Soberanes Fire aerial/MODIS/VIIRS data — 0630 8/13

The new aerial data looks more like what we hav been seeing, making yesterday’s abnormally quiet map an outlier, and, while not necessarily an error, at least mapped by different standards that we’ve become used to:

In the west, we can see the result of yesterday’s big back burn:

And what looks like a back burn near Cachagua, plus considerable activity to the southeast of there:

The old and new fire perimeters lais over each other, with arrows pointing to three probable back burns:

And arrows pointting to advancement of the wild fire:

Last night’s MODIS results:

Zooming in on the western fire, with an arrow pointing to the back burn:

This morning’s VIIRS data is old. The last of red squares does not mean the lack of fire:

The orange lines are the dozer fire breaks that were in as of 7/30, plus one that I added by hand. The pink lines are the ones that were planned as of that date. The fat black lines are the outlines of the fire’s perimeter on the official Cal Fire maps from last night.

How to read the MODIS/VIIRS heat indications: The size of the square represents the nominal margin of error. The fire could be anywhere in the square, not just at the center. Dark red squares were detected less than six hours before the data set was created. Light red squares were detected less than twelve hours before the data set was created. Orange squares were detected less than 24 hours before the data set was created. Yellow squares were detected less than six days before the data set was created. When the squares overlay other objects, the color of the square changes somewhat, but the color of the dot in the middle does not. So look at the dot if you’re uncertain what color the square should be. Since the fire is now over six days old, some of the early detections have dropped off the map. MODIS makes mistakes, sometimes missing outbreaks, and sometime misplacing them outside the nominal margin of error. It is also a snapshot of the activity at the time the satellite is overhead, and will definitely miss flare ups between passes. MODIS can’t tell the difference between wildfires and intentional back burns.