Dec/Jan Medium/Long Range Disco

[Ji]

12 minutes ago, psuhoffman said:

This was day 12-19 on guidance 10 days ago  

This is what it looks like now!

Amazing job by guidance!  You picked a weird time to start in with this anti long range crusade of yours when the long range guidance has been absolutely killing it lately.  

 

even the seasonal modeling has been crazy....i posted something in early November about how the Season model had a ton of precip starting around Nov 20 through Dec and we have been assaulted by precip. I think we had this disussion before but perhaps due to more southern stream than northern stream...models do better in Nino but i think that is for specific storms...and not long range patterns

[jayyy]

This was day 12-19 on guidance 10 days ago  

This is what it looks like now!

Amazing job by guidance!  You picked a weird time to start in with this anti long range crusade of yours when the long range guidance has been absolutely killing it lately.  
 

What’d you say to me the other day about debating the illogical with logic? Same person if I recall correctly it’s becoming quite clear that the member in question doesn’t understand how pattern changes work and that it takes some time for things to unfold downstream when the PAC reshuffles. The pattern beginning to change on the 29th doesn’t mean we will have a snow setup on the 30th. It typically means that we should begin to see snow chances pop up on guidance 7-10 days after, and that still hinges on other things lining up correctly. Some folks need a quick refresher it seems. I know it’s been snowless around here the past 2 years but damn.

On a real note, thanks for the quick fact check. Guidance has, so far, done a solid job with the longwave pattern 10-15 days out. No two ways about it. And you were the first person to say models were rushing a snowstorm for the 29th timeframe. The pattern change was still coming as advertised, but that there was very little shot things would come together within 4 days to see a snowstorm materialize. Makes sense given the number of moving pieces impacting the impending changes at H5.

January 4-5th is our first shot at *SOME* snow, but not as good as our chances for the 8th-9th. That could be the first true areawide SECS to track this winter

[psuhoffman]

21 minutes ago, jayyy said:

What’d you say to me the other day about debating the illogical with logic? Same person if I recall correctly it’s becoming quite clear that the member in question doesn’t understand how pattern changes work and that it takes some time for things to unfold downstream when the PAC reshuffles. The pattern beginning to change on the 29th doesn’t mean we will have a snow setup on the 30th. It typically means that we should begin to see snow chances pop up on guidance 7-10 days after, and that still hinges on other things lining up correctly. Some folks need a quick refresher it seems. I know it’s been snowless around here the past 2 years but damn.

On a real note, thanks for the quick fact check. Guidance has, so far, done a solid job with the longwave pattern 10-15 days out. No two ways about it. And you were the first person to say models were rushing a snowstorm for the 29th timeframe. The pattern change was still coming as advertised, but that there was very little shot things would come together within 4 days to see a snowstorm materialize. Makes sense given the number of moving pieces impacting the impending changes at H5.

January 4-5th is our first shot at *SOME* snow, but not as good as our chances for the 8th-9th. That could be the first true areawide SECS to track this winter

True but I thought you were going at it with Stormy. 

[jayyy]

WB 18Z GEFS time around Jan. 5th still looks good.

With the impending pattern change still on track, I’d be OK with settling for a snow thump to rain/dry slot setup around the 4th if it meant setting the stage for a legit storm around the 8-9th. Drag the boundary south, inject in some fresh cold air, and we see a low track up from the Gulf coast. Hints of high pressure being present in eastern Canada as well. Let’s get it done!

A few members of the 18z GEFS actually gave us significant snow from the initial wave, but there’s really not much support for that outcome *at this time*

[jayyy]

True but I thought you were going at it with Stormy. 

53 said I had errant beliefs but I can totally understand the mixup

[BristowWx]

I can’t believe that 192 panel on GFS is showing rain with those rates inside the 534 line.  That should show us getting clocked even though it’s fantasy range.  

[Kmlwx]

18 minutes ago, BristowWx said:

I can’t believe that 192 panel on GFS is showing rain with those rates inside the 534 line.  That should show us getting clocked even though it’s fantasy range.  

Even at fantasy range - a low in that position is not going to be good for most of us 

[CAPE]

2 minutes ago, Kmlwx said:

Even at fantasy range - a low in that position is not going to be good for most of us 

Yep. Surface up to 850 mb is too warm with that track. Ofc the Euro tracks the low off the SC coast for that window. Perhaps something a bit in between. 

[CAPE]

6z GEFS for the 2nd

[Heisy]

Don’t kill me too much, I know we have a window for something hopefully between 1/2-10, but this being the snow mean from the 6z GEFS through 300 hours is sad and discouraging. Just one run though .


.

[stormy]

At 192 that low is at least 75 miles too far north/northwest for D.C.....  It should be closer to Cape Charles..

That type of track would be ok for west of the Blue Ridge.

[osfan24]

It's still rain on the backside when the low is off the coast of Nantucket. Alarming. Going in the PSU book.

[WesternFringe]

44 minutes ago, osfan24 said:

It's still rain on the backside when the low is off the coast of Nantucket. Alarming. Going in the PSU book.

It hasn’t happened yet.  Can we at least wait until it occurs to put it in PSU’s book?

[psuhoffman]

I don’t agree with the analysis based solely on the surface track. Details matter.

The storm on the 6z gfs is tucked in tight but it’s coming at us from a southerly trajectory and it’s bombing and vertically stacked to 500mb by the time it tucks in close to DC.   

Notice the precip is wrapped up tight to the surface low.  There are examples of that track producing nice snows for us. Yea it probably should mix at the height but with a vertically stacked system wound up like that as soon as the low is east of our longitude it should flip in the deform band.  
 

The track argument is really silly if you pull back and don’t focus on our own yard.  How this frame isn’t conclusive and alarming is beyond me. 

What’s track have to do with it?  Even if you cling to the “it tracks to close for DC” its rain the way to the NW fringe of precip in the deform except for high elevations which mitigates the boundary layer.  
 

Frankly that frame is absolutely terrifying to me.  Were no longer a day into the pattern by then. We’ve had an NW flow into the eastern US for a week by then to establish a colder regime. Everything went 100% perfect for places a bit NW of DC (even DC should get a decent snow there) and it’s just rain.  

 

[psuhoffman]

4 minutes ago, WesternFringe said:

It hasn’t happened yet.  Can we at least wait until it occurs to put it in PSU’s book?

No because it’s irrelevant. The fact a sophisticated simulation (which frankly is biased cold) says that’s the most likely outcome based on its current data and physics is alarming. It shouldn’t be possible to have a vertically stacked bombing low there with a deform band right over us in January in a pattern where we’ve had a NW flow into the east for a week and get rain. How that doesn’t bother anyone is beyond me. 

[Terpeast]

2 minutes ago, psuhoffman said:

I don’t agree with the analysis based solely on the surface track. Details matter.

The storm on the 6z gfs is tucked in tight but it’s coming at us from a southerly trajectory and it’s bombing and vertically stacked to 500mb by the time it tucks in close to DC.   

Notice the precip is wrapped up tight to the surface low.  There are examples of that track producing nice snows for us. Yea it probably should mix at the height but with a vertically stacked system wound up like that as soon as the low is east of our longitude it should flip in the deform band.  
 

The track argument is really silly if you pull back and don’t focus on our own yard.  How this frame isn’t conclusive and alarming is beyond me. 

What’s track have to do with it?  Even if you cling to the “it tracks to close for DC” its rain the way to the NW fringe of precip in the deform except for high elevations which mitigates the boundary layer.  
 

Frankly that frame is absolutely terrifying to me.  Were no longer a day into the pattern by then. We’ve had an NW flow into the eastern US for a week by then to establish a colder regime. Everything went 100% perfect for places a bit NW of DC (even DC should get a decent snow there) and it’s just rain.  

 

Ignoring the surface panel for a second -

The 850 low tracks just underneath us. 700 mb low right overhead or just underneath if you’re north of DCA.

thicknesses are 534-540

This is a mostly snow look. It may indeed start out as rain initially as there’s a trowal with ~0 air at 850 and a warmer BL, but with heavier rates on the backside with a north wind, that’s going to be snow. 

I think the surface depiction of ptypes are wrong. At least 50% wrong on the backside. 

[psuhoffman]

I’m going to say this then I’m done commenting on that gfs run. If we actually get a few scenarios like that this winter (or like that Super Bowl storm in 2021) then my seasonal forecast will fail for one reason. I failed to correctly account for warning and it’s worse than I thought. 

[WxUSAF]

12 minutes ago, Terpeast said:

Ignoring the surface panel for a second -

The 850 low tracks just underneath us. 700 mb low right overhead or just underneath if you’re north of DCA.

thicknesses are 534-540

This is a mostly snow look. It may indeed start out as rain initially as there’s a trowal with ~0 air at 850 and a warmer BL, but with heavier rates on the backside with a north wind, that’s going to be snow. 

I think the surface depiction of ptypes are wrong. At least 50% wrong on the backside. 

I think I agree that there would be at least some snow in that deform band on the back with that look. But the torched boundary layer at that point is pretty alarming and discouraging. 

[WesternFringe]

6 minutes ago, psuhoffman said:

No because it’s irrelevant. The fact a sophisticated simulation (which frankly is biased cold) says that’s the most likely outcome based on its current data and physics is alarming. It shouldn’t be possible to have a vertically stacked bombing low there with a deform band right over us in January in a pattern where we’ve had a NW flow into the east for a week and get rain. How that doesn’t bother anyone is beyond me. 

Never said it didn’t bother me, so please don’t put words in my mouth.  I think it is perfectly relevant to distinguish between weather depicted at Day 8 on a model (with very little skill after Day 5) and weather that has actually occurred.  

I will have to respectfully disagree on this one.  When you say, “it shouldn’t be possible” it very well might not be.  There are plenty of times the experienced and knowledgable posters on here disagree with the surface depictions based off of the H5 in the Day 5-10 range.  But this time it is irrelevant that the event hasn’t occurred and is 8 days away?  C’mon, man!

[Kevin Reilly]

29 minutes ago, psuhoffman said:

I don’t agree with the analysis based solely on the surface track. Details matter.

The storm on the 6z gfs is tucked in tight but it’s coming at us from a southerly trajectory and it’s bombing and vertically stacked to 500mb by the time it tucks in close to DC.   

Notice the precip is wrapped up tight to the surface low.  There are examples of that track producing nice snows for us. Yea it probably should mix at the height but with a vertically stacked system wound up like that as soon as the low is east of our longitude it should flip in the deform band.  
 

The track argument is really silly if you pull back and don’t focus on our own yard.  How this frame isn’t conclusive and alarming is beyond me. 

What’s track have to do with it?  Even if you cling to the “it tracks to close for DC” its rain the way to the NW fringe of precip in the deform except for high elevations which mitigates the boundary layer.  
 

Frankly that frame is absolutely terrifying to me.  Were no longer a day into the pattern by then. We’ve had an NW flow into the eastern US for a week by then to establish a colder regime. Everything went 100% perfect for places a bit NW of DC (even DC should get a decent snow there) and it’s just rain.  

 

Common theme no cold high up north.

[StormyClearweather]

10 minutes ago, WxUSAF said:

I think I agree that there would be at least some snow in that deform band on the back with that look. But the torched boundary layer at that point is pretty alarming and discouraging. 

I don't know much of anything here, but when I click on the handy-dandy sounding from Pivotal, it shows a best guess of snow at 192. Maybe that doesn't matter, or maybe that just goes to show how borderline it is, which in itself is concerning? And yes, I realize 37/38 isn't ideal regardless of how you spin it. 

 

Edit: Oh, and at least Short Pump goes over to snow, based on the p-type map. 

[WxUSAF]

Yeah, freezing level is like 950mb in that deform band. It’s low, but also not right at the surface. So I think it would be pouring slush bombs at 34 if it happened like that. But it “should” be a 30-32F pasting. 

[psuhoffman]

22 minutes ago, Terpeast said:

Ignoring the surface panel for a second -

The 850 low tracks just underneath us. 700 mb low right overhead or just underneath if you’re north of DCA.

thicknesses are 534-540

This is a mostly snow look. It may indeed start out as rain initially as there’s a trowal with ~0 air at 850 and a warmer BL, but with heavier rates on the backside with a north wind, that’s going to be snow. 

I think the surface depiction of ptypes are wrong. At least 50% wrong on the backside. 

 

8 minutes ago, WxUSAF said:

I think I agree that there would be at least some snow in that deform band on the back with that look. But the torched boundary layer at that point is pretty alarming and discouraging. 

This…Terp everything you said is why I said it “should be snow”. But the surface is torched.  What’s terrifying imo is we all know our biggest years come in ninos typically without arctic air. This isn’t applicable to those times we get a wave in a true arctic regime. But we know 75% of our snow doesn’t come that way. If things keep warming eventually we will lose what makes up the large majority of our snow. I agree that one run is likely in error. But maybe we might be closer to that day then I thought. 

[Buddy1987]

I would say verbatim right now if you’re west of 64 and up and down 81 you feel halfway decent. A lot going to change though I’m sure.

[Kevin Reilly]

3 minutes ago, WxUSAF said:

Yeah, freezing level is like 950mb in that deform band. It’s low, but also not right at the surface. So I think it would be pouring slush bombs at 34 if it happened like that. But it “should” be a 30-32F pasting. 

Warm air trapped at the surface, many many cloudy days with fog at night, and very high humidity levels, you just can't get rid of the warmth even with a great set up.  Tracking a snowstorm in our area is like predicting a hurricane strike on the Mid Atlantic Coast. 

[NorthArlington101]

This…Terp everything you said is why I said it “should be snow”. But the surface is torched.  What’s terrifying imo is we all know our biggest years come in ninos typically without arctic air. This isn’t applicable to those times we get a wave in a true arctic regime. But we know 75% of our snow doesn’t come that way. If things keep warming eventually we will lose what makes up the large majority of our snow. I agree that one run is likely in error. But maybe we might be closer to that day then I thought. 

Well, at least the entire MA/NE is above freezing. We can all suffer together

Dynamic cooling bombs or bust. Otherwise head to the mountains.

[psuhoffman]

13 minutes ago, WesternFringe said:

Never said it didn’t bother me, so please don’t put words in my mouth.  I think it is perfectly relevant to distinguish between weather depicted at Day 8 on a model (with very little skill after Day 5) and weather that has actually occurred.  

I will have to respectfully disagree on this one.  When you say, “it shouldn’t be possible” it very well might not be.  There are plenty of times the experienced and knowledgable posters on here disagree with the surface depictions based off of the H5 in the Day 5-10 range.  But this time it is irrelevant that the event hasn’t occurred and is 8 days away?  C’mon, man!

You make a good point. But it HAS been happening. People have just been sticking their head in the sand when it does. Super Bowl 2021 was the best example. There was a perfect track rainstorm last winter also. 

[Ralph Wiggum]

12 minutes ago, WesternFringe said:

Never said it didn’t bother me, so please don’t put words in my mouth.  I think it is perfectly relevant to distinguish between weather depicted at Day 8 on a model (with very little skill after Day 5) and weather that has actually occurred.  

I will have to respectfully disagree on this one.  When you say, “it shouldn’t be possible” it very well might not be.  There are plenty of times the experienced and knowledgable posters on here disagree with the surface depictions based off of the H5 in the Day 5-10 range.  But this time it is irrelevant that the event hasn’t occurred and is 8 days away?  C’mon, man!

I agree with this. Guidance will adjust to thermals as storm times approach. Happens both ways....we've looked at LR programs and said " somehow the gfs snows with that look, we take". Then it rains and we bash the model. I've seen it show bl too warm and pop a snow event closer to game time. Not saying psu debate isn't valid but there are 2 sides/possibilities abd we've  seen both at times.

[Maestrobjwa]

37 minutes ago, psuhoffman said:

No because it’s irrelevant. The fact a sophisticated simulation (which frankly is biased cold) says that’s the most likely outcome based on its current data and physics is alarming. It shouldn’t be possible to have a vertically stacked bombing low there with a deform band right over us in January in a pattern where we’ve had a NW flow into the east for a week and get rain. How that doesn’t bother anyone is beyond me. 

If it's any comfort...if we are closer to "that day"...so is the entire east coast up 95. Like even up in Boston that's not snow. So whatever it is...at least it's not just down here while north is still cold enough, lol (Would the old joke of "just move north" Turn into "Just move north AND inland"?) That would be a crazy implication for it to happen to everybody at once, and seemingly flip on a dime like that!

[WesternFringe]

2 minutes ago, psuhoffman said:

You make a good point. But it HAS been happening. People have just been sticking their head in the sand when it does. Super Bowl 2021 was the best example. There was a perfect track rainstorm last winter also. 

I hear you, but let’s wait until it happens or at least gets closer and is continually modeled to add it to the book.  And maybe more than just one model showing it as well.

It is also perspective.  My elevation of 1550’ helps out here.  I got 8” on 2/6/21 for the superbowl and another 5” five days later.  This storm that we are discussing now drops 6” imby verbatim according to the GFS.  

Not sure what storm last year you are referring to, but it has happened out here as well.  Did we not used to get perfect track rainstorms in winters in the past?  I remember some in the 80s even in upstate NY that were disappointing rain even with a classic track.