JEFFERSON COUNTY FIELD-BURNING FORECAST
OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE
9:30 AM PDT MON SEPT 21, 2026
TODAY’S DISCUSSION:
The region will have SW winds aloft and dry, seasonable weather to start the week. Morning clouds will turn to sunnier skies for the afternoon. Mixing heights will be a little slower to rise today, reaching 3000 feet in the early afternoon and rising high. Winds will be light from S-SW this morning, then turn to NNW-N for the afternoon while staying mostly light.
TODAY’S FORECAST:
Mostly sunny and warm, winds from N at 4-6 mph
Madras’ Forecast High Today: 84°F (Sunday High: 84°F; Rainfall: 0.0”)
Transport Winds: S 4-6 mph this morning; then NW-NNW 6-8 mph this afternoon
Mixing Heights: Rising to 2000 feet this morning;
then up to 8000 feet this afternoon
Relative Humidity: Near 40% by 11 a.m.; down to 25% this afternoon
EXTENDED DISCUSSION:
The weather pattern stays mostly the same through Wednesday. SW flow aloft will come with dry weather and mostly sunny skies along with seasonable temperatures. Winds will come from N for much of Tuesday with some higher gusts during the evening. Wednesday will have winds from S-W early, then N for the mid to late afternoon. Mixing heights will rise high both days. An upper-level trough moves through for the end of the week. Showers are expected on Thursday and Friday with winds from SW early turning NW for the afternoon. Rainfall totals will stay under 0.10” each day. The weekend will be dry and cool.
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. Surface wind direction is the general expected wind direction.
at a specific point surface winds are highly dependent on local
terrain conditions.
4. Ventilation Index (if you want to calculate it) is the height of the
mixing layer times the transport wind speed divided by 1000.
This forecast is provided under an agreement between the Oregon Department of
Agriculture (ODA) and the Oregon Department of Forestry (ODF). For more information, contact ODA at 503-986-4701.
Sherri Pugh
ODF Meteorologist