Central PA Winter 25/26 Discussion and Obs

[mahantango#1]

 Capital  Weather  Gang:

We're going to get out ahead of this because we know we'll get questions. No, we do not believe the GFS (American) model (just in), which shows 3 feet of snow for DC Sunday-Monday. It is ranked 4th for accuracy for a reason + not supported by other models which generally show a modest event. We'll post our analysis of what's most likely early afternoon today.

 

Posted 11a Thursday.

[Itstrainingtime]

54 minutes ago, pasnownut said:

plenty of time for that to happen....

 

or not.  lol

with other models coming back around to the storm idea, at least that consensus is forming in a favorable way.  pretty wide goalposts tho and we are on the far left side.  Starting to feel like a plowable event is looking like a good possibility.

I honestly wished that I felt as confident as you...but I do not. 

Unless, and we certainly might, but if we aren't under that inverted trough I fear that we're looking at snow showers that have a hard time doing anything until Sunday night. At least as far as ground truth goes, right now I'm thinking about a 65% or so chance we end up with 3" or less. Maybe a 30ish% chance of 3-6" and a 5% chance we exceed 6". Nothing that I'm seeing looks conducive to heavy snowfall outside of the GFS. I was hoping for some notable steps from other models today at 12z but that really didn't happen. 

Edit: If your casa ends up squarely under the inverted trough, 6" becomes a valid goalpost. Problem is, only a relatively small percentage of us will be. 

Double Edit: Meant to say 65% of 3" or less to make my math actually consistent.   

[Blizzard of 93]

30 minutes ago, Itstrainingtime said:

I honestly wished that I felt as confident as you...but I do not. 

Unless, and we certainly might, but if we aren't under that inverted trough I fear that we're looking at snow showers that have a hard time doing anything until Sunday night. At least as far as ground truth goes, right now I'm thinking about a 65% or so chance we end up with 3" or less. Maybe a 30ish% chance of 3-6" and a 5% chance we exceed 6". Nothing that I'm seeing looks conducive to heavy snowfall outside of the GFS. I was hoping for some notable steps from other models today at 12z but that really didn't happen. 

Edit: If your casa ends up squarely under the inverted trough, 6" becomes a valid goalpost. Problem is, only a relatively small percentage of us will be. 

Double Edit: Meant to say 65% of 3" or less to make my math actually consistent.   

Checking in over lunch time & the 12z Euro agrees mostly with your current thoughts.

It is remarkable that the GFS doubled down at 12z. Even half of that run would be great to see.

This Euro run we get a few inches from the initial coastal low before it heads east. Then the LSV gets bullseyed with the Norlun Sunday night & tacks in a few more inches. In total, this run still brings Warning level snow to most of the LSV.

Maybe a compromise of some kind will still take place before game time?

Here is the 12z Euro.

[pasnownut]

1 hour ago, Itstrainingtime said:

I don't recall the last time I've seen an inverted trough show up on so many models so far in advance - someone will approach warning criteria snowfall from that alone. 

last norlun i can remember put 7" on my house, while 10 miles away it was 1" at a friends.  They are a rarity, but fun if you get in it. 

[pasnownut]

38 minutes ago, Itstrainingtime said:

I honestly wished that I felt as confident as you...but I do not. 

Unless, and we certainly might, but if we aren't under that inverted trough I fear that we're looking at snow showers that have a hard time doing anything until Sunday night. At least as far as ground truth goes, right now I'm thinking about a 65% or so chance we end up with 3" or less. Maybe a 30ish% chance of 3-6" and a 5% chance we exceed 6". Nothing that I'm seeing looks conducive to heavy snowfall outside of the GFS. I was hoping for some notable steps from other models today at 12z but that really didn't happen. 

Edit: If your casa ends up squarely under the inverted trough, 6" becomes a valid goalpost. Problem is, only a relatively small percentage of us will be. 

Double Edit: Meant to say 65% of 3" or less to make my math actually consistent.   

my "confidence" is that the storm isnt going poof and trending towards something.  That is all I'm confident about. 

Not for a second do I think the GFS is going to score a coup, and I dont think my wording suggested that, but GFS is liking a tucked storm, and other models have trended a bit sharper w/ trough axis as well as ticked W a bit.  doing a nooner WMB (Weenie Model Blend) suggests that a light/mod event is surely in play, (norlun or no norlun) for many Eastern pa folks.  

 

[Itstrainingtime]

12 minutes ago, pasnownut said:

last norlun i can remember put 7" on my house, while 10 miles away it was 1" at a friends.  They are a rarity, but fun if you get in it. 

I was recalling that event in my mind on my way to work today...

As I remember it, there wasn't any forecast of snow in Lanco the night of the event. I had pretty much tuned out the weather that evening as there wasn't anything for me to be watching out for. I went to bed, I remember looking out our window and seeing the moon shining brightly. Just a normal, chilly mostly clear night in Maytown. I had no idea what was happening 15 miles to my east...

Next morning, I'm driving to work. Still completely clueless. I get to the bottom of Chickies Hill at the 441/30 interchange and there's PennDot truck with a plow sitting there. I'm laughing because A, it was a sunny morning, B, the ground was completely brown, and C, well, it was PennDot doing "what PennDot does best." I get to work and after several minutes I start getting messages that colleagues in Lancaster and surrounding environs are going to be late or won't be in at all. Great, the flu bug hit, I'm thinking. Then one of my best friends from childhood who works with me and obviously knows I'm a weather guy runs in and says "can you believe what happened in Lancaster last night...isn't that wild that they got that much snow and no one else got anything?"

I go to MU's weather page and there's Horst with a picture of him standing outside of his MT house measuring 12" of snow. A foot! And 15 miles west, I had clear skies. 

Probably the only time in my life I felt like I was living in a snowbelt area and was just outside one of those bands. I'm still stunned to this day that it happened in Lancaster County/

[Itstrainingtime]

2 minutes ago, pasnownut said:

my "confidence" is that the storm isnt going poof and trending towards something.  That is all I'm confident about. 

Not for a second do I think the GFS is going to score a coup, and I dont think my wording suggested that, but GFS is liking a tucked storm, and other models have trended a bit sharper w/ trough axis as well as ticked W a bit.  doing a nooner WMB (Weenie Model Blend) suggests that a light/mod event is surely in play, (norlun or no norlun) for many Eastern pa folks.  

 

I 100% agree with this. 

[pasnownut]

15 minutes ago, pasnownut said:

my "confidence" is that the storm isnt going poof and trending towards something.  That is all I'm confident about. 

Not for a second do I think the GFS is going to score a coup, and I dont think my wording suggested that, but GFS is liking a tucked storm, and other models have trended a bit sharper w/ trough axis as well as ticked W a bit.  doing a nooner WMB (Weenie Model Blend) suggests that a light/mod event is surely in play, (norlun or no norlun) for many Eastern pa folks.  

 

and just like that the Euro stays open and more progressive looking.  Still has something, but in the spirit of the Olympics, its def the US vs Euro.  Gut says GFS caves a bit, and we still see snow.  Good enough for me.  

[Mount Joy Snowman]

8 minutes ago, pasnownut said:

and just like that the Euro stays open and more progressive looking.  Still has something, but in the spirit of the Olympics, its def the US vs Euro.  Gut says GFS caves a bit, and we still see snow.  Good enough for me.  

I still thought there were some notable improvements on the Euro, albeit slight.  I agree that an advisory type event is most likely at this point, perhaps low-end warning.

[pasnownut]

6 minutes ago, Mount Joy Snowman said:

I still thought there were some notable improvements on the Euro, albeit slight.  I agree that an advisory type event is most likely at this point, perhaps low-end warning.

Yeah nooners (sans GFS) were a touch better, which give me the confidence in thinking we are going to see something, but there is enough that are not showing much more than some light snow, and with seasonal tendencies in mind, progressive and too far east when winding up have been the theme for this winter. 

With spring approaching, it is a time where we can buck the trends though.  not saying thats evident here, but something I keep in my mental notebook of how we can snow in late season.  

[mahantango#1]

From our good friend  DT:

NEXT TIME SOME IDIOT ARGUES THE GFS HANDLES EAST COAST SNOWSTORMS WELL...

 

       TIME TO CANCEL THE GFS..... 

 

    33 INCHES OF SNOW DC ? Yeah its broken

 

 every Single run of the operational GFS for the past 3 days has showed a massive historic record shattering blizzard for some portion of the Middle Atlantic...

 

 now even the GFS AI is saying "WTF op-GFS !? " 

 

The 6z and 12z GFS ensembles are waaaaaay east 

 

The problem is that the operational GFS goes Bonkers with the 500mb LOW. It is over developing the 500 LOW amplification and it grabs the surface LOW and pulls a NW to just east of Wallops Island on the lower Virginia Eastern shore. Then every run of op- GFS stalls the LOW for 24 hours producing this incredibly heavy snow area from a monster rapidly intensifying Coastal nor'easter.

 

This is nonsense.  

 

There is a better chance of monkeys flying out of my ass on Sunday night or Monday morning then this solution as proposed by the operational GFS of a massive historic BLIZZARD of record shattering proportions in the Mid-Atlantic actually concurring

 

As I stated in the video there is an upstream kicker and all the other models see it except for the operational GFS.  

 

When the GFS AI and GFS ensembles don't even support this kind of extreme solution then you know the operational GFS is just busted.

 

I figure it's about 12 hours before somebody starts blaming immigrants for fucking with the model.

[Mount Joy Snowman]

Virtually no support for the ultra-tucked solution we saw on the 12z GFS.

[Mount Joy Snowman]

1 hour ago, Itstrainingtime said:

I was recalling that event in my mind on my way to work today...

As I remember it, there wasn't any forecast of snow in Lanco the night of the event. I had pretty much tuned out the weather that evening as there wasn't anything for me to be watching out for. I went to bed, I remember looking out our window and seeing the moon shining brightly. Just a normal, chilly mostly clear night in Maytown. I had no idea what was happening 15 miles to my east...

Next morning, I'm driving to work. Still completely clueless. I get to the bottom of Chickies Hill at the 441/30 interchange and there's PennDot truck with a plow sitting there. I'm laughing because A, it was a sunny morning, B, the ground was completely brown, and C, well, it was PennDot doing "what PennDot does best." I get to work and after several minutes I start getting messages that colleagues in Lancaster and surrounding environs are going to be late or won't be in at all. Great, the flu bug hit, I'm thinking. Then one of my best friends from childhood who works with me and obviously knows I'm a weather guy runs in and says "can you believe what happened in Lancaster last night...isn't that wild that they got that much snow and no one else got anything?"

I go to MU's weather page and there's Horst with a picture of him standing outside of his MT house measuring 12" of snow. A foot! And 15 miles west, I had clear skies. 

Probably the only time in my life I felt like I was living in a snowbelt area and was just outside one of those bands. I'm still stunned to this day that it happened in Lancaster County/

Are you referring to that overnight event that dumped like a foot in primarily the Lititiz/Manheim Township area?  That was crazy but I thought it was considered more of an unexplainable random convective event similar to a stray pop-up thunderstorm.  I thought they were having trouble determining the reasoning for the event, almost freakish in nature.  I didn't think it was associated with a norlun but I could be mistaken.  Perhaps we are talking about different events?  There used to be a really good LNP article talking about that exact event but I can't find it despite searching their website to the best of my ability.  Do you recall the date or even the year of the one you're talking about?  I do recall that photo of Horst with his foot of snow haha.

[Itstrainingtime]

4 minutes ago, Mount Joy Snowman said:

Are you referring to that overnight event that dumped like a foot in primarily the Lititiz/Manheim Township area?  That was crazy but I thought it was considered more of an unexplainable random convective event similar to a stray pop-up thunderstorm.  I thought they were having trouble determining the reasoning for the event, almost freakish in nature.  I didn't think it was associated with a norlun but I could be mistaken.  Perhaps we are talking about different events?  There used to be a really good LNP article talking about that exact event but I can't find it despite searching their website to the best of my ability.  Do you recall the date or even the year of the one you're talking about?  I do recall that photo of Horst with his foot of snow haha.

It stretched from the northern part of the county near Ephrata right down 501 through Lititz, MT, Lancaster and down 30 east way. We're thinking of the same event, I thought it was an inverted trough but maybe that was just conventional thinking? I recently found the article but I can't now either. If and when I do find it, I will post it. I want to say it was between 2008 and 2015? 

[Mount Joy Snowman]

1 minute ago, Itstrainingtime said:

It stretched from the northern part of the county near Ephrata right down 501 through Lititz, MT, Lancaster and down 30 east way. We're thinking of the same event, I thought it was an inverted trough but maybe that was just conventional thinking? I recently found the article but I can't now either. If and when I do find it, I will post it. I want to say it was between 2008 and 2015? 

Okay, yes that's the timeframe I was thinking of too.  I was thinking that event was more isolated than what you described but I guess I am thinking of the area that got a foot, which I believe was a narrow swath right over the heart of Manheim Township, which is where Horst resides.  Yeah, I would love to find that article again.  The LNP search engine is doing me no favors ha.

[Itstrainingtime]

3 minutes ago, Mount Joy Snowman said:

Okay, yes that's the timeframe I was thinking of too.  I was thinking that event was more isolated than what you described but I guess I am thinking of the area that got a foot, which I believe was a narrow swath right over the heart of Manheim Township, which is where Horst resides.  Yeah, I would love to find that article again.  The LNP search engine is doing me no favors ha.

The area of snow itself wasn't isolated, the 12" amount absolutely was, and it was centered in the heart of Manheim Township. Amounts tapered as you went both N and S from that area and most of those locations were more in the 4-8" range. @pasnownut said above he got 7" in Akron, for example.