OREGON DEPARTMENT OF FORESTRY WEATHER OFFICE

9:22 AM PDT WED SEPT 23, 2026

TODAY’S DISCUSSION:

A moistening WSW flow aloft will bring partly cloudy skies and seasonal temperatures today, as a weak cold front falls apart near the coastline.

TODAY’S FORECAST:

Partly cloudy. Light N-NW surface winds...turning SW-W at the mixing height.

Madras’ Forecast High Today: 73°F (Tuesday’s High: 74°F; Rainfall: .00)

Transport Winds: SSW 5-10 mph this morning; SW-W 10 mph this afternoon.

Mixing Heights: Rising to 2500 by 11 a.m.; 4000 feet by 2 p.m.

Relative Humidity: Dropping to near 50% by 11 a.m. and to near 25% by 5 p.m.

EXTENDED DISCUSSION:

A stronger weather system brings increasing clouds and SW transport winds along with good mixing on Thursday. This system will be strong enough to bring wetting rains to the region Thursday night and Friday along with much colder temperatures. Rainfall totals near or more than .10” are likely with high temperatures on Friday only near 60°F.

Partly cloudy and quite cool conditions are expected this weekend with possible freezing surface temperatures in the mornings and afternoon high temperatures in the 60s. A transitory ridge will warm temperatures to near 70°F by next Tuesday, before a weak weather system brings some clouds and cooling again on Wednesday.

National Weather Service’s digital forecast is available at:

http://forecast.weather.gov/MapClick.php?lat=44.68&lon=-121.14861&site=pdt&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. 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.

Pete Parsons

ODF Meteorologist