• Member Statistics

    15,731
    Total Members
    7,904
    Most Online
    wxRob_Coleman
    Newest Member
    wxRob_Coleman
    Joined
MAG5035

Central PA - Late Dec 2019/Jan 2020

Recommended Posts

Great forecast discussion by CTP this morning. If you are near I -81 or north & west of that, you are still in the game.

Here is CTP’s Discussion:

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Focus in the long term remains on the increasing likelihood of a highly elevation dependent snow event impacting the region beginning Friday night and continuing through much of Sat night as a Miller-B type surface scenario accompanies a well defined upper low that will develop across the Mid Miss valley and track east across Southern or Central PA Sat night. The 700 mb center is progged to move east along I-80 in Ohio and PA. After a mainly cloudy and rather mild Friday with temps in the upper 30s to around 40F, the boundary layer is expected to start out warm enough for primarily rain right at the onset in most areas. However, layer cooling associated with increasing uvvel, and evap cooling as the precip falls into the dry LLVl air will help to mix or change the precip over to wet snow across parts of Central and likely most or all of Ncent PA. Height falls and 1000-500 mb thicknesses falling to below 540 DAM will allow the precip to change over to snow, that will fall at a moderate to heavy rate at times late Friday night and Saturday. Of particular interest will be later Saturday morning into Sat afternoon when elevated instability being transported north toward South-central PA and areas of fairly strong 850-700 mb frontogenesis could lead to some 1-2 inch per hour, heavy snowfall rates anywhere northwest of the I-81 corridor. Critical thickness and 850 mb zero wet bulb line will exist somewhere between I-99 and I-81 during the mid to late morning hours Saturday, and this is where the greatest uncertainty is with respect to precip type and intensity. Again, we`re messaging the point that the initially warm boundary layer and periods of strong, dynamic forcing will lead to a very elevation dependent snowfall across Central and Northern PA with notably lower chances for significant snow near and to the SE of I-81. Snow accums by late Sat night could approach 8 inches at elevations over 2000 ft MSL in northern PA with 4-6 inches possible at the same elevations in Central PA. Accums in the valleys (depending on their exact elevation) will vary from 3-5 inches in the north to between 1-3 inches in most of Central PA. The threat for any sleet and/or FZRA is very minimal at this point. Increased pops for Friday night into Sat as a result of the anomalous southeasterly low level jet (over 50 kts at 850 mb) and plume of Atlantic moisture overrunning a dome of cold/stable air east of the Appalachians. This justifies categorical POPs Friday night into Saturday. The latest GEFS mean qpf ranges from 0.6 to 1 inch across the forecast area by Saturday evening.

Share this post


Link to post
Share on other sites
3 minutes ago, Blizzard of 93 said:

Great forecast discussion by CTP this morning. If you are near I -81 or north & west of that, you are still in the game.

Here is CTP’s Discussion:

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Focus in the long term remains on the increasing likelihood of a highly elevation dependent snow event impacting the region beginning Friday night and continuing through much of Sat night as a Miller-B type surface scenario accompanies a well defined upper low that will develop across the Mid Miss valley and track east across Southern or Central PA Sat night. The 700 mb center is progged to move east along I-80 in Ohio and PA. After a mainly cloudy and rather mild Friday with temps in the upper 30s to around 40F, the boundary layer is expected to start out warm enough for primarily rain right at the onset in most areas. However, layer cooling associated with increasing uvvel, and evap cooling as the precip falls into the dry LLVl air will help to mix or change the precip over to wet snow across parts of Central and likely most or all of Ncent PA. Height falls and 1000-500 mb thicknesses falling to below 540 DAM will allow the precip to change over to snow, that will fall at a moderate to heavy rate at times late Friday night and Saturday. Of particular interest will be later Saturday morning into Sat afternoon when elevated instability being transported north toward South-central PA and areas of fairly strong 850-700 mb frontogenesis could lead to some 1-2 inch per hour, heavy snowfall rates anywhere northwest of the I-81 corridor. Critical thickness and 850 mb zero wet bulb line will exist somewhere between I-99 and I-81 during the mid to late morning hours Saturday, and this is where the greatest uncertainty is with respect to precip type and intensity. Again, we`re messaging the point that the initially warm boundary layer and periods of strong, dynamic forcing will lead to a very elevation dependent snowfall across Central and Northern PA with notably lower chances for significant snow near and to the SE of I-81. Snow accums by late Sat night could approach 8 inches at elevations over 2000 ft MSL in northern PA with 4-6 inches possible at the same elevations in Central PA. Accums in the valleys (depending on their exact elevation) will vary from 3-5 inches in the north to between 1-3 inches in most of Central PA. The threat for any sleet and/or FZRA is very minimal at this point. Increased pops for Friday night into Sat as a result of the anomalous southeasterly low level jet (over 50 kts at 850 mb) and plume of Atlantic moisture overrunning a dome of cold/stable air east of the Appalachians. This justifies categorical POPs Friday night into Saturday. The latest GEFS mean qpf ranges from 0.6 to 1 inch across the forecast area by Saturday evening.

This is shaping up to be on of the storms where LSV's have to be happy for the folks in the mountains who miss out on most of the big coastal.  Going to take a fairly big shift at this point in the game to get LSV back into it.  50-100 miles.  When they say N/W of the I81 corridor I do not think they literally mean I81 they mean the whole valley encompassing I81....N/W of there.

 

 

Share this post


Link to post
Share on other sites
19 minutes ago, Bubbler86 said:

This is shaping up to be on of the storms where LSV's have to be happy for the folks in the mountains who miss out on most of the big coastal.  Going to take a fairly big shift at this point in the game to get LSV back into it.  50-100 miles.  When they say N/W of the I81 corridor I do not think they literally mean I81 they mean the whole valley encompassing I81....N/W of there.

 

 

Yes, it’s going to be tough for York & Lancaster to get back in this one.

But I think anyone along I -81 give or take a few miles & points west should still pay attention for now.

I agree that the bullseye appears to be the mountains, but I would settle here for the scraps of a possible few inches of snow along I -81, just like last nights 0z GFS.

Share this post


Link to post
Share on other sites
9 minutes ago, Blizzard of 93 said:

Yes, it’s going to be tough for York & Lancaster to get back in this one.

But I think anyone along I -81 give or take a few miles & points west should still pay attention for now.

I agree that the bullseye appears to be the mountains, but I would settle here for the scraps of a possible few inches of snow along I -81, just like last nights 0z GFS.

If the trajectory of the low were a bit different I would feel more confident for western LSV.  Look at this panel on the NAM and it is where we want it if it were going east by North east instead of North by North East.

 

image.png.7b5eb229eaeac2e1f3cdb26b8ac3d226.png

 

Share this post


Link to post
Share on other sites
Yes, it’s going to be tough for York & Lancaster to get back in this one.
But I think anyone along I -81 give or take a few miles & points west should still pay attention for now.
I agree that the bullseye appears to be the mountains, but I would settle here for the scraps of a possible few inches of snow along I -81, just like last nights 0z GFS.

Based solely on models, this has been trending in the wrong direction for LSV folks. And I feel it’s not done moving further north and west.

This is not our storm.


.
  • Thanks 1

Share this post


Link to post
Share on other sites
If the trajectory of the low were a bit different I would feel more confident for western LSV.  Look at this panel on the NAM and it is where we want it if it were going east by North east instead of North by North East.
 
image.png.7b5eb229eaeac2e1f3cdb26b8ac3d226.png
 

And if it were not stale cold air in place.


.

Share this post


Link to post
Share on other sites
Just now, Superstorm said:


Based solely on models, this has been trending in the wrong direction for LSV folks. And I feel it’s not done moving further north and west.

This is not our storm.


.

Hopefully the models will shift and we all end up with a suprise. 

Share this post


Link to post
Share on other sites
2 minutes ago, Superstorm said:


And if it were not stale cold air in place.


.

Right, I could only have one wish in per post.  LOL.  If we had arctic air this would be a bread and milk situation. 

 

 

  • Like 1

Share this post


Link to post
Share on other sites
50 minutes ago, Bubbler86 said:

If the trajectory of the low were a bit different I would feel more confident for western LSV.  Look at this panel on the NAM and it is where we want it if it were going east by North east instead of North by North East.

 

image.png.7b5eb229eaeac2e1f3cdb26b8ac3d226.png

 

^^^^this

well said.

 

Share this post


Link to post
Share on other sites
46 minutes ago, mahantango#1 said:

Hopefully the models will shift and we all end up with a suprise. 

Getting to close for sizeable shifts, but yes, 25 -50 miles is possible and can make a big diff. for some.  I've been out since Monday, so heck yeah, I'm rooting all of you on from the sidelines.

 

Share this post


Link to post
Share on other sites

In other news, if the GFS is remotely close to correct, we are nowhere near done tracking.  Plenty of decent events looming in the next couple weeks.  Need cold air and towards the end (as always), it looks fun.

 

Share this post


Link to post
Share on other sites

The overnight guidance I thought solidified a good bit with a more defined miller-B transition... perhaps a little bit high on the latitude with the primary before transferring but otherwise a workable track with plenty of QPF to be had in the region. The problem is becoming more about the marginal column temps in place ahead of the system as well the models predicting the secondary low a bit more inside the coastline, more of a coastal plain runner. That inside track hurts the Lower Sus Valley, especially York/Lancaster counties. But even more of a coastal track is an issue trying to get 850 temps cool enough in especially the LSV and it's close too.. only a matter of a couple degrees. The north-central is in the best shape with this currently, and the central between I-80 and the turnpike and  further NW of I-81 is as always.. the most complicated to nail down. Could be rain to 1-2" of junk or a 6-10" shallacking.. or both. One positive I have noticed is the high to the north has quietly been being progged a bit stronger as we've gotten closer. 

I see the 12z NAM has started things off in the wrong direction. 

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, pasnownut said:

Getting to close for sizeable shifts, but yes, 25 -50 miles is possible and can make a big diff. for some.  I've been out since Monday, so heck yeah, I'm rooting all of you on from the sidelines.

 

Nam is coming in a smidge North so not going to be good news for a miracle on this run.   Not only does the LSV not get snow there is almost no snow anywhere in PA outside the Western mountain ridges and some random lollipops other places. ...yuck.

Share this post


Link to post
Share on other sites

Nice write up Mag!

Myself I am kind of worried that the Canadian high looks weak,appears to be tapping into leftover cold air.

As usual not a whole lot of blocking.

Share this post


Link to post
Share on other sites
2 minutes ago, Bubbler86 said:

Nam is coming in a smidge North so not going to be good news for a miracle on this run.   Not only does the LSV not get snow there is almost no snow anywhere in PA...yuck.

No blocking to the N....no way to slow/hold the storm down.  Thats been my rub/ stance from early on.  HP centered just east of us brings the southerly flow right up and ruins what marginal 850s were there.  One then needs dynamics to overcome, and while they will, it will be more isolated/elevation driven vs widespread snowfall distribution.  I've little doubt some on some mountaintops say "look at me and all of my snow", but by and large, lots of staring out the window waiting for most of us. 

Gang, this is just me and my feelings on storm evolution based on my 10,000' view...not a forecast.  So wanna be wrong.  

Share this post


Link to post
Share on other sites

lol  i post and see Mags post above only after i hit submit.  

Hope your right Mag.  You know a little bit more than I do.....:P

Share this post


Link to post
Share on other sites

and fwiw, i do see the HP that is similarly placed to last weekends event (approx 200 miles N of Maine/Canadian border).  Not sure that a 1035 has enough power/input that far N.  Move it south to Lake Placid-Lake George, and I'm interested.  Just dont see a mechanism for that to happen w/ flow pattern were in. Too much ridging out ahead.  Need the letter H up where i referenced and i'm borderline giddy (or 50/50), or -AO.  Without neg NAO/AO, HP's just scoot along like LP's. 

Gotta block da flo yo

What the heck is wrong w/ me.....I think I'm broken.....

all this debbie stuff just aint my jam.  

namconus_z500_vort_us_42.png

Share this post


Link to post
Share on other sites
2 minutes ago, pasnownut said:

and fwiw, i do see the HP that is similarly placed to last weekends event (approx 200 miles N of Maine/Canadian border).  Not sure that a 1035 has enough power/input that far N.  Move it south to Lake Placid-Lake George, and I'm interested.  Just dont see a mechanism for that to happen w/ flow pattern were in. Too much ridging out ahead.  Need the letter H up where i referenced and i'm borderline giddy (or 50/50), or -AO.  Without neg NAO/AO, HP's just scoot along like LP's. 

Gotta block da flo yo

What the heck is wrong w/ me.....I think I'm broken.....

all this debbie stuff just aint my jam.  

 

It's not Debbie stuff.  We are here to discuss the weather, model output, etc...if you were trying to play the Nam and Icon as being good for snow then you would be bull shitting.  LOL.  Debbie is looking at a situation that looks decent but could go bad and saying it will go bad. Right now this does not look decent.  We have once again fallen prey to the seemingly always wrong 4-7 days EC and GFS depictions to hope for something and slowly seen it taken away as it gets closer.  Been a bad trend the last two winters especially this one. 

  • Like 1
  • Thanks 3

Share this post


Link to post
Share on other sites
23 minutes ago, pasnownut said:

and fwiw, i do see the HP that is similarly placed to last weekends event (approx 200 miles N of Maine/Canadian border).  Not sure that a 1035 has enough power/input that far N.  Move it south to Lake Placid-Lake George, and I'm interested.  Just dont see a mechanism for that to happen w/ flow pattern were in. Too much ridging out ahead.  Need the letter H up where i referenced and i'm borderline giddy (or 50/50), or -AO.  Without neg NAO/AO, HP's just scoot along like LP's. 

Gotta block da flo yo

What the heck is wrong w/ me.....I think I'm broken.....

all this debbie stuff just aint my jam.  

namconus_z500_vort_us_42.png

Telling the truth isn't being a Debbie downer, no way. We can't change the weather (well China is trying) so we have to be honest with what we're seeing. Good and bad. 

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites
15 minutes ago, Bubbler86 said:

It's not Debbie stuff.  We are here to discuss the weather, model output, etc...if you were trying to play the Nam and Icon as being good for snow then you would be bull shitting.  LOL.  Debbie is looking at a situation that looks decent but could go bad and saying it will go bad. Right now this does not look decent.  We have once again fallen prey to the seemingly always wrong 4-7 days EC and GFS depictions to hope for something and slowly seen it taken away as it gets closer.  Been a bad trend the last two winters especially this one. 

This! @pasnownut you're not being a deb, you're using logic and being realistic. And frankly I'm glad to read it. You might not "like" posting the way you are right now, but you're posting truth. It's just as foolish to post positive thoughts when the pattern doesn't support it as it is to be negative when the pattern does support it. People that are negative are made to feel like crap at times when the fact is...if the pattern sucks they're going to be (and have been) right. 

Bubbler...you could not have said it better. 

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites
18 minutes ago, Bubbler86 said:

It's not Debbie stuff.  We are here to discuss the weather, model output, etc...if you were trying to play the Nam and Icon as being good for snow then you would be bull shitting.  LOL.  Debbie is looking at a situation that looks decent but could go bad and saying it will go bad. Right now this does not look decent.  We have once again fallen prey to the seemingly always wrong 4-7 days EC and GFS depictions to hope for something and slowly seen it taken away as it gets closer.  Been a bad trend the last two winters especially this one. 

Yeah, your last sentence is the unfortunate truth.  While I'm no met and NEVER try to imply as such, I've done this for so long that i feel I've honed my senses/abilities enough to smell a rat if you will.  I've beat the horse a bunch, but with Miller B's we need a cold mechanism close by to work with.  While we are in peak climo and it is "officially" the easiest time to snow....this pattern is close but no cigar if you will.  The last 2 years we've been in a predominant cutter pattern, and until one of the mentioned indicies works into our favor (or PNA) changes, were kinda stuck.  Yes, we sure can score in less than stellar patterns (and some likely will this weekend), but we live on the latitude fringe of winter if you will.  If this upcoming event were shifted just a bit further south and east, I'd shut my pie hole. 

It could be worse, we could be in the MA who really is shutout in situs like this.  I don't say that in a demeaning way either.....they've got no chance verbatim.  At least we are in the game....till were out. ^_^

Share this post


Link to post
Share on other sites
8 minutes ago, Itstrainingtime said:

This! @pasnownut you're not being a deb, you're using logic and being realistic. And frankly I'm glad to read it. You might not "like" posting the way you are right now, but you're posting truth. It's just as foolish to post positive thoughts when the pattern doesn't support it as it is to be negative when the pattern does support it. People that are negative are made to feel like crap at times when the fact is...if the pattern sucks they're going to be (and have been) right. 

Bubbler...you could not have said it better. 

Thanks guys.  While I'm not a bit happy about it, I'm too old to bullshit and this weather stuff is serious bizz for us weenies.

Onward and eventually upward.....I hope.  

(watch this thing trend S/E and we get a shellackin).  Yall can come down and I'll by a round or 2 for wasting all of your time w/ my nonsense.  

That said, its why I'm here.  I love the chase.  

 

Share this post


Link to post
Share on other sites
25 minutes ago, pasnownut said:

Thanks guys.  While I'm not a bit happy about it, I'm too old to bullshit and this weather stuff is serious bizz for us weenies.

Onward and eventually upward.....I hope.  

(watch this thing trend S/E and we get a shellackin).  Yall can come down and I'll by a round or 2 for wasting all of your time w/ my nonsense.  

That said, its why I'm here.  I love the chase.  

 

Dude, i like yours and others write ups. You guys are a plethora of knowledge.

Teach us Sensei :clap:

  • Haha 1

Share this post


Link to post
Share on other sites
1 minute ago, Wmsptwx said:

Gfs looks bad forum wide...just no cold air to work with.

Yea, it (and the EC) really misled us for a few days. 

Share this post


Link to post
Share on other sites
1 minute ago, sauss06 said:

Dude, i like yours and others write ups. You guys are a plethora of knowledge.

Teach us Sensei :clap:

Sensei! I love it! As a former continuous improvement (Lean methodology) leader I never expected to read that term used on here. :lol:

  • Haha 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.