SILVERTON HILLS FIELD BURNING FORECAST
OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE
11:35 AM PDT TUE SEP 12, 2023
*** Final forecast of the 2023 field-burning season ***
WEATHER DISCUSSION:
An upper-level trough will push a very weak surface cold front onshore this afternoon and evening, maintaining onshore flow with moderate temperatures. Drizzle or sprinkles are possible along the north coast, but the Willamette Valley will see only a few clouds, at most.
BURN ADVISORY:
Recommended times for agricultural burning are from noon 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:
Mostly sunny.
Salem's high temperature today will be near 77°F (average is 79°F).
Relative humidity: Dropping to 40% by 5 p.m.
Surface winds: SW 5 mph at midday; becoming NW 5-10 mph this afternoon.
Transport winds: SW 5 mph at midday; becoming NW 5-10 mph this afternoon.
Mixing height: Near 3000 feet midday; rising to 5000 feet by 5 p.m.
Salem’s sunset tonight: 7:29 p.m.
(Salem Airport data for Monday, September 11th: High 77°F; Rainfall: .00”)
(Maximum Ventilation Index expected today: 50)
EXTENDED DISCUSSION:
A late-summer warm-up begins Wednesday, as a building ridge of high pressure clears skies and warms temperatures to near 80°F. The strengthening ridge should push temperatures into the upper-80s on Thursday and possibly into the low-90s on Friday with weak offshore flow.
The ridge weakens and shifts eastward this weekend, with temperatures progressively cooling back to near 80°F by Sunday. An upper-level trough may be strong enough to bring showers as soon as Monday with temperatures dropping below average. The latest computer models are now showing a return to sunny and warmer weather later next week.
Forecasts will resume next July! Thank you for another successful season.
The National Weather Service’s digital forecast is available at:
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.
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email address from this list, please go to:
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Pete Parsons
ODF Meteorologist