Phased Vort 1,074 Posted October 16, 2018 As a more trofy pattern starts to develop over the Northeastern CONUS and to some extent pver the Mid-Atlantic as well, the region becomes susceptable to precipitation, be it rain or snow, resultant from the so called Clippers. Some of these small weather makers, at times bring measurable precipitation and at other times can even develop into decent coastal storms for Long Island and New England. It seems that a clipper may indeed try to at least grace the region, especially the northern portions of the area, with precipitation in the form of rain and even some snow, as the clipper enters the region coming from the Great Lakes into westen NY and tracks toward northern New Jersey and then may try to deepen just south of Long Island and then get stronger just off the New Englando coast. As a result, precipitation will fall across the area, and could be enhanced should a coastal forms. That could then, allow some snowfall for some areas of New England. Please the latest ECMWF depiction of the this possible event: Spoiler Please contribute to this discussion with your welcomed thoughts. 1 Share this post Link to post Share on other sites
UTSwiinii 1,883 Posted October 16, 2018 18 minutes ago, Phased Vort said: As a more trofy pattern starts to develop over the Northeastern CONUS and to some extent pver the Mid-Atlantic as well, the region becomes susceptable to precipitation, be it rain or snow, resultant from the so called Clippers. Some of these small weather makers, at times bring measurable precipitation and at other times can even develop into decent coastal storms for Long Island and New England. It seems that a clipper may indeed try to at least grace the region, especially the northern portions of the area, with precipitation in the form of rain and even some snow, as the clipper enters the region coming from the Great Lakes into westen NY and tracks toward northern New Jersey and then may try to deepen just south of Long Island and then get stronger just off the New Englando coast. As a result, precipitation will fall across the area, and could be enhanced should a coastal forms. That could then, allownform some snowfall for some areas of New England. Please the latest ECMWF depiction of the this possible event: Please contribute to this discussion with your welcomed thoughts. There appear to be at least two, perhaps three, distinct cold fronts between now and then. Would not be surprised if more than the aforementioned "some areas of New England" see some type of frozen precip - as each front hammers down the "door" just a bit more with each one's passing. 1 1 Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 16, 2018 I'll outr the entire GYX long range disco here, as it mentions snow quite often. LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... The extended will continue the trend of ridge building across Wrn North America...which means trofing across the Ern CONUS. Wed night could almost be a carbon copy of today...with a strong cold front and gusty winds set to cross the area. Model guidance however is in agreement that the trof will be more anomalous...in the -2 to -3 standard deviation range...and that the trailing air mass will be colder. First...temps are generally a blend of a mixed down approach and raw 2 m temps from model guidance...given the well mixed boundary layer after the frontal passage. With H8 temps approaching -10C...mixed down temps are generally in the 30s for the mtns and low to mid 40s as you move towards the coast. Second...winds will become gusty once again behind the front. While the core of the winds does not look as strong or as low in the column as this morning...there is around 40 kts at H8. We should be able to mix down at least 30 kt gusts...and so I have bumped wind gusts up from the multi-model consensus in the Thu morning and afternoon time periods. Finally with the main trof passage there could be some light precip. Wly flow should help with some downslope drying SE of the mtns...but along and upstream will be aided by orographic lift. Any trapped low level moisture will be wrung out and given the very cold air mass arriving after the front...fall in the form of snow after some initial rain showers. Forecast Froude numbers look high...which makes sense in the CAA regime and well mixed environment...so some snow showers will likely cross the ridgelines and propagate downstream. The higher elevations check a lot of boxes for an upslope snow event...given the cyclonic flow...low level moisture...and cold temps aloft supporting efficient snow growth. So I have at least light accumulations in the lower elevations of the North County...with higher amounts in the mtns. Beyond the end of the work week the extended looks to remain a series of quick moving S/WV trofs and reinforcing cold shots. Mean trofing over the Ern CONUS will support temps at or below normal thru the period and thru next week. Notably...with plenty of colder than normal air in place and the positive PNA pattern supporting Nrn stream S/WVs potentially interacting with the subtropics...the pattern is ripe for East Coast cyclogenesis. Perhaps significant cyclogenesis. And if we are going to dig a little deeper...ECMWF EPS individual members are supporting low pressure late next week...and roughly 1 in 5 members has the first snowfall of the season for locations in Nrn New England. Food for thought. 1 Share this post Link to post Share on other sites
Phased Vort 1,074 Posted October 16, 2018 06Z GFS : Share this post Link to post Share on other sites
Phased Vort 1,074 Posted October 17, 2018 This event still looks possible as energy from the clipper may try to phase with energy ruuning northeastward along a cold front. If that occurs, then NE US could get a decent storm, with even decent snows. NOTE: Date has been fine tuned to better estabkish the event timing as we near the actual date. 2 Share this post Link to post Share on other sites
Phased Vort 1,074 Posted October 17, 2018 Gosh.... It seems the 12Z ECMWF decided to indeed do something dramatic with this event. We get the clipper and its energy and energy from low pressure wave riding on the cold front interacting and coming together to create a potent coastal storn for the NE US. Impressive run. This should keep this event and time period interesting. Share this post Link to post Share on other sites
TheDayAfterTommorow 349 Posted October 17, 2018 Very intriguing @Phased Vort. If only cold air were a little more abundant...good day to live in NH/VT, verbatim. ;) 1 Share this post Link to post Share on other sites
Phased Vort 1,074 Posted October 17, 2018 12Z ECMWF snow fall depth after this posible storm. Of course, just for fun now. Share this post Link to post Share on other sites
Uscg ast 1,088 Posted October 18, 2018 21 hours ago, Phased Vort said: Gosh.... It seems the 12Z ECMWF decided to indeed do something dramatic with this event. We get the clipper and its energy and energy from low pressure wave riding on the cold front interacting and coming together to create a potent coastal storn for the NE US. Impressive run. This should keep this event and time period interesting. Looks like it bombs the storm out a bit late. If it were earlier, I believe this could be a colder event for many. There is an abundant amount of low level cold air just up North. Share this post Link to post Share on other sites
Phased Vort 1,074 Posted October 19, 2018 The latest 00Z ECMWF, has a big Maine snow special with this clipper turning into a coastal storm. Getting closer to the event now. In a couple of days, we will have a better idea if this will let more areas of the region take part or if it will only be a Maine special, or maybe just a non event for the NE US at all. Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 21, 2018 Bit of an inverted trof look showing up in some modeling. Temps would be marginal for they most part, but you can get dendrites to form just below 0°C. GFS NAM Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 21, 2018 Ukie is trying, this just seems like it blooms too late. 1 Share this post Link to post Share on other sites
EstorilM 66 Posted October 22, 2018 So, I'm following this thread - but had a larger concern. Long shot, but figured people in this thread would know. Not a "typical" IMBY post ;) Sooo a few of us volunteers with the commemorative air force need to fly our wing's TBM Avenger to NAS Jacksonville from Northern VA on Thursday for an air show. Weather here looks great, but does ANYONE know what's going on with the low pressure system in the gulf? It's looking like it'll rain, but I'm trying to get a general idea of the timing, and if ceilings will be acceptable (the rain isn't the end of the world). If not, the plane goes Wed and I miss out on the experience of a lifetime - can't take three days off work this week. Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 22, 2018 GYX with a fun disco. LONG TERM /TUESDAY THROUGH SUNDAY/... Trend of high amplitude upper ridge building along 110w still indicating strong bundles of energy digging southeast thru the data sparse areas of Saskatchewan and Manitoba and then into the Great Lakes. US models finally coming more in line with EURO solution. For this reason using superblend which incorporates Euro but once again going with higher POPs than guidance and lowering temps. Redevelopment of coastal and mid level low expected somewhere along the southern Maine or NH coast area. 1.5-2.0 degs north of this center will be strong UVV and enhanced QPF. Ptype will be an issue as model temps much too warm due to seasonality and had to adjust them lower, also due to drainage cross isallobaric winds and damming cold air. Nice conveyer belt may also set up. The ole 72-96 hr rule of thumb for the proportional upstream/downstream development looking to work out nicely with models playing catchup. Confidence rather high mountains may get a decent accumulation of snowfall Tuesday night into Wednesday with a mix in some inland areas especially higher terrain. Also considering amount of latent/sensible heat due to the seasonably warmer ocean off the coast, expect this extra amount of energy to help enhance the system even further. Some heavy QPF may develop well inland north of the mid level track into the mountains but will only hedge for now to avoid flip flopping. 1 1 Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 22, 2018 NAM hits the Maine mountains pretty hard. 1 1 Share this post Link to post Share on other sites
JonSnow 211 Posted October 22, 2018 14 hours ago, EstorilM said: So, I'm following this thread - but had a larger concern. Long shot, but figured people in this thread would know. Not a "typical" IMBY post ;) Sooo a few of us volunteers with the commemorative air force need to fly our wing's TBM Avenger to NAS Jacksonville from Northern VA on Thursday for an air show. Weather here looks great, but does ANYONE know what's going on with the low pressure system in the gulf? It's looking like it'll rain, but I'm trying to get a general idea of the timing, and if ceilings will be acceptable (the rain isn't the end of the world). If not, the plane goes Wed and I miss out on the experience of a lifetime - can't take three days off work this week. If you have to turn that down due to work, I sure hope you earn some extra brownie points with your boss. And if you do make the flight, take a low pass over Roanoke, I would love to look up and see that. Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 22, 2018 SREFs doing their thing... Eustis, Maine. 1 Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 22, 2018 GYX likely snowfall. Share this post Link to post Share on other sites
EstorilM 66 Posted October 22, 2018 4 hours ago, JonSnow said: If you have to turn that down due to work, I sure hope you earn some extra brownie points with your boss. And if you do make the flight, take a low pass over Roanoke, I would love to look up and see that. I think we will be a little bit east of you, trying to track direct to the coast then hug it to JAX, probably around 8500' - it's pretty loud from the outside though! I just started a thread in the southeast forum - looks like there could be significant severe wx Friday - hopefully we can get in before the rain starts Thurs afternoon though. Biggest issue is we don't have as much daylight this time of year. 1 Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 22, 2018 59 minutes ago, EstorilM said: I think we will be a little bit east of you, trying to track direct to the coast then hug it to JAX, probably around 8500' - it's pretty loud from the outside though! I just started a thread in the southeast forum - looks like there could be significant severe wx Friday - hopefully we can get in before the rain starts Thurs afternoon though. Biggest issue is we don't have as much daylight this time of year. Here's the euro forecast for cloud cover,I don't know the altitude of each level, sorry. All these are valid at 2pm. High Medium Low Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 22, 2018 GYX, I don't expect to see snow IMBY. .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... In advance of the strong digging short wave thru the western Great Lakes expect light WAA overrunning pcpn to gradually develop as the baroclinic zone intensifies. Some areas over the higher terrain and mtns may see a mix of snow and rain at times while southern areas temps will be too warm. By Tue night the digging short wave approaches and allows a sfc low to redevelop along the NH/ME coast and then quickly develops vertically as the s/wv becomes negatively tilted as it moves thru central New England. EURO is model of choice and by far has had best continuity of development due to the upstream high amplitude upstream upper ridge at 110W. As the mid level low passes on a track along the coast there should be an area 1.5-2.0 degs north of the axis where heavy qpf occurs as per EURO. Meanwhile US models not wrapping offshore moisture into system as they continue to play catchup with development of low. Expecting a decent snowfall across the Maine mtns and portions of northern NH with even potential for some accumulations across the higher terrain above 1000ft in the foothills. For now opting to hold off on any headlines since it will be a 24 hr event with most of the QPF to be in the time frame of our 3rd-4th periods Tue night into Wed. Across southern areas primarily light rain expected as the low tracks overhead followed by downsloping on the backside. QPF totals were very close to RFC guidance and snowfall amounts are figured to fall in a range of 3-7 inches across a stripe from the western mountains of Maine into northern NH, this fits in very well with WPC snowfall guidance. Temps were once again lowered for Tue into Tue night. NAM DNG temps actually didn`t look that bad. Share this post Link to post Share on other sites
EstorilM 66 Posted October 22, 2018 17 minutes ago, MaineJay said: Here's the euro forecast for cloud cover,I don't know the altitude of each level, sorry. All these are valid at 2pm. High Medium Low Thanks, not sure what they consider "low level" but we'll do what we need to to stay out of them. My eyes always invert those maps - doesn't matter how long I stare at them, I think the yellow is the cloud cover lol. Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 22, 2018 28 minutes ago, EstorilM said: Thanks, not sure what they consider "low level" but we'll do what we need to to stay out of them. My eyes always invert those maps - doesn't matter how long I stare at them, I think the yellow is the cloud cover lol. I do the same. The GFS middle clouds looks very similar to the ECMWF, and these clouds are between roughly 12,000 to 25,000 feet. 1 Share this post Link to post Share on other sites
EstorilM 66 Posted October 22, 2018 1 hour ago, MaineJay said: I do the same. The GFS middle clouds looks very similar to the ECMWF, and these clouds are between roughly 12,000 to 25,000 feet. Perfect thanks! Yeah the oxygen system was removed during restoration, so we'll probably be around 8500 the entire time. Still thinking there's a solid window as long as we get on the ground before 1-2pm. 1 Share this post Link to post Share on other sites
MaineJay 2,062 Posted October 23, 2018 Updated GYX snowfall map, the afternoon shift is more bullish. Caribou Share this post Link to post Share on other sites