<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=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
/* Font Definitions */
@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:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:"Courier New";}
.MsoChpDefault
{mso-style-type:export-only;}
@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=blue vlink=purple><div class=WordSection1><pre>SILVERTON HILLS FIELD BURNING FORECAST<o:p></o:p></pre><pre>OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE<o:p></o:p></pre><pre>9:00 AM PDT TUE AUG 02 2011<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>BURN ADVISORY:<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Agricultural burning is not recommended.<o:p></o:p></pre><pre>Prep burning is not allowed. <o:p></o:p></pre><pre>Propane flaming is allowed from 1:00pm to 5:00pm. <o:p></o:p></pre><pre> <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>WEATHER DISCUSSION:<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>A broad but weak upper level trough again covers the northeast Pacific Ocean and the<o:p></o:p></pre><pre>Pacific Northwest. A weak disturbance moving through the trough has brought cloud cover<o:p></o:p></pre><pre>to western Washington and thickened the marine layer along the Oregon Coast. Satellite<o:p></o:p></pre><pre>pictures show scattered mid and high level clouds over the Willamette Valley and thick<o:p></o:p></pre><pre>marine clouds along the coast penetrating inland to the crest of the coast range. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>A burn opportunity is developing today as the marine air pushes into the Willamette<o:p></o:p></pre><pre>Valley. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>The morning Salem sounding showed just a very slight cooling since yesterday morning at<o:p></o:p></pre><pre>low levels. At least 5 shallow inversions were noted between the surface and 6000 feet. <o:p></o:p></pre><pre>All but the highest of these should mix out this afternoon as temperatures climb to the<o:p></o:p></pre><pre>80 degree mark. Winds on the sounding were generally southwesterly. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>8am surface pressures showed gradient stacking to the east. The Newport to Salem<o:p></o:p></pre><pre>gradient was 0.8 mb onshore; Salem to Redmond, 2.2 mb onshore; and total Newport to<o:p></o:p></pre><pre>Redmond gradient, 3.0 mb onshore. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Gradient stacking to the east should ease as temperatures rise and pressures fall in<o:p></o:p></pre><pre>central Oregon but clouds and fog limit heating along the coast. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre>TODAY'S FORECAST:<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Partly cloudy and warm.<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Salem's high temperature today will be near 80.<o:p></o:p></pre><pre>Relative humidity drops to 50% by 11am. Minimum relative humidity 31%.<o:p></o:p></pre><pre>Surface winds: WSW 3-7mph<o:p></o:p></pre><pre>Transport winds: SW 3-6 gradually veering to WNW 4-8 during the afternoon. <o:p></o:p></pre><pre>Mixing heights: The mixing height should reach 3000 feet by 1pm this afternoon and top<o:p></o:p></pre><pre>out at 4000 feet late this afternoon. <o:p></o:p></pre><pre>Sunset tonight: 8:37 pm <o:p></o:p></pre><pre> <o:p></o:p></pre><pre> <o:p></o:p></pre><pre>THREE-HOURLY DATA: <o:p></o:p></pre><pre> 11am 2pm 5pm 8pm <o:p></o:p></pre><pre> Temperature: 68 76 80 72 <o:p></o:p></pre><pre> Relative Humidity: 57% 40% 31% 43%<o:p></o:p></pre><pre> Surface Wind Direction: 260 280 290 280<o:p></o:p></pre><pre> Surface Wind Speed: 3 4 6 7 <o:p></o:p></pre><pre> Transport Wind Direction: 240 290 300 300 <o:p></o:p></pre><pre> Transport Wind Speed: 4 3 6 13<o:p></o:p></pre><pre> Estimated Mixing Height: 2100 3700 4000 1500<o:p></o:p></pre><pre> Ventilation Index: 8 11 24 20<o:p></o:p></pre><pre> <o:p></o:p></pre><pre>EXTENDED DISCUSSION:<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>The general pattern of weak troughiness over the western United states will continue<o:p></o:p></pre><pre>through the week. Weather should stay dry. A marine push today would leave a strong<o:p></o:p></pre><pre>inversion over the valley and strong gradient stacking east would likely preclude burning<o:p></o:p></pre><pre>tomorrow, but the pattern is generally favorable for potential burn opportunities<o:p></o:p></pre><pre>Thursday or Friday.<o:p></o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre>The National Weather Service’s digital forecast is available <a href="http://forecast.weather.gov/MapClick.php?lat=44.905&lon=-122.810">http://forecast.weather.gov/MapClick.php?lat=44.905&lon=-122.810</a>.<o:p></o:p></pre><pre> <o:p></o:p></pre><pre>Notes: <o:p></o:p></pre><pre>1. Mixing height, as used here, is the lowest height at which the <o:p></o:p></pre><pre> potential temperature exceeds the equivalent potential temperature <o:p></o:p></pre><pre> at the surface. As a practical matter it is the approximate height <o:p></o:p></pre><pre> to which a smoke plume will rise assuming good ignition, dry fuels, <o:p></o:p></pre><pre> and winds less than about 15mph. <o:p></o:p></pre><pre>2. Transport winds are a layer average through the mixing height, <o:p></o:p></pre><pre> weighted slightly toward the winds at the top of the layer. <o:p></o:p></pre><pre>3. Ventilation Index is the height of the mixing layer times <o:p></o:p></pre><pre> the transport wind speed divided by 1000. <o:p></o:p></pre><pre>4. Surface wind direction is the general expected wind direction. <o:p></o:p></pre><pre> At a specific point surface winds are highly dependent on <o:p></o:p></pre><pre> local terrain conditions.<o:p></o:p></pre><pre> <o:p></o:p></pre><pre>This forecast is provided under an agreement between the Oregon Department of<o:p></o:p></pre><pre>Agriculture and the Oregon Department of Forestry. For information contact ODA<o:p></o:p></pre><pre>at 503-986-4701. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Jim Little<o:p></o:p></pre><pre>ODF Meteorologist<o:p></o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><p class=MsoNormal><o:p> </o:p></p></div></body></html>