<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal">SILVERTON HILLS FIELD BURNING FORECAST<o:p></o:p></p>
<p class="MsoNormal">OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE<o:p></o:p></p>
<p class="MsoNormal">8:45 AM PDT MON SEP 18, 2017<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">BURN ADVISORY:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Agricultural burning is recommended to be limited to the hours of 8 a.m. to 5:30 p.m.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Prep burning is not allowed.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">WEATHER DISCUSSION:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">A strong upper-level disturbance is destabilizing the atmosphere, as a surface frontal system brings scattered showers and isolated thunderstorms across the Willamette Valley today. Wetting rains between 0.20-0.75 inches of rainfall have
fallen in the last 24 hours, and an additional 0.67 inches are expected to fall today across Marion County. The heaviest showers will occur this afternoon and persist overnight.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">TODAY’S FORECAST:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Windy with Thundershowers.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Salem's high temperature today will be near 61°F (average is 77°F).<o:p></o:p></p>
<p class="MsoNormal">Relative humidity: 70% or higher for the next 24 hours. <o:p>
</o:p></p>
<p class="MsoNormal">Surface winds: S 10-15 mph this morning, becoming SW 13-18 mph this afternoon.<o:p></o:p></p>
<p class="MsoNormal">Transport winds: W-SW 15-20 mph this morning, becoming SW 20-30 mph this afternoon.<o:p></o:p></p>
<p class="MsoNormal">Mixing height: Above 5000 feet for the next 24 hours.<o:p></o:p></p>
<p class="MsoNormal">Salem’s sunset tonight: 7:16 p.m.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">(Salem Airport data for Sunday, September 17th: High 67°F; Rainfall: .22”)<o:p></o:p></p>
<p class="MsoNormal">(Maximum Ventilation Index expected today: 150)<o:p></o:p></p>
<p class="MsoNormal">
<o:p></o:p></p>
<p class="MsoNormal">EXTENDED DISCUSSION:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Fall weather continues with little to no change between Monday night and the arrival of the Autumnal Equinox on Friday morning, when the calendar “officially” marks the end of the 2017 summer. The jet stream will remain over southern Oregon,
bringing polar air and stormy weather for the next several days. Cloudy skies with only brief periods of sunbreaks will limit any drying, though parched soil and stiff winds will help in a limited fashion. Occasional thundershowers with lingering rainfall
will continue to dampen fields until a ridge develops and forces the jet stream back north of the Silverton Hills, but current weather models indicate unfavorable field burning conditions for the next 7-10 days.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The National Weather Service’s digital forecast is available at:<o:p></o:p></p>
<p class="MsoNormal">http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Notes:<o:p></o:p></p>
<p class="MsoNormal">
<o:p></o:p></p>
<p class="MsoNormal"> 1. Mixing height, as used here, is the lowest height at which the<o:p></o:p></p>
<p class="MsoNormal"> potential temperature exceeds the potential temperature at the<o:p></o:p></p>
<p class="MsoNormal"> surface. As a practical matter it is the approximate height to<o:p></o:p></p>
<p class="MsoNormal"> which a smoke plume will rise assuming good ignition, dry fuels,<o:p></o:p></p>
<p class="MsoNormal"> and winds less than about 15 mph.<o:p></o:p></p>
<p class="MsoNormal">
<o:p></o:p></p>
<p class="MsoNormal"> 2. Transport winds are a layer average through the mixing height,
<o:p></o:p></p>
<p class="MsoNormal"> weighted slightly toward the winds at the top of the layer.<o:p></o:p></p>
<p class="MsoNormal">
<o:p></o:p></p>
<p class="MsoNormal"> 3. Ventilation Index is the height of the mixing layer (ft) times
<o:p></o:p></p>
<p class="MsoNormal"> the transport wind speed (mph) divided by 1000.<o:p></o:p></p>
<p class="MsoNormal">
<o:p></o:p></p>
<p class="MsoNormal"> 4. Surface wind direction is the general expected wind direction.
<o:p></o:p></p>
<p class="MsoNormal"> At a specific point surface winds are highly dependent on local<o:p></o:p></p>
<p class="MsoNormal"> terrain conditions.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> 5. In accordance with OAR 837-110-0090, all field burning shall be
<o:p></o:p></p>
<p class="MsoNormal"> banned when any two of the following criteria are present:<o:p></o:p></p>
<p class="MsoNormal"> A. Temperature of 95 degrees Fahrenheit or above<o:p></o:p></p>
<p class="MsoNormal"> B. Relative humidity of 30 percent or below<o:p></o:p></p>
<p class="MsoNormal"> C. Wind speed of 15 miles per hour or higher<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This forecast is provided under an agreement between the Oregon Department<o:p></o:p></p>
<p class="MsoNormal">of Agriculture (ODA) and the Oregon Department of Forestry (ODF). For<o:p></o:p></p>
<p class="MsoNormal">information contact ODA at 503-986-4701.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">To add/remove your email address from this list, please go to:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">http://listsmart.osl.state.or.us/mailman/listinfo/willamette-fcst<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Tom Jenkins, AEM<o:p></o:p></p>
<p class="MsoNormal">ODF Meteorologist<o:p></o:p></p>
</div>
</body>
</html>