Grass fires in northwest and southwest Oklahoma

April 12th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top) and Shortwave Infrared (3.9 µm, bottom) images, with hourly plots of surface reports [click to play MP4 animation]

1-minute Mesoscale Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the development and rapid spread of grass fires in northwest Oklahoma on 12 April 2018. Hot fire pixels are highlighted as red on the Shortwave Infrared images — and the rapid northeastward run of the larger fires was very evident. The intense heat of the fires produced pyrocumulus clouds, which could be seen on the Visible images. Additional images are available on the Satellite Liaison Blog.

SPC had highlighted parts of New Mexico, Colorado, Texas and Oklahoma as having conditions favorable for Extreme wildfire behavior due to strong winds, hot temperatures and very dry air behind a dryline boundary (below). Note that the surface temperature / dew point depression at Woodward, Oklahoma (KWWR) at 2255 UTC on 12 April was 100 ºF (temperature = 97 ºF, dew point = -2 ºF), with southwesterly winds gusting to 35 knots or 40 mph.

SPC Day 1 Fire Outlook [click to enlarge]

SPC Day 1 Fire Outlook [click to enlarge]

===== 13 April Update =====

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.9 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.9 µm) images [click to enlarge]

The fires in northwestern Oklahoma continued to burn into the following night — Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.9 µm) images at 0837 UTC or 3:37 AM local time (above) revealed the bright glow and hot fire pixels associated with the 2 large fire complexes in Woodward County (34 Complex Fire) and Dewey County (Rhea Fire). At least 2 fatalities (Wildfire Today | media report) have been attributed to the larger and longer-burning Rhea Fire in Dewey County (which had burned an estimated 241,280 acres by mid-day on 14 April).

During the following daytime hours of 13 April, GOES-16 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (below) showed the smoke plumes and hot pixels of the northwestern Oklahoma fires. The surface cold front moved over these fires around 18 UTC, with smoke transport transitioning more toward the east then southeast.

GOES-16

GOES-16 “Red” Visible (0.64 µm, top) and Shortwave Infrared (3.9 µm, bottom) images, with hourly plots of surface reports [click to play MP4 animation]

Farther to the southwest, new grass fires which began burning west of the Texas/Oklahoma border after 17 UTC quickly raced eastward and crossed the border into southwestern Oklahoma after 20 UTC (below).

GOES-16

GOES-16 “Red” Visible (0.64 µm, top) and Shortwave Infrared (3.9 µm, bottom) images, with hourly plots of surface reports [click to play MP4 animation]

===== 14 April Update =====

Three nighttime comparisons of (Preliminary, non-operational) NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.75 µm) images — each image pair separated by 50 minutes — (below; courtesy of William Straka, CIMSS) showed the bright glow and thermal hot spots of the ongoing Rhea fire complex.

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.75 µm) images at 0737 UTC [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.75 µm) images at 0737 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.75 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.75 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.75 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.75 µm) images [click to enlarge]

===== 15 April Update =====

250-meter resolution Terra MODIS true-color and false-color Red-Green-Blue (RGB) images from MODIS Today (below) showed the burn scars from the 34 Complex and the larger Rhea Fire at 1719 UTC on 15 April 2018.

Terra MODIS true-color and false-color RGB images [click to enlarge]

Terra MODIS true-color and false-color RGB images [click to enlarge]

Icebreaking in Whitefish Bay on Lake Superior

March 24th, 2018 |

GOES-16 ABI Band 2 “Red” (0.64 µm) Visible imagery, 2202 UTC on 22 and 23 March 2018 (Click to enlarge)

Dan Miller, the Science and Operations Officer (SOO) in Duluth sent the imagery above. Constant icebreaking has been ongoing on Whitefish Bay prior to the opening of the SOO Locks this weekend. A faint black line representing open water is apparent in the 22 March imagery, and it’s even more apparent in the 23 March imagery.

A toggle below, from 24 March 2018, shows the Band 2 “Red” (0.64 µm) Visible and the Band 5 “Snow/Ice” (1.61 µm) Near-Infrared images. The open water is apparent in both images — dark in contrast to the white snow and lake ice in the visible, darker than the adjacent ice in the 1.61 µm. Recall that horizontal resolution in Band 2 is 0.5 km at the sub-satellite point (nadir), and in Band 5 it is 1 km.

GOES-16 ABI Band 2 “Red” (0.64 µm) Visible and Band 5 “Snow/Ice” (1.61 µm) near-infrared imagery, 2202 UTC on 22 and 23 March 2018 (Click to enlarge)

Suomi NPP and NOAA-20 also viewed the icebroken path on 24 March, and favorable orbit geometry for NOAA-20 and Suomi NPP on 24 March (orbit paths from this site) meant 2 sequential passes from both satellites both viewed Whitefish Bay. The 4 images are shown in an animation below, with imagery from NOAA-20 first, then Suomi NPP (the labels all say Suomi NPP erroneously). Note that NOAA-20 data are provisional, non-operational, and undergoing testing still).

VIIRS Visible (0.64 µm) Imagery from NOAA-20 (1708, 1846 UTC) and Suomi-NPP (1756, 1937 UTC) on 24 March 2018 (Click to enlarge)

The break in the ice was also visible in Day Night Band Imagery from VIIRS at 0722 UTC (from NOAA-20) on 24 March 2018.  It is also apparent in the shortwave Infrared imagery from both GOES-16 (very subtly) and from VIIRS (which offers better spatial resolution).

The icebreaking track was also apparent on 250-meter resolution Terra MODIS True-color and False-color Red-Green-Blue (RGB) images from the MODIS Today site (below). In the False-color image, ice and snow (in areas of sparse vegetation) show up as shades of cyan.

Terra MODIS True-color and False-color RGB images [click to enlarge]

Terra MODIS True-color and False-color RGB images [click to enlarge]

2 structural fires: Beaver Dam, Wisconsin and San Francisco, California

March 17th, 2018 |

GOES-16 Shortwave Infrared (3.9 µm, left) and

GOES-16 Shortwave Infrared (3.9 µm, left) and “Red” Visible (0.64 µm, right) images, with hourly surface reports plotted in yellow [click to play animation]

As documented by NWS Milwaukee/Sullivan, the controlled burn of an apartment building occurred during the late morning hours on 15 March 2018. A comparison of GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) and “Red” Visible (0.64 µm) images (above) displayed subtle “hot spot” signatures (darker red pixels, circled) as well as an occasional hint of a small smoke plume during the early phase of the fire. At the bottom of the images, note the appearance of a few larger and hotter fires (black pixels) in northern Illinois — likely agricultural fires to prepare fields for Spring planting.

2 days later, another structure fire occurred in the San Francisco area during the early evening hours of 17 March 2018:

Hot spot signatures were observed on the 0247 UTC and 0252 UTC (7:47 and 7:52 PM local time) Shortwave Infrared (3.9 µm) images, along with subtle lighter gray pixels on the Near-Infrared (2.24 µm) images (below).

GOES-16 Shortwave Infrared (3.9 µm, left) and Near-Infrared (2.24 µm, right) images, with station identifiers plotted in cyan [click to play animation]

GOES-16 Shortwave Infrared (3.9 µm, left) and Near-Infrared (2.24 µm, right) images, with airport identifiers plotted in cyan [click to play animation]

A timely overpass of the NOAA-15 satellite scanned the fire at 02:43:50 UTC (7:43:50 PM local time), showing a well-defined hot spot (darker red enhancement) on the 1-km resolution Shortwave Infrared (3.7 µm) image (below).

NOAA-15 Shortwave Infrared (3.7 µm) image [click to enlarge]

NOAA-15 Shortwave Infrared (3.7 µm) image [click to enlarge]

Silt at the mouth of the Mississippi River

March 13th, 2018 |

CIMSS Natural True Color Imagery, 1515 – 1830 UTC on 13 March 2018 (Click to animate)

The CIMSS Natural True Color RGB, above, from 13 March 2018, shows the motion of alluvial sediment in the Gulf of Mexico in the outflow from various rivers. Muddy plumes from the Atchafalaya River in central Louisiana, the Mississippi River, and the Mobile River in Alabama are apparent. In particular, there is distinct northward motion during the 3 hours shown in this animation along the northern edge of the Mississippi River Delta.

A similar animation for 9 March 2018 is available here (courtesy Tim Schmit, NOAA and Mat Gunshor, CIMSS). Close monitoring of where the outflow from rivers is mixing with the Gulf of Mexico waters is a capability of GOES-16 Imagery when skies are clear.

Natural True Color is computed from GOES-16 Reflectance imagery using the “Blue” band (0.47 µm), the “Red” band (0.64 µm) and the “Veggie” band (0.86 µm), that latter being used to give information that in True Color Imagery from MODIS or Suomi NPP (for example) is supplied by a true “Green” band (0.55 µm).

The animation below shows True-Color imagery from MODIS for clear days between 30 January and 13 March 2018. The superior resolution of MODIS (on the Terra and Aqua spacecraft) and the presence of a 0.55 µm channel (in addition to 0.47 µm and 0.64 µm) allows for crisper imagery than from GOES-16; however, the ability to animate at small time scales over the Gulf of Mexico is a capability reserved for GOES-16 (and GOES-17, when it becomes operational). Terra and Aqua imagery are not useful if the overpass of the Polar Orbiters coincide with clouds; on days with variable cloud cover, GOES Imagery is more likely to provide useful information.

MODIS True Color Imagery for select dates between 30 January and 13 March 2018 (Click to animate)