of your points or premise here

[Deck Pic]

Nights like tonight are prime examples of why the nam should run hourly

 

As much as I bash the NAM (mainly because it is over relied on outside its money range when it isnt very good).  Tonight's run is probably the most important model run of any model of the storm so far.  I expect it to shift north.  If it doesn't it could presage what the Euro might do. I dont  think we should sleep on the Canadian at this range either.  

[Bob Chill]

Matt, I totally agree. That's a great post.

[nj2va]

My guess is that starting at 0z, if the NAM/Euro/Canadian agree on general track and placement of max stripe, then we have a pretty good solution, but not a locked in one...my guess is the NAM will tick north at 0z to look like the Euro/GGEM did at 12z.  The Euro/GGEM will hold serve or tick south very slightly.  Max Precip should generally end up from CHO to 30 mi SE DC, but I think there will be decent accumulating snow up to Central Jersey.  I would definitely use the Euro for QPF tonight.  I'd guess 1-1.25" for DC and BWI. 0.8"-0.9" for M/D line.  Flip to snow for DC around 3-4am after a period of sleet with the main thump, which could arrive at the same time, so sleet may be on the brief side.  Developing story will be early onset of frozen for FDK/HGR that could come with some frontrunning push.....the "light" rain Sunday evening may end up not being so light.  This isn't going to be a 2/13 style 8 hour lull.   Ultimately I think we go into tomorrow with a good consensus forecast of 6-10" for DC/BWI, 8-12 for western/NW burbs of DC, and 5-8" for far NE MD.  I think the folks at 0.75 - 1" do fine and get into good banding.  Hi-Res NAM is already hinting at it, and we know the periphery of decent modeled QPF gets into good secondary bands.  There is never only one primary precip max.  Good banding will develop 50-75mi NW of the primary max.  Notice I didn't mention the GFS.  It is low resolution, and I don't really care much what it says if the others agree.  It has been very poor at this range for our big ticket storms this year.  

 

100% agree with this.  I don't think the usual last minute north bump is valid with this storm due to the impressive PV pushing down acting like a psuedo-block.  Your 1"+ QPF call is pretty solid based on all guidance thus far, including room to our north of the 1"+ field for any further small shifts to the south.  

[Random Chaos]

I've only had intermittent access to Internet all day. Is this "trend" from the 18z suite or was there evidence of it earlier? I thought both the 12z GFS and Euro were huge hits. If I'm missing something please let me know. It seems the bullseye is where exactly the front ends up, which we won't fully know until game time. I'm not worried, yet.

 

I'm not sold on the GFS 18z run. The "shape" of the storm just doesn't align with the prior GFS runs, or any of the NAM or ECMWF runs. That southern blob of moisture that rides across southern VA just isn't present on the other model runs.

 

The southern trend could be true, but it just strikes me as not a good run overall.

[BTRWx]

The last recent winter storm that the region did well on also trended south, but still bulls-eyed the Mason Dixon folks. At this point a small trend in any direction shouldn't affect D.C. totals too much, imo.

[yoda]

I also think tonights SREFs run could be a precursor to what the NAM might do.  15z SREFs got the 0c 2m line through DCA around 06z MON.... but the SREFs didn't drag the 0c 850 line through till 11z or so... which suggested about 6-8 hrs of sleet and freezing rain before snow on top

[CAPE]

Channel 7 in DC just projected via their in-house model 4 inches after a bunch of sleet.

Am I the only one who cant bear to watch even a second of local weather? Or local news in general. Its like listening to Whitney Houston...makes my head explode like the martians in Mars Attacks.

[Bob Chill]

As much as I bash the NAM (mainly because it is over relied on outside its money range when it isnt very good). Tonight's run is probably the most important model run of any model of the storm so far. I expect it to shift north. If it doesn't it could presage what the Euro might do. I dont think we should sleep on the Canadian at this range either.

Because winners and losers are close together and the stripe is pretty narrow I think every piece of guidance deserves respect going forward. The 0z suite tonight is super important. We're done with big swings but have plenty of time for little swings to add up or subtract from our yards.

I'm just not nervous like I usually am. Maybe because the whole thing feels like an unexpected gift just dropped in my lap. Even if we get 3-5" we should all still feel pretty lucky.

[CAPE]

Because winners and losers are close together and the stripe is pretty narrow I think every piece of guidance deserves respect going forward. The 0z suite tonight is super important. We're done with big swings but have plenty of time for little swings to add up or subtract from our yards.

I'm just not nervous like I usually am. Maybe because the whole thing feels like an unexpected gift just dropped in my lap. Even if we get 3-5" we should all still feel pretty lucky.

Yeah just yesterday afternoon I was worried about a devastating ice storm, with maybe an inch or two of snow on top. This is a heck of a lot better.

[Ian]

Ha! We're very sic.

So you're thinking the south trend is going keep going I see. I'm just not worried for some weird reason. I keep thinking the precip field will end up larger than prog'd so wiggle room will grow a bit even with the maxima south of us.

I think we're done with the trend personally. We'll see what happens later.

Most storms move north in the final 24 or so but this isn't the classic north trender. I'd like to see the south trend stop soon one way or another. My guess is it will but there is no real reasoning behind that other than history as with anyone else saying there will be a north trend.

[dallen7908]

I'm worried that I can't figure out what to be worried about.

 

In an ideal world, we'd wait until the entire 00 UT suite comes in and then react.  However, we will be on a roller coaster with every blip of the models and then stress out over the high temperature on Sunday etc. ; things that don't matter ... unless they do?

[Ian]

If I only get 4" I will be devastated. Climo be damned.

[DDweatherman]

If I only get 4" I will be devastated. Climo be damned.

Climo doesn't support a monster pv that will move in an arctic boundary quicker than anticipated shunting a major snowstorm further into Virginia in March. Not an everyday occurrence.