Wednesday, November 30, 2011

Arctic Air Next Week?

Wednesday, November 30, 2011
1:01 P.M.

Yeah, I know No-Shave November is completely unrelated to weather. However, the model runs this morning made me hesitant about shaving my patchy, warming layer of facial hair. Remember how I was talking about how areas east of us would see very cold air next week due to the huge high pressure over our area creating a trough in the jet stream east of us where arctic air can invade? The big dome of high pressure is now forecast to move a little bit to the west next week or so.

If this holds true, we will see frigid temperatures, and if we have moisture, we will certainly see snowfall in the lowlands.

Take a look at the model from last night. I showed this picture in my previous blog post. The high is too far east for the Pacific Northwest to get cold air, but Montana would get frigid temperatures if this were to happen.

Valid 04:00 am PST Wed, 07 Dec 2011 - 180hr Fcst - UW 00z 36km WRF-GFS 1000-500mb thickness, SLP (last night's run)

This morning's run, just 12 hours later, is completely different. The high is further west, and Washington would be colder than a toilet seat in Siberia. Ok, maybe it won't be that cold, but high temperatures would be well below freezing, and low temperatures would be in the teens in Seattle with single digits in the suburbs.

 Valid 04:00 pm PST Wed, 07 Dec 2011 - 180hr Fcst - UW 12z 36km WRF-GFS 1000-500mb thickness, SLP

Look at that! Much colder air over our region, and the high is only slightly further west. This just shows the thickness of the atmosphere, where lower thicknesses generally equal colder temperatures since cold air is denser. Let's take a look at the surface temperature predicted at this time.
Valid 04:00 pm PST Wed, 07 Dec 2011 - 180hr Fcst - UW 12z 36km WRF-GFS 10m winds, 2m temp. SLP

In this picture, it is very cold over our region. There would also be strong winds through the Fraser River Valley as the cold arctic air spills into our region.
Valid 04:00 pm PST Wed, 07 Dec 2011 - 180hr Fcst - UW 12z 12km WRF-GFS 10m winds, SLP

Will this change? Absolutely. The models are not very accurate this far out. In fact, it could all change in tonight's run. However, it is interesting to see. Hopefully, it won't change. Models don't give us any moisture while we are this cold, but if moisture ever comes in, it will be in the form of snow for everyone.

Bottom line: don't get too excited yet, but there is hope for some interesting weather. 

Thanks for reading, and do some cold dances for me! Hopefully, you'll be doing snow dances next week. :)



  1. I'm doing a snow dance now hoping for snow next week! Why can't we get precip AND cold air at the same time?! It's so hard to get snow around here. Keep us posted!

    Mrs. Anonymous

  2. Hi Mrs. Anonymous! Thank you for posting. The model runs this morning continue the trend towards cold air, and are even colder. It is very exciting to see, but NOTHING is set in stone, especially this far out. I will blog about it this afternoon.

  3. Have you ever noticed that when TV meteorologists forecast higher temps and dry weather in the winter, they say that the weather will "improve". Clearly, they don't share our idea of what good weather is made of! In my book, the weather will have "improved" when there is a foot of snow on the ground! :) Thanks for the forecasts, Charlie!

  4. Thank you Megan! I agree wholeheartedly. I love "improving" weather in the summer... great for swimming in Lake Washington. In the winter, "improving" weather, as tv meteorologists put it, is pretty boring, especially when freezing fog and smog result. In my book, "improving weather" includes but is not limited to torrential rains, massive snowstorms, and fierce windstorms. The famous stormy trio that the Pacific Northwest is famous for. :)