Monday, December 30, 2013
The latest model runs have thrown some uncertainty into the short term forecast, especially for Wednesday morning, as one of the American models have brought the last wave for Wednesday morning across the area stronger than earlier forecast. What is more certain, however, is that there will be two main periods of snow occurring around mid-morning Tuesday and again after midnight Tuesday, with much lighter snow or even a break later Tuesday afternoon into the evening.
My gut feeling is to believe the snowier solution, so I might expect 6-12” by Wednesday afternoon for both storms. The lack of cold air will limit accumulations during the day Tuesday so that only 2-4” are expected by sunset, with an additional 4-8” early Wednesday morning into the early afternoon.
Snow showers will end Wednesday evening and mountain slopes should warm for Thursday and Friday with periods of sun. Another storm approaches the area for the weekend and light snow should begin again Friday night. Forecasts from a week ago had this wave heralding a pattern change to very cold temperatures, however current model trends keep this wave progressive and limit snowfall to only light amounts by Saturday morning with seasonably cool air.
It appears the sun returns later Saturday into Sunday morning as the west coast ridge rebuilds, forcing the storminess to our east. There is a lot of forecast uncertainty after that as the Gulf of Alaska ridge is forecast to either break down or be undercut by westerly Pacific flow for a period of time.
Sunday, December 29, 2013
A weak and dry wave will brush by our area on Monday leading to only cloudiness. Another wave in northwest flow should be far more productive forcing snow to begin Tuesday morning, however the absence of cold air will limit the big accumulations during the day. The last shortwave moving through the northwest flow will bring colder air early Wednesday morning, but this time the moisture is limited, though snow showers should will likely continue through the morning. A small shift to the north or south would change the forecast, but currently I expect 4-8” by noon Wednesday before a transient ridge moves over the area bringing some sun for Wednesday aftternoon and a sunny day for Thursday.
Showers will begin again Friday ahead of a much colder and more significant system that is currently forecast to sweep through the area Saturday. Earlier model solutions had this wave beginning a long-lasting pattern shift, but current model runs have the Gulf of Alaska ridge rebuilding and forcing the coldest air to slide to our east.
A cold and snowy weekend will then be followed by warming and drying early in the next workweek as the Gulf of Alaska ridge expands over our area.
Friday, December 27, 2013
A ridge in the Gulf of Alaska is keeping mild northwest flow over the area. The Storm Peak Lab near the top of Mt. Werner did not get much below 15F last night even as the valley reached 0F in the cold temperature-inverted airmass. A beautiful sunny and seasonably warm day on the hill is on tap for today before a splitting shortwave rounding the top of the ridge affects our area by midday Saturday beginning with high cloudiness and falling temperatures.
Snow is expected by midnight Saturday and through the rest of the night, but amounts are forecast to be light and only in the 1-4” range. A couple of disturbances in the northwest flow should influence our weather through midweek. The first wave will bring some more snow by late Monday night or early Tuesday with the second stronger and moister wave continuing heavier snows Tuesday night into Wednesday morning. Snow showers should continue through Wednesday evening before we may see some clearing on Thursday.
Another wave in this northwest flow may affect the area by Friday, although current forecasts have this one grazing us and producing only very light snow. After that, major disagreements in the models appear in the 10 day period as one is forecasting a pattern change by breaking down the Gulf of Alaska ridge while another keeps that ridge intact.
Thursday, December 26, 2013
As a weak wave exits the area today, warming should occur through Saturday morning on the mountain slopes as the valleys stay cold in well established temperature inversions.
Another weak and dry wave moves across the area later on Saturday bringing cooler temperatures, but no snow. However, another moister and stronger wave quickly follows and may produce some snow for Sunday. Models originally predicted this wave to our east, but have since trended further west improving our chances for precipitation.
A nice Monday morning before another wave is forecast to begin affecting our area by late Monday. Again, models have trended stronger and further west with this system, and current forecasts have snow starting late Monday as the cool wave approaches in moist northwest flow. Snow may continue Tuesday into Wednesday morning before ridging once again takes hold creating warmer and dry conditions to close out the workweek.
An active weather pattern appears likely to persist, with models tentatively predicting another storm for later in the weekend.
Tuesday, December 24, 2013
The well advertised wave moving through northwest flow did not begin to affect our area till around 4am this morning. We had a burst of snowfall between around 9-10am that was falling at several inches per hour, and another band looks to cross the area later this afternoon. The snow that fell earlier was relatively dense, and with some round graupel particles mixed in, the snow should fill in the tracks on the hill nicely. Temperatures should be falling through the day and hopefully we can get some accumulating snow crystals called dendrites to add a layer of light and fluffy powder for later today. I expect outstanding skiing on the hill today as the storm passes through.
If skies clear tonight, it could be a chilly start to the day tomorrow, although it should be a brilliantly sunny day. A dry wave passes Thursday and that may knock temperatures down a few degrees before they rebound to produce unseasonably warm weather by Friday. Valleys will likely stay cool as temperature inversions reform and persist over the the fresh snowpack.
Another weak wave to our north that grazes the area on Saturday will create more seasonable temperatures that look to last into and possibly through the next work week. Models are struggling with the forecast for the following weekend as one flattens the ridge in the Gulf of Alaska possibly leading to some weather for our area while another rebuilds the ridge and keeps us dry.