WeatherWatcher: Snow is back in the forecast, monthly graphs, last week's data

Snow has returned to the forecast later this week, almost right on time. You might remember I mentioned we could have another shot at snow and cold in my previous report on January 16. Cold air is surging south out of British Columbia once again this week. We are already seeing freezing temperatures Tuesday evening. Expect clear skies and low temperatures in the mid-upper 20's with highs in the upper 30's until Friday.

Friday morning through the weekend looks interesting and very inconsistent in the computer models. There are two low pressure systems wandering off the west coast, according to models for this weekend. First one, on Friday morning, is expected to bring showers starting as snow, then changing over to rain. Each model run changes the forecast to rain showers, while others hint at a more snowy pattern. I'd say the chance right now that we'll see any accumulating snow for Friday is about 20-30%.

The tracking of the low pressure centers, both Friday and over the weekend, are uncertain, and a slight change in their paths will put us into either snow, rain, or just cold. It's possible but not certain at this time that we could have a snowy weekend, possibly lasting well into next Tuesday.

Bottom line: It's far to early to tell at the moment because there is much uncertainty, but the right pieces are in place to possibly cause a snow event for the Shoreline area.

Month to date graphs:
I wanted to show that we've been below normal temperature for the majority of January, and rarely above normal, putting the month as a whole much colder than normal. Below are two graphs. The first is the daily average temperature compared to normal; the second is the daily high and low temperatures compared to normal.

Daily average temperature compared to normal.

Daily High and Low temperatures compared to normal.

On precipitation we are running just a little below normal, thanks to our arctic high pressure that dominated the first half of January, and a ridge in the jet stream that occurred in the last week of January.

Precipitation compared to normal plus snow accumulation.

Last week's data highlights (January 21 - 27):

High temperature: 51.3°F (Friday)

Low temperature: 31.8°F (Tuesday)

Rainiest day: 0.14 inches (Sunday)

Total rainfall: 0.16 inches

Warmest day: 44.1°F (Saturday)

Coldest day: 36.3°F (Tuesday

Average temperature: 40.3°F, normal for the week was 43.0°F (2.7°F below normal)

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