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.)