SILVERTON HILLS FIELD BURNING FORECAST

OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE

8:45 AM PDT WED SEP 11, 2024

 

*** Final forecast of the 2024 field-burning season ***

 

WEATHER DISCUSSION:

 

An upper-level trough will move over the region today.  Showers started overnight and will continue through the day.  Total rainfall over the region could reach 0.25-0.50”.  Some isolated thunderstorms are possible and they could produce higher rainfall amounts depending on their track.  Winds will decrease through today, turning from SSW to more WSW later. 

 

BURN ADVISORY:

 

Recommended times for agricultural burning are from 12 p.m. until 5:30 p.m.

 

Prep burning is not allowed.

 

Field burning is done for the season.

 

(See “Notes” below for difference between field burning and Agricultural burning)

 

TODAY’S FORECAST:

 

Cloudy with showers and cool temperatures with winds SW 7-10 mph.

 

Salem's high temperature today will be near 71°F (average is 79°F).

Relative humidity: Near 75% at 10 a.m.; near 60% late afternoon

Surface winds: SSW 8-10 mph this morning; SW-WSW 7-9 mph this afternoon

Transport winds: SSW 10-14 mph this morning; SW-WSW 8-12 mph this afternoon

Mixing height: Near 3000 feet by 12 p.m.; 4000 feet by 5 p.m.

 

Salem’s sunset tonight: 7:29 p.m.

 

(Salem Airport data for Tuesday, September 10th: High 84°F; Rainfall: Trace)

(Maximum Ventilation Index expected today: 48)

                                                                            

EXTENDED DISCUSSION:

 

Showers linger all day Thursday with the upper-level trough shifting east and NW flow aloft.  Amounts will generally stay under 0.05” and lessen into the evening.  Winds will turn from SW to WSW-W through the day.

 

Friday will be dry and mostly sunny with brief upper-level ridging.  Some morning fog is possible.  Winds will come from N and temperatures will warm-up closer to seasonable.

 

A weaker shortwave trough approaches for the weekend.  Showers are possible Saturday and Sunday with total amounts under 0.10”.  Winds will come from W on Saturday and NW on Sunday.  Temperatures will be a few degrees below average.

 

The National Weather Service’s digital forecast is available at:

http://forecast.weather.gov/MapClick.php?lat=44.90549606158295&lon=-122.8106689453125&site=pqr&unit=0&lg=en&FcstType=text

 

Notes:

                                                                    

     1.  Mixing height, as used here, is the lowest height at which the

         potential temperature exceeds the potential temperature at the

         surface.  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.

                                                            

     2.  Transport winds are a layer average through the mixing height,

         weighted slightly toward the winds at the top of the layer.

                                                            

     3.  Ventilation Index is the height of the mixing layer (ft) times

         the transport wind speed (mph) divided by 1000.

                                                            

     4.  Surface wind direction is the general expected wind direction. 

         At a specific point surface winds are highly dependent on local

         terrain conditions.

 

     5.  In accordance with OAR 837-110-0090, all field burning shall be

         banned when any two of the following criteria are present:

         A. Temperature of 95 degrees Fahrenheit or above

         B. Relative humidity of 30 percent or below        

         C. Wind speed of 15 miles per hour or higher

                                                            

     6.  Agricultural burning: Burning of any agricultural waste generated

         by an agricultural operation that uses or intends to use land

         primarily for the purpose of obtaining profit by raising,

         harvesting, and selling crops or animals. Prohibited materials

         such as tires cannot be burned, even in an agricultural setting.

         If you make your primary living from an agricultural operation,

         you are considered an agricultural operator and can agricultural

         burn. If you don't make your primary living from the agricultural

         operation, you are a backyard burner and subject to the rules of

         backyard burning.  Contact your local fire district for

         information about backyard burning.

                                             

     7.  Open field burning: Burning of any grass seed or cereal grain 

         crops, or associated residue, including steep terrain and species

         identified by the Director of Agriculture, or any “emergency” or

         “experimental” burning (ORS 603-077-0105(29)).

                                                    

     8.  Preparatory (prep) burning: A type of field burning where

         controlled burning of portions of selected fields is conducted

         for the specific purpose of reducing the fire hazard potential

         or other conditions which would otherwise inhibit rapid ignition

         burning when the field is subsequently open burned

         (ORS 603-077-0105(34)).

 

     9.  Test fires: A type of field burning where individual field burns

         are specifically authorized by the Department for the purpose of

         determining or monitoring atmospheric dispersion conditions (ORS

         603-077-0105(54)).

 

This forecast is provided under an agreement between the Oregon Department

of Agriculture (ODA) and the Oregon Department of Forestry (ODF).  For

information contact ODA at 503-986-4701.

 

To add/remove your email address from this list, please go to:

 

https://public.govdelivery.com/accounts/ORODA/subscriber/new

 

Sherri Pugh

ODF Meteorologist