Friday, November 18, 2016

The First Normal Day of Fall

Yesterday (Thursday) felt very different from virtually every other day this felt normal.

Thursday's high and low were virtually identical to the average for that day (see graphic), something that has not happened virtually the entire (very warm) fall.  Biking home last night, I felt the unaccustomed chill, sort of like a Hawaiian visiting the U.S. during winter.
The reason for normality of the past day? A temporary breakdown in the offshore low/trough, which was pushing southerly, warm winds northward.

Unfortunately, the persistent heat of the past weeks has greatly affected our snowpack. The following chart shows the percentage of normal snowpack as of Friday.  Most of the region has less than 50% of normal (red color),  with large portions of Oregon less than 20%.  The Olympics are at 10%  Only the north Cascades are near normal.

Over the next few days, a deep trough of low pressure over the eastern Pacific will bring strong flow as far south as California (see map for10 AM Saturday)
As a result, California will be unusually wet, although the Northwest will not escape the moisture (see 72 h total precipitation).

 Although the air mass over the western U.S. will be relatively warm, there will be sufficient moisture s0that the higher elevations (above 4500 ft) will get substantial snowfall (see 72h totals below).  Large amounts in the Sierra and BC high country.  Not so good for the central WA Cascades and down through Oregon, since they are lower.

Whistler will have enough to open on November 23.


Unknown said...

Calif rain = cheaper almonds

wff255 said...

Today I saw several flocks of geese in V-formations flying high and due south. Maybe they know something we don't?

Westside guy said...

Flying geese does not necessarily mean migrating geese. Depending on the time of day, they may have been just leaving their nighttime home in search of food, or returning to their preferred overnight spot.

Canada geese often overwinter in western Washington. They like to spend the night at or near bodies of water - Lake Tapps is one such popular spot somewhat near where I live. They depart in the morning to scavenge food from some of the area fields, then return to the lake at dusk.

JeffB said...

There's no such thing as normal in weather or climate.

Leftovers Lady said...

You may wish to correct your statement "a Hawaiian visiting the U.S. during winter" to " a Hawaiian visiting the mainland during winter" as Hawaii is part of the U.S. after all. All of my friends living in Hawaii get annoyed when people say "the states" or the "U.S.". It is more correct to say "the mainland".

Bruce Kay said...

JeffB ..... sure there is. What the hell do you think "climate" is anyway?