SILVERTON HILLS FIELD BURNING GUIDANCE WEATHER NORTHWEST WEATHER OPERATIONS CENTER 810 AM PDT FRI JUL 29 2016 DISCUSSION: Weak upper ridging will maintain very warm inland temperatures today. An upper level trough will increase night and morning clouds and cooler temperatures this weekend. Brief high pressure will move over the area Monday before another upper low impacts the clouds and temperatures Tuesday and Wednesday. FORECAST: Today: Sunny, with a high near 92. North wind 5 to 9 mph. Minimum RH: 32 Surface winds: Morning: N 8 Afternoon: N 11 Transport winds: Morning: N 13 Afternoon: NNW 17 Maximum mixing height: 3800 feet Sunset tonight: 8:36pm HOURLY GUIDANCE: Time: 10am 11am 12pm 1pm 2pm 3pm 4pm 5pm 6pm Temperature: 71 76 80 84 88 90 92 92 90 Humidity: 63 54 47 42 38 35 32 32 34 SFC Winds: NE 5 N 8 N 9 N 8 N 10 N 9 N 11 N 13 N 12 MxHt (ft): 1000 1300 1700 2300 3000 3600 3800 3300 2400 Trans Winds: N 14 N 13 N 14 N 16 N 16 N 16 NNW 17 NNW 20 NNW 23 OUTLOOK: Tonight: Clear, with a low around 56. North wind 6 to 11 mph becoming light north northwest in the evening. Saturday: Sunny, with a high near 82. Calm wind becoming north 5 to 7 mph in the afternoon. Smoke plumes reaching a range of 2900 to 3400 feet. Transport winds northwest 9 to 14 mph. Sunday: Partly sunny, with a high near 80. Calm wind becoming north northwest 5 to 7 mph in the afternoon. Expect smoke to rise to about 2700 to 3200 feet. Transport winds north 7 to 12 mph. Monday: Mostly sunny, with a high near 79. Maximum smoke rise generally 3900 to 4400 feet. Transport winds northwest 9 to 14 mph. Tuesday: Mostly sunny, with a high near 78. Smoke plumes reaching a range of 3300 to 3800 feet. Transport winds north 7 to 12 mph. Wednesday: Sunny, with a high near 81. Expect smoke to rise to about 3000 to 3500 feet. Transport winds north 7 to 12 mph. Notes: 1. This is a compilation of forecast guidance material formatted for convenient use by agricultural field burning interests in the northern Willamette Valley. 2. Mixing height (MxHt), as used here, is the model planetary boundary height. As a practical matter it is the approximate height to which a smoke plume will rise assuming good ignition, dry fuels, and winds less than about 15 mph. 3. Transport winds are a layer average through the mixing height, weighted slightly toward the winds at the top of the layer. 4. Surface wind direction is the general expected wind direction. At a specific point surface winds are highly dependent on local terrain conditions. 5. Frequent updated guidance information is available on Twitter with hashtag #wxnwfb. (Unauthorized reproduction or re-transmission prohibited.)