We are finding more and more support and reason's for trying to set up sounding towers through out NW Oregon Coast Range in the name of accurate winter forecasts, here's the NWS's opinion through Tyree and Dr. Robs statement. Dr. Rob is a highly educated and respectable buddy of mine on the weather email list, he offers a lot to the local weather community.
Tyree's Take (NWS of Portland):
Grant,
Temperature sensors at 500, 1000 and 1,500 feet (or tower top) would be very beneficial to help obtain freezing level information and help with rain/snow decisions during the winter months. As for wind, I suggest mounting the wind instrument at 10 meters (~33 ft), which is the standard height we place our wind instruments. That way, the wind data is useful to compare to other locations.
Tyree
Tyree Wilde
Warning Coordination Meteorologist
NOAA's National Weather Service
Portland, OR
Dr. Rob's View:
I believe it is imperative for the placement of two to three more towers located along the Coast Range. A temperature sensor, anemometer, and sounding reading would be highly vital if they were implemented. These should be placed roughly south of Forest Grove to just north of Salem. In the event of a southerly wind event/storm it would be exceedingly helpful to understand the winds below 950mb to get an idea how strong the winds are occurring below the 2,000' plateau and whether the temperatures are rising due to warm air advection which may result in improved mixing. These factors can be used to guesstimate wind speeds down into the Willamette Valley as the south/southwesterly winds descend and/or are mixed towards the surface ahead of a frontal system. Currently the Rockhouse1 RAWS is the only observation in 1,500' to 2,000' elevation to use as a measure for windy to high wind conditions in the Willamette Valley roughly from Salem northward. In past seasons when the wind gusts reach 70mph at Rockhouse1 RAWS gusts exceeding 50mph are shortly to follow into the Salem area. If we had such information farther north it would help greatly with wind speed projections into the western Willamette Valley areas for locations such as McMinnville, Newberg, Gaston, Sherwood, etc.
On the other side of the coin let's discuss the impacts additional towers and sounding, temperature, dewpoint, and wind readings would have on understanding the temperature column below 2,000'. Since the northern Willamette Valley has various micro-climates and when experiencing Wintry weather the Gorge is the main player in terms of the depth of cold air dome over the Portland/Vancouver area, wet bulb effect, evaporative cooling, to name a few. If such towers were in place we would have a much better understanding of the depth of the cold layer, the extent in which is lies to the south and southwest, whether or not it is being eroded from warmer pacific air, and to determine if the Cities of the Willamette Valley are going to experience snow, sleet, ice pellets, freezing rain, or just a cold rain. As of right now the main instruments used for cold layer depth are the KPTV Tower temperatures. That is just not enough information to help see or take a slice of the temperature column to our south/southwest.
For all of the reasons I have explained and discussed above I think it is important and should be a goal of constructing these towers.
- Dr. Rob
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