MAG5035

The GFS finally joined the party today with having Tuesday's system, bringing the whole model suite into general agreement on the developing low from the Lower Mississippi Valley toward PA and then transferring to a coastal system. Question becomes if we hold enough cold at the low levels for a quick snow event. We will have some preceding cold for a change so I think a good part of our subforum area could see something snow wise from this with the Lower Sus Valley and southern tier being most in question for p-type at the moment. Like I mentioned the other day, it's still looking like something of the 2-5" variety at best with the northern tier and central counties having the best shot at possibly the higher end of that range. Still quite doable that LSV places like Harrisburg or even points south sees at least an inch or so. This is a window of opportunity in an ugly progressive pattern. Also keep in mind we haven't busted the MJO way out into Phase 5 yet either. I know it isn't much but there is at least a little winter potential to be talked about in our region.

It beats the alternative. I took a peak in the Panic Room earlier this afternoon and  lol. I know most of you read our subforum neighbors to the south and I think we're all quite aware we're in a relatively uh.. unfavorable pattern alignment heading onward into January. The very positive AO (as well as the NAO) is a big player right now.. that has to neutralize and/or reverse. Low heights and a strong polar vortex (progressive pattern) near the pole keeps arctic air bottled up and limits intrusions. At least the silver lining(s) of the MJO pulse forecast to go way into Phase 5 is that the tropical forcing and associated effects (major central Pac ridging) may eventually perturb the PV enough to get some changes up there.. maybe. Most models also appear to progress the pulse pretty rapidly as well in their MJO forecasts. But for now just a really ugly alignment that we're served up the first half of this month. 

7 hours ago, Blizzard of 93 said:

@pasnownut & @MAG5035

What are your thoughts on the Saturday pm to Sunday am winter storm potential?

Right now I think it's yet another case of close but no cigar. Models do have quite a dynamic 500mb shortwave that passes in what would be a pretty decent position, though they differ a bit on surface reflection with GFS/NAM having more of a surface low through PA transferring to the coast while the Euro appears to do this underneath PA. The GFS/NAM solution isn't going to work to get anything synoptic snowwise in central PA (too far north). The Euro solution gives the best chance of a changeover scenario but the lower levels are still lagging just a bit too long, especially in the Sus Valley. We don't have established cold or anything to work with initially, and I think the pattern's too progressive to allow this dynamic system to wind up in time to actually present a changeover scenario. Thus, right now I feel the western mountains and especially NE PA seem to stand the best chance of seeing snowfall with this developing low.

The 12z Euro's version of the potential Jan 7-8 system delivered a snow event to the commonwealth today, joining the Canadian's insistence on such things the last several runs. Today's Canadian looked a bit too wound up overall with it's evolution of not only that system but the weekend system preceding it, but mega deep systems are a Canadian trademark. GFS hasn't had much of a system at all the last few runs in this timeframe. So tons of spread in solutions remains with this. 

The Euro solution still technically cuts but has some secondary reflection to the coast and is a weaker wave overall so cold air aloft doesn't get routed. The result is a slug of precip (likely snowfall) that runs across the state in a widespread 2-5" type solution. There's been plenty of discussion on the gloomy outlook of the pattern overall going forward, but a window of opportunity is going to be there early next week. 

Some decent squalls went through in the last couple hours, 0.5" new.

1 minute ago, Wmsptwx said:

Won't it be too warm MAG? Hadn't heard about squalls until now.

This will be occurring later in the afternoon with the shortwave ushering in the precip and reinforcing colder air. The biggest threat for issues is probably west of the I-99/220 corridor but CTP is being proactive given some of the high res short range models. One would have to watch for wet roads with initially warmer temps to become slick quickly if the heavier snow squalls materialize.

Meanwhile, outside of the Sus Valley tropics where the growing season apparently didn't end lol.. Special Weather Statement is out for a large portion of Central PA for the threat of snow squalls later today. Use caution if traveling that direction later on.. especially on I-80 where snow squalls seem to be synonymous with 30+ car/truck pileups on the regular. 

Quote

Special Weather Statement
National Weather Service State College PA
1036 AM EST Tue Dec 31 2019

PAZ004>006-010>012-017>019-024>028-033>035-037-041-042-045-046-
049>053-058-311800-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin-
Juniata-Somerset-Bedford-Fulton-Tioga-Northern Lycoming-Sullivan-
Southern Clinton-Southern Lycoming-Union-Snyder-Montour-
Northumberland-Columbia-Schuylkill-
1036 AM EST Tue Dec 31 2019

...DANGEROUS TRAVEL POSSIBLE THIS AFTERNOON AND EVENING...

Dangerous travel along highways is possible this afternoon and
early evening as snow squalls should drop visibilities below a
half a mile with icy roadways.

Snow squalls will begin in northwestern Pennsylvania early this
afternoon. These squalls will move through the northern and west
central portions of the state through the afternoon and early
evening hours. The heaviest snowfall will be in the northwest
mountains with a quick one to two inches possible.

It is also possible snow squall warnings may be needed this
afternoon and early evening, possibly along US Route 6, I 80, I
99 and US route 15 north of Selinsgrove, as this snow moves
through. Expect the snow to transition to lake effect snow showers
by early this evening.

If traveling this afternoon, be alert to rapidly changing visibility.
Untreated roads could become covered with snow during periods of
heavier snow.

Too bad we're talking D8-10+, but 0z Canadian and Euro op showing how we can capitalize with the colder pattern progged to set in at the end of this coming week.

It does appear we will set up for a more solid shot of cold toward the end of next week as we finally build some heights out west and in the Pac and dump a trough into the east. First though, we probably go through another potentially wet outcome late week as the potential system in that realm looks vulnerable to cutting with energy dumping into the west and driving up heights in the east. 500 pattern doesn't look bad overall prior to that this week with below normal heights across a majority of the US the first half of the week but not a lot of cold thats tapped quite yet. We should see a few seasonal days and probably some snow showers in the central and western mountains behind tomorrow into Mon's system. 

Models are in good agreement currently with this more significant pattern shift and cold shot beyond this week. The main questions being of course if we can score some opportunities and will it actually have some staying power (and at the current modeled strength). The current long range eventually really builds a central Pac ridge, which coupled with a -PNA, continued low heights overall near the pole (+AO) and no real blocking in the NAO realm still presents a potentially flawed pattern going forward. I'm talking beyond D8-10 with that, so nothing set in stone by any stretch of the imagination. 

If you think about it, you erase that lucky strike mid November snowstorm last year (which could have easily happened this November) and we're just about where we were at this time last year. A lot of us were shut out last December, which didn't quite happen this year, but we were looking towards the 2nd week or so of January for things to turn. Kinda why I'm not a fan of the cold November, you set up a good overall longer term pattern and typically they'll break down/transition after 30 days or so. The issues are a bit different this year, but we're still quite early in the game. If we get a decent pattern to set in as progged at the end of the week and it stick for a time.. we're only into the second week of January. 

Hope everyone had a good holiday.

Guidance is all over the place next week with respect to whatever system decides to come about within the first few days of the new year after another cutting storm slotted for late this weekend. We're talking past D7 so the uncertainty is to be expected. The differences between the 0z GFS and Euro are pretty big tonight in that range. The possibility of a system to deliver something to the area is there, but I'm seeing some fundamental issues with the pattern overall. Cold air availability and source region seems to be an issue. Despite the model differences, you don't see much anomalous cold up in Canada at all until you get way out into GFS long range. The Euro is especially warm in this respect, having a lot of anomalously warm 2m temps in Canada and the US. Tonight's Euro didn't even really settle in much cold behind the weekend system. The GFS has the better 500mb look next week, and would be fairly workable. But it doesn't look especially cold and we could end up with another system that has, for example an okay track but still ends up with p-type issues.

Also noticing a lot of low heights remaining near the pole. You don't see the PV (or a piece of it) centered over say, Hudson Bay. Low heights centered on the pole is indicative of a +AO regime, and the latest AO forecast is through the roof. +AO keeps the arctic air locked up poleward, and the fairly progressive regime in the mid latitudes (+EPO, no established PNA ridge, transient at best ridging in the NAO region) would seem to serve as reasonable explanation of our lackluster pattern at the moment. 

4 hours ago, paweather said:

Is it soon time for a new thread? Change our luck and no I am not starting it if so. :-) 

I'll see what I can do haha.

New thread and hopefully a new pattern for the better in the near future. 

55 minutes ago, Wmsptwx said:

Lol I hope the mid Atlantic gets a solid hit just to help cheer them up a little....some of them seem pretty down and depressed.

Typically at about the lowest point of hopelessness down there and when everything's canceled til next year by mid-Jan is when they get wacked with some once in 30 years type snowstorm. 

31 minutes ago, JTrout said:

I feel like this is a good time to ask this question with squalls around. I live in the very north west corner of Lancaster county outside of Elizabethtown. When tracking t-storms, squalls, clippers, then the bigger storms from the south, etc, I have to bounce around the different radar locations to see what is coming and the returns aren't accurate half the time. I think a couple of you guys are in the same situation placed between State College, Baltimore and the Philly radar. What does everyone in this area use live storm tracking? Is there a best service/app that blends the radars and gives a semi accurate radar for this area? I asked Horst this on twitter and he said im in a radar hole, especially for squalls and t-storms. 

Intellicast is a fairly decent regional radar to use that also doesn't do too bad with p-type depiction either, but yea York/Lancaster county is a tough spot in PA for doppler products as LWX or CCX only sees down to about 6-7K feet at best on the 0.5º tilt. Considering the Sus Valley is one of the more severe prone parts of the state and with the population you would think a doppler placed somewhere around there would be of interest. I say put one in Tamaqua. Between CCX, BGM, and DIX... Voyager can't see under 9-10k feet with any of them. 

Just now, Wmsptwx said:

Violent MVA around White Deer, sounds really bad. I 80 in Union County.

I was just about to post about that, they have I-80 closed the whole way back to Lock Haven (Exit 178) from Exit 212. 

Nice squall arrived, visibility 1/8 to 1/4 and roads caving. Looks like at least another decent one coming behind this one.

17 minutes ago, 2001kx said:

We basically had nothing on the ground before that band.

Geez that looks like at least 2”. I have about a half inch so far today. Radar looks good to get into some of what just went through you fairly soon.

I'll be the first to admit that I'm bummed out that we haven't capitalized the way we could have on a very active opening 17 days of December, but we have already had a better December overall than last December as we were pretty much shut out with a less workable pattern. At least this December has taken some swings, that major storm to open up the month was very close to being a big one, just missing the region with big snows and most of us still saw something from it. And then of course, yesterdays system. I'm sure some folks are getting antsy and whatnot but expectations seem higher than usual this year given the fact that I know it seemed like every winter forecast I've come across shared on social media during the fall or even the Farmers Almanac of all things were promising big things from the winter pattern. Buying in to all that of course is always a recipe for disappointment for at least somebody. Long range forecasting for general tendencies over a coming season can be difficult enough to predict much less anything specific, especially coming into a winter with no real dominant signal (the neutral ENSO for example). We're not even a full month into meteorological winter yet (which doesn't include March) either, and we worked into a winter-like pattern quite early all the way back in early-mid November. I don't always like the super early winter pattern like that because it's hard to capitalize in the snow department in November and it usually sets up for some kind of a change/breakdown sometime in December.

I'm not worried right now going forward. It's important to remember that even our big time winters we hold near and dear normally have some rough patches in them. We're going to get a break in things in the 4-7 days that includes Christmas in the middle and no, it's probably not going to be 75ºF Xmas Eve. The pattern may not look great at the moment but I also view it as continuing to be quite changeable and not necessarily locked into anything good or bad. This moderating trend we're looking at for the holiday appears to be a split flow regime with emphasis on the split, with a progressive northern branch way too far north and no amplification to interact with the southern stream. The most dominant teleconnection I've seen appears to be the AO, which has been running positive. +AO's keep arctic air tighter to the pole which can be a reasonable explanation for perhaps why we've generally been seasonally cold at best and have had only brief colder shots this month. That is currently progged to trend negative as we get to the end of the month.

C'mon back edge, I see you out there between here and Pittsburgh haha. 

Miserable night, basically an all freezing rain affair and temps remaining right near the 32ºF mark. I'm glad I salted the driveway this afternoon. Probably a tenth or so in the trees/railings/etc. The lack of a high pressure to the north shows... a decent snowfall is probably the primary impact of this system over a good part of our region with one given the track of the low. We've really wasted a lot of potential this month. 

Trying to mix some ice pellets in here. Notable feature on CCX radar (CC product) is a pretty established snow/mix line already pretty much running on I-80 and given that and mPing obs I've not really seen anything on that product that indicates to me any collapse of that southward with the column cooling enough. The knee jerk reaction to that would be that pretty much shuts down the prospect of seeing a 2 to perhaps 4 inch thump in the central counties below I-80..or in fact any additional snow at all, which would be a pretty sizable near term bust. I'll give it a couple hours but I don't like how things set up when the established precip came in, plus the new meso models haven't had it either. Williamsport still looks ok at the moment, I'd be curious to hear any obs from there. 

Precip has returned in the last hour and is arriving as straight freezing rain. Temp is 31ºF so untreated stuff is already glazed. 

The precip is also fairly light at the moment, so we'll see if the heavier stuff starts working on the column and frozen p-types mix back in. I would imagine with the long lull in precip today that the temps aloft were able to creep up some.

Additionally, it appears that CTP is angling toward the several hour period of frozen in the central counties that some of the meso models were hinting at earlier today and discussed in here, and the newer advisory products reflect as such. I'd be plenty happy if I ended up with 2-4 inches out of this whole event. Most of the Sus Valley I think will see frozen as well for at least the first few hours once the heavier precip gets back into the region. 

Quote

Main change in thinking this afternoon is for a brief thump of
heavy snow to accompany the second round of this winter storm
across the West Central and Central Mountains late tonight,
with most model guidance in agreement on late evening through
wee morning hours (04z to 08z) being the timing of heaviest and
steadiest snowfall and accumulation. Given impressive BUFKIT
omega/dendritic SGZ cross- hair signature during this timeframe
and nearly 10k ft deep isothermal layer down to the sfc just
below freezing, think a quick 2 to locally 4" of snow is likely
in the WC and C mountains late this evening and early Tuesday
morning. AFter the max omega passes to the east, precip will
transition to lighter mixed snow/sleet/freezing rain or perhaps
just plain freezing drizzle as rates drop off come daybreak.

Thinking remains similar to previous across the south with mixed
precipitation redeveloping across the south mid to late
afternoon and changing to sleet/freezing rain with significant
icing likely over the Laurel Highlands. Change to plain rain is
likely over the Lower Susq. by late evening. Perhaps the greatest
concern may be the potential of isolated power outages over the
Laurel Highlands, where the Freezing Rain Accumulation Model
projects ice accretions of around a quarter inch. Elsewhere,
expect any ice accretion to be minimal. Transition zone doesn`t
make it much farther north than 5-10 miles north of I-80. Mostly
snow and lighter amounts expected north of there with generally
1 to 3 inches expected over the N and NW.

Residing right around 31ºF and the inch of snow pretty much stuck around today. Just got the driveway salted down for whatever mess is coming tonight. 

Browsing the weather statement and came across this. How is this not an ice storm/winter storm warning designation for Somerset, Bedford and Fulton?

Quote

PAZ033>035-171200-
/O.CON.KCTP.WW.Y.0031.000000T0000Z-191217T1600Z/
Somerset-Bedford-Fulton-
Including the cities of Somerset, Bedford, and McConnellsburg
138 PM EST Mon Dec 16 2019

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM EST
TUESDAY...

* WHAT...Mixed precipitation. Additional snow accumulations of
up to one inch and ice accumulations of around four tenths of
an inch.

* WHERE...Somerset, Fulton and Bedford Counties.

* WHEN...Light snow will fall over the area early this morning.
Precipitation will likely taper off during late morning and
the afternoon, then expect sleet or freezing rain to
overspread the area this evening.

* IMPACTS...Untreated roads could be slippery. Isolated power
outages are possible over the high terrain tonight.

 

Up to 0.4" of ice is a significant ice event, and their ice map illustrates a pretty widespread area of 0.25"+ in those three counties. 

5 minutes ago, pasnownut said:

unfortunaely dp's are up so not much help there.  Yeah, we need good rates to score frozen down here.  Heh...just looked at the nooner NAM's and tippy top of Lanco flirts w/ frozen for round 2 through the whole next round.  If you look at snow panels (and understand the flaws within) - one can see the wet/white lines - and thats what i use them for in situ's like this.  

 

Yea obviously the TT snowmaps are quite flawed with mix scenarios, but the 12z NAM does continue to show the first few hours of the heavy precip temporarily cooling the column just a bit at the 850 and 925mb levels, and for places like State College and Harrisburg north and west that may be just enough for several hours of frozen before WAA aloft eventually does win out overnight. 

19 minutes ago, pasnownut said:

boy i wish i was north of 80 tonight.  Looks like a nice little event for them.  

I was just looking at that full length 12z HRRR too. Looks like I'll be riding the mix line for awhile as per usual. I'm hoping to at least maintain sleet for awhile over freezing rain as well as seeing maybe a couple more hours of snow on the front end of the main precip. That main batch of precip looks like it will be moderate to heavy, so that may hold down the column enough where it's marginal to perhaps score some more snowfall in the counties between the turnpike and I-80. 6z NAM kind of hinted at that too.  

Right at the 1 inch mark here with the first round, at least I got that out of the way finally (first 1"+ snowfall).