MAG5035

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.

The significant cold anomalies in the SW US have been remarkably persistent most of the winter (much like the SE ridge on this side), specifically the last 30 days but on a month by month basis November averaged well below average as well. The only fairly normal month temp wise in your neck of the woods was December. Unfortunately the really negative PNA that has been firmly established as of late looks to continue unabated and that’s going to weigh heavily towards discharge of Canadian cold centering towards the western half of the CONUS regardless of whether we push some cold into C-PA eventually. Revisiting my post from last Friday: So nearly a week later now, MJO as of the 1x per day update this morning incorporating 0z data is on the border of Phase 6/7. A tad slower but it still moved and is moving rapidly through these warm phases. All the guidance does get it into 8 now in the next few days. Key thing they are showing now, is a curl back instead of further advancement into 1-2. Here’s GFS as an example: Now this is better than yesterday’s version of this forecast, as the GFS looped it right back into the P5/6 region by the beginning of March. That scenario would figure to be quite a blow to setting up any kind of wintry run during the first half of the month where you can still put together a cold pattern that can keep snow on the ground in our region. I’m still not really enthusiastic about curving back into 7 either, as the pattern for that phase still looks an awful lot like what the models have generally been suggesting… which in shorthand is available cold weighed to the west but trying to press the SE ridge… setting a storm boundary that we may or probably won’t be on the right side of. As I said in the quoted post from last week, I think we need to carry that pulse of tropical forcing at least modestly into the colder phases 1-2 as I believe that is needed to force a big shuffle of the status quo. In the meantime, here’s what we’re faced with. This is no bueno. This index has been a primary driver in this SE ridge and cold western US regime and will continue to give us trouble. I feel like the PNA gets overlooked for the EPO sometimes when talking eastern cold. That kind of magnitude -PNA is a very dominant signal to overcome with a +NAO/AO. I don’t even think the +NAO/AO would be a problem because there’s finally a lot of really cold air progged to build and be available in Canada that can press. The period the models have been occasionally showing some mixed/frozen events for us coincide with a forecast dip negative in the EPO. The cold will try to press but that SE ridge induced by the super negative PNA western trough is going to make it hard. The other factor is the stratwarm, which is definitely a thing now and occurring currently as a full blown SSW. I’ve pretty much viewed the MJO forcing as our primary factor in getting potential winter weather back sooner, perhaps before the month is out while the stratwarm was more of a long game type thing that, in lieu of the MJO not working out in the interim.. probably makes the back half of March into April cold anyways when we’re pretty much over it. The stratosphere thing is definitely interesting. If you brave the terminology and discussion in Dr. Cohen’s weekly posting, he considers this event possibly a unique example as models continue to weaken/even potentially split the strat PV after the SSW. That type of stuff would suggest eventual blocking in the NAO realm. Guess we’ll see, I’m admittedly not super knowledgeable and still learning when it comes to the stratosphere stuff.

Temp here at home managed to crack 70ºF (70.2) yesterday. Here was some of the climo for yesterday per CTP. Bradford and Williamsport obliterated their daily record. Rainfall slated for today looks to come in two main parts.. a slug of rainfall that arrives around lunch time and lasts most of the afternoon and then another area associated with the frontal passage later overnight Thurs night/Fri morning. The stuff with the frontal passage may include some thunder but instability is likely to be elevated with low levels stable (cooler with the afternoon rain/clouds plus timing of FROPA later at night) in central/eastern PA. Latest HRRR that goes out that far (6z) tried to generate a little bit of CAPE in the Sus Valley right before frontal passage, likely trying to push a warm nose there. But again, I think convective elements are likely limited to potentially a few strikes/rumbles and maybe some gusty winds with the frontal passage. SPC D1

@canderson The GFS extended maintained some SE ridging (although a good bit colder overall in the east) but the latest run of the Euro weeklies that ran a couple nights ago definitely did not beyond week 2. It had the entire lower 48 cold with no SE ridging starting from about the end of week 2 the whole way through the end at D46. Week 3 (7 day anomalies) Week 4 It’ll be interesting to see what the MJO does. Most guidance gets it rapidly to Phase 8 as soon as the middle to latter part of next week. I think what happens after will be important, as maintaining convection in the 8-1-2 realm would probably go a long way to driving the wholesale change in the pattern at the mid latitudes we need to go on an actual wintry run. The MJO was persistently forecast to hit those phases in early to mid January but never actually emerged into any phase til it got to 3 late month. Theres also the stratosphere, as all guidance has been predicting significant warming and at least some stretching/displacement of the stratospheric PV and this starts occurring in the next week or so. The GFS/GEFS appears go as far as to try to split it. Either way, it’s significant enough that it will likely have an impact on the pattern down the road the next few weeks and a recent example of this is 2018. If it played out that way I think we’d be seeing snow opportunities well before Mar 23.

It’s likely to be quite a + departure by the end of next week. The system following the weekend one we had been watching slated to cut next week seems poised to drive an even more prolific warm push out ahead of it, probably centering on Wed/Thurs. Probably a record or near record challenging warm shot for us. 1 day anomalies over the northeast are nuts with ensemble means of the Euro and GEFS showing +20-30ºF over our area and the rest of the northeast. Other aspect is likely a potential severe weather outbreak at least into the Deep South some of the Ohio Valley. 12z Euro manages to drive up non negligible SBCAPE’s of a couple hundred J/kg all the way up into Ontario. Not at all a common thing to be seen at our latitude and higher in mid February. Def has the look of having some thunder with the frontal passage either way.

I mean I’m only describing what happens with calm winds at the surface and clear skies, radiational cooling. KABE is up to 48 now with a WSW wind blowing. There’s two other station’s in that area that are still cooler and others in the general area that have 20 degree differences between them.

CTP added their climo section on with their latest update an hour ago. MDT hit 61 during the day but JST and AOO spiked up to hit 64 right before midnight. Temps are falling now back this way. The 64 at a place like JST is nuts this time of the year, though apparently it also happened in 1925. Looked like MDT spiked up to 61 again after midnight as well, just missing the 2/10 daily record of 62 set back in 1960.