Wednesday, November 30, 2011
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. 🙂