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MAG5035

Meteorologist
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Posts posted by MAG5035

  1. The 0z Euro was a heartbreaker tonight, skirting the southern tier with decent snow while having a major cutoff and a majority of the subforum area mostly dry (Mid-Atl storm). However Euro ensemble mean and control run looked much better for us and got most into some snows. Looked similar to the Canadian maybe a bit further north with extent. GFS and its ensembles  are now on their own currently with cutting as far north as it does making for a mix. Meanwhile it looks like the Euro ensemble is solidifying a nice mean with a majority of members showing decent snows at most of our local stations now. Track is key, because if this does go south and not pull off what the GFS is trying to do, we're probably going to have to contend with a sharp cutoff on the northern extent of the precip somewhere.  

    Harrisburg:

    ecmwf-ensemble-KMDT-indiv_snow_24-1100800.thumb.png.6546fd30e353f75374258cfb5bc866d5.png

    ecmwf-ensemble-avg-ne-snow_48hr-1727200.thumb.png.6ebdeac21de812c5f10095eb93dd9efe.png

    ecmwf-ensemble-avg-ne-snow_24hr_ge_3-1684000.thumb.png.c40b3a5eb7d10b30aed3e2176247ba70.png

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  2. 12 minutes ago, paweather said:

    I'll take it in my zone forecast even though it is 30% LOL.

    Wednesday

    Scattered snow showers, mainly before 8am. The snow could be heavy at times. Partly sunny, with a high near 34. Northwest wind 8 to 17 mph, with gusts as high as 30 mph. Chance of precipitation is 30%. Little or no snow accumulation expected.

      

    CTP mentioned in their morning discussion today they were concerned about some scattered snow showers/squalls making it into the Sus Valley with a potent shortwave passage later tonight into tomorrow morning. 

  3. Boy it's quiet in here for what looked like a half decent 12z suite today. Models seem to be showing more muscle with the blocking and could be two different events as well. Starting to look like more of a tighter situation of getting somewhere in between too much block (suppressed) vs bringing the low up enough to force mixing before the blocking sends it east or even ESE. The most mixy of the bunch which was the GFS today still had a majority of the region having a sizable part of the storm as snow as the block forces the low under and changes the initial ice to snow as deeper cold gets drawn south. Then had a decent snow event regionwide with the following wave. 

     

  4. So far 12z guidance looks better today for the system, GFS is more of a classic coast to coast out the latitude it came in type system.. which would generally keep it just underneath PA. Canadian actually squashed it under us completely with another shortwave trying to approach at 240. It had much stronger blocking above us (too strong in this instance). Gonna be quite changeable given the range yet and models trying to handle the block. I should clarify that I do think this system is going to be a winter event for us, but whether we can get a mostly snow event is the challenge as this has so far shown a pretty icy look. Whatever comes out is going to get deflected by that block, how much it cuts before it does so is the question. 

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  5. Had 0.8" overnight, mainly between 10-2am or so. I'm sure that'll be gone by lunchtime like Sat night's measured 0.9" snowfall was yesterday. 

    Overnight guidance was meh on our potential longer range event. All the ops have the deeper system now which cuts. 0 and 6z GFS and 0z Euro have primary lakes cutters while Canadian tried to cut but forced a secondary (still a mix event). Ensemble guidance seems to look like it does something similar to the Canadian where front part of the storm cuts but secondary low takes over under PA. These are all mix event scenarios right now. This could trend colder to a more frozen event as it gets closer even if guidance still cuts the low, but I'm pessimistic on holding deep enough cold air for long for the reasons I discussed yesterday unless we force a secondary early enough. 

    Longer range pattern just has not looked good on guidance to me. Moving the Pac ridge all the way to the Aleutians or even west of that and dumping a trough into the western US (also gone in the progs is the more sustained -EPO/-WPO) is going to screw up what was looking like a really good period if it comes to fruition..especially so if the -NAO relaxes but it's going to affect it either way when it comes to the storm track and cold air. Of course the longer range is highly changeable, but I am somewhat concerned this change in things may be right. MJO has quietly tracked into a low amplitude phase 4, looking like it may be arcing for a 4-5 run instead of being in the null phase. It's notable because model guidance is completely whiffing on it right now. The MJO site updates once a day with 0z guidance, and today's isn't in yet, but look at yesterday. You can see the big separation between the plotted point and where the ensemble guidance starts it's spaghetti plot. This is like this on NCEP guidance too. Models could be starting to adjust to where the MJO actually is, which would actually support what guidance has the Pac eventually doing. I hate to be pessimistic after being really confident on a very good winter period coming up last part of the month, but just don't like how things have evolved the last few days.   

    ECMF_phase_MANOM_51m_small.gif.11686481be4b3c615a34c84fd2ae21c2.gif

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  6. This system in the longer range slated for early next week seems to be solidly in all guidance now in the general sense. All the op guidance last night tried to cut it to some degree, making messy solutions. Todays 12z GFS was more of the same with the Euro and Canadian now having a colder/weaker solution that does slide south and is all snow. GFS's deeper solution has more amplification and some northern stream interaction while Euro/Canadian run a weaker shortwave wave out with no interaction. One would have to worry more about suppression with the latter given the blocking. Either way big differences in the afternoon suite.

    I've def been as optimistic as the next person with this upcoming pattern but i've soured a bit the last few days on some aspects. I'm not a fan of the evolution that has come about of retro-ing the pac ridge far enough west that it dumps the main trough into the western US (aka solid -PNA). Yea, with the strong NAO block the storm track will generally try to stay under us but I see limited phasing/amplification opportunity and if you do get it lined up/amped enough to get something like the stronger solutions from last night or today's GFS, they will try to cut. That brings me to the next problem, temps. Now if this potential system does try to cut into the block... it's likely going to weaken and/or transfer, and normally i'd favor a mostly frozen outcome even if the primary did get west of us. Problem is we currently don't have an actual solid cold air connection, and if that main trough dumps into the western US right when we finally see negative anomalies with some teeth building in Canada.. we're not going to be much colder than we are now as a lot of that cold will dump into the trough. So my worry with even the scenario of a stronger system with miller B evolution is we don't have strong enough antecedent cold to stave off a messy wintry mix type event over what normally could be a mainly snow event. Obviously a weaker system like the 12z Euro/Canadian wouldn't have the precip issues as we maintain colder temps, but the weaker system would be more apt to get outmuscled by the -NAO and only give us a lighter event or even a southern or suppressed one. 

    Climo's on our side this time of the year with seasonable or marginal temps but we're going to get bit if we don't get some legit arctic air involved in the pattern. That goes double for the Mid-Atlantic region and the southern fringes of our region that can pretty much be an extension of the northern Mid-Atlantic climo. Current case in point... despite passage of a pretty deep trough where at 12z tomorrow morning there's sub 528 heights and sub 522 thicknesses across most of the state in mid-January, we're still going to be above average temp wise. That's something that normally could equate to a day that has highs in the teens to 20s-30ish NW to SE across the state with a run of the mill cold airmass. Harrisburg is forecast to still hit 41 tomorrow.  

    ecmwf-deterministic-conus-z500_anom_1day-1014400.thumb.png.1c4ac8314a84e6ae541a7e5615fee388.pngecmwf-deterministic-conus-t2m_c_anom_1day-1014400.thumb.png.a452fecba819cb29095ea01d0084dc7e.png

     

     

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  7. The two periods I have an eye on are D5-6 and D9-10 range. There's also going to be some weak shortwaves in the flow early this coming week but will likely primarily deliver periods of snow showers/light snow to the Laurel's and western PA. For the D5-6 (Thursday-ish) there's been some solutions that amp the northern branch just enough to generate a wave of precip to move across PA, esp on the Euro. This would probably be a light event if it occurred. Something's likely going to come out of this D10 range, but hard to say what at this point obviously. So far today the GFS and Canadian have something notable, but differ in the pattern somewhat. GFS dropped and phased a shortwave out of Canada making the huge storm it has. Canadian doesn't phase and also dumps the trough in the western US raising heights and making a more messy storm that tries to cut. 

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  8. 21 minutes ago, pawatch said:

    Don't think we have truly recovered from the drought last year.

    Here we are half way through January and Yuck.

    It's been dry so far this month, or essentially the last two weeks. But we were coming off a very active period with the big mid-December winter storm, the significant Christmas rainstorm/flood, and the New Years and Jan 3rd systems that delivered various types of precip (and another decent snow up your way). That's a pretty busy 15 day period. Drought monitor only has a small D0 area in a portion of the Mid Sus Valley, likely dealing more with the short term dry conditions of the last couple weeks and dead vegetation drying out. We had seen solid improvements in the drought conditions in the late fall going into last month and the aforementioned active period pretty much eliminated it completely with no part of PA having actual drought conditions. North-central had been dead center for the worst of the drought conditions this fall and that very deep snowpack from the snowstorm was a big part in helping eliminate it. 

    777244452_ScreenShot2021-01-15at10_08_43PM.thumb.png.7b8aa1e83ad9b46092c4b4f70f138992.png

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  9. I don't see too much in the upcoming shift in the overall pattern that argues we don't start seeing the results of the ongoing strat-warm event and continued -NAO/AO blocking. I've said a few times my eye has been on the back half of Jan, so this is materializing on time IMO. The EPO realm has been about the only sticking point, with persistent low heights in the Gulf of Alaska cutting off the source region for cold. That's set to reverse at the end of the week, with models/ensembles first building a ridge on the west coast eventually evolving to a full blown EPO ridge. Very strong and remarkably persistent ridging anchors over Greenland and that forms the bridge over the top when that -EPO ridge really cranks. So in sort, the table looks set for the arctic to invade the US in the next 1-2 weeks. Longer range seems to retro the EPO ridge further off the west coast, putting the western states in the trough and cold as well (-PNA), which with the strong -NAO/AO to fend off any significant SE ridging could help not completely squash our storm track with some actual arctic cold injected into the pattern. We're going to get the colder pattern, so the big thing will be what kind of storms we can get out of it. I think we'll have our chances. 

    One thing to watch is a frontal wave on the arrival of the start of this colder period this coming weekend. Models are starting to show a coastal low popping (and winding up getting up toward New England) and they all have some precip in at least the eastern half of PA with the wave.  

     

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  10. 16 minutes ago, Itstrainingtime said:

    I've always found it fascinating that Lancaster-based WGAL uses info from Harrisburg and not Lancaster. At least in most of Lanco, 1996 dropped more snow here than 2016 did. The 1983 storm dropped remarkably similar amounts in both locals - I measured 24.8" in the '83 storm. I don't remember 1945. :) 

    I like how they have a category for "type" of snowstorm. Like one of H-burg's top 5 snowstorms was going to come from a clipper or something lol. 

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  11. The overnight 0z guidance looks to be showing that this Tuesday system now in the D5 range for us might have some legs...with Euro and Canadian presenting a snow event over a good portion of PA and 0z/6z GFS not too far off for PA but still showing a fairly competent low trying to lift out of the Gulf states after developing in Texas. Difference with the GFS vs Euro/Canadian is GFS keeps streams separate and the Gulf system as a single southern stream shortwave. Euro/Canadian drop in and interact a northern stream shortwave just enough to make this more of an event. Ensembles showing the system but not very strongly yet when it comes to maybe running the low up the coast to impact our region. Euro EPS was probably best look, but we'll see how things evolve as we're still D5-ish. 

    I do like the look and the fact models are latching onto having something of substance. These Gulf lows can be more moisture laden than advertised, so if we can work it up to our latitude I think we could see a decent snow event. It's definitely starting to look like it could be one at the early stages all the way in the heart of Texas. 

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  12. 14 minutes ago, Blizzard of 93 said:

    @MAG5035

    What do you think of our chances for the coastal potential early next week?

    Like I said this morning, I think this stands a better chance than Friday's event which is now pretty solidly looking like a southern slider. And also as mentioned, models are wildly inconsistent with it. I had mentioned this morning about the 0z Euro basically having no system and you see what the 12z did. The overall pattern is better for the potential of the coastal storm, the big difference being the western ridge has really built in this timeframe along with some lessening of the dominance of the NAO block. That forces the northern branch to finally try to drop down in the east (dependent on how much amplification) and allow a potential phasing opportunity with the multitude of shortwaves running around. The Euro obviously succeeded at some phasing at 12z and I don't even think it was a complete one either. Can actually count up to 4 different shortwaves involved at one point in the early stages of this (135hr frame in this example), although ultimately it looked more like a typical phase once to the timeframe of initiating the coastal storm.

    ecmwf-deterministic-conus-vort500_z500-0344800.thumb.png.68d7a76ee1d310f0cd939dbf8471ba7b.png

    Now I'm not saying "OmG QuAdRuPlE PhAsE" here but it's a good example of the overall chaos and why we're seeing wild swings in model runs with a lot of imbedded shortwaves.  Basically it's the classic "storms and rumors of storms" setup you see a lot with established -NAO and some western ridging to go with an active pattern, which models usually have a lot of trouble with especially in the mid range. GFS seemed to keep the streams more separate but there's still a bunch of shortwaves in the flows with some different timing. Result is not much interaction and no coastal storm. Gonna be awhile til we see anything firm on where we go with this potential, but in the meantime we'll have to watch the next couple days if we get an overall storm signal out of this on a majority of guidance or if this fizzles completely. 

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  13. Friday's system is definitely shaping up to get blocked well under us. I thought a couple days ago this may eventually come back up enough to swipe at the DC region or perhaps even into the southern tier LSV. But now it's looking like interior southern VA is as close as it gets. Name of the game whenever you have a significant NAO/AO blocking regime, we're gonna lose some stuff underneath us. This system's coming at the point when teleconnection forecasts are generally at their most negative for the NAO in the forecast period (about a -3 on the WB forecasts). There's also isn't much western ridging to really amplify the system either at this point. The next system being progged out in that D6-7ish timeframe probably has a better shot but hasn't been really consistent. The overnight Euro for instance pretty much didn't even have it. That may end up being south too but I think it's a better chance for at least the Mid-Atlantic folks to get their first system, we'll see. 

    Still looking at the bigger picture here, I said a couple previous pattern posts ago that I was eyeing the second half of Jan more than the first half and I would consider scoring a snow event in the next couple weeks to near mid month a win. And really it has been even if some didn't get snow out of Sunday's system. Take away the dominance of the blocking regime we have in the NAO/AO realm with the current look in the Pac with that +EPO and very low heights in the Gulf of Alaska and we probably have very little chance in what would be a much warmer regime. The blocking is suppressing the storm track and providing just enough marginal cold air (in what really isn't at all a cold pattern) with the Pacific air flooded CONUS to give us a chance with each system the next 6-10 days. I think the system after next has a better shot since it seems we tone down the NAO/AO a little bit and it's in the timeframe where the Pacific/western US side of the equation is starting to look more favorable. Models/ensembles have all been showing a big shift in the Pac, building ridging in the EPO realm up into AK where we have very low heights now while keeping a -NAO/AO. We need to inject some actual Canadian cold into this pattern and that's how it gets done. This is also a better alignment to involve the northern branch better with any potential phasing opportunities. 

    Here was the overnight Euro ensemble for 12z this morning, D7 (near the timeframe of that second event) and D12. Look how much the Pac improves especially between the D7-D12 ones. The GEFS is doing the same general thing as well. Shaping up to be quite wintry after mid month if that comes to fruition. 

    Current:

    ecmwf-ensemble-avg-nhemi-z500_anom-9848000.thumb.png.e914b4bd05ca35e1060ef1e67f6e3a11.png

    Day 7:

    ecmwf-ensemble-avg-nhemi-z500_anom-0409600.thumb.png.a27f9c2d5a5558b12931045319447cac.png

    Day 12:

    ecmwf-ensemble-avg-nhemi-z500_anom-0841600.thumb.png.37ab94510dbf3d7d96e020c443d83cbb.png

     

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