Friday, January 15, 2010

Back from the dead !!!! MLK storm turns me into a fool

And although weather forecasting is far from an exact science, it should, at least in part, be judged based on one's ability to stick to a forecast rather than waffle back and forth from one idea to the next. I particularly hate writing an event off too early, particularly one that we had discussed at the SCWB in great detail a week ago. In the end, all the "he said and when he said it" stuff is irrelevant. I will gladly lay down and play the fool if it results in a snowy MLK day and powder on the slopes of MRG.

So, if your keeping score at home, this is I think the 5th or 6th time a system in the southern branch has defied some of the medium range model guidance and tracked farther north, farther west and proven to have a greater impact on the northeast. For coastal areas the impact will be rain but we across interior New England just barely, by the scariest of margins have enough cold air to get the result we are looking for. Absolutely amazing that in the current pattern, with a upper ridge positioned where it is currently positioned, that this can happen, but it could and the trend suggests that it will.

Both Saturday and Sunday will feature relatively mild temperatures relative to normal January levels in Vermont. Saturday's temperatures will exceed the freezing mark at the base and the flurries we might see at the middle and upper parts of the mountain could be sprinkles at the base. Sunday will be dry, and clouds enveloping the sky as the day progresses and afternoon temperatures near the freezing mark. El Nino, meanwhile will be at work again, energizing another juicy southern branch system and sending it our way. The atmosphere is very marginal for snow and the nature of snow and the amount of snow will be sensitive to elevation. Precipitation may even start out as something other than snow but as precipitation becomes heavier toward Monday morning, this should allow for the snow to both fall and accumulate. By first tracks time Monday much of MRG could see over 6 inches of snow. With near freezing temperatures the snow at the base could be wet as opposed to powdery but conditions could be powdery on the upper half of the mountain.

The news is also better in the long range. Recall the concern about all this energy piling up in the Rockies and the negative results were all the energy to stall there. In fact, this energy will indeed progress through the Rockies and keep the southern stream of the jet stream very active as one might expect given the El Nino's continued strength. This will mean a very active time as far as storminess goes and this could include MRG depending on the track of all these systems. Following MLK day it looks to be mostly dry for a few days but potentially stormy beginning Thursday and persisting into at least Friday. The supply of cold air is certainly a concern because it is very limited. Temperatures will be slightly above normal during the middle of next week and we are going beg for some home grown Canadian chill positioned over Quebec and Ontario in order to keep precipitation in the form of snow Thursday into Friday.

Tuesday, January 12, 2010

MLK storm potential fizzles and some rough sledding lies ahead

We had a 5-6 week period of ultra favorable teleconnection indices but our run looks to be coming to an end. I would call it a run of good fortune except that I would've hoped such a setup would have yielded a seasonal snowfall of well over 100 inches by now. Instead we have storm taking aim at the Atlantic Ocean and a pattern dominated by mild air and embedded within that pattern is at least one rain event before the 25th of the month.

We will see a gigantic thaw hit the middle third of the country over the next week but interior New England will stay within the range of seasonable. Temperatures will moderate substantially from current levels reaching the freezing mark by Thursday and likely exceeding it Friday. Passing disturbances will be benign in nature. Friday's weak clipper system may bring a few snow showers but in the end will only allow a re-enforcing shot of chill to encompass the region for the weekend. The weekend as a whole should be free of major precipitation.

Our MLK storm is lacking the right jet configuration for a major hit. Preferably, an upper ridge axis near 110 west (The Alberta, Saskatchewan border) west is what it takes for a coastal system to take the needed left turn up toward New England. In this case the ridge axis is between 90 and 95 west and thus it will be very difficult to avoid a deflection. The system is juicy and potent enough to challenge the prevailing mid-latitude jet but the current data is overwhelming in its suggestion that the steering currents will win out and guide this puppy out into the Atlantic Ocean before any mischief is created.

Seasonable temperatures will remain in place through MLK day plus a day or two but our arctic pipeline is closed for business thanks to a monstrous upper ridge which will extend from the Hudson Bay to lower Quebec next week. The ridge's strength is no doubt being fueled by a freight train of jet impulses that will fill the interior west with unsettled weather and ensure some epic powder for the southern and central Rockies beginning early next week and persisting well beyond next week. As mentioned in the last post, it is important this energy transgresses quickly through the Rockies and into the plains and southeast. Bottling this energy in the Rockies will allow mild air to flood the eastern half of the country and remain there for a lengthy period of time. I would expect at least one rain event from the upcoming pattern and 2 would not be surprising. The AO shows signes of drifting back into negative territory by around the 25th of the month and with it should be the return of colder weather. The El Nino also appears alive and well and should kick some more juicy systems into the plains during the last week of January and we will have to hope that enough cold air can return by then for what will be some much needed snow after the mild weather.

Sunday, January 10, 2010

Juicy "MLK weekend" system has my attention

So much so that I busted on the 8 inches of snow that fell Friday. Something I am certainly not proud of, but such blunders do happen and will surely happen again. Winter has a rather tight grip on the U.S. east coast from Maine down to Key West, Florida which came only a few degrees shy of recording an all time record low. Winter will loosen its grip and do so collectively so that every location will see a moderation in temperatures by the end of this week. Until then, MRG can expect some light snow from two passing clipper systems. The first passes well to our south but nonetheless succeeds at bringing 1-2 inches of fluff for first tracks time Tuesday. The second and weaker of the two passes right over us and could bring another similar light accumulation during the day Wednesday.

As mentioned we will get to enjoy some much milder temperatures later this week defined by afternoon readings just above the freezing mark on Thursday and Friday. This same period will feature a mix of sunshine and a high overcast which should allow for some good visibility on what should be some softened trails during the afternoons. Another in this series of clipper systems will then arrive late Friday with a re-enforcing shot of chill for the weekend. This system appears fairly dry based on the latest rounds of data but will allow for the much needed chill down ahead of a potential storm.

I say potential because it remains at this point just that. Most of the model simulations running out that far have taken this very juicy southern branch system to our south. A few however have moved it farther north and although there may be a limit to this storm's northward progression an MRG impact should not completely be ruled out. Working to our disadvantage will be the evolving steering currents at jet stream level which will have an upper ridge positioned over the Mid-Continent as opposed to the far west and will thus help to steer such storms out to sea. Working to our advantage is the juicy southern branch which will fuel this storm and fuel it well. The same areas which just received a heavy and unusual dose of arctic chill (in the deep south) will be receiving rain and a lot of it late this week. The trend this year is that this portion of the jet stream "rules the roost" and is making up its own rules as far as what weather it intends to dish out. Although the long wave pattern may suggest an out to sea deflection, this storm as many of its predecessors could track a few hundred miles farther north west and thus have an impact late on MLK weekend.

After MLK weekend there appears to be a pile of jet energy that will unload on to the Rocky Mountain west. It will be enough for a powder fiesta during the second half of the month across the southern and central Rockies. Unless this energy transgresses through to the southern plains and southeast, it will ultimately allow mild air to flood the eastern third of the country and give the region a thaw. The teleconnection indices which were so ultra favorable for a month show a sharp neutralization by the 20th of the month. This certainly opens the door for a rough period ahead but we should see what shakes out in the coming days.

Friday, January 8, 2010

Limited sunshine and some garden variety Vermont chill has us looking ahead to MLK

And while record temperatures are challenged and broken all across the deep south this weekend, Vermont weather will stay quite ordinary for January with clouds, some sun, some flurries and a biting wind at least for Saturday. After temperatures struggle past 10 on Saturday, the afternoon Sunday should feel a little more comfortable with temperatures not quite as cold and less wind. In my search for winter weather excitement, I jumped ahead to MLK weekend where by that time it should be milder but perhaps stormier.

Until then, we can expect flurries and snow showers from a benign clipper system Tuesday. This is a rather pathetic looking disturbance to be put it bluntly but could dust the mountain with a light accumulation by first tracks time on Tuesday. Temperatures will then remain below freezing through Wednesday but perhaps sneak above freezing on a few occasions late in the week as much of the eastern third of the country, Vermont included, undergoes a big temperature moderation. We discussed the causes of this in the last update and I certainly emphasized some concern over a total shutdown of the arctic pipeline by the time next weekend rolls around. It appears, however, as if there will be some cold to be had up in Canada and thankfully we should be able to grab a bit of this cold as next weekend arrives and perhaps a bit of snow to go along with it. The upper ridge axis as I mentioned will shift east next week and the front flank of this ridge will be quite split from the juicy and active southern branch of the jet. Toward the beginning of next weekend, we should see a disturbance slide down the front flank of this ridge and provide us with a bit of re-enforcing chill but hopefully a few inches of snow as it does this.

I am not so concerned with rain MLK weekend as it appears we will not get any but I am hoping, like so many of us, that this very moist system along the Gulf Coast will head our way as we move into Sunday and Monday of this holiday weekend. The jet stream configuration suggests this might be tough since the eastward movement of the upper ridge has also allowed the mean upper trough axis to move east and may prove to be a mechanism steering our beloved southern branch systems out to sea. Its early though and two days ago the American model suggested this storm would bring rain to Vermont and now suggest the storm will move well to our south.

At the very least, I am happy to see glaring signs of split flow in the jet since it will limit our downside risks in the coming weeks and should allow any mild outbreaks to be short lived. If the storm late on the MLK weekend indeed goes wide right, there will be chances for both little and larger events in the days that follow.

Wednesday, January 6, 2010

Dry and very cold weekend ahead followed by moderating temps

Cold weather continues to grip much of the nation but the chill hardly has made a dent in Northern New England where as of this morning the base of the mountain was warmer than Tallahassee, Florida. The sunshine state capital was indeed 18 degrees Wednesday morning and could be as low as 10 this weekend while freezing temperatures could reach the outskirts of Miami. It would be an incredible event for the Gulf Coast and devastating for the citrus crops if the intensity of the cold were to verify. The cold relative to normal continues to be very inverted so that the southern tier of the country is receiving or expecting record cold while New England enjoys very ordinary winter weather.

There is nothing extraordinary in terms of snowfall for the upcoming weekend. The next surge of arctic air is on its way south and heading straight south. There is a clipper system associated with this upcoming surge of cold and it is supported by a vigorous piece of jet energy. Unfortunately, the moisture along with the energy are passing well to our south and will actually lose some steam before moving off the Mid Atlantic coast. We can expect flurries throughout the day Friday with upwards of an inch before it turns sharply colder by Saturday morning but remains mostly dry through the weekend. Be prepared for well below zero wind chills on Saturday. Sunday's temperatures will start chilly but daytime temps will warm through the teens and the day will feature less wind.

The surging PNA has teamed up with the Davis Straits blocking for our latest blast of cold but there are signs of a breakdown or a shutdown I should say to the Arctic Pipeline. The blocking is indicated to remain but will reposition itself across the Hudson Bay as the pattern across the northern latitude Pacific Ocean becomes more energetic. This development has significant ramifications on the weather regionally in terms of the intensity of the cold but with southern stream energy still on the playing field we will need to find some supply of cold to keep precipitation in the form of snow by the time MLK weekend arrives. The El Nino is alive and well and this means that mild outbreaks can strike quick and hard. It does not appear as if temperatures will get exceptionally mild late next week but we will feel the impact of the next storm (as I promised) around this time and will need a bit of cold and a favorable track for a powdery outcome.

Sunday, January 3, 2010

One final encore for the New Years storm and some good old time New England chill awaits us

The New Years storm proved to be quite an event and will prove nearly impossible to tally in terms of inches. The wind blew and blew hard and is likely to blow much of the snow from the trails into the woods. The snow will continue to fly through much of the day Monday with lighter winds and tolerable temperatures hovering in the high teens to the upper 20's. An additional and very difficult to measure, 3-5 inches of snow is possible between Sunday night and Monday which will leave MRG with a powder day of sorts. This will be followed by more flurries and snow showers Tuesday and perhaps another few inches and another powder day of sorts. The flurries will continue even through the end of the week although accumulations will be light.

Temperatures through much of the week will be defined as seasonable and New England through Thursday will be one of the few places in the eastern half of the country that will be seasonable as opposed to below normal. The rest of the this region, particularly the south, will be experiencing some unusual chill and likely some snow late in the week as more mischief in the southern branch of the jet stream collides with this cold air. This storm later in the week will ultimately allow a blast of cold to encompass the eastern third of the country and send temperatures here in our beloved Vermont well below zero as we get to the weekend. The storm will make a left turn up the coast and we will watch it as it does this but the jet stream as of now is very suppressed and our snow through the end of the week will consist of flurries and snow showers.

The surge of cold stems from the surging PNA or a building upper ridge in western Canada. There will be a few clippers riding down the front flank of this very large ridge and much of our new snow between Saturday the 9th and Wednesday the 13th will be a result of these weaker weather systems. As we move toward the late part of that week there is evidence of a strengthening and very energetic southern branch of the Jet Stream and with it should come another significant east coast event. This is way out on the forecasting timeline but we can do that since that is the way we like it at the SCWB. Hopefully everyone got a nice taste of the New Years wind blown powder and had a safe holiday.

Saturday, January 2, 2010

Storm making its westward rotation

Snowfall accumulations have been on the light side so far but this is not unexpected. Snowfall rates were expected to be light until Saturday afternoon when the region attains access to a better plume of moisture. With any aggressive forecast, I am always concerned but I will stick to the call of 2-3 feet between Friday and Tuesday and if I am wrong I am wrong. In all honesty though, if we don't get an additional 8-12 inches of the fresh stuff by tomorrow morning I will likely be wrong. Either way, it still shapes up to be a nice powder day and if we don't get a foot tonight we will at least get some and the early risers should get rewarded with some fluffy turns during the Sunday AM.

It will be interesting to watch this storm do a southwestward sweep of Coastal New England before rotating out to sea. It is a monster and precipitation will extend well westward from its core. The most intense snow will not be much greater than an inch per hour and is indicated to fall between late Saturday and the pre-dawn hours of Monday. This still means two very solid powder days before snow tapers to flurries. Anyway I have to end this update early so I can head out for a little fishing in the Gulf of Maine ;)

All kidding aside, we should new snowfall limited to clipper systems and terrain enhancement from the middle of next week through around the 13th of the month. The PNA will make a surge into positive territory and we can credit the PNA with an assist in handing us perhaps our coldest weather of the season next weekend into early in the following week. The southern branch may be brewing some trouble again around the middle of the month and it is here when I expect our next chance for a "big" event.