The March 6 Storm- The (last) Great White Hope, Part II

[NOVAForecaster]

Now I am curious about snow totals. We've been talking about ratios in the as low as 5/7-1, but NWS was just talking about 7/8-1 on the low side and 10-1 on the high side (N/W). With QPFs in the 1.5 range (plus/minus) in the DC area are we really talking 10 inches on the low side?

Well the first bit is rain, but that's only about ~.2" of the QPF. After we get that, if an area were to get 1.3" QPF as snow with 8/1 ratios, it would be around 10", yes.

[dsnowman]

Looks like an outside chance of beating the '93 Superstorm totals for some parts of the area.

[WinterWxLuvr]

Looks like an outside chance of beating the '93 Superstorm totals for some parts of the area.

Maybe for local snow totals, but this storm isn't even in the same league as the Superstorm.

[WinterWxLuvr]

I did not see these new HPC maps posted - these are the human created ones not the computer ones.

And those are day 3 maps. Take a look at the day 2 maps.

[yoda]

Quick QPF recap for those that missed it

6z NAM -- 2"+ DCA/IAD/MRB/EZF. 1.5 to 1.75" BWI and FDK... CHO 1.5ish

6z GFS -- 1.75 to 2" DCA/IAD/EZF. Around 2" MRB (just SE and just W and NW of IAD). BWI is 1.5ish (prob a lil less). CHO 1.5ish.

[yoda]

And those are day 3 maps. Take a look at the day 2 maps.

Better for you guys as well But HPC even has 40% of 4" through 12z WED knocking on DC's door

[Minerva]

I apologize in advance, I know it's against the rules to post this stuff here, but there is no banter thread.  But I just want to say good luck to all here in the mid-Atlantic. It's not going to hit my area, but I'm always excited when you DC-MD folks can get in on the action.  You've seen your share of disappointments and I'm glad this one looks to be all yours!

[swimmatte]

I apologize in advance, I know it's against the rules to post this stuff here, but there is no banter thread. But I just want to say good luck to all here in the mid-Atlantic. It's not going to hit my area, but I'm always excited when you DC-MD folks can get in on the action. You've seen your share of disappointments and I'm glad this one looks to be all yours!

There's a banter thread, it's just not pinned.

[North Balti Zen]

I apologize in advance, I know it's against the rules to post this stuff here, but there is no banter thread.  But I just want to say good luck to all here in the mid-Atlantic. It's not going to hit my area, but I'm always excited when you DC-MD folks can get in on the action.  You've seen your share of disappointments and I'm glad this one looks to be all yours!

 

No worries...and, thanks, we really need this one. Not sure if all of us will cash in.

 

And...

 

banter!

 

http://www.americanwx.com/bb/index.php/topic/39538-rockin-march/page-21?

[Bob Chill]

Here's the last 4 runs of gfs qpf side by side. 6z today on the left through 12z yesterday on the right. Nobody is comforted by the euro's southern solution and the gfs is being doubted all over the board in every subforum but I gotta be honest here. I've analyzed the gfs for years. It has it's ups and downs like any model. But when I see 4 consecutive qpf panels like this side by side and also being inside of 4 days, I think the gfs is more right than the euro. 

 

 

[WinterWxLuvr]

Here's the last 4 runs of gfs qpf side by side. 6z today on the left through 12z yesterday on the right. Nobody is comforted by the euro's southern solution and the gfs is being doubted all over the board in every subforum but I gotta be honest here. I've analyzed the gfs for years. It has it's ups and downs like any model. But when I see 4 consecutive qpf panels like this side by side and also being inside of 4 days, I think the gfs is more right than the euro.

gfsqpfcomp.JPG

Why anybody would doubt the gfs this year puzzles me.

[usedtobe]

Bob, nice graphic.  what did the euro ens mean do compared the the euro?  I note that the sref median qpf is 1.61 and that the euro is on the lower end of the spectrum, possible but my guess would that we get more than 1.00 of liquid, something like .1.50 or so but that's a guess and I haven't really done any close analysis since yesterday's cwg piece. 

[North Balti Zen]

New storm specific model banter thread (and hopefully obs) thread here!

 

http://www.americanwx.com/bb/index.php/topic/39586-march-6th-storm-banter-and-obs-thread/

 

To the novices and snow weenies (which includes me), head there! This thread is for red taggers, pro mets, and learned amateurs. If you are not sure if you are a learned amateur, you probably are not (ask yourself before posting...wwzd (what would zwyts do)...he would post here, but you are likely not on his level)(phin, psuhoff, bobC, winterwx, Ji, mitch and a few others are...likely you are not)!

 

To the banter thread with you for commentary. But enjoy reading the disco in this one!

 

May the 0z suite be with everyone.

 

Except DT. I hope he loses.

[TalcottWx]

Bob, nice graphic. what did the euro ens mean do compared the the euro? I note that the sref median qpf is 1.61 and that the euro is on the lower end of the spectrum, possible but my guess would that we get more than 1.00 of liquid, something like .1.50 or so but that's a guess and I haven't really done any close analysis since yesterday's cwg piece.

I think this might be a rare occasion the euro is playing catchup since it seems to be a outlier somewhat. We shall see

[Bob Chill]

Here's the previous 24 hours of gfs runs (6z sunday on the left and 12z Sat on the right). 

 

I don't know what else to say other than the gfs has been pretty much locked into it's current solution for 48 hours with out a single meaningful hiccup.

 

The up the coast stuff is new but the reasons for that in those runs has little to do with what happens here. 8 straight runs of a dynamic slow moving and pivoting system with a serious deform area. 

 

[WxUSAF]

I admit to not following things uber-closely the last 36 hours or so, but after a quick check of the soundings, why are we discussing the possibility of rain or RASN for the big cities?  GFS and NAM soundings both are quite cold and look like they're sub-freezing from ~975mb on up (at worst) and only about 0.5-1C below that (at worst).  I assume the Euro is probably warmer, but that's not really a surprise...

[nflwxman]

Bob, nice graphic. what did the euro ens mean do compared the the euro? I note that the sref median qpf is 1.61 and that the euro is on the lower end of the spectrum, possible but my guess would that we get more than 1.00 of liquid, something like .1.50 or so but that's a guess and I haven't really done any close analysis since yesterday's cwg piece.

The euro ensemble mean matched close with the op with the low. might have a been a little further south even.

[usedtobe]

I admit to not following things uber-closely the last 36 hours or so, but after a quick check of the soundings, why are we discussing the possibility of rain or RASN for the big cities?  GFS and NAM soundings both are quite cold and look like they're sub-freezing from ~975mb on up (at worst) and only about 0.5-1C below that (at worst).  I assume the Euro is probably warmer, but that's not really a surprise...

I think only because the sounding might be warmer if the precip is lighter than the GFS and NAM are forecasting.  While the euro in the past has sometimes been too warm,  its lighter qpf would argue for temps to be a little warmer. 

[NOVAForecaster]

We're inside of GFS/Euro ensemble range now, and just about at the SREF and NAM wheelhouse. I don't expect many more shifts, except the Euro going 2/3 of the way to the GFS and them both meeting around there. I think the models are a little dry actually, as we have seen with other systems this year. Somebody between FRR and CHO is going to get over 2' IMO. 6"-10" is my best guess for DC and the west suburbs, and 3"-6" east; taking a NAM/GFS and slight Euro blend. However, any 50 mile shift could change the totals dramatically.

[psuhoffman]

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?

[Quasievil]

With it being less than 48 hours away from the start, I am shocked at how different the qpf numbers are for DC/BWI between the Euro and GFS. Not sure what to make of that.

[winterymix]

Bob, nice graphic.  what did the euro ens mean do compared the the euro?  I note that the sref median qpf is 1.61 and that the euro is on the lower end of the spectrum, possible but my guess would that we get more than 1.00 of liquid, something like .1.50 or so but that's a guess and I haven't really done any close analysis since yesterday's cwg piece. 

I'm not Bob but am happy to read his stuff as well as your stuff, Wes.

 

I don't know where to find statistical output for EURO but do know how to access animated EURO features over at Weather Underground. 

As such, it puts the bullseye at Centerville, VA.  Both the EURO and GFS show attenuation just north and east of me.

 

Simply put, on a line from Centerville to Philadelphia, the precip. reduces significantly towards the eastern-most location of the MD Line.

 

Jim Cantore should go to Centerville.

[needbiggerboat]

We're inside of GFS/Euro ensemble range now, and just about at the SREF and NAM wheelhouse. I don't expect many more shifts, except the Euro going 2/3 of the way to the GFS and them both meeting around there. I think the models are a little dry actually, as we have seen with other systems this year. Somebody between FRR and CHO is going to get over 2' IMO. 6"-10" is my best guess for DC and the west suburbs, and 3"-6" east; taking a NAM/GFS and slight Euro blend. However, any 50 mile shift could change the totals dramatically.

That's probably a bit underdone for the western burbs. Based on the latest NAM and GFS and the 500 depictions. I'd expect conducive temps throughout the column to support higher snow totals IAD and west. I'm thinking 12-16 is a good bet out here, more where the deform band parks.

[mitchnick]

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

[Bob Chill]

6z gfs dc sounding @ hr 39. Precip knocking on the door. Looks like light rain to start but wetbulb to near freezing will be quick:

 

 

 

@ hr 42 it's snow as long as the rates are ok. From then on it's all snow with the same caveat of rates. Temps look excellent to be honest considering there's no big cold air source and it's march.

 

[Huffwx]

NWS RNK went big--

 

4-8 western zones-- 6-14 east, including Lynchburg. 

 

That's 100% Euro, very little GFS blend. (The mean would be lower if they blending because the Euro is about 10 inches here and gfs is little 2. 

 

I'd be nervous throwing those numbers out there, but they do have support from the HPC

[Bob Chill]

I want to add to my earlier comment about me thinking the gfs is more right than the euro. That doesn't mean I think it's totally right. Euro made a very subtle shift last night for the better but it also held firm to it's more southern solution overall. With that being said, even splitting the difference between the 2 is a pretty big hit for dc burbs s&w. If 12z euro makes a subtle or not so subtle shift south then it's a big red flag. However, if all other guidance keeps going towards the gfs today then euro would be on an island.

 

History has shown that wrapped up dynamic systems will end up verifying further north with the precip max even if the slp/500 track don't waver much. Deform bands are powerful and hard to nail down to under 50 miles of accuracy. Especially with a global model. 

[WxUSAF]

@ hr 42 it's snow as long as the rates are ok. From then on it's all snow with the same caveat of rates. Temps look excellent to be honest considering there's no big cold air source and it's march.

 

dc6zhr42.JPG

That's snow in nearly every imaginable situation if that occurs verbatim.  With full sun today, it will be interesting to see what we get to temp-wise.  I think the airmass overperformed a bit on cold this weekend at least.  

[Huffwx]

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

 

 

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. 

[H2O]

That's snow in nearly every imaginable situation if that occurs verbatim.  With full sun today, it will be interesting to see what we get to temp-wise.  I think the airmass overperformed a bit on cold this weekend at least.  

 

 

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.