Is Winter Over?

Well the answer on the calendar is no, but meteorologically it might be over, let me explain.

Here in the Pacific Northwest our winter usually ends after about February 25-28. In March our chances of an arctic outbreak or any lowland snow dramatically decrease, however mountain snow and wind events are still possible. You might be thinking so what, its only the 2nd week of February.

Here  is why I think our lowland winter is over.

Currently we have a big ridge of high pressure sitting just to the west of us causing the storm track (jet stream) to go over us and giving us mild temps. 

Now here is an image of the 18z GFS ensemble mean 500mb heights at hour 288 (2/23/12)

Notice the ridge of high pressure is still sitting there almost 2 weeks from now.

However there is only one last chance of winter that models are hinting at.

The image below is the 18z GFS ensemble mean 500mb heights at hour 324 (2/25/12) 

Notice how the ridge moves to the northwest allowing the cold air to seep in.

Now if this does not happen then our winter is over for the lowlands.

My forecast:

Timberline Forecast via NWS:

Sunday: Increasing clouds, with a high near 32. West wind between 5 and 8 mph. 

Sunday Night: Snow likely. Cloudy, with a low around 23. West southwest wind between 5 and 8 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 3 inches possible. 

Monday: Snow showers likely, mainly before 4pm. Cloudy, with a high near 24. Northwest wind around 8 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 3 inches possible. 

Monday Night: A 30 percent chance of snow showers, mainly before 10pm. Cloudy, with a low around 22. North northwest wind between 6 and 8 mph. Little or no snow accumulation expected. 

Tuesday: A 30 percent chance of snow, mainly after 10am. Mostly cloudy, with a high near 26. Little or no snow accumulation expected. 

Tuesday Night: A 40 percent chance of snow showers. Mostly cloudy, with a low around 21. Little or no snow accumulation expected. 

Wednesday: A chance of snow showers. Partly sunny, with a high near 28. 

Wednesday Night: A slight chance of snow showers. Mostly cloudy, with a low around 27.

Thanks for reading

-Michael