MAG5035

To answer your question from yesterday, here was a portion of my post from a couple days prior back on Friday.. which actually also refers to a post the day before haha. My thoughts are usually around but they typically get buried when it gets active and the snowmaps start flying. So with 3 days advanced since that post there’s no changes to that opinion although as I’ve mentioned the last couple posts for the late week event that I was really high on the potential. It’s crazy how sideways this went in the last 24-36hrs on the progs.. and the last couple days overall when the Euro had the main snow swath to the south of us. Storm gets too wound up too early. It’s going to hit the block and try to go to the coast but that strong primary is going to get west of us instead of sliding under us by the looks of it. The result is instead of honing in a mostly snow event for C-PA it’s going to be trying to figure out the degree of front end and mixing (sigh). I think if we stay as is with what most guidance has as the track today that we probably eventually correct to having some kind of a reasonable front end with resistance at the low levels, especially east of the Alleghenies. Global models have been presenting various degrees of mixing amongst various different scenarios of WAA aloft. That won’t start being resolved until we get into range of the short term/high res guidance. At any rate here’s where we’re at this week during these two events EPO WPO MJO So first off, MJO is squarely in phase 7 during this timeframe, some of the other guidance touches all the way back into 6 the next couple days with the loop. Pretty much everything isn’t getting into 8 after the first week into March (generally 7th to 8th or so). Phase 7 MJO isn’t ideal for storm track as it still favors southeast ridging. Like I mentioned, we probably can get away with a weaker storm sneaking under us but not a wound up 970s low coming up into Missouri. The first two charts are the EPO and WPO, the gigantic reversal to negative doesn’t completely occur until pretty much the timeframe that the MJO gets to 8. This big shift occurs (and the MJO to 8) right after the late week storm timeframe. These are all the keys to the pattern change we’ve been looking for. We haven’t made it into 8-1 all winter in the MJO and the brief time the WPO was negative was the arctic discharge in December. -EPO has also coincided with our brief winter opportunities/attempts. So the fact that all those teleconnections are headed that way while the stratwarm induced high latitude blocking (-NAO) is already getting established probably bodes well for a cold/unsettled pattern setting up for us. The EPO/WPO flip allows for direct arctic sourced cold into the US which will press across the CONUS even with some western troughing (-PNA). In the pattern related post I had before the above one I quoted, I was lamenting the fact that the MJO backtracking was going to delay this occurring. If it would’ve driven right into 8/1/2 I think we would’ve been rocking right now. Instead we’re probably talking mid month and onward. You can see the response of these aforementioned teleconnection flips in the longer range of the deterministic guidance/ensembles now.. not just the weeklies and extended GFS. There’s a cold period coming. It’s getting close though in the meantime this week, this current system tonight is going to finallly get NYC solidly on the board with a decent event. The interior upstate NY/New England over to the top third to half of the 95 corridor is starting to catch up on snow departures.

I would’ve assumed it’d be too windy to fly one in lol.

Already issuing the it’s too warm for snow watches this week when it probably makes a run at 60ºF Wed/Thur ahead of this system lol. I hate to be the counter to all the good model runs overnight as I’m pretty high on this storm threat for us but can’t forget the GFS/GEFS which is still running it’s track (mean track on GEFS) too high and it’s kind of went the wrong way for us a bit in the 0 and 6z runs for that. I’m sure there’s still front end in that scenario but I’m go big or go home at this point. Like I said recently, if I saw another snow to mix/junk system in the next 10 years it’d be too soon. This one’s going to have a big snowfall swath for someone, so hopefully it’s us.

For the 3/3-4 event, it’s definitely starting to catch my attention with the Euro op starting to pick up on it the last few runs. GFS has been the most wound up of the bunch in terms of low strength, and today vs 12z the 18z has edged southeast a bit. Ensemble guidance has been painting pretty good support for a swath across C-PA that has been building. Trends, at MDT: Euro EPS: GEFS: Snow plumes at MDT: 12z Euro EPS 18z GEFS Several big hits in both ensembles and you can also see the difference between the two camps for Monday night with the Euro suite adding snow from that as well. The really big hits do drive up the mean but both ensembles are presenting most members showing accumulating snow and 18z GEFS has a little clustering of members in that 5-10” range. The thing with the GFS/GEFS suite is that it’s collectively more amped and rides that snow/mix line through PA. Early in the game for anything certain but I do like the signal for it.

This Monday/Monday night thing is still fairly intriguing. The progged secondary low popping off the Delmarva acts to anchor solidly sub 0ºC 925/850mb temps east of the Alleghenies while the associated slug of precip crosses PA on guidance like the Euro/3k NAM while guidance like GFS/RGEM shows the same scenario but doesn’t quite pull in/anchor those kind of temps outside of about the NE quarter of of PA. It kind of presents a similar scenario to what we saw Wednesday with the arrival of heavier precip delivering flakes to places it wasn’t even in the forecast. Secondary low is key in this circumstance. Front end mixing is probable in spots as well but the main potential occurs when the secondary gets going. This possibility is being brought by the developing blocky regime up top and a 50/50 type low. 18z Euro by the hour: HR 57 HR 58 HR 59 See how the column aloft responds by cooling as the secondary low develops. These are also hourly plots. That darker blue is heavy 1-2”/hr type snowfall rates. So what’s on the table is after the front end mixing/frozen that probably favors interior central and NE PA (where this might be an all snow event) is a 2-4 hr period of heavier precip that flips to snow as the coastal gets going. And then also sort of similarly to last Wednesday, once this coastal moves away… we lose the column and eventually surface temps moderate going into later Tuesday and mid-week. But that’s after most or all of the precip is done. The warmth won’t be nearly as prolific as last week obviously.

Regarding the 3/3 event, the Euro op might be doing it’s best GFS impression being the most progressive at the moment but the Euro ensemble mean does indicate there’s some support for the more robust GFS/Canadian type solution. The individual low tracks that make up that mean are definitely not anything resembling clustered but there is enough among the members to yield a half decent precip mean across PA considering range. I do think this particular event presents the best legit threat of a widespread wintry event in awhile for us but I like to reel this thing in a good bit further without it ending up heading to the lakes in the process before I get super confident about it. The much closer Mon-Tues event also bears a bit of watching as well. That one will depend mainly on development of the secondary low. Euro was the most aggressive developing a noteable secondary in VA to the Delmarva. The result was keeping mixed/frozen in NC/NE PA with the threat of some icing further south into central PA. I see that as more of an interior C-PA threat either way in the best case scenario given the alignment of the primary already in the lower lakes and the secondary developing a bit late. NE PA probably in the best position in terms of PA locations. The other aspect to that system would be preceding cold on the front end but there’s not much high support. Though low 980s primary to the lakes attacking a 1020ish high in Ontario is still a half decent gradient. Overall, preceding cold isn’t much to write home about but it may still bear some watching for the front end for some ice in spots. If we do end up hitting on that 3/3 event I’d actually consider it a bonus because even at that point we’re not set up in terms of the overall pattern other than the already established -NAO. The EPO/WPO nosedive starts occurring right after this event timeframe and most guidance doesn’t get the MJO back into 8 until after the first week of March. The result in the east is continued changeable weather in terms of temp anomalies and possibly even dealing with another cutter after the potential 3/3 storm. When it does get back there, it appears it may be of a much stronger magnitude. I touched upon those things in my post yesterday and how I think the MJO loop back served to delay this big pattern change that I feel has to come at some point given eventual lining up of all these supporting teleconnections.

I still can’t over higher elevations of Los Angeles and Ventura Counties getting 2-5 FEET with isolated 7-8’ possible this weekend. What a winter in the SW US and Rockies. I think it was LA NWS’s first issued blizzard warning since 1989.

Last 70ºF day in Harrisburg until sometime in April, buy or sell? Lol

67ºF here currently. It went from 35ºF to 58ºF in about an hour this morning (8-9am) when the winds finally mixed down.

I typically don’t even bother with +snow depth maps as I don’t think they’re really meant to be applied to actual event snowfalls. It seems like those guys use them the most and it’s kind of the same mentality as saying “well it was warm the day before so the snow isn’t going to lay on anything”. The GFS has over an inch of QPF in 6 hrs in that DC-Baltimore corridor that’s mostly conditional snow. Obviously the D8-10 disclaimers aside, If that actually happened as modeled (which looked to be 2”+ hr rates for a few hours at one point), there’s absolutely no way you’d only have a plus depth change of 1-4” at the end of the event as it has for that area. It is a lot to consider with all the different snow maps. I warn in here at least once or twice a season about using TT snowmaps in particular since they include sleet/ice with the 10:1 snow totaling. But each method has their flaws/limitations and it’s important to know what kind of setup you’re looking at when trying to determine the best snow map to use for a given area for an event. Do we have marginal temps aloft in the column? Abnormally cold temps? Climo (which is >10:1 in Jan/Feb in C-PA), etc, etc. For example, given the marginal nature of literally every single snowfall that has come our way this winter in our general area…I’ve been mostly paying most attention to whichever map was less out of Kuchera vs straight 10:1. Typically, the Kuchera calculates higher than 10:1 around here. But since temps (surface and aloft) have been so marginal and warmer than average climo in the snow events that have materialized in C-PA…it’s been putting out less than 10:1 in most circumstances in our region this winter. For that D8-10 event, The 8-12”+ the straight 10:1 puts out in DC-Baltimore corridor is more of a 6-9” on the Kuchera (implying <10:1). I think that’s more than reasonable considering what the model is outputting in terms of conditional snow and temps. The 10:1 is reasonable too, really. Neither of those methods involve actual dynamics related to snow crystal growth. You can be 32ºF at the surface but if the lift is in the right spot in the snow growth zone aloft inside a death band you can still put down much greater than 10:1 ratios. Using the right snow map is definitely not a perfected science haha.

It sure did, and it’s still there. Getting some sleet and freezing rain now and temps at 30°F.

I’m not a fan of the MJO backtrack loop back into 7, which serves to delay what I think is has to come at some point. We are seeing the fruits of the stratwarm event propagating into the troposphere with the developing blocking that eventually retrogrades into a nice -NAO block and overall blocking over the top. PNA remains solidly negative on all guidance, even on the farther ranges of the GFS extended and Euro weeklies. We’ll have to contend with some degree of western troughing and continued relentless - temp anomalies biased toward the western half of the country. I think the real change for us comes after the EPO and WPO reverse to negative… which guidance has been showing happening during the first week of March. Extended guidance then keeps those teleconnections there. If/when that sets up, the combo of that and the blocking over the top via the -NAO should put us into a decidedly colder and more favorable regime for snow chances despite the -PNA. I felt a progressive MJO pulse that continued into 8-1-2 without looping would have driven that kind of change much sooner. But I think we’re going to contend with it sooner or later. The hope is it’s soon enough to salvage some decent snow opportunities without it being too offensive to the spring crowd. In the meantime, we’re going to continue to be vulnerable to cutters and in and out cold shots as there is ample cold available on our side of the hemisphere now. Big beneficiaries of the developing -NAO blocking the next 10-15 days without the implied Pac help (EPO/WPO) would appear to be upstate NY and a good portion of interior New England. Deterministic ensemble guidance is indicating that some of those folks are going to go a long way towards recouping a lot of their big time snow deficits.

1.1” in under half an hour. Went to measure since there’s big sleet pellets mixing in now. Best rates I’ve seen all winter.

I’ll say lol, it’s pouring snow right now. Might as well get what will prob be the only snow pic of the month in. First measurable since 1/31. Splotchy roads caved

32/24ºF and moderate snow.

Snow showing on the 511 cams in the US 219 and 22 corridors in the Laurel’s (Cambria co). A likely indicator the I-99 corridor (Altoona/State College) is going to have a period of snow that might accumulate a bit when the main slug of precip arrives shortly.

Precip just started. Pingers and 31/23ºF

#Snowtown #BaseState #NewNormal lol LOX’s discussion is pretty fun. Also mentioned in their full discussion in addition to 2-5feet of snow above 4k feet is the possibility that downtown LA goes 8 consecutive days without cracking 60ºF if the temp forecasts are correct.

30/23ºF here with precip pretty close to arriving. I’m expecting more frozen (probably sleet) over ZR during the mixed phase of this event this morning. Short range guidance like the 3k NAM show a lot of freezing rain despite wet bulbing 925 and even 850mb temps below zero pretty far down into the central mountains.. so I don’t buy the widespread ice accrual outside of the ridge tops and the eastern Allegheny Front. I dunno if it’ll happen here, but I wouldn’t be surprised if a place like UNV sees a period of snowfall up front. Like I said yesterday, could be pingers mixed in with rain for a time outside of the advisory area (Sus Valley) as 925mb temps cool below zero with precip arrival but surface temps probably stay above freezing. As it looks currently, probably the Harrisburg area is the non-advised area in the LSV that has the best chance of that scenario.

High gust on my station so far today has been 33mph, so nothing too crazy. Dewpoints have been nosediving this afternoon. 47/11ºF.

It’s def been a weird couple days. This is occurring with all of PA having sub 540dm thickness. It’s plenty cold aloft but not at the surface/low levels being disconnected from a low level arctic air source currently. Add in the increasing solar input/daytime heating with today’s instability too to make the radar look a bit summery. With regards to the overall column up to 500mb, It was same thing yesterday without the convection. Sus Valley cracked 60 being aided by dry air/downsloping but still technically having a “snow column” in terms of 1000-500mb thickness. Literally the first winter headlines I’ve had in nearly a month haha. Looking at the HRRR, <0ºC 850mb gets routed pretty quickly after precip arrival but the 925mb (3000ft) level seems to wet bulb down a bit and it is fairly solidly below freezing in most of the Sus Valley the first couple hours after the precip onset. Could indicate a period of pingers or rain mixed with pingers even in some parts of the non advised areas of the Sus Valley. Any ZR issues I feel will mainly be confined to parts of the central and north central where there will be somewhat colder surface temps hanging in. Surface temps in the Sus Valley are generally mid-upper 30s when precip gets there. A snow supporting column will hang on for a bit after precip onset the further NE one goes in PA, especially above I-80.

You definitely outdid yourself taking winter with you this year haha. This is a 10 day average for D5-15 coming up.

Hurricane Hazel in 1954 for sure, still the only Cat 4 to ever impact North Carolina. It was being pulled up by an approaching frontal boundary and was moving rapidly enough that it still had hurricane force wind gusts when it crossed into southern PA. DCA and PHL had gusts to near 100mph, BAL 84mph, Harrisburg 69mph. The mid 1950s were quite a time for major east coast hurricanes.

Our latest two spring fling February frolics into the 70’s in 2017 and 2018 both eventually yielded to key major winter storms in C-PA and overall favorable periods, esp in 2018. The March 12-15, 2017 storm was a NESIS 3 and 2018 had 4 NESIS ranked events in March consisting of two 2’s and two 1’s of which one was the March 22-23rd snowstorm.

Figured this was appropriate to some of the general discussion, posted courtesy of NWS PIT’s Facebook a little bit ago. It is what it is, the overall winter pattern to date is evident in the placement of these departures. Lack of any cold westerly or northwesterly cyclonic flow is especially evident in the Alleghenies stretching down into WV, the LES belts in NW PA and non Buffalo extreme SW NY, and Rochester/Syracuse off of Ontario. The somewhat less crappy - departure area in interior SC PA was aided by scoring the 3-6” event that hit in Mid-November when we were in a colder than average regime. I had the biggest event of the season from that Mid-Nov event here (5.5”), and that’s pretty much what has this one ahead of what 19/20 delivered in the snow department in this area. I’m not looking for any sympathy since I’ve been one of the lucky ones in the subforum but as someone who likes to hit the slopes and one that favors snowpack retention, I’ve generally been on the same footing as everyone else (no snow on the ground) aside from a few days in November, the 7-10 days centered on X-Mas and those few days in late January. It seems like forever ago that we managed the coldest Christmas Eve on record here. Also, I could go a decade without seeing another snow-mix/rain event and it wouldn’t be long enough. This winter has definitely been warmer than 19/20.. specifically after the turn of the new year. 19/20 had some different driving factors, mainly a record strong PV and associated ++NAO/AO that wouldn’t quit. This hasn’t been quite like that in that realm with the December blocking that didn’t deliver and some other instances of PV stretching that led to some of our other brief attempts at winter weather. This winter has been mainly Pac and MJO driven in my opinion. The major SSW event that is ongoing is likely to be a big factor in eventually ensuring a different result this March as compared to that March. Big question will be can we finally capitalize and get some decent snow events.