The contents of the last post included a prognostication of what the contents of this post would be; specifically, talk of significant new snow in the days ahead. Indeed there is much to talk about in that regard. The recent cold weather has moved January of '07 well ahead of January '06 in terms of skiing quality but new snow remains in high demand. Using the Mt Mansfield snow depth graph as a reference (since it is readily available on the web at http://www.uvm.edu/skivt-l/?Page=depths.php ) there is certainly evidence of significant gains during the last two weeks, but we remain over a foot below average and in a pattern like this I would certainly like to make up that ground and then some. Today's update is going to get lengthy with all of the goings ons since new snow will come at us in varying forms and varying times. There is also more very cold weather on the horizon which is poised to impact the western High Plains then Midwest and deep south perhaps in record breaking fashion. It will take a bit longer but this cold will eventually push into northern New England early next week.
Tuesday/Wednesday
Short term details could really bog us down on a day like this but to summarize, we will have to accept a wide-right on Tuesday's alberta clipper system which should bring a few inches to southern New England. A much weaker disturbance will bring light amounts of new snow to the northern Greens later Wednesday yielding the possibility of a few inches of the fresh stuff by Thursday morning.
Friday's Winter Storm
So this is how the board will get set on Thursday. The massive western ridge positioned near the B.C. coast which was hyped in the last post because of its amplitude will trigger a massive intrusion of arctic air which will make U.S. entry in Montana. Meanwhile, a southern branch system gathers moisture and awaits Polar Jet interaction. The result is alot of speculation, banter and all-out debate amongst eastern U.S. snow enthusiasts over what may go down late this week. The southern feature has a head start and indications are that it will move way out ahead of the arctic push and allow a storm to gather in force over dixie. What is more critical however is that the southern branch will ultimately get flattened by the strength of the pattern or the magnitude of the polar jet. My flight from Kansas City to Baltimore, MD Monday took less than two hours thanks largely to the strength of this jet. What this means essentially, is that although moisture will move up the Atlantic coast in impressive quantities (thanks mostly to that westward trough shift discussed in last Thursday's post), the failure of the southern branch impulse to perturb the polar jet will prevent this moisture from wrapping itself deep into interior sections of New York and New England for a long duration as the storm proceeds up the New England coast and thus prevent a huge Friday snowfall in central and northern Vermont. Forecasters look for a storm to attain what is called a "negative tilt" which indicates how much moisture will is thrusted west of the track With that said, I do think some of the deep moisture makes its way into Vermont for at least a shorter period of time allowing for what would amount to a few hours of moderate to heavy snow early Friday and an initial guess of 3-7 inches.
A complete upcoming weekend synopsis
A subsequent update refining these ideas will be needed of course but a as of now, a break in the snowfall is anticipated later Friday as an area of subsidence in the wake of the aformentioned non-negatively tilted storm moves through. As this is occurring the flow will gradually align itself vertically and allow terrain induced snow to develop across the entire chain of the Green Mountains either Friday afternoon or Friday Night. The snowfall could enhance for a time as the upper air impulse marking the advance of the very cold arctic air approaches. Terrain/Mountain induced precipitation is difficult to forecast both in duration and amounts this far in advance but the shear, stability and boundary layer moisture parameters will be met for at least a time (all part of the Braeton checklist !) prior to and during opening of the single Saturday morning. What does this all mean ? To summarize the guess is for two periods of snow, one early Friday and one early Saturday enough to produce a pair of powder days and an initial guess of 10-20 inches of snow for the period Thursday night through Sudnay. Wind will become a factor Saturday as will the cold weather. High temperatures Saturday will be in the low teens followed by a Sunday where temps fail to make it out of the single numbers.
Cold takes center stage
The big story for next week is the cold weather. In terms of both expansiveness and intensity, the attack of cold this weekend into early next week across the nation is as impressive as anything we have seen since December of 2000, perhaps dating back to 1996. It will make some headlines especially across the deep south. New England is one place which as seen its share of cold in more recent years and I refer mostly to January of 2004. Whether or not we can challenge some of those 2004 numbers which exceeded -20 in many areas remains to be seen but if it were to happen, Tuesday and Wednesday (February 6th and 7th) would be the time frame. Just prior to the peaking of the cold over the north country, we will be watching another system track near or just off the southeast coast. This system, a product of the southern branch may prove to create headlines either in the Mid-Atlantic or Southeast but it does not stand a chance against next week's overwhelming polar jet which will at some point, shunt this system out to sea before it plays any role in determing the weather at MRG. The polar jet will in fact ensure a fairly dry week for MRG overall with snowfall through the middle part of next week limited to the high terrain and falling in small increments.
Longer Range
As we move toward the weekend of February 10th, the ensembles do clearly suggest a relaxing of the polar jet. Even as this is occurring the Arctic Oscillation will remain at its lowest levels of the winter (-1) which will suggest that Arctic air will remain on the playing field in some fashion. This type of evolution, if viewed optimistically, would be interpreted as a chance to get some of the southern branch's deep moisture in the form of a well developed storm system up this far north. Pessimestically speaking, if the longwave trough/ridge structure were to align in the worst possible way it would allow for the possibility of a rain event. The latter would not be my guess. Recall that our early winter struggles were largely forced by an AO of positive 4. If the AO were to maintain a negative state it will be difficult for low pressure centers to track north 50 N along the east coast, a track necessary to bring rain to MRG. I do think temperatures move from their much below status to slightly below in the period between the 10th and 14th of the month. It also seems reasonable to expect at least one snow event after the very cold but fairly dry period between February 6th and 10th.
The Quick Summary
Snow will fall for varying weekends between early Friday and the end of the weekend. This is followed by very cold weather next week and then closer to normal temperatures for the weeek beyond.
Tuesday, January 30, 2007
Thursday, January 25, 2007
Another solid weekend and a promising early February
New England's north country has been the focus of the latest U.S. outbreak of cold. By the end of the month, many places across Vermont which saw temperatures average 12 degrees above normal for the first half of January will finish only 3-5 above normal thanks the to the late month cold rally. We also have some much needed momentum heading into the all important skiing month of February, a month which appears will start in a big way and hopefully continue. This update will contain a quick and detailed look at the weekend and a glimpse into the next two weeks which will contain some important fundamental changes as we head toward the first weekend of February.
The Weekend
In the last post we discussed the weekend Alberta Clipper system which at this juncture is still on the radar screen. It will dive out of Canada as a powerful jet impulse but will lose some potentcy by the time its effects are felt over Vermont. The system will spread clouds into the Green Mountain chain during the day Saturday and light snow will develop during the afternoon. The many forecasts I have seen up here are saying a 50 percent chance of snow showers or a "few snow showers" but I expect a significant period of light snow out of this system in spite of its weakening. By Sunday morning the mountain itself should squeeze at least 2-5 inches out of the limited available moisture but check the local NWS forecasts for updates Saturday morning. There is the concern of course about the intense cold weather but this should peak across all of New England Friday with a temperature moderation for the weekend; in fact, both days should top out in the teens and with less wind relative to Friday.
Slight pattern shift and meaningful results
The pattern from the perspective of the wide-angle-lens will change little over the next 10-14 days but there is a subtle and important shift next week involving the position of jet stream features which will impact MRG greatly by the first weekend of February. The focus of the cold which determined by the mean position of the trough will shift from New England late this weekend and early next week to the Midwest by the first of February. The pattern will on the overall still be dominated by cold over a broad area of eastern North America but the extreme cold will focus on the upper Midwest while below normal temperatures are more "garden-variety-like" across New England. The shifting of the mean position of the trough will better make use of the baraclinicity created by the Atlantic Ocean which is a better way of saying that approaching storms will pull Atlantic Ocean moisture deep into New England more effectively. The end result ? Well, I think there will be one to two significant weather systems leading to snow which will prove worthy of discussion in the next update. The first will occur leading up the weekend as the initial Midwest trough amplification occurs around February 1st. Subsequent to that will be another chance for a significant storm system around the 4th or 5th. I am obviously getting a bit ahead of myself but its exciting to watch the pattern engineer what I hope will be a historic comeback for us.
The Quick Summary
Light snow leading to an accumulation this weekend and then a subtle shifting in the pattern should bring the chance for much bigger things in early February.
The Weekend
In the last post we discussed the weekend Alberta Clipper system which at this juncture is still on the radar screen. It will dive out of Canada as a powerful jet impulse but will lose some potentcy by the time its effects are felt over Vermont. The system will spread clouds into the Green Mountain chain during the day Saturday and light snow will develop during the afternoon. The many forecasts I have seen up here are saying a 50 percent chance of snow showers or a "few snow showers" but I expect a significant period of light snow out of this system in spite of its weakening. By Sunday morning the mountain itself should squeeze at least 2-5 inches out of the limited available moisture but check the local NWS forecasts for updates Saturday morning. There is the concern of course about the intense cold weather but this should peak across all of New England Friday with a temperature moderation for the weekend; in fact, both days should top out in the teens and with less wind relative to Friday.
Slight pattern shift and meaningful results
The pattern from the perspective of the wide-angle-lens will change little over the next 10-14 days but there is a subtle and important shift next week involving the position of jet stream features which will impact MRG greatly by the first weekend of February. The focus of the cold which determined by the mean position of the trough will shift from New England late this weekend and early next week to the Midwest by the first of February. The pattern will on the overall still be dominated by cold over a broad area of eastern North America but the extreme cold will focus on the upper Midwest while below normal temperatures are more "garden-variety-like" across New England. The shifting of the mean position of the trough will better make use of the baraclinicity created by the Atlantic Ocean which is a better way of saying that approaching storms will pull Atlantic Ocean moisture deep into New England more effectively. The end result ? Well, I think there will be one to two significant weather systems leading to snow which will prove worthy of discussion in the next update. The first will occur leading up the weekend as the initial Midwest trough amplification occurs around February 1st. Subsequent to that will be another chance for a significant storm system around the 4th or 5th. I am obviously getting a bit ahead of myself but its exciting to watch the pattern engineer what I hope will be a historic comeback for us.
The Quick Summary
Light snow leading to an accumulation this weekend and then a subtle shifting in the pattern should bring the chance for much bigger things in early February.
Monday, January 22, 2007
Polar Jet ready to show its ferocity !
This is my first ever update from the basement of the MRG basebox, no doubt a bit different then blogging in the safe confines of your own home. January 22nd marks the 20th anniversary of one of the great east coast storms, a poor mans version of the '93 superstorm dumping 1-3 feet of snow up the spine of the Appalachians into interior New England. The storm tracked up through eastern Massachusettes and precipitaiton in Boston actually went to rain while heavy snow continued to fall over most of Vermont. It was my hope that we might see something similar late this week but the southern branch would simply prefer to stay on the sideline, at least as it relates to the production of new snow in our neck of the woods this week. The pattern appears to be manifesting itself into a ferocious positive PNA regime, one dominated by frequent intrusions of very cold arctic air on the wings of a very powerful polar jet. Of more importance will be the not so infrequent powder days, which will come mostly from Clipper systems or terrain induced events such as what fell Friday night and Saturday We have gone over the catylists but the intensity of the pattern is beginning to really impress me since it is one I have not seen on this widespread of a scale since December of 2000 and to a smaller degree, January 2003.
Short-term-casting
I have to admit that the short term analysis leading up to this past weekend was a bit lacking. It wasn't overly wrong but did not do justice to Friday's snow event and the subequent high winds which hit northern Vermont on Saturday. Sometimes I just get a bit too far ahead of myself so I will try and put a bit more of an effort into the short term casts leading into the weekend. On that note I do have to credit Scott Braeten who writes an occasional column for "firsttracksonline.com" . His January 18th analysis of the upcoming "oragraphic" Friday/Saturday snow event was terrific and he has a very thorough checklist designed specifically to deal with terrain induced snow events. HIs blog can be found at the link below.
http://www.firsttracksonline.com/index.php?name=News&catid=&topic=9
I am not expecting much in the way of new snow Monday night. A dusting to a few inches would be my guess and most of Tuesday and Tuesday night will be dry. This leads us to the approaching clipper system Wednesday and our next chane for significant new snow. We had hoped for big things out of the trough amplification which is expected late this week but the southern branch does not want to cooperate and the trough will not deepen at the rate needed and at the longtitude needed for a major storm. Nonetheless, we still have the amplifying and stenghening clipper which will spread snow into the region Wednesday, and as this storm continues to strengthen upon moving east, mountain/terrain indueced snow will continue Wednesday night into Thursday bringing with it a real chance for more significant powder to a building MRG base. Very cold weather will also be moving in on the heals of his storm, enough to make Thursday night easily the coldest of the year across the north country.
Good news for the weekend
It may never make it above the symbolic "0-degree" barrier (-18 C) Friday on the moutain but the good news is that both the wind and the cold will subside somewhat by Saturday. Even better is that the next in a series of clipper systems will spread more and much-welcomed new snow to the mountain during the day Saturday. A major storm is not anticipated on Saturday but it is clearly a good set-up with a well-established warm-advection overrunning area which is closely associated with the very important "left-exit" region of the jet max. I should re-name this type of clipper the "left-exit" clipper in hopes of getting us all to feel the positive vibe while at the same time getting stuck in technicalities (which it appears I have already done). It is very early and snow amounts will depend heavily on the systems track (and the left exit track) but a broad 4-8 inche area of snow is very reasonable over northern Vermont with this system and this would add to the snow which has already fallen Wednesday and Thursday.
Polar Jetted
To best assess the intensity of a given cold pattern it is often not the depth of the trough which needs to be addressed (I like to say) but the height of the western ridge. We have discussed, at the risk of over-stating, the stagnant B.C. ridge which has helped fuel the recent pattern change. Originally the ridge formed over Alaska, extended to the pole and helped to bring record cold into the West. Since then we have continued to see the ridge play an influence, only it has assumed a more favorable eastward position and has not extended all the way to the pole. Ensembles however suggest this may change as a trough amplfies south of the western Aleutian Islands and has the effect of strengthening the ridge in Western Canada, perhaps so it reaches to within the vicinity of the pole. This will have ramifications, the most important of which will be the intensity of the cold which become more impressive and more widesread over eastern North America. It may also have the effect of allowing the Polar Jet to completely overwhelm the pattern, eminating the southern branch as a major influence. I am still skeptical and hopeful that we can somehow phase the two like we did in late January of '66 which may turn to be a similar season in many respects consisting of a slow start to winter and a much bigger finish. Assuming the end results are more in line with the "overwhelming polar jet" solution we still should be kept happy with plenty of clipper and terrain/mountain induced snow events.
The Quick Summary
Polar Jet dominates bringing plenty of cold and frequent light to moderate snowfalls. A polar jet domination does lessen the chance for the biggest storms but they can still happen and always worth watching for, even up the last second.
Short-term-casting
I have to admit that the short term analysis leading up to this past weekend was a bit lacking. It wasn't overly wrong but did not do justice to Friday's snow event and the subequent high winds which hit northern Vermont on Saturday. Sometimes I just get a bit too far ahead of myself so I will try and put a bit more of an effort into the short term casts leading into the weekend. On that note I do have to credit Scott Braeten who writes an occasional column for "firsttracksonline.com" . His January 18th analysis of the upcoming "oragraphic" Friday/Saturday snow event was terrific and he has a very thorough checklist designed specifically to deal with terrain induced snow events. HIs blog can be found at the link below.
http://www.firsttracksonline.com/index.php?name=News&catid=&topic=9
I am not expecting much in the way of new snow Monday night. A dusting to a few inches would be my guess and most of Tuesday and Tuesday night will be dry. This leads us to the approaching clipper system Wednesday and our next chane for significant new snow. We had hoped for big things out of the trough amplification which is expected late this week but the southern branch does not want to cooperate and the trough will not deepen at the rate needed and at the longtitude needed for a major storm. Nonetheless, we still have the amplifying and stenghening clipper which will spread snow into the region Wednesday, and as this storm continues to strengthen upon moving east, mountain/terrain indueced snow will continue Wednesday night into Thursday bringing with it a real chance for more significant powder to a building MRG base. Very cold weather will also be moving in on the heals of his storm, enough to make Thursday night easily the coldest of the year across the north country.
Good news for the weekend
It may never make it above the symbolic "0-degree" barrier (-18 C) Friday on the moutain but the good news is that both the wind and the cold will subside somewhat by Saturday. Even better is that the next in a series of clipper systems will spread more and much-welcomed new snow to the mountain during the day Saturday. A major storm is not anticipated on Saturday but it is clearly a good set-up with a well-established warm-advection overrunning area which is closely associated with the very important "left-exit" region of the jet max. I should re-name this type of clipper the "left-exit" clipper in hopes of getting us all to feel the positive vibe while at the same time getting stuck in technicalities (which it appears I have already done). It is very early and snow amounts will depend heavily on the systems track (and the left exit track) but a broad 4-8 inche area of snow is very reasonable over northern Vermont with this system and this would add to the snow which has already fallen Wednesday and Thursday.
Polar Jetted
To best assess the intensity of a given cold pattern it is often not the depth of the trough which needs to be addressed (I like to say) but the height of the western ridge. We have discussed, at the risk of over-stating, the stagnant B.C. ridge which has helped fuel the recent pattern change. Originally the ridge formed over Alaska, extended to the pole and helped to bring record cold into the West. Since then we have continued to see the ridge play an influence, only it has assumed a more favorable eastward position and has not extended all the way to the pole. Ensembles however suggest this may change as a trough amplfies south of the western Aleutian Islands and has the effect of strengthening the ridge in Western Canada, perhaps so it reaches to within the vicinity of the pole. This will have ramifications, the most important of which will be the intensity of the cold which become more impressive and more widesread over eastern North America. It may also have the effect of allowing the Polar Jet to completely overwhelm the pattern, eminating the southern branch as a major influence. I am still skeptical and hopeful that we can somehow phase the two like we did in late January of '66 which may turn to be a similar season in many respects consisting of a slow start to winter and a much bigger finish. Assuming the end results are more in line with the "overwhelming polar jet" solution we still should be kept happy with plenty of clipper and terrain/mountain induced snow events.
The Quick Summary
Polar Jet dominates bringing plenty of cold and frequent light to moderate snowfalls. A polar jet domination does lessen the chance for the biggest storms but they can still happen and always worth watching for, even up the last second.
Friday, January 19, 2007
Short Term Friday Night/Saturday update
Based on some comments I have received and observations from today and this evening, it is fair to say that my forecast of 4 or more inches of snow between tonight and tomorrow is not doing this short term situation justice. Radar imagery shows moisture continuing to stream into Vermont and the snowfall is certainly getting enhanced by both the lakes and the mountains in loose association with the decaying clipper. 4-5 inches has already fallen Friday and there is every indication that much more will fall particularly Friday Night. At this point I would not hesitate to say that 6 more inches will fall Friday Night with some additional snow Saturday. This will certainly make Saturday the best ski day at MRG so far this year.
Nickles, dimes and then there is late next week
The models at face value have us reaching for the change jar and counting its contents on the living room coffee table. I am always surprised at how much money can be accumulated in change and even if one were to hug the medium range models, we would still be surprised how well we can do counting the nickles dimes and quarters this pattern yields us. I expect much more though in a regime such as this; otherwise, I would have not gone out and predicted 300 inches of snow at MRG this year, a prognostication which still seems ready for spontaneous combustion. The week of January 21st to January 28th continues to bear watching as a couple of potent southern branch weather systems lurk in a pattern ready for amplification. Beyond that I can only continue to hype a pattern dominated in North America by a nearly stagnant ridge situated over the Canadian province of British Columbia and marginally favorable teleconnection indices. Its a pattern that now appears will be with us through the early part of February which is very much needed good news for us skiers loyal to Vermont.
The update for the weekend
The New York city metropolitan got a taste of snow Friday but by this storm reaches its full maturation, it will be too far north and east of Vermont and will end up doing more harm than good, robbing both energy and moisture from the approaching clipper system to our west. NWS has "3-5" inches possible in its forecast for Friday night, an outcome which at least to me seems only possible at the higher elevations. I am willing to go with a loose prediction of 4 or more inches between Friday night and Saturday on the mountain itself with lesser amounts in the valley. Snow showers will linger into part of Saturday night before the atmosphere dries and Sunday evolves into a Sunny but chilly day. We certainly could have done better but with new snow to ski on at least one and possibly both days this weekend it certainly qualifies as the best so far this season.
Making some sense out of next week
As mentioned there are two systems in the southern branch of the jet stream that bear watching. At the same time, the polar jet will be busy trying desperately to take matters into its own hands and cook up the good stuff for us particularly Wednesday - Friday of next week. The first southern branch system moves into the plains Sunday but this is too fast since it comes between east coast trough re-amplifications. I have watched this system closely since I believed it had potential. Models however have disagreed and have been suggesting that I am making a mountain out of a mohill. The consensus, which I am forced to go along with, would be to bring Sunday's snow to the Mid-Atlantic Monday and then off the coast in rather benign fashion. A weaker disturbance rotating through the lakes early next week will ultimately be responsible for any snow Monday or Tuesday and that is that.
The potential for late next week
There are two options with the second southern jet feature and models, particularly the European have gone back and forth on the issue over the last two days. In short, the feature either gets stuck in New Mexico or becomes somehow involved in the major east coast trough re-amplification which is expected to take place late next week. The re-amplification will be triggered by the polar branch of the jet and the disturbance responsible will in and of itself prove very productive. So the argument really boils down to whether or not any snow late next week comes from a clipper turned coastal storm or a major east coast snow event. In snow amounts this translates into an argument between either a 6-12 inch event or a 1-2 foot storm. Its nickles and dimes vs crisp dollar bills.
Looking beyond
Ensemble forecasts strengthen the existing pattern by next weekend and beyond although teleconnection indices seem most favorable in the upcoming week. I am referring mainly to the block east of Greenland which is in the process of forming and is not only responsible for finally sending the NAO index into negative territory but the major changes in the weather across Europe starting with the destructive storminess of the last few days. All this aside, it is important to focus on the patterns most dominant feature which is the all-important ridge across British Columbia. So long as that remains in place in some form and at some intensity, the new snow will, in some form, continue to pile up over the Green Mountains and in many other places. There remains strong evidence that this above mentioned ridge will maintain its existence through the end of the month and into early February. The individual model simulations can get a little melodramatic when simulated out that far but the potential for new snow will be continuous in this pattern.
The Quick Summary
Our focus shifts to late next week for something big but smaller amounts of new snow can really add up in a pattern like this
The update for the weekend
The New York city metropolitan got a taste of snow Friday but by this storm reaches its full maturation, it will be too far north and east of Vermont and will end up doing more harm than good, robbing both energy and moisture from the approaching clipper system to our west. NWS has "3-5" inches possible in its forecast for Friday night, an outcome which at least to me seems only possible at the higher elevations. I am willing to go with a loose prediction of 4 or more inches between Friday night and Saturday on the mountain itself with lesser amounts in the valley. Snow showers will linger into part of Saturday night before the atmosphere dries and Sunday evolves into a Sunny but chilly day. We certainly could have done better but with new snow to ski on at least one and possibly both days this weekend it certainly qualifies as the best so far this season.
Making some sense out of next week
As mentioned there are two systems in the southern branch of the jet stream that bear watching. At the same time, the polar jet will be busy trying desperately to take matters into its own hands and cook up the good stuff for us particularly Wednesday - Friday of next week. The first southern branch system moves into the plains Sunday but this is too fast since it comes between east coast trough re-amplifications. I have watched this system closely since I believed it had potential. Models however have disagreed and have been suggesting that I am making a mountain out of a mohill. The consensus, which I am forced to go along with, would be to bring Sunday's snow to the Mid-Atlantic Monday and then off the coast in rather benign fashion. A weaker disturbance rotating through the lakes early next week will ultimately be responsible for any snow Monday or Tuesday and that is that.
The potential for late next week
There are two options with the second southern jet feature and models, particularly the European have gone back and forth on the issue over the last two days. In short, the feature either gets stuck in New Mexico or becomes somehow involved in the major east coast trough re-amplification which is expected to take place late next week. The re-amplification will be triggered by the polar branch of the jet and the disturbance responsible will in and of itself prove very productive. So the argument really boils down to whether or not any snow late next week comes from a clipper turned coastal storm or a major east coast snow event. In snow amounts this translates into an argument between either a 6-12 inch event or a 1-2 foot storm. Its nickles and dimes vs crisp dollar bills.
Looking beyond
Ensemble forecasts strengthen the existing pattern by next weekend and beyond although teleconnection indices seem most favorable in the upcoming week. I am referring mainly to the block east of Greenland which is in the process of forming and is not only responsible for finally sending the NAO index into negative territory but the major changes in the weather across Europe starting with the destructive storminess of the last few days. All this aside, it is important to focus on the patterns most dominant feature which is the all-important ridge across British Columbia. So long as that remains in place in some form and at some intensity, the new snow will, in some form, continue to pile up over the Green Mountains and in many other places. There remains strong evidence that this above mentioned ridge will maintain its existence through the end of the month and into early February. The individual model simulations can get a little melodramatic when simulated out that far but the potential for new snow will be continuous in this pattern.
The Quick Summary
Our focus shifts to late next week for something big but smaller amounts of new snow can really add up in a pattern like this
Wednesday, January 17, 2007
New/improved pattern and plenty of sports analogies
The snow is starting to pile up as the new jet stream regime is firmly entrenched across North America. The how and the when regarding the new snow remains a question and it got me to thinking about offensive philosophy's of various NFL football teams. Its a borderline ridiculous analogy but I am a victim of my own thought process. Many times in recent years, the Mad River Valley plays the west coast offense which relies on "dink and dunk" 3-6 inch snows during favorable patterns instead of getting the big play or 2 feet of powder all at once. Since we are playing from behind and its getting close to halftime we are in need of a big play to even the score or at least to ensure that my rock ski's remain in the basement where they belong. It has been a decadal phenomenon, or so it seems. In the 90's, much of interior Pennsylvania, New York and interior New England were the focus of the heaviest snow yet for much of this decade, the big storms have hit coastal areas harder while in many cases missing the interior locations thus forcing us to play the west coast offense. I was hoping that the juicy southern branch El Nino-fueled systems might reverse this recent trend but in the case of this year there hasn't been any trend because there hasn't been much in the way of storms.
Friday/Saturday
The newly established ridge west/trough east scenario with arctic air on the playing field in an El Nino year is like pitching to David Ortiz in the 9th inning and throwing him all fast balls. At some point we got to connect ! The first opportunity comes Friday as an incoming Alberta Clipper system collides with a wave of low pressure moving up the coast. Models suggest that any phasing here occurs too late and that our new snow Friday will come from the more moisture-starved Clipper system. Once the phasing does occur, the storm will strengthen into quite a snow-producer across the Canadian Maritimes. One result of this will be that moisture gets wrapped around back into the St Lawrence Valley and down the northern half of the Green Mountain chain. Jay Peak often does very well off this type of set-up but areas farther south can also pick up a fair share fresh powder as well. Between Friday and Saturday, the mountain could easily pick-up 3-6 new inches of powder and no, there won't be any sleet mixing in. If the phasing can occur a bit sooner on Friday, our prospects for more snow would improve.
Still lots of potential with the early/middle part of next week
I have had my eyes on the early to middle part of next week for some time and for good reason. The southern branch is poised to spit a moisture-rich system out of the Rockies while at the same time, the polar jet is poised to re-amplify across the eastern United States. These two items may not be timed in perfect coordination but the ingredients for a major east coast system are in the mixing bowl. To further make the case for such an event would be to show how terribly the medium range models have dealt with the strength of the southern branch. The ice-storm in Texas, which is the major event of the winter so far was for the most part not on the medium range model radar screen at least not for 3 days in duration. It would be therefore easy to suggest that any southern branch system next week will also be mis-handled by guidance both in terms of strength and intensity. At this point the best way to look at the Monday-Wednesday time frame next week is in the form of best case/worst case. Best case being big storm and worst case being another Alberta clipper and a light accumulation. Hey, its another fast ball and another chance to hit one out.
Looking Beyond
Beyond the middle part of next week there are not any changes to discuss. The medium range models have oscillated on the intensity of the pattern but the ensembles which can act to filter out some of the statistical noise in the long range have remained consistent that the pattern remains golden at least through the rest of the month. Embedded within this period will be additional chances for storms but its difficult for me to speculate on what and when considering how much trouble we are having nailing this all down within a week. I always like to say, get the pattern right first and the rest takes care of itself and it certainly applies here.
The Quick Summary
New pattern to produce plenty of new snow, at least in small increments but the question remains can we hit one out and soon ?
Friday/Saturday
The newly established ridge west/trough east scenario with arctic air on the playing field in an El Nino year is like pitching to David Ortiz in the 9th inning and throwing him all fast balls. At some point we got to connect ! The first opportunity comes Friday as an incoming Alberta Clipper system collides with a wave of low pressure moving up the coast. Models suggest that any phasing here occurs too late and that our new snow Friday will come from the more moisture-starved Clipper system. Once the phasing does occur, the storm will strengthen into quite a snow-producer across the Canadian Maritimes. One result of this will be that moisture gets wrapped around back into the St Lawrence Valley and down the northern half of the Green Mountain chain. Jay Peak often does very well off this type of set-up but areas farther south can also pick up a fair share fresh powder as well. Between Friday and Saturday, the mountain could easily pick-up 3-6 new inches of powder and no, there won't be any sleet mixing in. If the phasing can occur a bit sooner on Friday, our prospects for more snow would improve.
Still lots of potential with the early/middle part of next week
I have had my eyes on the early to middle part of next week for some time and for good reason. The southern branch is poised to spit a moisture-rich system out of the Rockies while at the same time, the polar jet is poised to re-amplify across the eastern United States. These two items may not be timed in perfect coordination but the ingredients for a major east coast system are in the mixing bowl. To further make the case for such an event would be to show how terribly the medium range models have dealt with the strength of the southern branch. The ice-storm in Texas, which is the major event of the winter so far was for the most part not on the medium range model radar screen at least not for 3 days in duration. It would be therefore easy to suggest that any southern branch system next week will also be mis-handled by guidance both in terms of strength and intensity. At this point the best way to look at the Monday-Wednesday time frame next week is in the form of best case/worst case. Best case being big storm and worst case being another Alberta clipper and a light accumulation. Hey, its another fast ball and another chance to hit one out.
Looking Beyond
Beyond the middle part of next week there are not any changes to discuss. The medium range models have oscillated on the intensity of the pattern but the ensembles which can act to filter out some of the statistical noise in the long range have remained consistent that the pattern remains golden at least through the rest of the month. Embedded within this period will be additional chances for storms but its difficult for me to speculate on what and when considering how much trouble we are having nailing this all down within a week. I always like to say, get the pattern right first and the rest takes care of itself and it certainly applies here.
The Quick Summary
New pattern to produce plenty of new snow, at least in small increments but the question remains can we hit one out and soon ?
Sunday, January 14, 2007
Our pot of gold is getting near
We are on the leading edge of a fantastic period of winter weather in the northeast with many powder days inevitable following the snowfall MLK day and Tuesday. The pattern, as discussed in previous posts will be dominated by upper air ridge in British Columbia which will be accompanied by a healthy southern branch of the jet. The medium range models have had an especially difficult time with this because the interactions between the Polar Jet and Southern Jet are very difficult to pin down more than a few days in advance. For the last few days models have in fact indicated a very dormant southern branch which I have taken with a grain of salt primarily because of the ENSO state. The last cycle of model runs just released was finally beginning to turn on this issue and show the potential for two partially significant to significantly significant events over the next 10 days. This not surprisingly would result from the southern branch.
1) First chance comes on Friday as the newly established baroclinic area over the southeast coast will be the focusing mechanism for the development of a coastal wave of low pressure. There is already an Alberta Clipper which is expected to impact the region that day so the question becomes whether the former and latter mentioned systems interact constructively or destructively. The result can vary by region so its difficult to know or make any determination. Certainly we can establish that there is a very good chance for new snow leading into the weekend of the 20th and 21st.
2) The southern branch could then make a more definitive impact in the period between the 23rd and 25th. The ensembles have shown that during this period the eastern trough weakens somewhat only to subsequently restrengthen for the last few days of the month. This is probably the reason why we have yet to see any indications of a phase and a major storm. Since the mean trough position is in the east however the threat is certainly there and will certainly be worthy of some speculation in the days to come.
Winter should make some big amends over the next few weeks.
1) First chance comes on Friday as the newly established baroclinic area over the southeast coast will be the focusing mechanism for the development of a coastal wave of low pressure. There is already an Alberta Clipper which is expected to impact the region that day so the question becomes whether the former and latter mentioned systems interact constructively or destructively. The result can vary by region so its difficult to know or make any determination. Certainly we can establish that there is a very good chance for new snow leading into the weekend of the 20th and 21st.
2) The southern branch could then make a more definitive impact in the period between the 23rd and 25th. The ensembles have shown that during this period the eastern trough weakens somewhat only to subsequently restrengthen for the last few days of the month. This is probably the reason why we have yet to see any indications of a phase and a major storm. Since the mean trough position is in the east however the threat is certainly there and will certainly be worthy of some speculation in the days to come.
Winter should make some big amends over the next few weeks.
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