Mid/Late February will be rocking. (This year we mean it!) February long range discussion.

[psuhoffman]

4 minutes ago, Baer16 said:

Are we all just going to ignore the trends for Tuesday's storm? 18z NAM gets DC N&W basically back in the game. 

Oh I’m seeing it. But there is another thread and even if that does trend better I’m likely to do a lot better so I’m sensitive in those scenarios not to say much.  I feel bad for everyone else when I get snow and they don’t. 

[BTRWx's Thanks Giving]

Was eps a dud?

[Weather Will]

Latest from NWS for the upcoming Pres. weekend, 30% is bullish a week out.

Uncertainty lies amongst the models for the upcoming weekend. On
Saturday a cold front will sit near the region with an area of low
pressure developing along the Gulf/southern U.S. The placement of
the front and track of the low has yet to be resolved along with the
placement of high pressure over eastern Canada. Temperatures will be
cooler as a result with highs in the 30s and 40s. Given model
uncertainty in regards to the track and placement of the
aforementioned features a wide array of precipitation types are
possible. We`ll continue to monitor this system as it evolves in the
coming days.

Saturday

A chance of snow. Mostly cloudy, with a high near 42. Chance of precipitation is 30%.

Saturday Night

A chance of snow. Mostly cloudy, with a low around 28. Chance of precipitation is 30%.

[BTRWx's Thanks Giving]

1 hour ago, psuhoffman said:

I agree with a lot of this. But why did you expect a +pna in a -PDO Nino?  There have been 4 Moderate/strong -PDO Ninos. None featured a +pna. Mean for the 4 is below. 

3 of the 4 were some of the snowiest winters in history here including 2010!  The one exception was 1973 which was a +QBO and has a crazy +++AO

So if we agree that was an outlier and toss all 3 examples of a -pdo moderate or stronger Nino featured both a -pna and a shit ton of snow.  
 

Actually if you simply take all moderate to strong ninos the mean is a -pna.  It’s only weak modoki ninos like 2003 and 2015 that feature a +pna.  But Baltimore averages 40” of snow in -QBO ninos despite the fact the pna is typically negative.  
 

I never expected a +pna this winter.  My analogs that produced a mean snow of 42” were  -PNA city.  There is something else going on.  It’s not the pna because the pna was negative in past epic snowy ninos.  

 

That's really interesting.

[GaWx]

1 hour ago, psuhoffman said:

I agree with a lot of this. But why did you expect a +pna in a -PDO Nino?  There have been 4 Moderate/strong -PDO Ninos. None featured a +pna. Mean for the 4 is below. 

3 of the 4 were some of the snowiest winters in history here including 2010!  The one exception was 1973 which was a +QBO and has a crazy +++AO

So if we agree that was an outlier and toss all 3 examples of a -pdo moderate or stronger Nino featured both a -pna and a shit ton of snow.  
 

Actually if you simply take all moderate to strong ninos the mean is a -pna.  It’s only weak modoki ninos like 2003 and 2015 that feature a +pna.  But Baltimore averages 40” of snow in -QBO ninos despite the fact the pna is typically negative.  
 

I never expected a +pna this winter.  My analogs that produced a mean snow of 42” were  -PNA city.  There is something else going on.  It’s not the pna because the pna was negative in past epic snowy ninos.  

 

 @Stormchaserchuck1 has a very good chance at getting his +PNA for 2023-4 (assuming that’s what he predicted). More on that below. Also, according to the NOAA monthly PNA table for DJFM, 1963-4 and 2009-10 both averaged +PNA with 1963-4 at +0.5 and 2009-10 at +1.0. It has 1972-3 at neutral (+0.1). Only 1965-6 of these 4 averaged a -PNA (-0.4):

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table
 
 2023-4 is so far averaging +PNA with both Dec and Jan positive. Feb 1-11 has also averaged +PNA. The forecast through Feb 18 is for more +PNA before dropping to neutral and then moderately negative. (See image below) So, there’s a very good chance that Feb overall will average a modest +PNA with a small chance to end up neutral.

 Thus with only March to go, 2023-4 has a very good chance to end up averaging +PNA in the table though I give it a small chance to end up neutral (that would obviously require a strong -PNA in Mar). I consider neutral to be +0.25 to -0.25:

 

[Kevin Reilly]

Umm I am NOT ignoring the trend on the NAM clearly more south and a bit stronger!

That is from the NAM an undeniable switch to heavy snow just after 6 am in Delaware County. 

[psuhoffman]

22 minutes ago, GaWx said:

 @Stormchaserchuck1 has a very good chance at getting his +PNA for 2023-4 (assuming that’s what he predicted). More on that below. Also, according to the NOAA monthly PNA table for DJFM, 1963-4 and 2009-10 both averaged +PNA with 1963-4 at +0.5 and 2009-10 at +1.0. It has 1972-3 at neutral (+0.1). Only 1965-6 of these 4 averaged a -PNA (-0.4):

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table
 
 2023-4 is so far averaging +PNA with both Dec and Jan positive. Feb 1-11 has also averaged +PNA. The forecast through Feb 18 is for more +PNA before dropping to neutral and then moderately negative. (See image below) So, there’s a very good chance that Feb overall will average a modest +PNA with a small chance to end up neutral.

 Thus with only March to go, 2023-4 has a very good chance to end up averaging +PNA in the table though I give it a small chance to end up neutral (that would obviously require a strong -PNA in Mar). I consider neutral to be +0.25 to -0.25:

 

Numerical indexes don’t often match the realities of the long wave pattern.  That’s why I post the h5 never index values.  Anomalies in one part of a domain can skew the values. Also what we focus on as the “pna” is actually only one small part of the domain (western US) but it’s the part that matters most for our snow. When people day PNA there usually what they’re referring too, a western US trough, even if technically the pna might not be negative due to other parts of the domain. 

[DarkSharkWX]

2 hours ago, psuhoffman said:

I agree with a lot of this. But why did you expect a +pna in a -PDO Nino?  There have been 4 Moderate/strong -PDO Ninos. None featured a +pna. Mean for the 4 is below. 

3 of the 4 were some of the snowiest winters in history here including 2010!  The one exception was 1973 which was a +QBO and has a crazy +++AO

So if we agree that was an outlier and toss all 3 examples of a -pdo moderate or stronger Nino featured both a -pna and a shit ton of snow.  
 

Actually if you simply take all moderate to strong ninos the mean is a -pna.  It’s only weak modoki ninos like 2003 and 2015 that feature a +pna.  But Baltimore averages 40” of snow in -QBO ninos despite the fact the pna is typically negative.  
 

I never expected a +pna this winter.  My analogs that produced a mean snow of 42” were  -PNA city.  There is something else going on.  It’s not the pna because the pna was negative in past epic snowy ninos.  

 

this is very interesting, especially 1964

but to be fair though the block is defintely weaker than previously modeled, and the pac has gotten worse too

i wish there was a way to properly compare the 500h archive maps on psl to what models have right now; do you still think the pattern is good and can produce considering the downtrends we've been seeing?
 

[MDScienceTeacher]

3 hours ago, stormy said:

I will be brief with an answer before deferring to the C.C. Thread.

You obviously misunderstand the premise.

This study suggests that the Glacial-interglacial cycles are not germane anymore because of our CO2 transgressions.

The climate gurus at the U.N. said 5 years ago that it would be more than 300 years before the AMOC shuts down.  Now, many scientists are saying with the AMOC at its weakest in 1,600 years, it could shut down completely between 2025 and 2095.

The cycles depicted above are caused by variation in the earths orbit and the resulting impact on solar radiation.  That’s an external force that is so much greater than manmade C02 emissions. It will be interesting to see if the current warming has any impact on glacial interglacial cycles but to say that they are not germane any more is foolish.  Anything generated by the earth follows the laws of conservation of mass.. this generally limits the level of impact human beings can have on climate.   Solar radiation on the other hand will likely trump anything that comes from the earth itself. 

[Terpeast]

4 hours ago, psuhoffman said:

The Dec “anafront” wave that I got 4”. It wasn’t actually an anafront. It was on long range guidance. It morphed into a nice caboose wave where the mid level and surface track was perfect for DC and Balt. I was actually NW of the best precip with that wave.  Only reason I was the snow max was the places further east that should have been were too warm!
 

 And the 850s were displaced well southeast of the actual rain snow line, east of 95, the whole event. Historically with these trailing waves behind a front the 850 and snow line are not that disconnected!  
 

Imo if I showed you just the h5, h7, h85, mslp, and qpf plots and said “where is the snow max” you’d probably say a nice 3-6 stripe right through DC/Balt. But they got white rain instead.  
 

I know it wasn’t as significant as the Jan 7 wave. That one could have been 6-10” if it was just colder. I know the slp took a slightly inside track but that’s because of the crap thermals. The mid and upper track of that wave was perfect and with better thermals the slp doesn’t jog inside and end up under mid level low like that imo. But those little 3-4” snows being subtracted add up.
 

 I’m not saying all 3 definitely should have been snow. I’m not saying every perfect track system in a bad thermal regime was snow in the past. But a significant % was. So I take note when they all seem to fail. If we go back through the last 7 years which we all know have been the worst snow period in DC/Balt recorded history, if we simply flip about 1/3 of all these perfect wave pass winter rainstorms to snow, it still wouldn’t be some epic good period. But we wouldn’t be talking about it the same way. We would simply be in the midst of one of our more typical down snow cycles that happen regularly through history. What’s made it awful instead of just bad is this phenomenon imo. 

I don’t know what the 3rd one was, but that dec event - I’m not sure I agree that its a good example. It was more of a function of timing with cold air’s arrival during the precip event. It morphed from an anafront to a wave along the front. It would have happened the same way 60 years ago vs today, and had that wave been 6 hours slower, we would have gotten a nice 3-6” event across the metros. 

Jan 7 is the more glaring example, to me. That’s what prompted me to lower my expectations for the rest of the season. Had it been colder, the low would have taken a track 50-100 miles souther than it did, and we’d have gotten 6-12”+

[psuhoffman]

5 minutes ago, Terpeast said:

I don’t know what the 3rd one was, but that dec event - I’m not sure I agree that its a good example. It was more of a function of timing with cold air’s arrival during the precip event. It morphed from an anafront to a wave along the front. It would have happened the same way 60 years ago vs today, and had that wave been 6 hours slower, we would have gotten a nice 3-6” event across the metros. 

Jan 7 is the more glaring example, to me. That’s what prompted me to lower my expectations for the rest of the season. Had it been colder, the low would have taken a track 50-100 miles souther than it did, and we’d have gotten 6-12”+

My conviction on this is not 100%  Im open to having my mind changed on the Dec wave. But what I noted was the cold at the mid levels got in ahead of the wave. But the boundary, even up here, was a mess. Places close to 95 had snow for hours it just couldn’t really accumulate.  I don’t even think it was getting colder in the boundary. It seemed to me what cold there was got in in time it just want cold enough and not sure another 6 hours would have mattered that much. But again I could be wrong here. That one I’m willing to adjust my opinion on. But Jan 7. There was no excuse for that ish. 

[psuhoffman]

@Terpeast the 3rd wave is tomorrow. It’s actually a sneaky ok long wave pattern to get an unexpected snow. I saw a few 4-8” type wet snow events in this type of setup in my case studies. It’s sneaky because none of the features is anomalous and sticks out but there is a subtle 50/50, subtle western ridge, a nice little ridge near Hudson and it’s an stj wave coming across at a low latitude. You. A see the suppressive influence in that the wave can’t gain much lat despite no cold at all in front of it. prime climo I think it’s reasonable to say we could have snuck some snow out of this despite the crap airmass in front of it in the past. Not for sure. Again it’s not any one or these it’s the accumulation that’s troubling. 

[stormy]

20 minutes ago, MDScienceTeacher said:

The cycles depicted above are caused by variation in the earths orbit and the resulting impact on solar radiation.  That’s an external force that is so much greater than manmade C02 emissions. It will be interesting to see if the current warming has any impact on glacial interglacial cycles but to say that they are not germane any more is foolish.  Anything generated by the earth follows the laws of conservation of mass.. this generally limits the level of impact human beings can have on climate.   Solar radiation on the other hand will likely trump anything that comes from the earth itself. 

  Foolishness will have to be taken up with the scientists who conducted this study because they are saying that an abrupt interruption of natural cycles very similar to the Younger Dryas may be coming soon. It could have devastating impact around the world.

When you say that the level of impact that humans can have on the climate is limited, I believe You and I could be friends.

Enjoy the Super Bowl.

[SnowenOutThere]

14 minutes ago, stormy said:

When you say that the level of impact that humans can have on the climate is limited, I believe You and I could be friends

Blud thinks he assembling a team

[stormy]

2 minutes ago, SnowenOutThere said:

Blud thinks he assembling a team

Its already 2 - 1

[Stormchaserchuck1]

1 hour ago, GaWx said:

 @Stormchaserchuck1 has a very good chance at getting his +PNA for 2023-4 (assuming that’s what he predicted). More on that below.  

I forecasted a +PNA, but a lot of the CPC's calculations include Alaska and the Gulf of Alaska.. I'm mostly referring to Aleutian islands central-north N. Pacific trough, in reference to +PNA. In that regard, this Winter has not matched usual ENSO correlations, and really the whole event has been like that, since the Nino developed in April. 

[Terpeast]

35 minutes ago, psuhoffman said:

@Terpeast the 3rd wave is tomorrow. It’s actually a sneaky ok long wave pattern to get an unexpected snow. I saw a few 4-8” type wet snow events in this type of setup in my case studies. It’s sneaky because none of the features is anomalous and sticks out but there is a subtle 50/50, subtle western ridge, a nice little ridge near Hudson and it’s an stj wave coming across at a low latitude. You. A see the suppressive influence in that the wave can’t gain much lat despite no cold at all in front of it. prime climo I think it’s reasonable to say we could have snuck some snow out of this despite the crap airmass in front of it in the past. Not for sure. Again it’s not any one or these it’s the accumulation that’s troubling. 

Yeah, if we had a cold airmass in place, we might have gotten a CAD thump (when’s the last time we had CAD?) before a dry slot during the coastal transfer then a ULL pass with additional snow. 

This year, the only way it snowed was with a -EPO/-NAO combo. PNA didn’t seem to matter. STJ? Any stj wave by itself was too warm. We needed that EPO to deliver the cold air, and a beast NAO to hold it down. 

[Weather Will]

WB 18Z GFS, congrats New England, epic period for them...

[Weather Will]

WB 18Z GEFS, lows ticked closer to coast....

[stormtracker]

@CAPE 120 and prime rib. It’s happening 

[psuhoffman]

58 minutes ago, Terpeast said:

Yeah, if we had a cold airmass in place, we might have gotten a CAD thump (when’s the last time we had CAD?) before a dry slot during the coastal transfer then a ULL pass with additional snow. 

This year, the only way it snowed was with a -EPO/-NAO combo. PNA didn’t seem to matter. STJ? Any stj wave by itself was too warm. We needed that EPO to deliver the cold air, and a beast NAO to hold it down. 

yea. And this brings me back to a discussion from last winter I remember. Wish I could remember who it was with. But I was pointing out that historically the epo isn’t correlated to our snowfall. That’s because an epo ridge can dump the cold west. It can also be a dry pattern. Yes there are specific epo patterns that are very snowy. But there are also -epo ones that aren’t and various +epo patterns that are. 

The problem is the last 8 years a vast majority of our snow has come from a -epo dominant pattern.  It’s the only times we’ve been cold enough!  But -EPO isn’t suddenly more snowy and that’s why we’ve been in a rut, all the other various combos that should work haven’t been so much.  

 

[Ji]

WB 18Z GFS, congrats New England, epic period for them...

With the south trends all winter looks like we are in good shape

[CAPE]

21 minutes ago, stormtracker said:

@CAPE 120 and prime rib. It’s happening 

yeah baby!

[stormtracker]

2 minutes ago, CAPE said:

yeah baby!

Jesus Christ dude. It’s like drinking beer out of a bourbon barrel.  I’m gonna nurse the fuck out of it  whooo  

 

[Terpeast]

Just now, Ji said:

With the south trends all winter looks like we are in good shape

You aren’t kidding. This is why I’m not calling TOD on this winter yet. 

[EastCoast NPZ]

1 hour ago, Weather Will said:

WB 18Z GFS, congrats New England, epic period for them...

Is this a nino or nina?

[Weather Will]

6 minutes ago, EastCoast NPZ said:

Is this a nino or nina?

New Nino, instead of snowing in the south it snows in New England.

[Maestrobjwa]

1 minute ago, Weather Will said:

New Nino, instead of snowing in the south it snows in New England.

New England hasn't been doing well with snow until now, though. In fact...BWI had more than Boston at the beginning of the month!

[Ji]

What is this?

[NorthArlington101]

What is this?

Wrong thread