708
FNUS76 KPDT 172051
FWSPDT

Spot Forecast for Rosenbaum Fire...Oregon Dept of Forestry CIMT3
National Weather Service Pendleton OR
151 PM PDT Mon Aug 17 2026

Forecast is based on forecast start time of 1800 PDT on August 17.
***Thunderstorms imply gusty and erratic winds      ***
***Winds are 20 foot 10-minute averages             ***
***CWR: Chance of wetting rain 0.10 or greater      ***
***Ventilation Index is derived from transport wind
   multiplied by the mixing height in 100`s of ft.
   Categories are a generalized indicator only:
   low (< 200), moderate (200-500), high (500-700),
   and very high (> 700).                           ***

If you have questions or concerns with this forecast, please
contact our office at (541) 276-8134.

.DISCUSSION...Winds will be mostly from the north to northwest
in the afternoons, with strengthening winds Tuesday afternoon.
Winds will become drainage winds in the valley in the overnight
hours, with northwest to west ridgetop winds. RHs will be in the
lower teens Tuesday and Wednesday afternoon, with poor to fair
overnight recoveries.

.TONIGHT...

Sky/weather.........Partly to mostly cloudy (30-60 percent).
Patchy smoke late in the evening.
CWR.................0 percent.
Chance of lightning.2 percent.
Min temperature.....61-64.
Max humidity........34-39 percent.
Wind (20 ft)........North winds 5 to 8 mph becoming drainage winds
around 5 mph after 11PM.
Ridgetop wind.......North winds 6 to 12 mph shifting to the
northwest 4 to 8 mph after 11PM.
Mixing height.......600 ft AGL in the evening.
Transport winds.....Northwest 7 to 12 mph shifting to the west 5 to
                    6 mph overnight.
Ventilation Index...Moderate (320) decreasing to low (30)
                    overnight.

TIME (PDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Chc of ltng (%).0   0   0   0   0   0   0   0   0   0   0   0
Temp............86  84  79  75  73  71  69  68  67  66  63  63
RH..............23  25  28  31  32  32  31  32  33  35  36  39
20 FT wind dir..N   N   N   N   N   NW  NW  NW  NW  NW  NW  NW
20 FT wind spd..8   8   8   7   5   5   5   4   4   4   4   4
20 FT wind gust.11  10  10

.TUESDAY...

Sky/weather.........Sunny (5-15 percent). Patchy smoke in the
                    morning.
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....Around 90.
Min humidity........12-17 percent.
Wind (20 ft)........Drainage winds becoming west 5 to 10 mph
after 9AM, then shifting to the northwest
6 to 12 mph after 2PM.
Ridgetop wind.......Northwest winds 4 to 8 mph shifting to the
west 5 to 11 mph around 8AM, then shifting
to the northwest 9 to 15 mph with gusts up to
23 mph after 2PM.
Mixing height.......7400 ft AGL early in the morning.
Transport winds.....West 5 to 14 mph increasing to around 15 mph
                    late in the afternoon.
Ventilation Index...Low (50) increasing to high (630-640) in the
                    afternoon.

.TUESDAY NIGHT...

Sky/weather.........Mostly clear (15-25 percent).
CWR.................0 percent.
Chance of lightning.0 percent.
Min temperature.....Around 60.
Max humidity........38-43 percent.
Wind (20 ft)........Northwest winds 6 to 12 mph becoming drainage
winds around 11PM.
Ridgetop wind.......Northwest winds 9 to 15 mph with gusts up to
23 mph shifting to the west 4 to 8 mph around
11PM.
Mixing height.......500 ft AGL.
Transport winds.....Northwest 7 to 15 mph shifting to the southwest
                    around 5 mph overnight, then becoming light
                    early in the morning.
Ventilation Index...Moderate (330) decreasing to low (30)
                    overnight.

.WEDNESDAY...

Sky/weather.........Sunny (15-25 percent).
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....89-92.
Min humidity........12-17 percent.
Wind (20 ft)........Drainage winds becoming northwest 5 to 8 mph
around 1PM.
Ridgetop wind.......West winds 4 to 8 mph shifting to the northwest
5 to 10 mph around 1PM.
Mixing height.......6000 ft AGL early in the morning.
Transport winds.....Light winds becoming west 5 to 12 mph late in
                    the morning.
Ventilation Index...Low (30) increasing to moderate (230) in the
                    afternoon.

$$
Forecaster...Lawhorn
Requested by...Greg Wagenblast
Type of request...WILDFIRE
.TAG 2619691.2/PDT
.DELDT 08/17/26
.FormatterVersion 2.0.0
.EMAIL Greg.Wagenblast@odf.oregon.gov