Soberanes Fire MODIS data — 0600 8/2

Before I show you last night’s MODIS data, I’m going to show you some older, and far more accurate data. Here are the official fire lines as of last night and the night before:

The darker red area is the growth in the official fire boundary from the night before last to last night.

Let’s zoom in on the White Rock and Cachagua areas:

Most of the fire’s progress was towards the south, but there was a new fire to the east and some growth in that direction. I think the new fire is just the map catching up with events, as we have seen MODIS hot spots in that region.

Now I’ll add the overnight MODIS data:

There is, and, from the colors, has been, a lot of fire activity to the south of the official fire lines in the east. You see the same kind of thing in the western part of the fire’s south boundary, but in that case there is reason to believe that some of the southernmost hot spots are back burns, as they are old and there has been plenty of time to get them on the official map if they had been wildfires.

A closer look at the Cachagua and White Rock areas:

The fire’s activity to the south is evident. Things are quiet up by White Rock. I don’t know if the new activity near the Cachagua dozer lines represents back burning or real fire activity. The orange square very near the dozer line paralleling Cachagua Road is almost certainly a back burn.

The orange lines are the dozer fire breaks that were in as of 7/30. The pink lines are the ones that were planned as of that date. The hotspots near the dozer breaks are back burns. Some of the fire to the west of there may be as well, but it’s hard to tell from these satellite images.

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.

Added 0700:

Now I’ve got high resolution VIIRS data, and it explains a lot:

Zooming in on White Rock/Cachagua:

See that line of red squares to the south of the south-pointing angle in the orange dozer break? Although it didn’t even show as planned on the 7/30 Cal Fire Google Earth dozer break data set, for the last couple of days construction of another dozer freak south of that point has been taking place, and it shows up as completed on last night’s ops report. So that activity is almost certainly intentional.

Here’s a piece of the index to today’s operations map, and you can see the new breaks — they’re indicated by the XXXXs.

{Added 1000]

I got the results of a new VIIRS pass. This is also the high resolution band:

More back burns are evident.

Zooming in, after I added an orange line at the approximate location of the new dozer fire break:

The activity to the south is striking. If, as I think likely, all or most of the fire activity around the new fire break is back burning, then it appears that Cal Fire is making a serious attempt to stop the fire before it gets to the fire break near Cachagua Road. That makes me feel better.

For completeness, here is Cal Fire’s infrared map of about the same area as of two o’clock this morning:

Here’s what the markings mean:

[Added 1200]

I now have a VIIRS visible band image from yesterday. The MODIS images are not useful: the image boundary is too close to the fire.

As you can see, there’s a lot of fog, which kept the fire tamped down somewhat. You can see the smoke from the southern end of the fire zone. I don’t know why the coastal outline is split in some places. It’s also clearly wrong in places.