Think Snow, Tweet Snow !!!

Sunday, November 30, 2008

Sunday night event will fall short of expectations but high hopes remain for December

The old adage "be careful what you wish for" is what first comes to mind regarding our Sunday night event. The storm was a hot prospect a few days ago potentially turning into a big early season snow event. Unfortunately everything is came together a bit too fast. The primary storm center back in the Midwest is too strong and became so too fast and is thus sucking energy away from the coast and flooding the eastern seaboard with mild air at key levels of the atmosphere. Mad River will still make out just fine out of all this. Precipitation will start as a period of snow this evening, accumulate several inches before changing to a mix of sleet and freezing rain sometime within a few hours of midnight on Monday. The layer of warmth responsible for the change to "non-snow" is a fairly potent one and it will be interesting to see how warm Mt Washington gets since the inversion should encompass the summit. My guess is the observatory there will be 5-10 degrees warmer than the base of Mad River Monday morning but we will see.

Light snows and some light accumulations across the high terrain can be expected later Monday, Monday night and into Tuesday stemming mostly from the upper trough induced instability. Dry weather can then be expected Wednesday into early Thursday and temperatures could climb into the 40's by Thursday afternoon as mild air makes a brief appearance out ahead of an approaching cold front.

The pattern has been generally cold across southeastern North America over the past few weeks mainly due to the fortuitous global positioning of upper ridges in troughs. I remain very optimistic going well into December although fundamentally the above mentioned global positioning of ridges and troughs will undergo some changes. The most glaring is that the ridging and blocking will make a high latitude migration. By the tenth of the month, two areas of ridging will be noted one across the Bering Sea and another across Northern Europe. The two features will force most of the most intense cold to the North American side of the globe and will be centered over Canada by the middle of month making frequent intrusions into at least northern areas of the United States including northern New England. This is a different pattern than the prevailing pattern of the last two weeks where the center of the cold was deep in the southeast. Most of Canada in fact has a had a very warm month of November with much of the country running 3 degrees above average or more for the month.

As far as snow is concerned we should also fair quite well. A few rain showers could precede the turn to colder weather late on Thursday. Terrain induced instability snow showers should then grace the mountain going into the weekend and may provide the necessary shot in the arm for an opening at MRG. It will be a pattern consisting of a relatively inactive southern branch and a powerful polar jet so our snow beyond the 7th will result mostly from clipper systems. They could prove to be quite frequent however with accumulating snow on the mountain once every two days either of the terrain induced variety or from the clippers themselves. All told I would not be surprised to see some of the best December skiing since 2000 by the time we reach the 15th or the 20th of the month.

It will be a good month to be unemployed ;)

Tuesday, November 25, 2008

Yes, the time has come for 2008-2009...

And based on the number of emails I have received over the past two weeks it seems we are ready for a taste of winter, some powder and a trip up the single chair. My apologies for not getting things kicked started a bit earlier. I am still alive and so is the blog, which to be honest is a bit of a comfort considering the temporary peril my career seems to be in at the moment and the thought of having to test a rather challenging job market. At the very least there is plenty of time for blogging and if we can get a good early start to winter I might get the chance at a few mid-week powder days. I mean if we could put a price on a powder day at Mad River then why the heck would anybody start a blog like this ? So with all that said, the 08-09 season begins and hopefully turns into a memorable one for I could very much use it.

The seasonal part arrives a big late so I will summarize my thoughts and then move quickly into some prognostications for the next few weeks. Completely ignoring the current state of affairs and all the early snow, my favorite early season indicators appear to be very similar to last year. The one exception is the state of the ENSO; which, when compared to last year is running much closer to average. The ENSO describes the state of the equatorial Pacific and an ENSO event includes the likes of an El Nino or La Nina which is synonymous with sea surface temperatures that are running above or below average respectively. This years temperatures in the equatorial Pacific are closer to average, a sharp contrast to last year where clearly La Nina was clearly establishing itself as an early and dominant force on the weather. The La Nina indeed proved to be such a force last winter though its impact was wide ranging. It did as predicted bring numerous and quite disruptive rain events but a persistent storm track provided plenty of powder. It was a headache to keep track of the changes but the results were at least better than I expected. With the ENSO in a neutral state, my expectations have risen considerably. With the lack of a strong southeast ridge, I would expect the storm track to be further south and the weather pattern to resemble the current one for long stretches of the winter (more on that later).

There are a set of negatives that accompany the perceived improvements with the ENSO situation. The index used to measure the Pacific Decadal Oscillation (PDO) remains very negative. Such a state encourages a trough in the western part of North America (similar to last year). Snow cover over the northern hemisphere for October and November has also been very unimpressive. It has lagged the 30-year average through the entire month of October and although making a half-hearted comeback in November, still lags the normal build-up of snow in the northern hemisphere in autumn. It should be noted that the build-up of ice in the Arctic has been faster than last year. It should also be noted that the ice in the same regions of the Arctic did not fall to the insanely low summer levels of 2007. This makes intuitive sense when one looks at the data for 2008 and sees that temperatures have actually ticked cooler verses 2007. Through October, 2008 temperatures are the 9th warmest in 129 years of data while 2007 ranked 2nd. Anyway, without going off on a complete tangent, the build-up of snow/ice overall does not argue for colder than average temperatures throughout the winter in spite of the cold which has occurred.

So in summary I am more optimistic than last year but in spite of some of the early similarities to the 2000-2001 dream season, I would expect this season to fall short of that one. Snowfall will run within the normal range this year totaling anywhere between 220-280 inches. Temperatures will run above the 30-year average for the winter by about 2 degrees and we will likely encounter a real mild stretch that could cripple skiing for a few weeks. Right now I would guess this occurs in January.

Enough of that though. Seasonal forecasts are made and then forgotten and often turn out be wrong however fun they are to create. The shorter term is both predictable and more important. We also happen to be in the midst of a extremely favorable early season characterized by a strong western U.S. ridge and equally strong eastern trough. Cold weather has been the result along with 20-30 inches of early season pre-thanksgiving snow. Better yet, we appear to be locked in to a very favorable teleconnection induced long-wave pattern. The Pacific-North American (PNA) index is making a run into positive territory while the North Atlantic Oscillation appears to want to throw an all out negative-state bash. The pattern over the past few weeks is relatively blocked at high latitudes while cold in many of the important middle latitudes including both in Europe and in the eastern United States.

In the very short term, the strong upper low, or the driving force behind the Monday-Tuesday snow is becoming relatively stuck in the eastern Great Lakes. It would be nice to get the fruits of its labor but through Wednesday it will be depositing its snow farther west. By Thanksgiving day and then on Friday, some of this upper level energy will get booted eastward and this should allow for a slow decline in temperatures on the mountain and accumulating snow of the light and elevation induced variety. Any snow will taper to flurries Saturday before it turns completely dry Sunday.

The next chance at a real significant event arrives Sunday night into early Monday. The snow would result from a clipper potentially gone wild as it interacts with the Atlantic Ocean. Such things do happen when eastern troughs amplify in a big way and such an amplification is expected to occur early next week. Colder weather will again follow which is very good news in this early season and a few more weaker clippers should reinforce the early start to winter this year. We will update continuously as the situation evolves and as Mad River Glen decides how and when it decides to open.

Happy Thanksgiving to all and welcome back. The comments are always appreciated even if I don't have time to respond to them all !!