Awatchfire

Malheur County, Oregon

Big Grass Fire

Burning 26.0 miles south-west of Jordan Valley, since Thursday 23 July.

Map of Oregon. The Big Grass Fire burns 149 miles from Baker City and 223 miles from Bend, and 326 miles from the state capital, Salem.
The fire sits 149 miles from Baker City and 223 miles from Bend.

578,637

acres burned so far — about 904 square miles

36

days burning so far

93%

of the perimeter held

The picture as of 2:52pm today

The Big Grass Fire is still listed as active, and has not been looked at lately. Nothing has given off fresh heat for 48 hours. What is burning has shifted 1.87 miles south over the last six hours.

No fresh look at this fire for 48 hours. Everything on the map below was seen before then.

Shaded relief map of the Big Grass Fire. Amber flames mark every place that gave off heat in the last day; the shading is the shape of the ground.
Heat in the last day Higher ground pale, valleys dark

48hours

since anything was last seen giving off heat — about 2:20pm on Wednesday, local time.

59% less

energy in the last 6 hours of the record than in the 6 before them — the fire was cooler when it was last seen.

22.4miles

is how close the heat has come to Jordan Valley at any point in the record. In the last day the nearest heat has been None miles from it.

8.7miles

is the furthest any heat has been seen from the point on the official record — the width of the ground involved so far.

One larger fire is burning outside this frame: Mustang Fire 7.2 miles west at 13,379 acres. None of their heat is counted here.

Smoke has been recorded lying over this ground nine times so far. The thickest of it was moderate between 2:00pm and 5:30pm local time. The last of those windows closed 21 hours ago, so what is overhead now is not known.

Where the heat is

No cluster large enough to call a separate front. The heat is in one piece.

Conditions measured 4.9 miles from the fire: 80°F, air at 18% humidity, a 10 mph wind out of the west.

How it got here

Two days of record on a day-37 fire

The record here begins at 3:25pm on 25 Aug and runs to 2:21pm on 26 Aug — 23 hours, 144 readings of heat. The fire is on day 37, so the first 35 days are missing: nothing showed up from above until the fire was large enough and the sky over it clear enough for it to be seen. There is no long arc to draw yet. What follows is what has actually happened.

Animated map of the Big Grass Fire across the whole record, with a time bar along the bottom showing energy released and the local date.
The whole record, 30 frames at 1 hour a frame. The bar along the bottom is energy released; the moving line is the clock.

Hour by hour local time

Tue 3:00pmWed 2:00pm

Each bar is one hour of local time, sized by how much energy the fire gave off in it. This fire is too young for a day-against-day comparison to say anything, so the hours are shown instead.

Day by day 2 days of record

  1. Map for Tue 25 Aug: flames mark every place that gave off heat that day.

    Tue25 Aug

    First readings

    • 44 heat readings
    • Heat from 3:25pm to 9:19pm
    • Spread 7.6 miles from the recorded point at its furthest
    • Burning through the afternoon and night
  2. Map for Wed 26 Aug: flames mark every place that gave off heat that day.

    Wed26 Auglatest

    Cooling off

    • 100 heat readings — the most of any day
    • Energy 87% down on the day before
    • Heat from 2:58am to 2:21pm
    • Spread 8.7 miles from the recorded point at its furthest
    • Burning through the pre-dawn, morning and afternoon

93% of the perimeter is being reported as held. 389 people are assigned to it. It has grown from 1 acres when it was first written down to 578,637 now. Nothing has looked at it for 48 hours, and the record still lists it as active.