OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE

11:45 AM PDT MON SEPT 21, 2026

WEATHER DISCUSSION:

Clouds have held on for much of the morning with partly sunny skies expected for this afternoon. Winds have been mostly light and variable, likely to turn more NW-N for the afternoon. Mixing heights are slow to rise and will be near 3000 feet by 3 p.m.

BURN ADVISORY:

Agricultural burning is not recommended.

Prep burning is not allowed.

Field burning is a possibility today, depending on weather conditions.

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

TODAY’S FORECAST:

Partly sunny and seasonable, winds from NNW at 3-5 mph.

Salem's high temperature today will be near 74°F (average is 77°F).

Relative humidity: Near 70% now; near 50% by late afternoon

Surface winds: NW 2-4 mph now; NW-N 3-5 mph this afternoon

Transport winds: NNW 3-5 mph now; NNW-N 6-8 mph this afternoon

Mixing height: Near 3000 feet by 3 p.m.; 3600 feet by 5 p.m.

Salem’s sunset tonight: 7:11 p.m.

(Salem Airport data for Sunday, September 20th: High 78°F; Rainfall: 0.0”)

(Maximum Ventilation Index expected today: 29)

EXTENDED DISCUSSION:

Tuesday will be similar to Monday with onshore flow, SW winds aloft, and NW-N surface winds. Mixing heights will rise more quickly and climb to 3000 feet near midday. Morning clouds will again decrease to partly cloudy and dry weather. A weak trough will move through overnight.

An upper level trough will move closer to the region Wednesday, but skies stay dry and partly sunny. Winds are likely to come from N much of the day. Mixing heights will rise high.

Potential for showers increases for Thursday and Friday as the upper trough moves through. Rainfall amounts on Thursday will range from 0.25-0.50”. Friday has could have lower rainfall totals under 0.10” but with an increased chance of thunderstorms. Drier weather is expected for the weekend.

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