Holy Fire in southern California, as viewed by 4 GOES

August 9th, 2018 |
Shortwave Infrared (3.9 µm) images from GOES-15, GOES-14, GOES-17 and GOES-16 [click to play MP4 animation]

Shortwave Infrared (3.9 µm) images from GOES-15, GOES-14, GOES-17 and GOES-16 [click to play MP4 animation]

 * GOES-17 images shown here are preliminary and non-operational *

GOES-15 (GOES-West), GOES-14, GOES-17 and GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) images (above) showed the thermal anomaly or “hot spot” (black to yellow to red pixels) associated with the Holy Fire that was burning in southern California on 09 August 2018. This comparison demonstrates how fire detection can be affected by both satellite viewing angle and shortwave infrared detector spatial resolution (4 km at satellite sub-point for the GOES-14/15 Imager, vs 2 km for the GOES-16/17 ABI).

On the previous day, a 30-meter resolution Landsat-8 False Color Red-Green-Blue (RGB) image visualized using RealEarth (below) provided a more detailed view of the Holy Fire, showing active fires (brighter red) around the northern and eastern perimeter of the burn scar and the smoke plume that was drifting to the north and northwest.

Landsat-8 False Color image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

Smoke from Mendocino Complex fires in California

August 4th, 2018 |

GOES-16

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

GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the smoke and thermal anomalies or “hot spots” (red pixels) associated with the Mendocino Complex burning in Northern California on 04 August 2018. Smoke was reducing the surface visibility to 2.5 miles at nearby Sacramento International Airport KSMF and Marysville KMYV. As of 7pm local time on 04 August the Mendocino Complex had burned 229,000 acres.

A 30-meter resolution Landsat-8 False Color Red-Green-Blue (RGB) image viewed using RealEarth (below) showed active burning along the eastern edge of the Ranch Fire (part of the Mendocino Complex) at 1845 UTC. The larger fire was producing a pyrocumulus cloud in addition to the dense smoke plume drifting northeastward.

Landsat-8 False Color image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

GOES-16 Upper-level (6.2 µm), Mid-level (6.9 µm) and Low-level (7.3 µm) Water Vapor images (below) revealed a southwest-to-northeast oriented band of moisture and fast flow associated with a middle to upper-tropospheric jet streak that was moving over the region (300 hPa analyses). “Red” Visible (0.64 µm) images showed the smoke plume drifting rapidly northeastward over California and Nevada, and visible Derived Motion Winds — which are calculated for pressure levels at and below 700 hPa —  tracked the smoke moving as fast as 58 knots at 2337 UTC. This speed was faster than 00 UTC winds at or below 700 hPa on rawinsonde data from either Oakland KOAK or Reno KREV.

GOES-16 Upper-level (6.2 µm, top left), Mid-level (6.9 µm, top right), Low-level (7.3 µm, bottom left) Water Vapor and "Red" Visible with Derived Motion Winds (0.64 µm, bottom right) [click to play MP4 animation]

GOES-16 Upper-level (6.2 µm, top left), Mid-level (6.9 µm, top right), Low-level (7.3 µm, bottom left) Water Vapor images and “Red” Visible (0.64 µm, bottom right) images with Derived Motion Winds [click to play MP4 animation]

===== 07 August Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm), Near-Infrared (1.61 µm and 2.25 µm) and Shortwave Infrared (3.75 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm), Near-Infrared (1.61 µm and 2.25 µm) and Shortwave Infrared (3.75 µm) images [click to enlarge]

A comparison of NOAA-20 VIIRS Day/Night Band (0.7 µm), Near-Infrared (1.61 µm and 2.25 µm) and Shortwave Infrared (3.75 µm) images (above; courtesy of William Straka, CIMSS) showed the nighttime glow and thermal signatures of the Mendocino Complex fires on 07 August 2018. As of 8:30am the fire had burned over 290,000 acres, becoming the largest wildfire on record in the state of California.

 

Transport of Saharan Air Layer dust across the Atlantic

August 3rd, 2018 |

GOES-16 Split Window (12.3 µm - 10.3 µm) Saharan Air Layer product [click to play MP4 animation]

GOES-16 Split Window (12.3 µm – 10.3 µm) Saharan Air Layer product [click to play MP4 animation]

The GOES-16 (GOES-East) Saharan Air Layer (SAL) infrared Split Window (12.3 µm – 10.3 µm) product (above) showed a large outbreak of SAL dust that emerged from the northwest coast of Africa on 30 July 2018, eventually moving over the Lesser Antilles and Puerto Rico late in the day on 03 August.

During daylight hours, the dust-laden SAL was also evident in GOES-16 Natural Color Red-Green-Blue (RGB) imagery (source) on 01, 02 and 03 August (below).

GOES-16 Natural Color RGB images [click to play MP4 animation]

GOES-16 Natural Color RGB images [click to play MP4 animation]

GOES-16 Split Window 10.3 µm - 12.3 µm) images [click to play animation | MP4]

GOES-16 Split Window (10.3 µm – 12.3 µm) images on 02 August [click to play animation | MP4]

The AWIPS version of GOES-16 Split Window (10.3 µm – 12.3 µm) imagery with a different color enhancement (above) showed the westward motion of the SAL dust (shades of cyan) on 02 August. The corresponding GOES-16 Dust Detection product (below) verified the presence of dust within the SAL plume. Since the Dust Detection product uses Visible and Near-Infrared bands, it is only available during daytime hours (and at solar zenith angles less than 60 degrees).

GOES-16 Dust derived product [click to play animation | MP4]

GOES-16 Dust Detection product on 02 August [click to play animation | MP4]

GOES-16 Split Window (10.3 µm - 12.3 µm) product [click to play animation | MP4]

GOES-16 Split Window (10.3 µm – 12.3 µm) product on 03 August [click to play animation | MP4]

GOES-16 Split Window (10.3 µm – 12.3 µm) imagery from 03 August (above) showed the continued westward motion of the SAL dust (shades of cyan). The corresponding GOES-16 Aerosol Optical Depth (AOD) product (below) provided a more quantitative measure of airborne dust. Like the Dust Detection product shown previously, the AOD product also uses Visible and Near-Infrared bands — so it too is only available during daytime hours (and at solar zenith angles less than 60 degrees). Additional information on GOES-R Aerosol Detection Products in AWIPS is available here and here.

GOES-16 Aerosol Optical Depth product [click to play animation | MP4]

GOES-16 Aerosol Optical Depth product on 03 August [click to play animation | MP4]

The 03 August GOES-16 imagery indicated that the leading edge of the SAL began to move over Puerto Rico late in the day. A comparison of morning and evening rawinsonde data from San Juan (below) revealed that the temperature inversion at the base of the SAL became more well-defined at 00 UTC on 04 August.

Plots of rawinsonde data from San Juan, Puerto Rico [click to enlarge]

Plots of rawinsonde data from San Juan, Puerto Rico [click to enlarge]

Large hail and high winds in South Dakota and Nebraska

July 27th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with SPC storm reports plotted in red [click to play MP4 animation]

A supercell thunderstorm which developed in southeastern Montana during the afternoon hours on 27 July 2018 produced damaging wind-driven hail as it moved southeastward across western South Dakota into far northern Nebraska (SPC storm reports | NWS Rapid City summary). 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the evolution of this storm.

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) revealed minimum cloud-top infrared brightness temperatures in the -60 to -70ºC range (darker red to black enhancement) with the strongest pulses of overshooting tops. The storm began to exhibit a well-defined “enhanced-V” signature once it crossed the South Dakota / Nebraska border after about 0200 UTC.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with SPC storm reports plotted in purple [click to play MP4 animation]

 


===== 30 July Update =====

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

Terra MODIS True Color and False Color RGB images, with hail damage swath highlighted by red arrows [click to enlarge]

A comparison of 250-meter resolution Terra MODIS True Color and False Color Red-Green-Blue (RGB) images from the MODIS Today site (above) showed the northwest-to-southeast hail damage swath across southwestern South Dakota on 30 July.

Before/after (16/30 July) comparisons of MODIS True Color RGB images viewed using RealEarth and MODIS Today (below) further illustrate the appearance of the hail damage swath.

MODIS True Color RGB images from 16 July and 30 July [click to enlarge]

Terra MODIS True Color RGB images from 16 July and 30 July [click to enlarge]

Terra MODIS True Color RGB images from 16 and 30 July [click to enlarge]

Terra MODIS True Color RGB images from 16 July and 30 July [click to enlarge]

In a comparison between the 30 July Terra MODIS Visible (0.65 µm) image and the corresponding Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) products (below), within the core of the hail damage swath (near Oglala) LST values warmed into the 90s F and NDVI values were reduced to the 0.2 to 0.3 range (compared to cooler LST values in the 80s F and higher NDVI values of 0.3 to 0.6 over healthy vegetation areas immediately adjacent to the damage swath).

Terra MODIS Visible (0.65 µm) image and Land Surface Temperature and Normalized Difference Vegetation Index products [click to enlarge]

Terra MODIS Visible (0.65 µm) image and Land Surface Temperature and Normalized Difference Vegetation Index products [click to enlarge]

===== 31 July Update =====

MODIS True Color RGB images from Terra (14 July) and Aqua (31 July) [click to enlarge]

MODIS True Color RGB images from Terra (14 July) and Aqua (31 July) [click to enlarge]

In a better, more cloud-free before/after comparison of MODIS True Color images from 14 and 31 July (above), it can be seen that the NW-SE oriented hail damage swath extended into Nebraska (where hail as large as 3.0 inches was reported).