Tuesday, October 16, 2018

Still No Snow

With rain and very mild temperatures today (up to 48°F so far), Fairbanks is moving further into uncharted territory in terms of the lack of any wintry weather so far this season.  Today the airport has reported 0.05" of rain and no snow, there's zero snow on the ground, and the temperature seems very likely to stay above freezing through midnight.

Putting aside the lack of snow on earlier dates, there are only two other days in Fairbanks history that meet these conditions at this late date in the autumn: October 23, 1981, and October 28, 2013.  In 1981 several inches of snow had fallen earlier in the month and then melted out; the situation in 2013 was more similar to this year, but even then there had been hints of winter's approach with occasional light snow in both September and October.  Here's my post from late October 2013: http://ak-wx.blogspot.com/2013/10/record-warmth-again.html

Here are some non-wintry webcam views from Fairbanks-land this afternoon.

Cleary Summit (2200' elevation) on the Steese Highway:

UAF's webcam on the West Ridge of campus:

Ester Dome:

In view of the bare ground, an interesting question to ask is, "How cold can it get without snow cover?"  The quick answer is, of course, "Pretty cold"; in December 1934, after the great chinook melted Fairbanks' snow cover, the temperature dropped to -29°F on Christmas Eve with only a trace of snow reported on the ground.

A more comprehensive search for cold conditions with no snow cover is complicated by the fact that Alaska's cooperative observers have often reported zero snow depth in error (instead of new snow amount, for example), and missing snow depth is often recorded as zero.  I did find a couple of interesting examples, though.  Just a couple of years ago (Nov 2016) the Fort Yukon SNOTEL site reported -36°F with a zero-inch snow depth, and the Fort Yukon RAWS saw -34°F the same day.  I don't really trust the snow depth number, however; I suspect there could easily have been an inch or two on the ground.

Perhaps a more credible instance is November 11, 1984, at Chandalar Lake in the Brooks Range, when -33°F was reported with only a trace of snow on the ground.  However, in this case a "trace" may just mean "less than an inch", as preceding conditions suggest there might have been a very thin but continuous snow cover.

I haven't investigated to see what Alaska's lowest reported temperature is with zero snow on the ground - if anyone has an idea, please leave a comment!


  1. Another anomaly is the level of the water table and soil saturation with water. Near Fairbanks rivers are still high and rain has soaked the soils. Any precipitation that falls as liquid soon adds to both unlike snow that defers to later melt.

    Current Alaskan hydrology: https://water.weather.gov/ahps2/index.php?wfo=pafg


    1. Good point, Gary. The timing of seasonal hydrological changes is greatly altered with conditions like this.

    2. We've discussed this increase in water table and river level previously. I believe it's a recent event for a few years but haven't researched the trend in gauge levels. Certainly the local ponds have been high prior to freeze-up and that mirrors the underlying water table.

      There was finally thin ice forming 10/18 on the shore of shallow ponds. It used to be they'd be frozen over by 10/10-15. Not scientific just an observation.


    3. Addendum to local pond freezing: 10/22 the Fairbanks International Floatplane pond was about 80%+ covered with a thin layer of ice. Overnight radiational cooling was likely the cause. Today 10/23 it's ice free again due to warming air yesterday at the surface (+47*F) and today (+43*F) plus increasing cloud cover. It was a nice winter while it lasted.


    4. Thanks for the information, Gary. The persistence of the warmth is really remarkable: only two days so far with a high below 40F, which is a record for this late in the season. Typically Fairbanks would have had at least one day with a high around 20F by now.

    5. The water temperature at the surface is mid to lower 30's F and conducive to the formation of ice. Given windless conditions and radiational loss or cold air above it can form initially on the surface in shallow near shore areas.

      But any surface water mixing via wind, cloud cover, or warm air can raise the water's temp. Warmer water below the surface down to the pond's bottom adds to the tenuous condition. It'll take a few calm below freezing and ideally clear days to establish the initial ice cover.

      Maybe by Pumpkin Day we'll see changes.