Sunday, November 27, 2011

Big warm-up on the Way

Trung asked about the big warm-up in the current forecast in a couple days. Here's why:

Big pattern change is underway for Alaska and will bring much milder weather to the Interior by midweek. First, here is the 500mb heights and 850mb temperatures for this past Saturday morning (from the ECMWF). This shows a closed low west of Anchorage and a fairly chilly airmass over most of mainland Alaska; the blue colors are 850mb (~4500 MSL) temperatures of -16C or lower.

Now, here is the forecast from the 12Z Sunday ECMWF valid at 3am AST Wednesday Nov 30th. Deep southwest flow from the north Pacific covers most of the state, with the chilly air having retreated the Brooks Range. This could wind up being a fairly snowy pattern for Fairbanks-land, but as always in these situations, if the winds aloft are just a little bit too southerly, then we will "chinook out". At this point though it looks to me like the best forecast is for some snow the middle and end of this week.


  1. Always enjoy reading your comments, Rick. Explains a lot of the "grand picture" of commercial weather reports/forecasts. But then I don't think most readers/reporters really care what they read - and for that matter, perhaps most listeners don't care why things happen :-)