Typhoon Tip Posted January 23, 2017 Share Posted January 23, 2017 In this modern era of atmospheric modeling for the purpose of deterministic 'art' of weather forecasting, I have at times mused to self over the years. Reading AFDs and/or just gathering in the collective impressions of media in general leading interesting events, and there seems a tendency to over-analyze ... overthink (perhaps trying to 'outwit') the guidance to ferret out some kernel of truth that no one else has/had seen. Sometimes that works.... Most times that does not. In this case, I wonder (and I'm only wondering here; don't pin a forecast on me) if the weeds of the virtual (model products) are obscuring the pathway ahead here. When I arrived home after the Patriots sound drubbing of the Steeler's at 10:30 last evening, it was 37 F with a light mist. There were occasional small cat-paws at the time. To any lay person, those gestures would certainly go unnoticed. To us ... ? Mmm. This morning, all the beads of water on my car were solid as clear rock. It was 31 F with a picturesque white stenciling about the landscape. Light flits of snow festooned the biting breeze. I noticed as I cruised through town in route to Rt 2, the flags were taut pointing SW, and the steam from atop corporate complexes ripped immediately in the same direction. Later I check the area obs and indeed, most location in the interior from N CT all the way up and W of I-95 have DPs now in, or approaching the 20s, with temperatures in that 28 to 33 F range. If this were just naked draining of cold ...if perhaps augmented by lowering surface pressure approaching from the S, I would take less issue with the modeled handling of the lowest 200 mb of atmosphere. But, this is different. This is different because of the position and evolution (in the same models!) of the fresh, new, polar high to the N during the total evolution of this coastal storm. It is quintessentially ideal for supplying CAD with what essentially amounts to an endless supply of actually mass - this is colloquially referred to as being "back built" I just think that anywhere west and N of I-95 is going to get a helluva short duration ice storm if this thing attempts to ptype over to liquid. Ain't happening. Several of us were commiserating the other day that it is possible to have a big high impart lousy air. Okay. However, that example has set sail on this event. I'm seeing dew point temperatures in the middle teens in Maine; what happened the last time we saw dew point temperatures in the middle teens in Maine, with a +PP offering and endless supply of mass delivery into a heavy precipitating column underneath a warm layer? If anything, it almost looks a like a perfect storm of variables point to a significant icing event. We get a burst of snow... temps in the 30 F range with a blue air ZR taking over. At the end of the day, I don't think I have ever seen a set up this way go above freezing -but there is always an opportunity to learn. In a lot of ways, this reminds me of the ptype consternation before December 23, 1997. The same, Dec 5-7, 2002 ... These were storms where a cold high was situated near 55N/ 75 W, was actively nosing into the region in the analysis, and lows of non-analogical structure approached that set up from the SW or S. What invariably takes place is that the cold overwhelms due to the enormous corrective wind vector/forcing, the event complexion busted colder. I'm seeing this almost not differently in concept to that which transpired in so many lessons of our collective pasts. Link to comment Share on other sites More sharing options...
powderfreak Posted January 23, 2017 Share Posted January 23, 2017 2 hours ago, ThatGirlWhoSkis said: If anyone has any information on lower Central VT ski areas (killington, Okemo, etc) potential snowfall amounts to share please, that would be appreciated. I'm honestly still not sure... going to be at this most of today. Trying to forecast this event even up north is a pain in the arse. The NAM has a fugly warm layer of even +4C at MPV aloft and actually wants to give a decent ice storm after a couple inches of sleet. The warm layer actually gets into the 875mb layer which is generally the level used for the 4,000ft peaks. I haven't gotten into the 12z NAM yet but the 6z might even change to plain rain at the summits with an ice storm below 3,500ft. The GFS cools the column through omega and goes to a wet snow bomb for like 8 hours. So basically anything from 8" of snow to losing power in an ice storm seems to be on the table. I'm still leaning 3-6" of sleet/snow mixture though for now for most of the Greens with QPF in the 0.7-1.2" range. Its sort of a cop out as its the middle ground solution right now I think. Link to comment Share on other sites More sharing options...
CoastalWx Posted January 23, 2017 Share Posted January 23, 2017 There is a significant difference in the 850 low placement from the GFS and NAM. NAM looks like it wants to tuck into NJ area. Link to comment Share on other sites More sharing options...
powderfreak Posted January 23, 2017 Share Posted January 23, 2017 Just now, CoastalWx said: There is a significant difference in the 850 low placement from the GFS and NAM. NAM looks like it wants to tuck into NJ area. The mid level warmth differences between those two models is startling...at least the 6z runs up here. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted January 23, 2017 Share Posted January 23, 2017 I'd kill for a 12/23/97 redux....too bad these dynamics are aged by the time they reach our latitude. That was the obscene 8"/hr snowbomb in Ayer, MA. Link to comment Share on other sites More sharing options...
OceanStWx Posted January 23, 2017 Share Posted January 23, 2017 1 minute ago, powderfreak said: The mid level warmth differences between those two models is startling...at least the 6z runs up here. Euro and GFS are definitely in the cooler camp. Link to comment Share on other sites More sharing options...
powderfreak Posted January 23, 2017 Share Posted January 23, 2017 1 minute ago, powderfreak said: The mid level warmth differences between those two models is startling...at least the 6z runs up here. Like what do you do with this on a 24 hour forecast? 6z for Montpelier/East Slope location. NAM...roasted. Its at the end of the event but it gets as warm as +6C at 825mb. GFS... actually wet bulbs to snow there during main precipitation shield. Link to comment Share on other sites More sharing options...
dryslot Posted January 23, 2017 Share Posted January 23, 2017 I mentioned this would end up a nowcast situation and that looks to not have changed, Time to puul up the SPC meso site and some radars 4 minutes ago, OceanStWx said: Euro and GFS are definitely in the cooler camp. Are you on short term? Link to comment Share on other sites More sharing options...
CoastalWx Posted January 23, 2017 Share Posted January 23, 2017 3 minutes ago, powderfreak said: The mid level warmth differences between those two models is startling...at least the 6z runs up here. GFS is a snowbomb for nrn MA and esp SNH. NAm has the stubborn warm layer, probably because it tries to tuck. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 23, 2017 Author Share Posted January 23, 2017 2 minutes ago, OceanStWx said: Euro and GFS are definitely in the cooler camp. HRRR any use?, and hey at the sudden massive dynamic cooling in wV and PA forecast, those elevated areas could get raked. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 23, 2017 Author Share Posted January 23, 2017 4 minutes ago, dryslot said: I mentioned this would end up a nowcast situation and that looks to not have changed, Time to puul up the SPC meso site and some radars Are you on short term? i posted Mesos on the other thread Link to comment Share on other sites More sharing options...
dryslot Posted January 23, 2017 Share Posted January 23, 2017 3 minutes ago, Ginx snewx said: i posted Mesos on the other page Cool Link to comment Share on other sites More sharing options...
OceanStWx Posted January 23, 2017 Share Posted January 23, 2017 3 minutes ago, dryslot said: I mentioned this would end up a nowcast situation and that looks to not have changed, Time to puul up the SPC meso site and some radars Are you on short term? I am. 1 minute ago, Ginx snewx said: HRRR any use?, and hey at the sudden massive dynamic cooling in wV and PA forecast, those elevated areas could get raked. HRRR doesn't go out far enough, but the HRRRX is a snow bomb into the ORH Hills. But the RAP has nothing. So that's not very helpful. Ha. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 23, 2017 Author Share Posted January 23, 2017 Just now, OceanStWx said: I am. HRRR doesn't go out far enough, but the HRRRX is a snow bomb into the ORH Hills. But the RAP has nothing. So that's not very helpful. Ha. HRRR 18 hrs or hrrx Link to comment Share on other sites More sharing options...
CoastalWx Posted January 23, 2017 Share Posted January 23, 2017 HRRR already is too warm. Link to comment Share on other sites More sharing options...
dryslot Posted January 23, 2017 Share Posted January 23, 2017 4 minutes ago, OceanStWx said: I am. HRRR doesn't go out far enough, but the HRRRX is a snow bomb into the ORH Hills. But the RAP has nothing. So that's not very helpful. Ha. Good luck Chris, You will earn your $$$ on this one Link to comment Share on other sites More sharing options...
dryslot Posted January 23, 2017 Share Posted January 23, 2017 Looking at the last 3 Nam runs, I think the 06z run went a little overboard with tucking the low around the NJ coast and 12z backed off some on it. Link to comment Share on other sites More sharing options...
powderfreak Posted January 23, 2017 Share Posted January 23, 2017 The one thing with the NAM products is that I'm looking at the BTV4 and from the 6z run it thinks it should be -2C right now at 850-875mb. Its currently -6C (21F) at 4,000ft (875mb). So the 6z BTV4 is off by 4C at like 6 hour lead time. Looks like the 32km NAM here was off by about 2C right now. Link to comment Share on other sites More sharing options...
OceanStWx Posted January 23, 2017 Share Posted January 23, 2017 4 minutes ago, Ginx snewx said: HRRR 18 hrs or hrrx I mean if the HRRRX is right, BOX has some work to do on their forecast. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 23, 2017 Author Share Posted January 23, 2017 Just now, powderfreak said: The one thing with the NAM products is that I'm looking at the BTV4 and from the 6z run it thinks it should be -2C right now at 850-875mb. Its currently -6C (21F) at 4,000ft (875mb). So the 6z BTV4 is off by -4C at like 6 hour lead time. yep just look at the Mesoanalysis map and then look at Nam init, way off Link to comment Share on other sites More sharing options...
dryslot Posted January 23, 2017 Share Posted January 23, 2017 3 minutes ago, Ginx snewx said: yep just look at the Mesoanalysis map and then look at Nam init, way off So there is one to toss Link to comment Share on other sites More sharing options...
powderfreak Posted January 23, 2017 Share Posted January 23, 2017 Just rolling through guidance... holy crap was the 00z ECM so much colder than the 6z NAM. Definitely ECM/GFS combo right now is snowy while the NAM products are an ice storm on the mountain. If the 12z ECM holds then the forecast gets a lot easier I think. 00z ECM temps are verifying much better at 875mb right now.... -5C forecast and -6C verified at MMNV1. Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted January 23, 2017 Share Posted January 23, 2017 7 minutes ago, Ginx snewx said: yep just look at the Mesoanalysis map and then look at Nam init, way off Good Its a mid level torch fest for days So long as 12z gfs doesn't move nw with mid level lows im content w now cast And large dendrites falling currently (still) Its accumulating now on roads and vis has been lowest of morning last hr Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 23, 2017 Author Share Posted January 23, 2017 3 minutes ago, powderfreak said: Just rolling through guidance... holy crap was the 00z ECM so much colder than the 6z NAM. Definitely ECM/GFS combo right now is snowy while the NAM products are an ice storm on the mountain. If the 12z ECM holds then the forecast gets a lot easier I think. 00z ECM temps are verifying much better at 875mb right now.... -5C forecast and -6C verified at MMNV1. Save a horse Link to comment Share on other sites More sharing options...
powderfreak Posted January 23, 2017 Share Posted January 23, 2017 Just now, Ginx snewx said: Save a horse Not going to lie, I do enjoy this type of forecasting a bit more from the challenge than just figuring out QPF and applying a ratio to it. These cross sections are so close and yet so different in sensible weather. Link to comment Share on other sites More sharing options...
RUNNAWAYICEBERG Posted January 23, 2017 Share Posted January 23, 2017 Not sure how or if it applies but...out walking the dogs at 630am, it was relatively warm, I was out in a t shirt. Thought this cant be good. When I left at 745, I was much colder. Didnt look at the temp drop officially but it was interesting the sudden funneling of cold air. Got to Prospect at 830 and it was snowing. That's my "point a wet finger at the sky" observation anyway. Hopefully this is a good sign for folks up north. Link to comment Share on other sites More sharing options...
RUNNAWAYICEBERG Posted January 23, 2017 Share Posted January 23, 2017 8 minutes ago, powderfreak said: Not going to lie, I do enjoy this type of forecasting a bit more from the challenge than just figuring out QPF and applying a ratio to it. These cross sections are so close and yet so different in sensible weather. ha, same here. Though Im on the wrong side this time but Ive had enough of the systems where If I drive 15 miles south or east the snow is doubled, and if I go same distance west or north, I see grass. And these are always sand too so if I luck my way to 4", it looks like a coating by the time the shovel is put to use. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted January 23, 2017 Share Posted January 23, 2017 All systems go for 2-3". Link to comment Share on other sites More sharing options...
dryslot Posted January 23, 2017 Share Posted January 23, 2017 5 minutes ago, Baroclinic Zone said: All systems go for 2-3". Rain? Link to comment Share on other sites More sharing options...
powderfreak Posted January 23, 2017 Share Posted January 23, 2017 RGEM looks a tick colder at least up this way in p-type. That is so close to destroying BTV with heavy wet snow as a pivot point. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.