Storms!

Friday, November 16, 2012

8:50 A.M.
I’m happy. You know why I’m happy? Because we will finally see a string of strong storms that will streak from ocean to peak through next week. Now that was clever.
Let’s look at the timeline for our storms. 
Our first storm comes in on Saturday morning. This one looks pretty impressive in the model, but the front will stretch out and weaken before it hits the Western Washington lowlands. It won’t be a notable storm, but it will open the door for the other storms to follow.
Valid 07:00 am PST Sat, 17 Nov 2012 – 27hr Fcst – UW 12km 12z WRF-GFS 3 hour precip
It will also bring some solid wind to some areas, mainly the coast. The map below shows the surface temperature, and more importantly, the isobars over the region at the given time. It also shows wind barbs, but unless you have the eyesight of a Peregrine Falcon, they are hard to see. It looks like there will be gale-force winds off our coast, though.
Valid 07:00 am PST Sat, 17 Nov 2012 – 27hr Fcst – UW 12km 12z WRF-GFS SLP, 2m temp, 10 wind
We’ll get another storm Sunday night. This one will be significantly wetter but probably won’t be as windy. Look at the three-hour precipitation map below, and you’ll get an idea of the front of this storm.
Valid 07:00 pm PST Sun, 18 Nov 2012 – 63hr Fcst – UW 12km 12z WRF-GFS 3 hour precip
But the main thing that the meteorological community is looking at right now is a storm slated for Monday night. This storm will bring heavy rainfall totals here and massive amounts of rain in southern Oregon. It also has the potential to bring high winds to the area. Let’s take a look.
The WRF-GFS brings a 982 mb low, deepens it to 979 mb, and brings it into southern Vancouver Island. This would certainly bring gales to the coast and would probably bring 25-35 mph sustained winds over Puget Sound, with gusts up to 50 in exposed regions, like Alki Point. Places. The pressure orientation isn’t quite right for super high winds in the Puget Sound area, as there won’t be a massive pressure gradient between Bellingham and Portland. In the 2006 Hanukkah Eve Storm, there was a pressure difference of over 22 mb between the two sites, and the current WRF-GFS shows a maximum pressure gradient of 9mb or so. It will still be our windiest storm of the season though, and it’s a ways out. It bears watching
Valid 10:00 am PST Mon, 19 Nov 2012 – 78hr Fcst – UW 12km 12z WRF-GFS 10m wind, SLP
The bigger story with this storm will be the massive amounts of rain it will bring to the Pacific Northwest, especially southwest Oregon. In 48 hours, places like Brookings could see well over 10 inches of rain.
Valid 04:00 pm PST Tue, 20 Nov 2012 – 108hr Fcst – UW 12km 12z WRF-GFS 48 hour precip
In fact, the Portland office for the National Weather Service has issued a hydrologic outlook for Kelso, WA to Eugene, OR. South of Eugene, the Medford office is in charge, and they haven’t issued any hydrologic outlooks yet, but they are predicted to see even heavier rain. 
Yesterday, in my WeatherOn long range blog, I mentioned that this would be a “Pineapple Express” type setup. Well, I read Cliff Mass’ blog yesterday, and he had a better name for it: the “Teriyaki Express.” He dubbed it as such because the moisture is originating from the higher latitudes closer to Asia than the subtropics from Hawaii. During true Pineapple Express events, the temperature can rise into the 60s. The warmest temperature recorded at Sea-Tac in December was 63 degrees and occurred during a Pineapple Express… at 2 A.M. in the morning! I’m only expecting highs into the mid 50s, which is still a bit milder than normal, but isn’t too bad. The snow level will likely peak around 5,000 feet for the Monday storm. During a full-fledged Pineapple Express, the snow level can rise to 11,000 feet, meaning that it is raining in every single location in the state except the tops of Mt. Rainier and Mt. Adams.
One more thing… the track of the Monday storm is still pretty uncertain. It will be wet and windy, but it’s hard to pin down the details at this point. As always, I’ll keep you posted as the event comes closer.
TGIF!
Charlie
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