A Sopping Start to December

Four days into the month, and we’ve already measured more rain than we saw in the first 27 days of last December.

Unlike moisture-starved December 2011, which went into the books as Seattle’s fourth-driest on record, this December has started out on an especially damp note. Since Saturday, 1.87 inches of rain has fallen at Sea-Tac Airport—more than an inch above the norm for the first four days of the month. (Total 2012 precipitation now stands at 43.28 inches.) The month’s wet beginnings couldn’t be any more opposite from last December, when just .01 inches fell in the first ten days—and barely a quarter-inch through Christmas.

While we won’t be spoiled by a December 2011 repeat anytime soon, things will dry out considerably around the metro area as we head into the latter half of the week. Already, the steady rains that fell early this morning have moved off to our east, leaving skies mainly dry, with even some sunbreaks in downtown Seattle.

Showers trailing behind the front are likely later this afternoon and evening, but they should be pretty light. After spending a good part of the day in the low- to mid-50s, temperatures will drop back into the 40s for tonight.

Any lingering rain should subside by tomorrow morning, making for a mostly dry—and partly cloudy—day. Highs will also nose back closer to the early December average of 47 degrees.

The circa-December 2011 weather takes a hiatus on Thursday as a frontal system slides into Western Washington from B.C. Amounts with this latest round of moisture will range from a third to half an inch of rain—similar to the totals observed around the Sound this morning. Because the system will be coming at us from the northwest, temperatures will stay on the cool side, with highs on Thursday dropping into the mid 40s.

Another bout of showers is likely early Friday, before drier conditions set in as a ridge of high pressure in the eastern Pacific moves closer to us. Temperatures will also continue to fall as colder air trickles in from the north, with maximum readings on Friday in the lower 40s.

High pressure is expected to remain nearby through the coming weekend, keeping our temperatures solidly below average—and diverting most of the wet weather to our north and east. Occasional showers are still possible at times, though, especially on Sunday.

After all, this is no December 2011.