Saturday, February 7, 2015

What Happened to Winter in January

(See the next post for last night's update on course conditions as well as the status of next week's Cupid Cup).

Lee Warnick, who teaches media courses at BYU-Idaho (and is a self-proclaimed life-long weather and climate wonk) sends out a detailed weather report at the end of each month.  He kindly gave me permission to let me re-post his report here.  It's nice to see the what and why of the weather.  Our El Nino year explains our troubles with ski conditions.
You can also subscribe to his weather reports  (Rexburg Weather Group/Google Groups).

January Rexburg Temperatures

High temperatures: 29.9 / 2.0 degrees above normal
Low temperatures: 14.8 / 4.2 degrees above normal

Zero or below days: 4     Normal: 6.6
Highest wind gust: 40 mph on the 5th
Number of windy days: 1     Normal: 3.3

Highest temperature: 44 on the 27th
Lowest temperature: -14 on there 1st
Lowest wind chill: -28 on the 2nd

     • Our post-Christmas cold snap lasted briefly into the new year, but within a few days we were several degrees above freezing, setting a daily record of 40 by the 7th. For the rest of the month we rode temperature roller coasters that peaked in the 40s each time before retreating into the 20s and 30s.

     • What helped keep this from being a near-record-breaking, El Niño-fueled month was the frequent moderate-to-dense fog that seemed to return whenever the few puny storms coming our way weren't clearing things out. By my count, we had at least decent fog on almost half of our days in January. And that fog was thick enough often enough to knock our daytime temps down significantly. This was the year we seemed to have just the perfect test-tube combination of snow on the ground along with just-so temps, humidity and a predominantly stable airmass. Did you notice how the fog many times seemed to almost magically materialize just after the sun went down? 

     • Stable airmass? I'd say so! The barometric pressure was above 30.00 (which is marginally above "neutral" level) on all 31 days at the time I took my morning reading. Most of the time the barometer was well above 30.00. Not a lot of action will be taking place under this kind of high pressure dominance.

January Rexburg Precipitation

Precipitation: 0.72 / 73 percent of normal
Snowfall: 6.2 / 44 percent of normal

2014-15 water year precipitation (4 of 12 months): 3.49 / 85 percent of normal
2014-15 seasonal snowfall: 36.4 / 91 percent of normal

     • With the kind of high pressure dominance we experienced in January (not a surprise in an El Ni ño winter), the relative lack of snow was also not surprising. As you can see above, we got less than half our usual January total. The snow we did receive came in one decent storm on the 16th, a few piddly little things that barely covered the ground, and even some eerie fog-generated stuff that left trees ghostly well into the afternoon on some days. Finally, a third of our January precip came from an all-rain system on the 27th-28th.

     • Rexburg sees lots of snow -- nearly 5 feet per year. But unlike the places you've been hearing about lately that have been dumped on by a single storm with snow measured in feet, we tend to receive our snow in more frequent, lighter doses. In other words, it snows a little a lot in Rexburg. That hasn't been the case this year, however. I've counted four storms so far that have left four inches or more of snow. It hasn't snowed as often as is usual this winter, but when it has, it's tended to be more productive.

     • Our relative lack of January snow is nothing compared to what our neighbors in Utah saw. Salt Lake City got virtually no snow in January -- they usually receive a foot. We were down there last weekend and were amazed to see not just a lack of snow on the ground in the valleys (not even in drifts) but the snow level on the mountains as high as 8,000 feet. That's more like April than January! But really, once you travel just a little ways south of Rexburg, the snow cover largely vanishes. We have more than our share around here and more than could reasonably be expected in this kind of year (we're at 91 percent of normal snowfall so far this season).

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