Jump to content
  • Member Statistics

    17,794
    Total Members
    7,904
    Most Online
    manaja
    Newest Member
    manaja
    Joined

Pittsburgh/Western PA Winter 2024-2025 Thread


Rd9108
 Share

Recommended Posts

9 hours ago, Rd9108 said:

Gfs is close. I wouldn't give up on the weekend 

gfs_asnow24_neus_19.png

I am always highly skeptical of the totals when they show that sharp linear cutoff along the south edge. I know Joe Bastardi has a saying "you have to be close enough to smell the sleet (or rain?)" but I don't think that's ever been true in our part of the world. Usually the mixed precipitation continues further north cutting down on totals, and there is usually an area where it's snowing but the ratios are pathetic in this type of a setup. It's a subtype of snow that's extremely moisture laden and not very puffy or air-filled and ineffective at accumulating where ratios could be as low as 6:1. Those super sharp cutoffs are usually reserved for the northern edge of the precipitation, like the January 2016 snowstorm. Or, of course, to a smaller extent, with occasional lake effect snow bands which tend to favor some of the northern and northwestern communities. So I'm not super impressed with this depiction, even if it is showing some heavy snow in the northern parts of the metro. I don't think going from inch or two in southern Allegheny, to 8-12 inches in northern Allegheny is a plausible outcome for this setup. More like an inch or two around Pittsburgh, to perhaps several inches up near I-80.

Link to comment
Share on other sites

Where have we seen this before this season lol. While Im not expecting much, I wouldn't complain if we got a few hours of light snow either.

761903232_KPBZ_0(1).gif.561104eb163d8d29c55efc515c8e6c64.gif

Honestly with the rain coming tomorrow Im kinda glad this is a whiff. In some weird way I get anxiety waiting for the snow to get melted.

Anyways... Definitely an element of bad luck so far.

Screenshot_20250211-151818.thumb.png.5f7b0687e8864e690f5586b8353bb1fb.png

Link to comment
Share on other sites

5 hours ago, TheClimateChanger said:

I am always highly skeptical of the totals when they show that sharp linear cutoff along the south edge. I know Joe Bastardi has a saying "you have to be close enough to smell the sleet (or rain?)" but I don't think that's ever been true in our part of the world. Usually the mixed precipitation continues further north cutting down on totals, and there is usually an area where it's snowing but the ratios are pathetic in this type of a setup. It's a subtype of snow that's extremely moisture laden and not very puffy or air-filled and ineffective at accumulating where ratios could be as low as 6:1. Those super sharp cutoffs are usually reserved for the northern edge of the precipitation, like the January 2016 snowstorm. Or, of course, to a smaller extent, with occasional lake effect snow bands which tend to favor some of the northern and northwestern communities. So I'm not super impressed with this depiction, even if it is showing some heavy snow in the northern parts of the metro. I don't think going from inch or two in southern Allegheny, to 8-12 inches in northern Allegheny is a plausible outcome for this setup. More like an inch or two around Pittsburgh, to perhaps several inches up near I-80.

I think he was just showing that map as a "hey, its far enough out, could end up further SE". I agree though, I wouldn't be sleeping easy that close the the southern edge.

GFS does show a decent front end WAA snow, but did nudge back NW for the 15th. I think if that storm was a day or two later it would be a hit. PV is to far west and blocking is just getting established so it is able to cut, roll forward a day or so and it probably gets steered on a better path. CMC on the other hand little WAA snow, but maybe a decent change over Sunday.

Storm on the 20th may be the opposite, blocking might be to strong by then and it gets shoved SE.

To far out for any absolutes, but based on the setup modeled today those are my two fail scenarios. As we know in 6 hours there will be a new set of variables to dissect.

Link to comment
Share on other sites

The outlier 0Z Canadian was surprisingly close to an all-snow event for Pittsburgh.  Took the surface low on a line from about Charleston to Martinsburg.  GFS cuts straight up to Weirton.  Euro brings it to Allegheny County.  Latter two drive into the finger lakes.

I think it remains quite a long shot to see a moderate snowfall from the weekend event.  Front-end snow is uncertain, but I think the ceiling for that is probably 2" tops, and that's from the most aggressive GFS.

The Euro is about 1" total.  That's largely where my expectations lie.

The reason for the difference in the CMC vs. Euro/GFS camp is the lag in the TPV on the latter two.  The former moves the TPV eastward much quicker, placing it almost due north of the system.  That means the system has more trouble cutting west.

We are going to need that confluence to speed up, because the southeast ridge is pumping the heights ahead of the system and setting the boundary basically right over us or even to our north.

If we don't get that timing right, it's a full-on rain storm.  Maybe we can find a way to get lucky, but there's not much support for it in the modeling as of now.

Link to comment
Share on other sites

3 hours ago, jwilson said:

The outlier 0Z Canadian was surprisingly close to an all-snow event for Pittsburgh.  Took the surface low on a line from about Charleston to Martinsburg.  GFS cuts straight up to Weirton.  Euro brings it to Allegheny County.  Latter two drive into the finger lakes.

I think it remains quite a long shot to see a moderate snowfall from the weekend event.  Front-end snow is uncertain, but I think the ceiling for that is probably 2" tops, and that's from the most aggressive GFS.

The Euro is about 1" total.  That's largely where my expectations lie.

The reason for the difference in the CMC vs. Euro/GFS camp is the lag in the TPV on the latter two.  The former moves the TPV eastward much quicker, placing it almost due north of the system.  That means the system has more trouble cutting west.

We are going to need that confluence to speed up, because the southeast ridge is pumping the heights ahead of the system and setting the boundary basically right over us or even to our north.

If we don't get that timing right, it's a full-on rain storm.  Maybe we can find a way to get lucky, but there's not much support for it in the modeling as of now.

I am hoping this is overdone off to our northwest. Is it really plausible that Detroit could pick up 14 inches of snow in the next 5 days? I don't buy it. This first storm looks like a 2 to 4-inch deal up there, and the weekend event looks like it will bring P-type issues again. I don't see why the Kuchera would be so much more than 10:1. This looks like a 10:1 type setup for most areas given the marginal atmospheric profile.

snku_acc-imp.us_ma.png

Link to comment
Share on other sites

Ehh I'm less optimistic about seeing any notable snow anytime soon. The weekend system is a mess and then the next big storm next week will most likely be a near miss with the i95 cashing in.  Alot can change but the seasonal trend is for everything to be south and east of us. 

Link to comment
Share on other sites

Maybe some heavy snow / squalls this afternoon and evening. Not much else going on unless you like to track flood watches Saturday into Sunday.

In the wake of the cold front, expected an uptick in snow
shower/snow band activity between 4pm to 7pm with a passing
shortwave. Hi-Res models depict reflectivity returns of 20DBZ to
30DBZ with snow bands which could create hazardous travel and
visibility concerns. The snow squall parameter is also
maximized between 20Z Thurs to 00Z Friday over western PA due to
steep lapse rates and instability values between 40J/kg to
75J/kg. Short-fused Special Weather Statements (SPS) or Snow
Squall Warnings may be needed this evening. Probability of 1"/hr
snowfall rates are low (less than 10%) but 0.3"/hr to 0.5"/hr
could be embedded within bands.
Link to comment
Share on other sites

Euro has an interesting setup for the possible storm next week, but a couple key differences with the GFS which is further SE / faster. Euro digs the energy coming in off the PAC into a closed low in the SW partially at least due to the ridge out west not getting knocked down allowing the storm to slow down and consolidate the energy allowing for an almost double barrel type low look getting good snow into our area. 

Euro.thumb.jpg.8cb56be609336377e8939d0c6bc1b156.jpg

GFS on the other hand has the ridge getting knocked down with that piece in Canada allowing the energy to move east and kick the storm out before it can get it's act together. 

GFS.thumb.jpg.98da102b106992fcab6a238d3e755f84.jpg

CMC seems a bit slower bringing that PAC energy on shore but also starts to dig it a bit and is much more Euro like. 

cmc.thumb.jpg.bf9528d8879ddd106c43727b3335ed0e.jpg

That will be what I keep an eye on as we get closer to this potential. It's been hard to slow the PAC down lately, so my gut says the GFS may be closer to right here, but it's so far out right now some of those variables may not even be there as we close in or something else could manifest to counteract. 

Link to comment
Share on other sites

2 minutes ago, TheClimateChanger said:

That would be brutal. Let's hope CPC is right about this period. It looks like their outlook from yesterday assumed any major storm would scoot off the Mid-Atlantic coast.

610prcp.new.gif

 

FWIW, the 12z run of the GFS has a look very consistent with this outlook.

Link to comment
Share on other sites

The flow is just too progressive every time we see a possible big storm. We need to see this phase sooner but right now if I'm the coast I would like where I sit. DC will probably get it's 3rd 6+ storm in the past 2 months.

Link to comment
Share on other sites

6 minutes ago, Rd9108 said:

The flow is just too progressive every time we see a possible big storm. We need to see this phase sooner but right now if I'm the coast I would like where I sit. DC will probably get it's 3rd 6+ storm in the past 2 months.

Honestly our best bet was the storm tomorrow. Once the PV started getting modeled further west which was needed to supress the flow a bit and keep it from going to far NW we were cooked.

Next week always looked like a coastal. Baring some insane perfect timed phase with a piece of the PV the best we can probably hope for is to grab a 4-6 inch type deal off the NW side and even that might be a stretch. 

Link to comment
Share on other sites

Just now, RitualOfTheTrout said:

Honestly our best bet was the storm tomorrow. Once the PV started getting modeled further west which was needed to supress the flow a bit and keep it from going to far NW we were cooked.

Next week always looked like a coastal. Baring some insane perfect timed phase with a piece of the PV the best we can probably hope for is to grab a 4-6 inch type deal off the NW side and even that might be a stretch. 

Euro shows how we can possibly score atleast a warning event. 

Link to comment
Share on other sites

16 minutes ago, RitualOfTheTrout said:

But even it being the most amped is like 2-4 inches (based on .3qpf) or am I missing something? Its still pretty far east with the low.

I had it wrong. It's gonna be a coastal storm. Looking at H5 there's just no way it can get far enough west. Still time but it's looking unlikely. 

Link to comment
Share on other sites

31 minutes ago, Rd9108 said:

I had it wrong. It's gonna be a coastal storm. Looking at H5 there's just no way it can get far enough west. Still time but it's looking unlikely. 

Theres to many maps and models to keep track of so no worries. I was hoping I was wrong. :lol:

I think its possible this *could* come together a little faster and further west which would bring more moisture our way but if I had to bet Id say it goes the other way. 

Ill be curious to see if any of the eps individuals show that scenario, or if the op is about the best case.

Link to comment
Share on other sites

15 minutes ago, RitualOfTheTrout said:

Theres to many maps and models to keep track of so no worries. I was hoping I was wrong. :lol:

I think its possible this *could* come together a little faster and further west which would bring more moisture our way but if I had to bet Id say it goes the other way. 

Ill be curious to see if any of the eps individuals show that scenario, or if the op is about the best case.

 

20250214_151204.jpg

20250214_151159.jpg

Link to comment
Share on other sites

I believe there's a very high correlation between a deep -AO spike relax and a significant nor'easter.  Something like 90%?  I can't remember off the top of my head, but we just peaked at about -5 on the Arctic Oscillation and will immediately shoot back in the other direction.

That sort of quick-change is volatile.  It lends credence to the idea of a major storm occurring soon, but the details are TBD.  The one big problem is this not being a Nino, we don't have the typical Miller A southern juice.

We can "fake" that in a way with a big phased element, but I think the overall setup is more tenuous than if this were a typical warm-ENSO pattern with overrunning.

January 1996 was one of those extreme outliers, and we haven't seen that again in the 30 years since, so you know how rare it is.

If you get that Gulf of Alaska low to spike that west coast ridge more, or sag the TPV lobe quicker, oriented more north-south, you could trigger an earlier phase that pulls in a more western component to the storm or start developing a wider precip shield.  I think that's how Pittsburgh wins from this, but it is more difficult in this overarching pattern, and even 1996 - as the most extreme case - is barely a Top-10 snow for PIT.  Granted, there's no history of anything until it happens.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...