Central PA - Early/Mid December 2016

[WmsptWx]

I'm about to be crucified here, but I have yet to buy Christmas present one and really need cooperative weather this weekend (pref Sat) so that warm air needs to surge.

[sauss06]

3 minutes ago, Atomixwx said:

I'm about to be crucified here, but I have yet to buy Christmas present one and really need cooperative weather this weekend (pref Sat) so that warm air needs to surge.

Shut yo mouth.   I hear the stores are open tonight, Thursday and Friday??

I'm looking forward to our resident Mets to talk about this weekend as well as next week. Looks like we have a couple chances leading into Christmas. 

 

 

[canderson]

CTP suddenly is all-in on a decent snow for Harrisburg Friday night/Saturday am. They don't have the flip until mid afternoon. 

[pasnownut]

2 hours ago, sauss06 said:

Shut yo mouth.   I hear the stores are open tonight, Thursday and Friday??

I'm looking forward to our resident Mets to talk about this weekend as well as next week. Looks like we have a couple chances leading into Christmas. 

 

 

[canderson]

3 hours ago, Atomixwx said:

I'm about to be crucified here, but I have yet to buy Christmas present one and really need cooperative weather this weekend (pref Sat) so that warm air needs to surge.

Didn't know Amazon went out of business.

[AllWeather]

2 hours ago, canderson said:

CTP suddenly is all-in on a decent snow for Harrisburg Friday night/Saturday am. They don't have the flip until mid afternoon. 

I'm not sure if I agree with that. However, a nice front end thump of snow is a good bet before the changeover. HP not exactly in ideal condition to prevent scouring the cold air out, and LOOK at the 850 jet cranking (see image). Directly out of the SSW. Going to be torched aloft, but the question is does the cold air at the surface hold, especially with some fresh snowcover. I like holding on to FZRA into mid AM for areas south of the Turnpike...north probably middayish. 

Whereever that 850 jet points, is who is going to get thumped the hardest initially before the changeover (hence why GFS has a mini bullseye in SE PA). NAM is more N/S oriented and blasts the interior, while the GFS/CMC is farther SE and oriented more SE/NW. 

 

 

PS - hope you guys have all been well! Haven't been on here in a while...bought a house now my wife and I are expecting our first child so things have been crazy to say the least! Glad to be back to see your guys' input. 

[AllWeather]

Now that I'm looking at the new 12z GFS rolling out...same story. LL jet in virtually an identical spot. 

[pasnownut]

3 hours ago, Atomixwx said:

I'm about to be crucified here, but I have yet to buy Christmas present one and really need cooperative weather this weekend (pref Sat) so that warm air needs to surge.

keep it up and we'll be "going gangster" on you.  (see his signature).

 

Nut

 

[sauss06]

Tell your wife its winter for god sakes  

Pop in any time when you have a spare moment, we appreciate your thoughts

[pasnownut]

6 minutes ago, AllWeather said:

I'm not sure if I agree with that. However, a nice front end thump of snow is a good bet before the changeover. HP not exactly in ideal condition to prevent scouring the cold air out, and LOOK at the 850 jet cranking (see image). Directly out of the SSW. Going to be torched aloft, but the question is does the cold air at the surface hold, especially with some fresh snowcover. I like holding on to FZRA into mid AM for areas south of the Turnpike...north probably middayish. 

Whereever that 850 jet points, is who is going to get thumped the hardest initially before the changeover (hence why GFS has a mini bullseye in SE PA). NAM is more N/S oriented and blasts the interior, while the GFS/CMC is farther SE and oriented more SE/NW. 

 

 

PS - hope you guys have all been well! Haven't been on here in a while...bought a house now my wife and I are expecting our first child so things have been crazy to say the least! Glad to be back to see your guys' input. 

Congrats on all of the big news.  Unfortunately we cant argue.  Was looking at the 700/850 panels last night during 0Z runs and i was thinking the same thing.  Best chance to hold on is NEPAville (of course he moves away and this ones for him.......)

Just not sure how we can avoid, despite how CAD typically is undermodelled.  That said, every hour of extra white/pingers beats the heck outta last years mess.

Next week and beyond sounds like much the same.  No toaster baths needed...even if we end up wet and not white with some storms.

 

Nut

[WmsptWx]

As I expected. Thanks for going in dry, fellas. 

 

And thank you for reminding me that when it comes to ridicule, it is far better to give, than receive.

Be ready to receive...

[pasnownut]

6 minutes ago, Atomixwx said:

As I expected. Thanks for going in dry, fellas. 

 

And thank you for reminding me that when it comes to ridicule, it is far better to give, than receive.

Be ready to receive...

LMAO.

 

I almost spit my drink....

 

Nut

 

[pawatch]

2 hours ago, AllWeather said:

PS - hope you guys have all been well! Haven't been on here in a while...bought a house now my wife and I are expecting our first child so things have been crazy to say the least! Glad to be back to see your guys' input. 

Congratulations on the house and expecting your first child!!

Thanks for sharing your thoughts. Myself I'm a little worried about the icing

[canderson]

AllWeather, welcome back and congrats! Thanks for your insight, I'd rather it be just rain this weekend myself too.

[2001kx]

Winter Weather Advisory Weather Updated: Dec 14 3:07PM Issued by the National Weather Service en-US WINTER WEATHER ADVISORY FROM 1AM EST THU UNTIL 3PM EST THU ...WINTER WEATHER ADVISORY IN EFFECT FROM 1 AM TO 3 PM EST THURSDAY... ...WIND CHILL ADVISORY IN EFFECT FROM 3 PM THURSDAY TO 10 AM EST FRIDAY... THE NATIONAL WEATHER SERVICE IN STATE COLLEGE HAS ISSUED A WINTER WEATHER ADVISORY FOR SNOW...BLOWING SNOW AND LOW WIND CHILLS...WHICH IS IN EFFECT FROM 1 AM TO 3 PM EST THURSDAY. A WIND CHILL ADVISORY HAS ALSO BEEN ISSUED. THIS WIND CHILL ADVISORY IS IN EFFECT FROM 3 PM THURSDAY TO 10 AM EST FRIDAY. * LOCATIONS...THE LAUREL HIGHLANDS. * HAZARD TYPES...MODERATE TO HEAVY SNOW ACCUMULATION...BLOWING SNOW AND LOW WIND CHILLS. * SNOW ACCUMULATIONS...2 TO 4 INCHES. * TIMING...SNOW WILL BEGIN AROUND OR JUST AFTER MIDNIGHT AS AN ARCTIC COLD FRONT MOVES DOWN FROM THE NORTH. SOME VERY HEAVY SQUALLS WILL OCCUR LATER TONIGHT. THE SNOW SHOWERS WILL TAPER OFF ON THURSDAY AFTERNOON. WIND CHILLS WILL GET PROGRESSIVELY LOWER TONIGHT AND THURSDAY BUT WILL BE COLDEST FRIDAY MORNING. * IMPACTS...THE HEAVY SNOW AND WIND WILL CREATE SNOW COVERED ROADS AND PRODUCE SCATTERED POWER OUTAGES. DANGEROUSLY LOW WIND CHILLS MAY QUICKLY PRODUCE FROSTBITE ON EXPOSED SKIN. * WINDS...WEST 15 TO 25 MPH WITH GUSTS UP TO 40 MPH. * WIND CHILLS...AS LOW AS 18 BELOW DUE TO TEMPERATURES ZERO TO 11 ABOVE ZERO...AND WINDS FROM THE WEST AT 10 TO 20 MPH WITH GUSTS UP TO 35 MPH.

[Rickg2]

Allerather, conga-rats on the house and child. that seems to happen a lot.

I just had a round of scarey cancer. Quite by accident my family  doctor found a small mass in my lung. (I never smoked) and I had to have it biopsied twice. Turns out it was malignant. I had about half of one of my lungs removed. IT was really fun and the recovery time is about one year due to the separation of the ribs. 

Anyway, This weekends storm looks like a mess. Local mets are saying  up to 6 inches of snow, then sleet and freezing rain.

How about the upcoming cold snap?

[Blizzard of 93]

The main models for the last couple of days have shown 3-6 inches of snow for most of CTP before the flip to ice & rain.

It will be interesting to see where the final bullseye lands. Regardless of exactly how much we end up with, I am happy that we are getting our first widespread winter storm about a month earlier than last year!

[Itstrainingtime]

I'm skeptical on some of the snow amounts being thrown around, especially for MDT and points S & E. 

I'm not being a deb, but far too often these events under-perform snow-wise around these parts. Rarely do we pick up more than a slushy inch or two before the flip...I guess time will tell as each event can provide surprises both good and bad. 

[canderson]

39 minutes ago, maytownpawx said:

I'm skeptical on some of the snow amounts being thrown around, especially for MDT and points S & E. 

I'm not being a deb, but far too often these events under-perform snow-wise around these parts. Rarely do we pick up more than a slushy inch or two before the flip...I guess time will tell as each event can provide surprises both good and bad. 

Yeah we tend to do better if the 850s don't soar. They're set to do just that.

[lte5000]

Eric Horst said 1-3, maybe 2-4, in his video today.

Also mentioned an area of 6-8 possible for north central PA / the Rt. 80 corridor.

[skiier04]

Seems like a classic underperforming setup to me as well... not expecting more than an inch or two here before we start pinging then it's all over.

[sauss06]

8 hours ago, maytownpawx said:

I'm skeptical on some of the snow amounts being thrown around, especially for MDT and points S & E. 

I'm not being a deb, but far too often these events under-perform snow-wise around these parts. Rarely do we pick up more than a slushy inch or two before the flip...I guess time will tell as each event can provide surprises both good and bad. 

 

8 hours ago, canderson said:

Yeah we tend to do better if the 850s don't soar. They're set to do just that.

I'm with you 2. The guys were asking me last night while we were on a crash, i said i thought we'd have snow, probably the ground will be covered but i didn't think we'd get what was being thrown around. I think it switches to rain quicker.

[WmsptWx]

Steven DiMartino at NYNJPAWeather has a 3-6 setup for the HBG region, which I would assume stretches along the US 22 corridor out towards Toontown. 4-8 from 80 on northward.

Locally, Bret Thackara has 1-3. 

Probably closer to Thackara than DiMartino.

[canderson]

When is the precip supposed to arrive Fri? 

We have dinner plans in Carlisle and don't really want to transverse 81 in a snowstorm! 

[djr5001]

21 hours ago, AllWeather said:

I'm not sure if I agree with that. However, a nice front end thump of snow is a good bet before the changeover. HP not exactly in ideal condition to prevent scouring the cold air out, and LOOK at the 850 jet cranking (see image). Directly out of the SSW. Going to be torched aloft, but the question is does the cold air at the surface hold, especially with some fresh snowcover. I like holding on to FZRA into mid AM for areas south of the Turnpike...north probably middayish. 

Whereever that 850 jet points, is who is going to get thumped the hardest initially before the changeover (hence why GFS has a mini bullseye in SE PA). NAM is more N/S oriented and blasts the interior, while the GFS/CMC is farther SE and oriented more SE/NW. 

 

 

PS - hope you guys have all been well! Haven't been on here in a while...bought a house now my wife and I are expecting our first child so things have been crazy to say the least! Glad to be back to see your guys' input. 

Congrats!!

What are your thoughts on the current very low dew points and how that will impact the onset of precip??  The dew point anomaly maps are quite impressive for today into tomorrow.  Does it limit initial thump from producing much due to virga or does it allow for surface temps to stay below freezing longer (with early on evaporational cooling holding temps down) than models are projecting into Saturday (snow to ice storm)? 

[Santa Clause]

I already like last winter better! Checked models out, looks like snow to rain Saturday morning. Running a youth basketball tourney, so wouldn't mind a warm bust.

[AllWeather]

Thanks everyone for the kind words and congratulations!

 

As for the overnight trends, the LLJ is still there providing solid QPF for a limited period of time. However, the GFS has shifted the best lift SE with the stronger core of the low-level jet. This area of better lift has trended farther south into the milder air, thus the GFS is not showing the snow max that it once showed for SE PA. Other globals seems to be generally agreeing. Looks like a 1-3 southeast of I-81/78 and 3-6 north of there. 

As for the low level cold air, it's been my experience that no matter how much snowcover you have, if the high isn't in a good CAD position, the warm air has NO problem surging in and changing things over/mixing to the surface. The preceding snowfall may add a few extra minutes to icing, but generally should be a quick flip to plain rain. My goodness, 850s rocket...around -5 to +8 at KMDT in about 6 hours Saturday morning. I would think SE PA doesn't have much pinger action...probably snow -> brief wintry mix -> rain, then drizzle. Farther north is trickier, but I don't think many in this forum escape the blowtorch. 

 

djr5000 - I think wetbulbing should counteract the warm advection initially as precip moves in, but some virga is likely as you said. Perhaps that initial band moistens things enough to get some light snow down, then the LLJ kicks in and there's a burst of moderate/heavy snow for 1-3 hours before changing over quickly. That's my $.02

[heavy_wx]

Guidance suggests we will have some modest forcing in the lifting branch of a jet streak Friday night/Saturday morning. Bufkit profiles from the 4K NAM and GFS show a brief period of snow here before the mid-levels become subsaturated as the forcing weakens. We get into a region of good isentropic lift late Saturday morning; however, the warm layer near 850 mb will change precipitation over to sleet and eventually to freezing rain and rain later Saturday.

I'm not sure if we end up with a net gain of snow here; the GFS brings surface temperatures into the mid 40s F by late Saturday with rain. We'll have to watch the initial light snow early Saturday and how quickly we change over as the forcing increases later in the day.

[Santa Clause]

Yea, good info. Profiles have warmed sneakily the last few runs.

[MAG5035]

To add to the last couple comments, I think whether or not places like the central (under I-80) and Sus Valley end up with a sizable front end snowfall hinges not so much on the eventual surge of warm air but on the positioning/intensity of the preceding WAA snowfall. I've noticed modeling as of late has been concentrating that on a more northerly axis... pretty much square over the Great Lakes region and into northern PA/NY state. Given lack of a positioned high where we need it, that may well be the better bet as to what happens. That leaves the rest of the region not seeing much precip or perhaps a lighter snowfall until the heavier stuff associated with the strong southerly surge arrives Sat morning, which of course invites a quick mix as 850s warm in a hurry. With things as the are currently, I could get on board with a 1-3" event snow-wise in the Sus Valley below I-80 (less south, more north).. but not much more than that unless I see more QPF associated with the WAA snow back further south in PA. 

On that note, while 850s torch very quickly on Sat, 925mb and surface temps look to be really lagging. Taking the Euro for example, the 850 0 line at hour 60 runs very roughly southeast through PA from north of Pitt through the AOO/UNV region thru Harrisburg and then down to York and to the MD Line. The 925mb temps at this same frame have the far southern tier at -4ºC to –6ºC and everyone else in our region colder than –6ºC (north central from UNV north below -8ºC). Sleet would figure to be a pretty dominant transitional p-type for awhile with that much of a difference between those two levels. I would look for warning level ice potential in some of the higher elevations in the eastern Laurels (essentially at the 925mb level). The central counties and especially from I-80 northward may eventually have this potential as well as it is hard to rid the cold air at the surface in the valleys. Even with a setup that isn't particularly favorable for CAD, we still have to scour out an antecedent arctic air mass. 

44 minutes ago, heavy_wx said:

Guidance suggests we will have some modest forcing in the lifting branch of a jet streak Friday night/Saturday morning. Bufkit profiles from the 4K NAM and GFS show a brief period of snow here before the mid-levels become subsaturated as the forcing weakens. We get into a region of good isentropic lift late Saturday morning; however, the warm layer near 850 mb will change precipitation over to sleet and eventually to freezing rain and rain later Saturday.

I'm not sure if we end up with a net gain of snow here; the GFS brings surface temperatures into the mid 40s F by late Saturday with rain. We'll have to watch the initial light snow early Saturday and how quickly we change over as the forcing increases later in the day.

I'm not sure temps surge at the surface quite that fast in the Centre region..especially in the valley, unless by late Saturday you meant the overnight hours. I would imagine temps will creep above freezing but not too much more when there is a lull in precip since there figures to be two distinct waves of heavier precip.. the second of which is associated with the actual frontal passage. It will likely take that second wave of precip and frontal passage to actually mix down the warm temps aloft and finally send temps into the 40s, but it may only last a few hours before they start falling behind the front Sunday morning. That's often how these setups go around here, in the meantime you'll see western PA well into the 40s and 50s.