Central PA - Winter 2020/2021

[paweather]

Deform band:

[paweather]

Final tonight:

[canderson]

Euro is a Perry County special. The 12 people in that county will be stoked once the horse arrives with the message. 

[paweather]

3 minutes ago, canderson said:

Euro is a Perry County special. The 12 people in that county will be stoked once the horse arrives with the message. 

It's a special for all of us in comparison to last year. WOW what a consistency. 12" plus.

[paweather5]

[MAG5035]

1 hour ago, canderson said:

Euro is a Perry County special. The 12 people in that county will be stoked once the horse arrives with the message. 

I dunno, looks more like a C-PA forum special lol. Euro places ground zero of the deform up between I-99 and I-81 up through IPT into NE PA. Until this gets into short range, I'm only posting 10:1 maps if I throw up a snow map. Just trying to keep the top end capped while addressing the storm til we get into short range. But with that said, gotta acknowledge that models are dialed in to an excessive event right now... with every major op (CMC/EURO/GFS) having a 20"+ swath.  The key is WHERE that excessive swath is located, which models haven't really nailed down yet. 

These Kuchera maps are nuts. IPT for example is 33.8" on 2.09" of QPF. That's a 16:1 ratio, which is probably doable wherever that intense deform sets up given pretty decent column temps where there's going to be monster 700mb lift, and there's a big swath of these accums in central to NE PA. Even a more standard 12-13:1 ratio is in excess of 2 ft. The knock on Kuchera is it calculates ratio solely on temperature by simply calculating a ratio from the warmest part of the lower 500mb of the column. It doesn't factor snow growth characteristics, omega, etc like BUFKIT data or the Cobb method would show. I have access to a Cobb map from the Euro and it's just as crazy amount wise but a touch east with pretty much I-81as the axis line, likely matching up where the best lift actually is. Actually gives Harrisburg an even bigger total than the Kuchera. Crazy numbers these models are putting out. 

Lastly here's the Euro's U wind anomaly at 850 mb at 102hrs (height of the event). Basically this is an indication of the strength of the easterly fetch. A highly anomalous easterly flow is a hallmark of the big ones. A -4 to -6 anomaly is through the roof... that's Feb 5-6, 2010 level stuff in terms of that indicator... key phrase being "in terms of that indicator". 

Should note GFS has similar anomalous flow, just not penetrating into PA as much as the Euro, which is why it's heavy swath further southeast.

 

 

 

 

[Cashtown_Coop]

2 hours ago, MAG5035 said:

I dunno, looks more like a C-PA forum special lol. Euro places ground zero of the deform up between I-99 and I-81 up through IPT into NE PA. Until this gets into short range, I'm only posting 10:1 maps if I throw up a snow map. Just trying to keep the top end capped while addressing the storm til we get into short range. But with that said, gotta acknowledge that models are dialed in to an excessive event right now... with every major op (CMC/EURO/GFS) having a 20"+ swath.  The key is WHERE that excessive swath is located, which models haven't really nailed down yet. 

These Kuchera maps are nuts. IPT for example is 33.8" on 2.09" of QPF. That's a 16:1 ratio, which is probably doable wherever that intense deform sets up given pretty decent column temps where there's going to be monster 700mb lift, and there's a big swath of these accums in central to NE PA. Even a more standard 12-13:1 ratio is in excess of 2 ft. The knock on Kuchera is it calculates ratio solely on temperature by simply calculating a ratio from the warmest part of the lower 500mb of the column. It doesn't factor snow growth characteristics, omega, etc like BUFKIT data or the Cobb method would show. I have access to a Cobb map from the Euro and it's just as crazy amount wise but a touch east with pretty much I-81as the axis line, likely matching up where the best lift actually is. Actually gives Harrisburg an even bigger total than the Kuchera. Crazy numbers these models are putting out. 

Lastly here's the Euro's U wind anomaly at 850 mb at 102hrs (height of the event). Basically this is an indication of the strength of the easterly fetch. A highly anomalous easterly flow is a hallmark of the big ones. A -4 to -6 anomaly is through the roof... that's Feb 5-6, 2010 level stuff in terms of that indicator... key phrase being "in terms of that indicator". 

Should note GFS has similar anomalous flow, just not penetrating into PA as much as the Euro, which is why it's heavy swath further southeast.

 

 

 

 

I received a text from one of my CTP met friends that made the Feb 5-6 2010 comparison last eve.   I ended up with 27” from that one. Hard to believe this is real.   

[Jns2183]

My friends 8 year old daughter asked him last night if zoom will know it's a snow day....ouch

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[Jns2183]

I dunno, looks more like a C-PA forum special lol. Euro places ground zero of the deform up between I-99 and I-81 up through IPT into NE PA. Until this gets into short range, I'm only posting 10:1 maps if I throw up a snow map. Just trying to keep the top end capped while addressing the storm til we get into short range. But with that said, gotta acknowledge that models are dialed in to an excessive event right now... with every major op (CMC/EURO/GFS) having a 20"+ swath.  The key is WHERE that excessive swath is located, which models haven't really nailed down yet. 
These Kuchera maps are nuts. IPT for example is 33.8" on 2.09" of QPF. That's a 16:1 ratio, which is probably doable wherever that intense deform sets up given pretty decent column temps where there's going to be monster 700mb lift, and there's a big swath of these accums in central to NE PA. Even a more standard 12-13:1 ratio is in excess of 2 ft. The knock on Kuchera is it calculates ratio solely on temperature by simply calculating a ratio from the warmest part of the lower 500mb of the column. It doesn't factor snow growth characteristics, omega, etc like BUFKIT data or the Cobb method would show. I have access to a Cobb map from the Euro and it's just as crazy amount wise but a touch east with pretty much I-81as the axis line, likely matching up where the best lift actually is. Actually gives Harrisburg an even bigger total than the Kuchera. Crazy numbers these models are putting out. 
Lastly here's the Euro's U wind anomaly at 850 mb at 102hrs (height of the event). Basically this is an indication of the strength of the easterly fetch. A highly anomalous easterly flow is a hallmark of the big ones. A -4 to -6 anomaly is through the roof... that's Feb 5-6, 2010 level stuff in terms of that indicator... key phrase being "in terms of that indicator". 

Should note GFS has similar anomalous flow, just not penetrating into PA as much as the Euro, which is why it's heavy swath further southeast.
 
 
 
 

Mag, the only December storm I can think of even remotely comparable, and only in the state college & Somerset area is the Dec 11, 1992 Noreaster. State College had around 18" and Somerset 27" . Somehow IPT only recorded 7.5" on a little over an 1" of qpf, state college was over 2" qpf and South. Mountain had 15" on close to 5" of qpf.

Regardless, if MDT somehow walked away with 24" of snow, they would break the all time record for snow for the entire month of December and I believe almost double the previous December storm record. That kind of anomaly is hard to even fathom.

I remember us waiting for MDT to officially call the jan 2016 storm the GOAT that morning during the tail end of that storm. Imagine beating the December storm record just as the Deform band started.

Over the last 20 year's we have been spoiled for sure with big storms, especially in Jan to March peak winter. These amounts are insane for peak winter. Below are the max daily snow amounts and year for MDT by month, then mean amount and (ratio).

Dec. 10.1" 1963. 5.8" (1.74)
Jan. 26.4" 2016. 9.2" (2.86)
Feb. 24" 1983. 9.6" (2.5)
March 20.3" 1993. 6.1" (3.33)

One of these is not like the others. If this storms dumps between 14..5" and 19.5" during one calendar day at MDT then that changes. It should also highlight just how rare an event this has the potential to be.

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[Jns2183]

Well, the LSV can't really ask for anything more

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[Jns2183]

This list could hilarious by Thursdsy

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[pasnownut]

6 hours ago, MAG5035 said:

Hmm, well at least on the WeatherBell products it appears the op data for the GFS and Euro is 0.25º and 0.1º respectively while their ensembles are both at 0.5º resolution. Without getting into a whole thing on GIS/mapping/degrees to meters conversion, the short answer would be yea the ensembles are run at a lower resolution (higher degree number). The high res Euro at 0.1º would be a bigger resolution difference vs it's ensemble. 

So I guess it could be implied that the lower resolution could flatten mesoscale features and thermal boundaries a bit and that difference could show with coastal low development, especially with how warm the water is off the eastern seaboard. Also, ensembles aren't going to see CAD as well as an op or especially a meso model for that same general reasoning. The higher resolution of the ops might be promoting a more explosive coastal response (and also closer to the coastline) just simply on the premise of modeling a sharper clash of warm vs cold. Given the +SST anomalies present on the eastern seaboard and a fairly respectable cold air air mass being supplied by the Canadian high, it may be wise to lean that direction with trying to blend guidance. 

Ultimately, I'm not sure how much the resolution difference actually plays in the grand scheme of things, as an ensemble is made of individual members that have their own specific conditionals to form a mean within a range of possible outcomes, which pretty much can have a similar effect as lower resolution flattening features out. Thing with ensembles is we're typically looking at them to get a handle on overall larger scale things with these events (QPF fields, pressure/height fields, accumulation probabilities, etc).. especially at this middle range where we don't have our short range or meso models in range quite yet. 

That what just a fantastic read. All weenies need to read this 2x and save it. 

[pasnownut]

6z gfs less robust with qpf distribution but it did bring better amounts into NC mtns. It’s one run and is slightly colder so I’m taking that as a +. I think ctp is staring down the barrel of a snow cannon. Just need to figure out where it’s going to be aimed. 

[Blizzard of 93]

Good morning!
Great coverage of the Euro on here last night everyone! I needed to get some sleep. It’s going to be an awesome week of tracking!

Here is the 0z EPS. Great mean low placement and a tremendous amount of precip.

 

[Blizzard of 93]

Looking beyond the pending major storm this week, the 0z Euro is dialing up another winter storm chance next Sunday into Monday.

Could you imagine if we had 3 measurable snows in 1 week!?!

[Blizzard of 93]

Back to the present, the 6z GFS and NAM both have some snow for the LSV with the appetizer event tomorrow.

 

[Cashtown_Coop]

Regarding the Wed system, I’m thinking models continue a se trend through the next 24 hours before the Inevitable north trend starts Monday into Tuesday.   If the euro continues to remain steady then bow to the king.  

[Cashtown_Coop]

Adams grid now showing 2-4” tomorrow with snow heavy at times.   Advisory coming ?

lwx showing 1-3” for Frederick county and 3-5” for Washington county.   Good trend 

[Blizzard of 93]

3 minutes ago, Cashtown_Coop said:

Adams grid now showing 2-4” tomorrow with snow heavy at times.   Advisory coming ?

It sounds like an Advisory may be incoming for tomorrow for the LSV. CTP has a fantastic discussion on tomorrow’s appetizer event. They really brought their “A” game for this write up!

“A decent short wave trough over the lower MS valley around midnight will zip northeast and not really tilt negative, rather ride on the SWrly flow aloft. The influx of moisture will deepen a sfc low over the Deep South, scooting it mainly east, crossing the East Coast around Norfolk Monday afternoon. The dynamics do impress with a good shield of warm-advection precip overspreading the Mid-Atlantic states. The northern extent of the precip looks like it will be around I-80 or just to the north. The temps aloft are favorable for snow for all of the CWA, with good omega/up-motion in the favorable dendritic snow growth zone of -10 to -15C layer aloft. A deep moist layer beneath this DGZ will fatten the dendrites. Lift looks like it will be maximized over the srn tier, esp right along the PA Turnpike on Monday morning. Expect temps to fall into the l-m30s during the first part of tonight before the clouds and snow move in. While there could be a mix of rain and snow along the Mason-Dixon Line and just a few miles north, much of the initial precip should be snow, and a wet/high-water-content snow at that. Some of the hi- res models are projecting a risk of 1"/hr rates in the morning as banded precip should develop on the NW side of the baroclinic leaf. The higher probabilities of the brief heavy snow rates will be along the Turnpike and either side of it by 30-40 miles. The trips here are the sfc temps and fast forward motion of the storm. The storm is only producing precip over the CWA for 6-8 hrs. The temps in the area where the snow is falling should wet-bulb down to near and slightly below freezing and stay there until the snow starts to lighten up. Have tried to paint that into the temp grids. The highest snowfall totals will be in the higher elevations in the first tier of counties. Mt Davis, South Mtn and the Furnace Hills will likely see 1-3" more than the lower elevations around them. We have chosen to raise the snowfall numbers. After collaboration with our neighboring offices, we decided to not issue an advisory at this time, but this looks like a fairly solid advy (2-3") snowfall for much of the srn tier or two of counties, esp due to the timing (morning rush). The next shift may have to do the heavy lifting. The morning rush hour is a worry at this point because of the expected arrival/start time of the snow. This may be an accumulation which occurs mainly on the grass and colder surfaces. But, if the road temps are warmer, the travel impacts may turn out to be less than currently expected.”

 

[Cashtown_Coop]

3 minutes ago, Blizzard of 93 said:

It sounds like an Advisory may be incoming for tomorrow for the LSV. CTP has a fantastic discussion on tomorrow’s appetizer event. They really brought their “A” game for this write up!

“A decent short wave trough over the lower MS valley around midnight will zip northeast and not really tilt negative, rather ride on the SWrly flow aloft. The influx of moisture will deepen a sfc low over the Deep South, scooting it mainly east, crossing the East Coast around Norfolk Monday afternoon. The dynamics do impress with a good shield of warm-advection precip overspreading the Mid-Atlantic states. The northern extent of the precip looks like it will be around I-80 or just to the north. The temps aloft are favorable for snow for all of the CWA, with good omega/up-motion in the favorable dendritic snow growth zone of -10 to -15C layer aloft. A deep moist layer beneath this DGZ will fatten the dendrites. Lift looks like it will be maximized over the srn tier, esp right along the PA Turnpike on Monday morning. Expect temps to fall into the l-m30s during the first part of tonight before the clouds and snow move in. While there could be a mix of rain and snow along the Mason-Dixon Line and just a few miles north, much of the initial precip should be snow, and a wet/high-water-content snow at that. Some of the hi- res models are projecting a risk of 1"/hr rates in the morning as banded precip should develop on the NW side of the baroclinic leaf. The higher probabilities of the brief heavy snow rates will be along the Turnpike and either side of it by 30-40 miles. The trips here are the sfc temps and fast forward motion of the storm. The storm is only producing precip over the CWA for 6-8 hrs. The temps in the area where the snow is falling should wet-bulb down to near and slightly below freezing and stay there until the snow starts to lighten up. Have tried to paint that into the temp grids. The highest snowfall totals will be in the higher elevations in the first tier of counties. Mt Davis, South Mtn and the Furnace Hills will likely see 1-3" more than the lower elevations around them. We have chosen to raise the snowfall numbers. After collaboration with our neighboring offices, we decided to not issue an advisory at this time, but this looks like a fairly solid advy (2-3") snowfall for much of the srn tier or two of counties, esp due to the timing (morning rush). The next shift may have to do the heavy lifting. The morning rush hour is a worry at this point because of the expected arrival/start time of the snow. This may be an accumulation which occurs mainly on the grass and colder surfaces. But, if the road temps are warmer, the travel impacts may turn out to be less than currently expected.”

 

Sweet snow on snow 

[Voyager]

During the last big rainer, I was noting how since Hurricane Isaias, the Lehigh Valley and points south and east seemed to be the qpf jackpot, and I wondered aloud (here) if the pattern set up for this winter was going to feature a lot of SEPA specials. Perusing the models this morning, it seems that every one, sans the ECMWF, wants to do just that with the heaviest qpf axis running I-81 to I-78 and south east. Hopefully this trend doesn't hold, as I'm kind of tired of seeing I-95 jackpots.

[sauss06]

Crazy what I just read over the past 2 pages bring it home fellas

 

[Jns2183]

Where can I find this site?

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[Anduril]

Man, figures I get sucked into playing Cyberpunk 2077 and sleep and come back to three pages to read through 0_o lets bring this storm home!

[pasnownut]

12k and 3k starts the nooners off nicely and looks more robust in qpf distribution. 3k really amped up. Verbatim entire subforum gets an appetizer tomorrow. Adams to Allentown stripe of best snow. Today’s a big day. Hope this is the start of a good one. 

[Blizzard of 93]

22 minutes ago, pasnownut said:

12k and 3k starts the nooners off nicely and looks more robust in qpf distribution. 3k really amped up. Verbatim entire subforum gets an appetizer tomorrow. Adams to Allentown stripe of best snow. Today’s a big day. Hope this is the start of a good one. 

Let’s do this! I am fired up!

[Blizzard of 93]

Here are the 12z NAMs for tomorrow.

They have indeed juiced back up!

 

[CarlislePaWx]

Wow...both NAM's give me 5" of snow tomorrow.  Will it come to fruition is the question?

 

[Blizzard of 93]

The Lancaster crew will love the 12z GFS but the I-99 crew will not!

 

[Blizzard of 93]

With the low tucked in to the DelMarVa like the GFS shows, I think the precip shield would push heavier snow further north & west in PA.