Central PA - Early December

[wawarriors4]

Agreed. If you take the 12z Euro grid interpolations verbatim, for MDT there'd be a quick dusting of snow at the onset before 850s torch and they go over to rain (just under 1.5" of it too). Lancaster, York, Gettysburg could see some flakes initially, but it would be a quick change-over. The entire event would be done on Wednesday morning. 

 

UNV stays frozen the entire time and picks up 3-6" of snow.

 

IPT is all frozen...3-6" of snow

 

Again, that's just the pure grid interpolations from the 12z Euro via the Accuweather Pro website. 

 

A nighttime arrival would argue for a colder solution, but that's about it...there's just not enough northern stream interaction for below 0c temps throughout the column for the entire event (with the exception of NW of MDT...but there you'll be shorted on precip). 

Best estimate for AVP?

[djr5001]

Agreed. If you take the 12z Euro grid interpolations verbatim, for MDT there'd be a quick dusting of snow at the onset before 850s torch and they go over to rain (just under 1.5" of it too). Lancaster, York, Gettysburg could see some flakes initially, but it would be a quick change-over. The entire event would be done on Wednesday morning. 

 

UNV stays frozen the entire time and picks up 3-6" of snow.

 

IPT is all frozen...3-6" of snow

 

Again, that's just the pure grid interpolations from the 12z Euro via the Accuweather Pro website. 

 

A nighttime arrival would argue for a colder solution, but that's about it...there's just not enough northern stream interaction for below 0c temps throughout the column for the entire event (with the exception of NW of MDT...but there you'll be shorted on precip). 

It's like it wants to interact but another wave to the west tries to push it out before the southern energy can fully phase... a surface low develops well north of the main southern upper level energy

 

Best estimate for AVP?

overall close to an inch of precip but looks to begin as light snow, possibly change over to a mix/rain, then back to snow... some areas around there may stay all snow while others change over for a bit

[wawarriors4]

It's like it wants to interact but another wave to the west tries to push it out before the southern energy can fully phase... a surface low develops well north of the main southern upper level energy

 

overall close to an inch of precip but looks to begin as light snow, possibly change over to a mix/rain, then back to snow... some areas around there may stay all snow while others change over for a bit

thank you, making the drive from VA to PA on tuesday to the parents house.........Parents house is at 1700 feet just a bit southwest of Scranton

[djr5001]

Winter Weather Advisory for Westmoreland/Fayette ridges and Lake Effect Snow watch for northwest PA counties - fyi if anyone traveling this weekend out that way

[EasternUSWX]

From trip to NWS today.

 

 

 

 

[NeffsvilleWx]

18z gfs brings back snow to MDT on the front and backside, with freezing rain in between.

Same for RDG, with a brief period of rain in the middle. Roughly 4" of snow for UNV and IPT and roughly 8" for AVP. PHL, on the other hand, starts off with freezing rain then transitions to rain.

 

A more realistic solution than the 12z, IMO, but I still favor the 12z euro solution (for no other reason than it makes the most sense according to what I've experienced).

[MAG5035]

Winter Weather Advisory for Westmoreland/Fayette ridges and Lake Effect Snow watch for northwest PA counties - fyi if anyone traveling this weekend out that way

 

Travel could get pretty dicey Sat night/Sunday in the western third to half of the region with the arrival of the Arctic front and potential snow showers and squalls that accompany it. The rapid temp drop after the frontal passage could promote a flash freeze of some roads. We will see the lake effect establish itself behind the frontal passage as well... and it could be a pretty major event in the favored areas given the warm lakes and the downright frigid air mass for this time of the year passing over them (-14 to -16ºC at 850mb). NWS Pittsburgh's going pretty hard with lake effect/winter storm watches in it's northern tier counties. Their snow map would be supportive of eventual advisories for their US 422 corridor counties. 

 

 

CTP hasn't produced a snowfall map yet but I expect them to probably issue one. Would also watch for advisory products to get expanded up to Cambria and possibly Clearfield with lake effect products up in their snow belt (Elk, Cameron, McKean counties). Off the mountains, the corridor west of I-99 could see an inch or two. 

[2001kx]

Travel could get pretty dicey Sat night/Sunday in the western third to half of the region with the arrival of the Arctic front and potential snow showers and squalls that accompany it. The rapid temp drop after the frontal passage could promote a flash freeze of some roads. We will see the lake effect establish itself behind the frontal passage as well... and it could be a pretty major event in the favored areas given the warm lakes and the downright frigid air mass for this time of the year passing over them (-14 to -16ºC at 850mb). NWS Pittsburgh's going pretty hard with lake effect/winter storm watches in it's northern tier counties. Their snow map would be supportive of eventual advisories for their US 422 corridor counties. 

 

StormTotalSnowFcst.png

 

CTP hasn't produced a snowfall map yet but I expect them to probably issue one. Would also watch for advisory products to get expanded up to Cambria and possibly Clearfield with lake effect products up in their snow belt (Elk, Cameron, McKean counties). Off the mountains, the corridor west of I-99 could see an inch or two. 

 

No snowmap yet from them but 1-3 for my area.

 

• Saturday A chance of snow showers, mainly after 4pm. The snow could be heavy at times. Mostly cloudy, with a high near 36. West wind 5 to 10 mph increasing to 13 to 18 mph in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 50%. New snow accumulation of less than a half inch possible.
• Saturday Night Snow showers likely, mainly after 7pm. The snow could be heavy at times. Cloudy, with a low around 18. Breezy, with a west wind 14 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 3 inches possible.

[EasternUSWX]

GFS can't make up it's mind... back to the south. Time to throw that model out since it is the only one doing this. Not even it's own ensembles agree. 

[Mallow]

GFS can't make up it's mind... back to the south. Time to throw that model out since it is the only one doing this. Not even it's own ensembles agree.

 

Some of them do.

[EasternUSWX]

Some of them do.

 

Not many. Most are west. Basically all models vs. GFS right now. 

[MAG5035]

Canadian running a low up inside over Philly and stays an inland runner. Snow to rain in the Lower Sus Valley, snow to freezing rain in a stripe from AOO-UNV-IPT. Generally all snow northwest of that. The P-type link is just below. I feel like the Canadian is going to be setting up the western edge of guidance again. 

 

http://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type/pcpn_type_gem_reg.html

[MAG5035]

European is def still on board with the storm affecting C-PA. Haven't seen the maps yet but rough text data would suggest highly marginal snow profiles running that JST-UNV-IPT line and a likely thin stripe of accumulating snow. UNV seemed to be the best looking station with 850s staying below zero (barely) and about 0.7" of QPF. IPT has 0.85" but a frame where 850 temps are a whopping 0.4ºC. Surface temps remain below freezing.. I would argue it could be a wet snowfall type profile but a mixing threat exists.  Harrisburg sees 1.4" of all rain. 

[NortheastPAWx]

At this point, even if not snow, we could just use the precip for the homefront.

[MAG5035]

At this point, even if not snow, we could just use the precip for the homefront.

 

Agreed, this does look like one of the more moisture laden systems we've seen in awhile.. so hopefully it doesn't get supressed. But regardless of what happens with this system, this looks like on of the coldest Thanksgiving week into early December periods we've seen in years. After the coastal goes by the Euro doesn't get PA above -10ºC at 850 all the way thru hour 240. 

[AllWeather]

Agreed, this does look like one of the more moisture laden systems we've seen in awhile.. so hopefully it doesn't get supressed. But regardless of what happens with this system, this looks like on of the coldest Thanksgiving week into early December periods we've seen in years. After the coastal goes by the Euro doesn't get PA above -10ºC at 850 all the way thru hour 240. 

 

It's only right to decorate for the holidays when it's freezing outside, rather than when it's warm enough for shorts. I can't get in the Christmas mood when temps are above average.

[Santa Clause]

GFS pretty consistent with this suppressed/progressive idea.

[Santa Clause]

I think I'm alone in saying I'd rather rain and 40s than dry and 24 with a howling wind. Just how I roll I guess, never understood the appeal of bitter cold.

[EasternUSWX]

Gfs is pretty clueless. Lol. Nam has massive rain with super amped system just like the rest while gfs still has no clue.

[Santa Clause]

Easy man, with this progressive flow it could very well be correct.

[EasternUSWX]

Easy man, with this progressive flow it could very well be correct.

With 0 support from any other models I would say it is unlikely.

[djr5001]

Gfs is pretty clueless. Lol. Nam has massive rain with super amped system just like the rest while gfs still has no clue.

Go home GFS, you're drunk

 

it is the only model with no interest in any interaction with the northern stream... that model is so bad with handling phasing... sometimes it ends up right but other times really bad

[Mallow]

Here's to hoping for a compromise between the 12z NAM/00z Canadian and the 12z GFS (a la the 00z Euro).

[Santa Clause]

I'm just hoping this disorganized suppression thing doesn't happen.

[JamieOber]

Go home GFS, you're drunk

 

it is the only model with no interest in any interaction with the northern stream... that model is so bad with handling phasing... sometimes it ends up right but other times really bad

12Z GFS is a drunk in a rural PA dive in a camo hat and Tractor Supply hoodie standing on the bar screaming "'MERICA" over and over.

[JamieOber]

No doubt in my mind, in true Central PA fall is dead and we are in winter now. I'd argue autumn began dying last week.

[jm1220]

I'm just hoping this disorganized suppression thing doesn't happen.

The GFS ensembles are west of the OP which almost always means the OP is trash, and every other model is well west of it. I would put a lot more stock in those than the GFS.

 

I think maybe I-99 through Rt. 220 is the one corridor that has a chance at real snow from this. The storm just looks too disorganized and warm for a larger area of snow in cold enough air.

[jm1220]

12Z GFS is a drunk in a rural PA dive in a camo hat and Tractor Supply hoodie standing on the bar screaming "'MERICA" over and over.

Or a drunk Penn Stater running down Beaver Ave at 3AM chasing after a toilet seat.

[pawatch]

NWS forecast: Looked at tonights icon and it says heavy snow...
Then looked at tonights written forecast: Chance of precipitation is 30%. New snow accumulation of less than a half inch possible.
Just kind of made me chuckle.

http://forecast.weather.gov/MapClick.php?CityName=Garden+View&state=PA&site=CTP&textField1=41.2565&textField2=-77.0487

 

First week of December usually has had some kind of snow storm. Seems like an active period.
It will be interesting to see how much the models are in agreement with the Tuesday storm come Monday.

[Mallow]

The GFS ensembles are west of the OP which almost always means the OP is trash, and every other model is well west of it. I would put a lot more stock in those than the GFS.

 

I think maybe I-99 through Rt. 220 is the one corridor that has a chance at real snow from this. The storm just looks too disorganized and warm for a larger area of snow in cold enough air.

 

There are actually quite a few more of the 20 GFS ensembles that are suppressed for the 12z run than the previous runs. I wouldn't discount "nothing" as a possible solution just yet.