Rain

UW Atmospheric Sciences Composite Northwest Radar Loop: Valid 2:24 P.M. 4/4/2013

“Hey buddy! It’s been awhile! How are you? What have you been up to lately? Do you and the jet stream still have that thing, or are you cut off from her lovely geostrophic flow?”

That’s what I found myself saying to myself this morning as I walked around campus. We’ve had some very nice weather around here, but I’m very happy to see the rain. While it is sad to see the raindrops knocking the flowers on the cherry blossoms in the Quad to the ground, the rain has done wonders for my allergies, and it’s always nice to have a change. I don’t know how valid this is, but I always have this image in my head of the Earth just getting dirtier and dirtier the longer we are rain-less, and it’s wonderful when the Earth finally takes a shower and cleans herself off.

Let’s take a look at what is happening out there. Here is the latest water vapor satellite picture from GOES-West

Valid 02:30 pm PDT Thu 04 Apr 2013 – UW 4km West Coast Water Vapor Imagery

As you can see, we have a rather unorganized system rolling through our area. The occluded front is what is bringing us the rain. A little meteorology 101: an occluded front forms when a cold front overtakes a warm front. I have some more info on fronts here.

Below is the WRF model output for the surface winds, temperature, and pressure from the 12z GFS run this morning. You can see the low pressure system making its way up the coastline. It is not very compact, so it is not bringing strong winds to the area, even on the coast. That’s not to say it isn’t a bit breezy; there are small craft advisories for most of the coast and gale warnings extending from Willapa Bay to Florence, Oregon, but this is nothing out of the ordinary.

Valid 02:00 pm PDT Thu, 04 Apr 2013 – 9hr Fcst: UW 12z WRF-GFS 12km SLP, 10m winds, and temp