Think Snow, Tweet Snow !!!

Friday, December 19, 2014

Join the movement ! Sign the petition ! Keep the warm air out !

If there seriously was a community-action type movement, I would certainly put a sign in my yard. I even wonder if I made a tee-shirt "keep the warm air out" and sold them at the Mad River Glen general store, would they sell. They should this week..

I am certainly a little disappointed at Santa Claus for the partial Christmas debauchery that models are currently indicating for the mountain. Especially for a week that showed such promise a week ago only to turn so horribly wrong the last few days. The model consensus has moved away from the "Midwest hurricane" which was indicated a few days ago. This would have a more dire scenario with, warm air, rain, wind, and high dewpoints dealing the mountain a crippling blow heading into the New Year. The period of 40-plus warmth and rain appears limited to a smaller window now but needless to say it will still do some damage.

In the very short term, we will get a chance to dry out this weekend. Limited sunshine and a higher ceiling should allow for better visibility. Temperatures will also remain below freezing through Monday. Part of our "How the Grinch Stole Our Snow" story next week involves how a storm which originally seemed to destined to be a big east coast hit Sunday/Monday, has fizzled to nothing (Monday looks entirely dry) and how all the action now is confined to the massive mid-continent jet amplification which will have a clear dominance over the battlefield.

As of now, there appear to be a few pieces to the Christmas storm and although this is still hardly ideal, it is better than the alternative as I had mentioned - the bomb/hurricane looking system over the Midwest. The first wave brings it's moisture into interior New England Tuesday; in fact, temperatures at that point might still be able to support snow for a time before going to some freezing rain or drizzle. If the storm conglomerate remains a conglomerate, the near freezing temperatures will put up some resistance and we will avoid any substantial melt-off through early Christmas Eve. After that though, the region will see a tremendous surge of both Atlantic Ocean moisture and air and this will allow readings to climb into the upper 30's. The rain could be heavy and be accompanied by wind - it won't be pretty. There are indications on some of the medium range models that temperatures spike into the mid-40's, though I am still holding out some hope that we remain in the 30's, partially limiting the damage.

With the trough amplification occurring much farther west than we would have preferred and the upper air energy associated with this storm drifting north into eastern Canada late next week, it will actually take a bit of time to chill the mountain down again. Wrap around moisture might be able to sweep back into Vermont by the 26th but snow will be limited and valley temperatures might remain above freezing. There is a second weather system that should come out of the Rockies late in the week which could bring mixed precipitation or snow to the region around the time of the 27th. Hopefully this begins our road back.

We still expect the emergence of a jet stream block over Alaska and a loosening of the jet in the mid-latitude Pacific. Eventually, even the NAO is expected to make a run into negative territory. This will support the presence of cold arctic air across much of the country including New England. There has been a trend in recent days to shift the main thrust of this arctic air westward allowing the east coast to be more in a battle zone of air-masses. This works fine for us since it usually means storminess, and we will need that after the Grinch steals our snow Christmas eve.

Wednesday, December 17, 2014

Potential Christmas storm looking more like a "meltdown"

I almost felt that we had some authentic "mojo" this year, the chaos of New England weather can put the kibosh on those good vibes very quickly. I sincerely wish I had better news for the Christmas holiday but I don't today. We knew it was going to be a stormy week, a week with some potential but it looks today like mother nature could take us to the woodshed.

In the short term the mountain will be fine. Snow on Wednesday night into Thursday will amount to 3-6 inches and we will temporarily rid ourselves of the dreary dampness. Bluer skies should arrive Friday will be accompanied by seasonable temperatures and this will be followed by a fantastic visibility day Saturday, again with seasonable temperatures.  By the end of the weekend, we could see some clouds move into the region but even Sunday should be precipitation-free.

All the action comes during the upcoming Christmas week. There are still two weather systems worthy of mention but the 2nd will hog most of the headlines. The first will do a slow lollygag along the Gulf Coast this weekend and try and gather some energy as it reaches the Atlantic Sunday. I had much higher hopes of this system honestly, as did many others in the meteorology community. For now however, it appears this storm will struggle to attain any significant strength and although it will proceed up the east coast Monday it will only bring limited moisture into New England early in the week. I am not giving up entirely on this system but current indications are for a limited accumulation if anything at all.

After that is when our headache might begin. The 2nd in the series of southern branch features will follow closely on the heels of the first, but the 2nd will make it's eastward progression just as a major piece of Pacific energy is cascading southeast out of the Northern Rockies. This is an extremely unfortunate turn of events if it were to play out this way. The two systems will phase in the middle of the country, way, way too far west for our liking. A storm will thus explode in the Ohio Valley and Great Lakes region and the storm could be strong enough to suck extremely warm air from the Atlantic Ocean through all New England and even deep into Quebec. There could be wind, high dewpoints and a lot of rain, all of which contribute to the dreaded meltdown which we really wouldn't want. I am seriously calling for a lifeline on this, especially since the list of ingredients could have produced some exceptionally positive results if we could simply mixed all this stuff together a little differently.

Is there a way out ? Please ! It was such a resounding statement from two of the major computer models today that I am cowering in fear right now. I hate rain on Christmas anyway and I double hate it when it's melting snow. Yes though, I will keep the slight possibility of a way out. My hope right now is that the southern branch feature can haul ass early next week, get well out in front of the trailing Pacific energy and thus allow for a later amplification. The storm in that case might be able to jump to the coast before exploding and flooding us with warm air. If your planning to ski on Christmas day or just beyond, my advice would be to join me in prayer in that regard.

The trend toward a colder pattern, anchored mostly by the emergence of blocking across Alaska and the Yukon and a much looser Pacific jet remains on track around Dec 27-28. The new "colder" pattern could also be accompanied by more storminess as there remains indications of split flow in the jet. We should be able to keep this going through the early part of January as well so at least we have that.

Monday, December 15, 2014

Evolving weather pattern will bring back the cold while storm potential continues

Though it may be categorically "above-normal", a thaw it has not been. Temperatures have generally remained below-freezing on the mountain and the deep snow has so far held its ground. The next storm system will bring its precipitation to the mountain Tuesday night and we still expect temperatures in the lowest 5,000 feet to be very marginal. This being said, models are only allowing these "marginal" temps to get to about 34 or 35 which keep the door open for mixed precipitation as opposed to plain rain. The summits might be able to keep the precip-type completely frozen. This system is eying the St Lawrence Valley as it's favored track but it will make that important jump to the coast during the day Wednesday and in doing so will allow the lower troposphere to cool enough to support some snow. What does fall later Wednesday into Wednesday night will be of the terrain-enhanced variety and could accumulate 2-5 inches by first tracks time Thursday.

There is lots to talk about today including some potential storms and some big-picture changes that will have a profound impact on MRG weather as we head toward the end of 2014. In spite of all the snow, the pattern has not been anchored by favorable teleconnection indices and the jet stream in the Pacific has been much too tight for my liking allowing the EPO index to remain positive. Over the next 7-10 days, the jet in the Pacific will loosen dramatically, a ridge will establish itself over Alaska and the Polar jet will make it's presence known. The country as a whole has seen very limited amounts of cold over the first two weeks of December and MRG has had a very limited supply to work with during the last two recent snow events (though we managed to come out on top anyway). After Christmas, this will be very different, cold will cover much of the country, New England included, and so long we can keep the southern branch of the jet stream active (which is legit question), things will get very interesting.

Actually things are already interesting and this refers back to our last discussion a few days ago. There are two systems of note and one or both or none could have a significant impact on the region between the 21st and 26th of the month. The first is a strong southern branch system, yet another in this El Nino winter, which will progress across part of the country by the 20th and then attempt to make a northeastward turn as it heads toward the Atlantic Coast. Models over the last three days have produced a variety of results regarding the outcome of this system. As of Monday afternoon, the consensus of information actually allowed the storm to simply move out over the ocean and remain a non-event for most of New England. I bring it up however because it is hardly game-over with this system. The polar jet will remain rather uninvolved in the weather pattern through the 21st and thus the door is open for this thing to make critical northward turn. I wouldn't at all be surprised to see models sing a different tune on this storm either tomorrow or the next day.

Potential storm #2 will impact the region around Christmas as cold air invades a large swath of the plains and Rocky Mountains. There is legitimate concern that the pattern could initially amplify too far west and allow any storm to ride into the Great Lakes but it's early and their are lots of moving parts here. Incoming polar jet, southern stream energy and changes in the pattern at a big picture are level are all going to have some impact.

Friday, December 12, 2014

Mild air won't dent us too much over the next few days so lets discuss more interesting stuff down the road

The big nor'easter has left MRG sitting pretty on December 12th with a terrific base to work of off. Hopefully as many of you as possible were able to make it out for opening day, the earliest in a decade if memory serves. To provide some perspective, I remember years where no one has been up the single until mid-January

Although flurries will continue through Saturday, we are entering a brief drier and milder stretch of days. I say mild but the relative "warmth" will merely consist of a few comfortable above-freezing afternoons Sunday, Monday and Tuesday and when I say "above freezing" I am talking mid-30's. All three of these days should feature some great visibility as well which the mountain hasn't had since Monday. If there is a upcoming concern, it involves a potential weather system that is expected to swing through the region Tuesday night. Temperatures will be quite marginal and we may see rain or mixed precipitation. There is a Great Lakes low pressure center with this system that is likely to pass to our west but it is possible that the storm makes a jump to the coast. If it does this quickly, and the coastal system can intensify quickly, it could keep precipitation mostly frozen and even allow for a few inches of snow before more seasonable below freezing temperatures are ushered back into the region later in the week.

There are two very visible, and very intriguing looking southern jet disturbances that have been on many of the recent ensemble runs over the past two days or so. They begin a progression across the southern part of the country late next week and move into Texas by the weekend of the 20th/21st. Meanwhile, the pattern fundamentally will begin to take on a different shape. The blowtorch across Canada will subside and this should start to open the door for colder weather to enter the weather picture (although I don't think this really happens until after Christmas). The system in Texas next weekend will need some help, a wingman so to speak. If a disturbance, either Pacific or Polar, can come and provide a little assistance, this could again wind up being a significant east coast system in the days prior to Christmas. The same goes for the 2nd disturbance which should trail the first by a few days.

In short, with the threat of a big warm-up now mitigated, we can now focus on what could wind up being a very exciting period around the days of the Christmas holiday, with all this occurring after an early open and 45 inches of snow which has already fallen this month. I'll talk more about some of the longer range stuff come this Sunday when we could perhaps have a clearer view at particulars.

Wednesday, December 10, 2014

Snowflakes are back and they should start to pile up

Beautiful looking swatch of moisture rotated back into interior New England and ultimately Vermont Wednesday afternoon bringing heavier precipitation back to Vermont. The light freezing rain and sleet changed back to some snow and this should continue into Wednesday evening as the lower troposphere continues to cool; in fact, we should see less and less sleet/freezing rain and more and more snow as the hours go by.

The decaying surface low pressure center will drift, ever so slowly, toward the Canadian Border tonight into tomorrow. The various conveyors of moisture currently on radar won't be as pronounced allowing select locations to get lucky while others are less than lucky. Still, we should begin seeing some good terrain enhancement tomorrow which should persist through Friday and then taper to flurries or very light snow Saturday. Hopefully opening day ! Additional accumulations beginning now and ending by early in the day Saturday could easily be a foot.

We still have a few above-freezing afternoon's to contend with beginning Sunday and ending Tuesday but the end of next week appears categorically cooler or normal.

Tuesday, December 9, 2014

Heavy snow overspreads the Green Mts Tuesday but will it continue ?

Just a quick update...

Good moderate to heavy snow is falling across the Green Mountains as of early evening Tuesday. We need this to keep up because the snow is falling through a small but very marginally above-freezing layer in the atmosphere. Would not at all be surprised to see some sleet and freezing rain mix into the snow later this evening. It could be a bit of a back and forth battle during the overnight depending on the intensity of the precipitation. The heavy stuff will come down more as snow while the light stuff will be more of a sleet/freezing rain mixture. By Wednesday morning, most of the heaviest precipitation will be over with and we will see sleet, freezing rain or even some plain rain for much of the day. I really do think total accumulations (5-10 inches) will be held down by the mixing but we will see a very healthy water equivalent out of this which means we have a great foundation to build on.

The atmosphere will cool enough Wednesday night for snow to re-commence and continue both Thursday, Friday and possibly into Saturday. The storm will have occluded, essentially meaning that it has reached its final state of maturation and will decay but it will only move very slowly as it does this. This is a set up that favors terrain enhanced snow and we could see an additional 6-12 inches over the 2-3 day period. We won't see the kind of snowfall rates we saw Tuesday evening but the steady light snow should add over the course of 3-days.

Still looking at some milder days late this weekend into early next week. A feared massive thaw is starting to look less lightly as come chillier air will sneak back into the region later in the week.

Monday, December 8, 2014

Variety pack of weather set to hit MRG with mid-week nor'easter

Almost game time with this storm though it's only beginning to take shape as of Tuesday afternoon.  It is a rather unique merging, almost collision of two garden variety weather systems. One, well off the Mid Atlantic coast that will migrate northwestward toward the coast, and another passing rather innocently through the Great Lakes. The two will phase in magnificent fashion Tuesday morning and the fireworks show ensues. Rain and snow will light up the radar screen by Tuesday afternoon and snow should spread into MRG by the middle of the afternoon. Cold arctic air snuck its way into New England Sunday night and will continue a tenuous grip on the region through the onset of precipitation tomorrow. It should get quite fun for a time with huge snowfall rates Tuesday evening into early Tuesday night allowing accumulations to get as high as a foot and very quickly.

The track of this quite powerful nor'easter is expected to proceed to southern New England before becoming nearly stationary. Warm air will thus get sucked around the top side of the storm in counter-clockwise fashion. I expect we will see a lull in the precipitation as this happens, often referred to as a dry slot. Once precipitation does re-commence during the day Wednesday, it is unlikely to be snow.  There are some interesting temperature profiles being shown by some of the shorter range computer models and they run counter to some of my thoughts from the last post. During the day Wednesday, a layer of above freezing temperatures is expected to cover northern Vermont between 6,000 and 10,000 feet. Below that, readings struggle to reach the freezing mark. One would look at this storm and quickly conclude that it is not an "overrunning-style" event but temperature profiles show that type of structure. So instead of a elevation sensitive rain/snow day on Wednesday, it looks more like sleet/freezing rain/rain type of day. Any powder that falls Tuesday evening is going to get a very quick glaze or get mashed up by the sleet.

After a period of the non-snow type stuff Wednesday, temperatures in the lower troposphere should cool enough to support snow, particularly at the high elevations. The storm is expected to occlude by this point and although this eliminates the chance for extremely heavy precipitation. Elevation sensitive snow should be able to persist through Thursday into Friday. I am still hoping that the storm just gets a small second wind while repositioning itself near the coast Thursday. This could allow a period of at least moderate snow Thursday or Thursday night. Whatever does fall Thursday into Friday will be wet at low elevations and only powdery near the summits and accumulations will range from a relatively low few inches in the valley's to upwards of an additional foot near the summits. Because of the sleet/freezing rain/rain situation Wednesday, I highly doubt we will ever have 2 feet on the ground at the end of the storm. We are more likely to get a good 6-12 inch thump Tuesday night which will get compressed Wednesday with another layer of 6-12 inches between Wednesday night and Friday. Classic New England !

I've seen some maps suggesting a widespread 1-2 foot storm for Vermont. This might work for the Adirondacks but I think this is too aggressive for all of Vermont. Don't think we will score those results unless you above 2000 feet but fortunately most of Mad River is.

We still are going to have to contend with a nasty string of mild days beginning late this weekend. The Pacific is not friendly right now with the positive EPO (Equatorial Pacific Oscillation) creating the dreaded evil empire. We will have an active southern branch of the jet next week into the Winter Solstice but with very limited cold air. Expect several above freezing days next week and a day with some plain rain. Unfortunately, the pattern could linger until just before the Christmas holiday.