Weekend Snowfest/Rainfest/Mixed Mess?

[showmethesnow]

4 minutes ago, MillvilleWx said:

 

I feel the same way. Models are giving a solid indication of what we will be fighting today, but by no means will it be gospel. I actually liked the increased QPF and distribution over the region this past run. Of course, caveat is the warm intrusion over the boundary layer, so there were some negatives, and glaring ones at that. I’m sticking with a general 1-3” with 3-5” embedded for now. Cities will ultimately struggle given the warmer layer present from surface to 925mb.

I normally hate making last second adjustments, but I can’t ignore the slightly warmer boundary layer models are printing out. They are up to something. On the bright side, looks snowy up by Valley Forge area. Put a $100 on red for me and enjoy your Bday weekend!


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Looking at some soundings yesterday around DC and it gave me some pause when I was seeing a warm nose showing up around 900-950 mb. At that point it was very manageable, being shallow and just a hair above freezing. But looking at some of the soundings I saw posted are troubling. Though temps are marginal what really bothers me is that the warm nose is much deeper now extending towards 850. Really think the make or break will occur there and that rates will be the determining factor.

[MillvilleWx]

Still sticking pretty much to my thoughts from a couple of days ago which many are probably going to find quite bullish. 1 to 2 just south and east of 95. 95 corridor,2-4 with the higher amounts to the north. As far as the hell hole around DC proper 1-2 if they slant stick ). Still like 3-6 north and west of 95 with the higher amounts in the favored higher elevations and the northern portions. 

Hope you’re right! Usually I take a more aggressive forecast, but marginal setups have left a bad taste in my mouth in the past. Playing a bit more conservative this go around. We shall see. 3k performed very well out in the SW where I forecast. We’ll see how it does with the energy as it rolls east.


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[psuhoffman]

7 minutes ago, showmethesnow said:

Just started glancing over the runs. We always knew this would be a marginal setup at best where slight differences with rates, temps, extent and depth of the warm nose around 900 mb, etc... could flip this one way or the other. Have felt for a while that this was going to be a now-cast situation and that is exactly what it is turning out to be. Models slid a bit over night but what I am seeing is it is generally just a matter of a touch less precip and/or very marginal temp increases. Would take very little to flip it back to the snowier/icier solutions. So for those baling, I probably wouldn't just quite yet.

Not bailing. I'll track this to the bitter end. But I think the writing is on the wall for a bitter end. Im not a stick my head in the sand person. If it's good it's good but if it looks bad I'm not gonna just grip hope and say it's ok. It's just snow we will be alright lol. 

I've said all week the typical error bias with this kind of setup is for guidance to adjust north the last 36 hours. So when that exact thing starts to show up I can't then ignore the evidence. Its universal across all guidance.  There was a reason I said I wanted the best snow to be just south of us heading into the final 36 hours.   How often once the north trend starts at the last minute does it reverse itself?  I'll hold out hope for some quick thumpage before the warm layer takes over but I think our hope for a significant event (2-4" cities 3-6 up here) is fading away. That looks like it's up in PA now. And not even southern PA it might end up along 81/78 from Harrisburg to Allentown. That was over us just 2 runs ago. Here is how the real snow band has shifted the last 2 runs 

 

tell me you don't see where that's clearly headed...the real snow band isn't even close to us anymore really it's shifting well up into PA and we're left praying for scraps from convective cooling and banding to get a slushy accumulation before it goes to rain  

 

[showmethesnow]

12 minutes ago, MillvilleWx said:

 

I feel the same way. Models are giving a solid indication of what we will be fighting today, but by no means will it be gospel. I actually liked the increased QPF and distribution over the region this past run. Of course, caveat is the warm intrusion over the boundary layer, so there were some negatives, and glaring ones at that. I’m sticking with a general 1-3” with 3-5” embedded for now. Cities will ultimately struggle given the warmer layer present from surface to 925mb.

I normally hate making last second adjustments, but I can’t ignore the slightly warmer boundary layer models are printing out. They are up to something. On the bright side, looks snowy up by Valley Forge area. Put a $100 on red for me and enjoy your Bday weekend!


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Thanks by the way. I think. Sucks getting old. 

Have liked the Valley Forge area for snow for awhile now. Would be a nice present to see 4-6 up there in between gambling. 

[MillvilleWx]

Looking at some soundings yesterday around DC and it gave me some pause when I was seeing a warm nose showing up around 900-950 mb. At that point it was very manageable, being shallow and just a hair above freezing. But looking at some of the soundings I saw posted are troubling. Though temps are marginal what really bothers me is that the warm nose is much deeper now extending towards 850. Really think the make or break will occur there and that rates will be the determining factor.

Yup. This is main reason I lowered my forecast. PSU showed it spatially with the warm layer now into 850mb. If that’s true, that’s tougher to overcome, so rates become even more of a factor. DGZ is way upstairs too, so it’s not like we’re going to have that working in our favor either. Lots of Q’s on the table. Ers mentioned last few days he was going conservative, and it may end up the right play. Might be a little different than his initial thinking, but the concept still applies to the forecast. Marginal events are fickle and we end up on wrong side slightly more often than not. Hoping for the not


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[showmethesnow]

7 minutes ago, MillvilleWx said:

 

Hope you’re right! Usually I take a more aggressive forecast, but marginal setups have left a bad taste in my mouth in the past. Playing a bit more conservative this go around. We shall see. 3k performed very well out in the SW where I forecast. We’ll see how it does with the energy as it rolls east.


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Actually feel fairly comfortable with my 3 to 6 north and west of the cities. Though the models have been showing/hinting at banding through that region (Carroll, N Baltimore and over to Mappyland) I think they are under playing it. Sort of expect some better rates through that region then currently being shown. Of course that would be better precip totals as well as a better temp rpofile. Think it will be a nice little event through that region. Where I really question is 95 and south and east. I can see very easily where I get a big fail there.

[psuhoffman]

3 minutes ago, MillvilleWx said:

 

Yup. This is main reason I lowered my forecast. PSU showed it spatially with the warm layer now into 850mb. If that’s true, that’s tougher to overcome, so rates become even more of a factor. DGZ is way upstairs too, so it’s not like we’re going to have that working in our favor either. Lots of Q’s on the table. Ers mentioned last few days he was going conservative, and it may end up the right play. Might be a little different than his initial thinking, but the concept still applies to the forecast. Marginal events are fickle and we end up on wrong side slightly more often than not. Hoping for the not

 

Ers was right but he thought it would be suppressed. In the end over amped and warm looks like the dagger.  I want to be wrong. I keep looking for evidence I'm wrong. But the shift north of the thermal profile the last 12 hours is so dramatic across all guidance. I'm basically now dealing with what D.C. was looking at 24 hours ago temperature wise up here. When I'm worried about the rain snow line here that's not good for 95. 

The only way this works now is an extreme thump, and I do think there will be some of that but looking at how warm the mid levels are I see that as a quick 1-2" in spots before the warm layer wins out. That warm layer is becoming a bit more then I think can be overcome ultimately to hold on to snow long enough to get more then that. This had real potential to be more than just another 1" event. 

I really hope I'm wrong and the snow comes in fast and furious and it's like another feb 2007 event where it puts down 3-5" before the warm layer can get in but I'm skeptical of that given latest guidance. 

[showmethesnow]

10 minutes ago, psuhoffman said:

Not bailing. I'll track this to the bitter end. But I think the writing is on the wall for a bitter end. Im not a stick my head in the sand person. If it's good it's good but if it looks bad I'm not gonna just grip hope and say it's ok. It's just snow we will be alright lol. 

I've said all week the typical error bias with this kind of setup is for guidance to adjust north the last 36 hours. So when that exact thing starts to show up I can't then ignore the evidence. Its universal across all guidance.  There was a reason I said I wanted the best snow to be just south of us heading into the final 36 hours.   How often once the north trend starts at the last minute does it reverse itself?  I'll hold out hope for some quick thumpage before the warm layer takes over but I think our hope for a significant event (2-4" cities 3-6 up here) is fading away. That looks like it's up in PA now. And not even southern PA it might end up along 81/78 from Harrisburg to Allentown. That was over us just 2 runs ago. Here is how the real snow band has shifted the last 2 runs 

 

 

tell me you don't see where that's clearly headed...the real snow band isn't even close to us anymore really it's shifting well up into PA and we're left praying for scraps from convective cooling and banding to get a slushy accumulation before it goes to rain  

 

Wasn't saying you were baling. I know you are just like me and will go down with the ship.  

I agree, the models have definitely slipped. But the slippage was very minor in my mind. It will not take much at all to flip this back to a snowier/icier solution (1/2 degree here or there, slightly better rates, etc..) especially for the northern tier. We could definitely Fail big here, but in my mind I can just as easily see a big win as well. 

[showmethesnow]

14 minutes ago, MillvilleWx said:

 

Yup. This is main reason I lowered my forecast. PSU showed it spatially with the warm layer now into 850mb. If that’s true, that’s tougher to overcome, so rates become even more of a factor. DGZ is way upstairs too, so it’s not like we’re going to have that working in our favor either. Lots of Q’s on the table. Ers mentioned last few days he was going conservative, and it may end up the right play. Might be a little different than his initial thinking, but the concept still applies to the forecast. Marginal events are fickle and we end up on wrong side slightly more often than not. Hoping for the not


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To be a successful pro forecaster in this region you should always hedge towards Fail. But I am a half glass full sort of guy so more often then not I bet on the win. Guess that is why I am not a successful pro forecaster. 

[MillvilleWx]

Actually feel fairly comfortable with my 3 to 6 north and west of the cities. Though the models have been showing/hinting at banding through that region (Carroll, N Baltimore and over to Mappyland) I think they are under playing it. Sort of expect some better rates through that region then currently being shown. Of course that would be better precip totals as well as a better temp rpofile. Think it will be a nice little event through that region. Where I really question is 95 and south and east. I can see very easily where I get a big fail there.

Ahhh. I see where you’re coming from. That could very well be the case. Typical spots from Northern MoCo up toward Northern Harford on a N/NE line will likely be the prime spots here. If anyone sees a bust high, it’ll likely be within that corridor as you mentioned. I live right down road from Damascus in Northern MoCo, so I still think my area can do well. It’s pretty astounding the difference in temp and where rain/snow line falls along Rt 27 down here. I’ve seen it rain at my office in Germantown and fatties plastering everything up the road 2.5 miles. It’s remarkable. Could be another case here too.


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[showmethesnow]

Has anyone formed an opinion of the 3K NAM yet? Especially the temp profiles? 

[psuhoffman]

2 minutes ago, showmethesnow said:

Wasn't saying you were baling. I know you are just like me and will go down with the ship.  

I agree, the models have definitely slipped. But the slippage was very minor in my mind. It will not take much at all to flip this back to a snowier/icier solution (1/2 degree here or there, slightly better rates, etc..) especially for the northern tier. We could definitely Fail big here, but in my mind I can just as easily see a big win as well. 

I think we're coming at it from two different POV. Yes we're still close and a 1-2 degree cold adjustment makes this a big win. And that's minor. Bit a 1 degree warmer look and it's almost all rain. You're taking the it could go either way approach. I'm factoring in the trends now plus historical trends with these to say it's way way way more likely it continues to adjusts warmer from here and not reverse. I'm kind of assuming the bleeding continues right up to gametime and we can't afford any more bleeding. We had almost no wiggle room to start with and now we're close to bleeding out.

so yea the optimist view is we're right on the line and a slight cold adjustment and we win. My view is given all the evidence I think it's 80/20 it adjusts even warmer from here.  But if I'm wrong and it reverses and the models are just 1-2 degrees too warm then your right. I really hope so. I want to be wrong bigly. 

[Mordecai]

NWS updated their forecast. 

[MillvilleWx]

To be a successful pro forecaster in this region you should always hedge towards Fail. But I am a half glass full sort of guy so more often then not I bet on the win. Guess that is why I am not a successful pro forecaster. 

Sad but true story for this area lol. I don’t forecast here for a living, but I actually enjoy the challenge. Learned a lot over the years from trying to understand the climo and forecasting incatracies for the region. We do fail well here, but we also have our share positive busts in many areas. I forecast in areas where weather is difficult due to presence of upper level features that have minds of their own. Isentropic upglide, upper lows, powerful jet streaks, nocturnal low level jets, cold fronts, dry lines, thermal troughs, monsoon, severe, and that’s just the Western and South Central US. I forecast for tropics too. And everything is aviation based, so wind and turbulence. I see it all. Forecasting here and there is like night and day. I like being able to do both. Keeps my skills sharp.


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[psuhoffman]

2 minutes ago, showmethesnow said:

Has anyone formed an opinion of the 3K NAM yet? Especially the temp profiles? 

I based a lot of my points above on the 3k. Actually I've found once inside 24 hours it's been very useful and for a meso reliable. I like it better then the 12k. Seeing it shift the best banding with the snow as far north as it did was probably the biggest determinate of my pessimism right now. The last few times it blasted a warm layer way north like this it was right. It nailed the mixing all the way up to you with the march storm last year when most other guidance was still all snow for us. 

[showmethesnow]

 

3 minutes ago, psuhoffman said:

I based a lot of my points above on the 3k. Actually I've found once inside 24 hours it's been very useful and for a meso reliable. I like it better then the 12k. Seeing it shift the best banding with the snow as far north as it did was probably the biggest determinate of my pessimism right now. The last few times it blasted a warm layer way north like this it was right. It nailed the mixing all the way up to you with the march storm last year when most other guidance was still all snow for us. 

Last March was a different beast. I called that sleet mess all the way up to our area days in advance. It wasn't a hard a call to make whatsoever in my mind. Got a lot of Flack for that from some on these boards. But I am a big boy, I could handle it.  In this case with a weak low progressing south of us that doesn't really start ramping up until it hits the coast it is a whole different setup. Think the models may be overplaying the northward intrusion of the warm air at mid levels somewhat. I really wish the High would have verified overtop when I first brought this possible event up instead of scooting OTS. Would have made this pretty much a slam dunk for our region.

[psuhoffman]

4 minutes ago, showmethesnow said:

 

Last March was a different beast. I called that sleet mess all the way up to our area days in advance. It wasn't a hard a call to make whatsoever in my mind. Got a lot of Flack for that from some on these boards. But I am a big boy, I could handle it.  In this case with a weak low progressing south of us that doesn't really start ramping up until it hits the coast it is a whole different setup. Think the models may be overplaying the northward intrusion of the warm air at mid levels somewhat. I really wish the High would have verified overtop when I first brought this possible event up instead of scooting OTS. Would have made this pretty much a slam dunk for our region.

Yea it was a good call. I wasn't comparing the setups just pointing out the 3k has been very accurate in its placement of mid level warm layers. It wasn't just that storm. I've found it to be pretty good at meso scale features once inside 24 hours like we are now. 

[showmethesnow]

2 minutes ago, psuhoffman said:

Yea it was a good call. I wasn't comparing the setups just pointing out the 3k has been very accurate in its placement of mid level warm layers. It wasn't just that storm. I've found it to be pretty good at meso scale features once inside 24 hours like we are now. 

I'll have to keep that in mind. Still trying to form an opinion on it myself and that is hard to do when we really haven't had much to track since it was put into place.

By the way, just saw your snowmap in Banter. That is some great stuff. 

[dallen7908]

The Euro for the College Park area shows precipitation arriving around 4 PM with a surface temperature of ~38F and an 850T of -2.4C. 

By 7PM the surface temperature cools to 33 but the 850 T, which seems to be the warmest in the profile, rises to 1.5C. Temperatures are near freezing from the surface to 920 hPa, rise from 920 to 850, and then fall below freezing by 820 hPa. 

By 10 PM when the storm ends the surface temperature is 34.5 with an 850 T of 0.3C. 

Total precipitation from 3-4 PM is 0.01, 4-7 PM is 0.29 from 7-10 PM is 0.16

Wrong forum: but the Euro shows high temperatures in the 70s for 5 of the next 7 days beginning next Monday

[psuhoffman]

I guess I'll just hug the rgem and ignore the fact it's had a cold bias all year. 

[psuhoffman]

42 minutes ago, showmethesnow said:

Has anyone formed an opinion of the 3K NAM yet? Especially the temp profiles? 

The HRDPS isn't as good but it's another high res that agrees with the 3k on placing the band of heavy snow well north into central PA. Gfs does it too if you account for its low resolution missing the qpf with the banding there but it's clearly placing the best banding in the cold up there. Right now the area of 3-6" snows to me looks like it's up there from Harrisburg to Allentown area.  We will get some snow for sure but it will be scraps while up there wins again just like the last 2 waves in this pattern  

 

[AfewUniversesBelowNormal]

This is like a April 15 storm

I can't wait. NAM has 0.75" here and it's likely to be really heavy snow, big flakes

[clskinsfan]

2 hours ago, psuhoffman said:

Not bailing. I'll track this to the bitter end. But I think the writing is on the wall for a bitter end. Im not a stick my head in the sand person. If it's good it's good but if it looks bad I'm not gonna just grip hope and say it's ok. It's just snow we will be alright lol. 

I've said all week the typical error bias with this kind of setup is for guidance to adjust north the last 36 hours. So when that exact thing starts to show up I can't then ignore the evidence. Its universal across all guidance.  There was a reason I said I wanted the best snow to be just south of us heading into the final 36 hours.   How often once the north trend starts at the last minute does it reverse itself?  I'll hold out hope for some quick thumpage before the warm layer takes over but I think our hope for a significant event (2-4" cities 3-6 up here) is fading away. That looks like it's up in PA now. And not even southern PA it might end up along 81/78 from Harrisburg to Allentown. That was over us just 2 runs ago. Here is how the real snow band has shifted the last 2 runs 

 

tell me you don't see where that's clearly headed...the real snow band isn't even close to us anymore really it's shifting well up into PA and we're left praying for scraps from convective cooling and banding to get a slushy accumulation before it goes to rain  

 

I know it' an imby game. But the 81 corridor still looks good. We have been so snow starved out this way though so I am expecting disappointment.

I am down to 24/20 this morning. 

[AfewUniversesBelowNormal]

*Can you believe the front hasn't cleared Dallas, TX

[EastCoast NPZ]

2 hours ago, clskinsfan said:

I know it' an imby game. But the 81 corridor still looks good. We have been so snow starved out this way though so I am expecting disappointment.

I am down to 24/20 this morning. 

Looks good for what, an inch?  That map has us - maybe - in the 2" range and that doesn't even account for ****ty ratios and snow that melts on contact.  Add in the bright sunshine today utterly destroying the low-level and surface, and we are ripe for non-accumulating snow, if it even snows at all.  You are north of me some and have a better shot, but I see little chance of eclipsing a inch of slush, even on the grass.  This looks like another POS event to throw on the ever-growing pile from this winter.

[mappy]

RAP has the warm nose too, at 23z straight up the 95 corridor

 

[MN Transplant]

The HRRR is basically a two hour storm for DC. We lose the column by 00z, but the precip is already winding down (which is probably why we lose the column).

[clskinsfan]

45 minutes ago, EastCoast NPZ said:

Looks good for what, an inch?  That map has us - maybe - in the 2" range and that doesn't even account for ****ty rates and snow that melts on contact.  Add in the bright sunshine today utterly destroying the low-level and surface, and we are ripe for non-accumulating snow, if it even snows at all.  You are north of me some and have a better shot, but I see little chance of eclipsing a inch of slush, even on the grass.  This looks like another POS event to throw on the ever-growing pile from this winter.

Pretty sharp cutoff through our area in all honesty. Up by me most models are showing 2-4 with less to the S/E of Winchester. Who knows at this point? It's a nowcast situation once again.

[cae]

I've only started paying attention to the Swiss model recently, but it has been good with surface temps in the past.  It's a little colder than the 3k NAM.  The high resolution snow depth map really shows the benefit of elevation.  This is the 06z run.

Fwiw, the 06z run is a little better than 00z for places north of DC (especially those with elevation) and a little worse for those SE of DC.

[mappy]

I've only started paying attention to the Swiss model recently, but it has been good with surface temps in the past.  It's a little colder than the 3k NAM.  The high resolution snow depth map really shows the benefit of elevation.  This is the 06z run.

Fwiw, the 06z run is a little better than 00z for places north of DC (especially those with elevation) and a little worse for those SE of DC.

Amazing how easy it is to see the Parrs Ridge favored areas on that map .


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