Camp Fire in northern California

November 8th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), “Clean” Infrared Window (10.3 µm, bottom left) and Fire Temperature (bottom right) [click to play animation | MP4]

The Camp Fire started at 1433 UTC or 6:33 AM local time on 08 November 2018 in Northern California; the rapid spread of the fire prompted evacuations and forced road closures. GOES-16 (GOES-East) GOES-16 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.3 µm) and Fire Temperature (above) showed the evolution of the fire at 5-minute intervals — especially noteworthy were the rapid vertical jump of the smoke column seen at 1547 UTC (which cast a long shadow), and Fire Temperature values that exceeded 2000 K (bright red pixels) at numerous times with a maximum value just over 2300 K.

A GOES-16 Mesoscale Domain Sector was positioned over California beginning at 2115 UTC, providing imagery at 1-minute intervals — a comparison of Visible and Shortwave Infrared images (below) showed how quickly the hot thermal signature of the fire (yellow to red enhancement) advanced southwestward during the remaining 3 hours of daylight. Just northwest of the fire, Chico (station identifier KCIC) reported very low relative humidity values (6% at 21 UTC), as seen by the large spread between temperature and dewpoint late in the day.

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

1-km resolution NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images (below) showed the bifurcation of the smoke plume as well as the large, very hot thermal signature of the fire at 1712 UTC or 9:12 AM local time.

NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared "Vegetation" (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µµ) images [click to enlarge]

NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-20 Visible (0.64 µm), Near-Infrared

NOAA-20 VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Higher spatial resolution views were provided by NOAA-20 VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.45 µm) images (above) and by Aqua MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images (below). [Note: the NOAA-20 VIIRS images are incorrectly labeled as Suomi NPP]

Aqua MODIS Visible (0.65 µm), Near-Infrared

Aqua MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Alternative views of the NOAA-20 VIIRS and Aqua MODIS images are shown below (using legacy AWIPS-1).They include Shortwave Infrared images from the 2 satellites, which reveal the very large (approximately 10 miles in length) thermal anomaly or fire “hot spot”. Due to the very dry atmosphere over the region (MODIS 6.7 µm Water Vapor image), the smoke could be clearly seen on the MODIS 1.37 µm Cirrus image (since there was very little attenuation of upwelling 1.37 µm radiation by middle/upper-tropospheric water vapor).

NOAA-20 Visible (0.64 µm), Day/Night Band (0.7 µm), Near-Infrared "Snow/Ice" (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 Visible (0.64 µm), Day/Night Band (0.7 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm), Near-Infrared "Cirrus" (1.37 µm), Near-Infrared "Snow/Ice" (1.61 µm), Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm), Near-Infrared “Cirrus” (1.37 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

As a result of the unusual dryness air mass across the region, the 00 UTC Oakland sounding set a record low Total Precipitable Water value for the date (3 mm or 0.12 inch):

 

The Aqua MODIS Total Precipitable Water product at 2123 UTC (below) showed widespread values in the 3-5 mm range (darker shades of brown) over much or northern California. 12 hours later, the TPW value from the 12 UTC Oakland sounding was slightly lower (2.9 mm or 0.11 inch) — and the MODIS TPW product at 0921 UTC continued to show widespread dry air over California.

Aqua MODIS Total Precipitable Water product and Visible (0.65 µm) image at 2123 UTC [click to enlarge]

Aqua MODIS Total Precipitable Water product and Visible (0.65 µm) image at 2123 UTC [click to enlarge]

True Color Red-Green-Blue (RGB) imagery from NOAA-20 VIIRS (below) provided a good view of the smoke.

NOAA-20 VIIRS True Color RGB image [click to enlarge]

NOAA-20 VIIRS True Color RGB image [click to enlarge]

A NOAA-15 AVHRR Shortwave Infrared image at 0225 UTC or 6:25 PM local time (below) depicted the very large thermal anomaly of the fire.

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image; major highways are plotted in cyan, with Interstate highways plotted in red [click to enlarge]

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image; major highways are plotted in cyan, with Interstate highways plotted in red [click to enlarge]

The smoke had an adverse  impact on air quality over 100 miles from the fire source: the surface visibility dropped to 1 mile at Santa Rosa KSTS and 2 miles at San Francisco International Airport KSFO (below).

Time series of surface observations for Santa Rosa [click to enlarge]

Time series of surface observations from Santa Rosa [click to enlarge]

Time series of surface observations from San Francisco International Airport [click to enlarge]

Time series of surface observations from San Francisco International Airport [click to enlarge]

===== 09 November Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

Nighttime VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images from NOAA-20 at 0849 UTC (above) and Suomi NPP at 0942 UTC (below) revealed the bright glow and the large, hot thermal anomaly of the Camp Fire.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

VIIRS True Color RGB images from Suomi NPP at 2104 UTC and NOAA-20 at 2154 UTC (below) showed the broad extent of the smoke from the Camp Fire in northern California as well as the Woolsey Fire in southern California. These images were captured and processed by the CIMSS/SSEC Direct Broadcast ground station.

Suomi NPP VIIRS True Color RGB image at 2104 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2104 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2154 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2154 UTC [click to enlarge]

An animation of 1-minute GOES-16 Visible and Shortwave Infrared images (below) revealed several plume jumps over the fire source from 15-19 UTC — and toward the end of the day, a decrease in the areal coverage and intensity of hot pixels indicated that extreme fire conditions were easing and containment efforts were slowing the spread of the fire.

GOES-16 "Red" Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

Abnormally dry to extreme drought conditions across California were a contributing factor to this and other wildfires across the state.

US Drought Monitor conditions as of 06 November [click to enlarge]

US Drought Monitor conditions as of 06 November [click to enlarge]

====== 11 November Update =====

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images [click to play animation]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images [click to play animation]

A sequence of Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images centered at Paradise, California viewed using RealEarth (above) showed the spread of the Camp Fire thermal anomaly (dark black pixels) during the period 1943 UTC on 08 November to 1046 UTC on 11 November.

1-minute GOES-16 Visible and Shortwave Infrared images (below) showed the development of new smoke plume and hot thermal signatures around the periphery of the ongoing Camp Fire during the day on 11 November. As of 1849 UTC (10:49 AM local time), the fire had burned 109,000 acres and was listed as 25% contained.

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

The new smoke plume — as well as residual smoke from previous days of burning — could be seen on VIIRS True Color RGB imagery from Suomi NPP at 2029 UTC and NOAA-20 at 2114 UTC (below). The entire image swaths as captured and processed by the Direct Broadcast ground station at CIMSS/SSEC can be seen here and here.

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

The Camp Fire has claimed 42 lives and destroyed 6,522 homes and 260 businesses, making it both the deadliest and the most destructive wildfire on record for the state of California.

Blowing dust from the Copper River Valley in Alaska

November 1st, 2018 |

NOAA-20 VIIRS True Color RGB images [click to enlarge]

NOAA-20 VIIRS True Color RGB images [click to enlarge]

Strong gap winds accelerating out of the Copper River Valley along the southern coast of Alaska were lofting fine particles of glacial silt/sand and transporting those aerosols southwestward across the Gulf of Alaska on 31 October and 01 November 2018. A sequence of NOAA-20 VIIRS True Color Red-Green-Blue (RGB) images viewed using RealEarth (above) showed that the plume was more widespread on 01 November.

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images (below) showed the plume at 2022 UTC on 01 November. The map overlay has been removed from one set of images, to better reveal the dust plume source region. Note that the plume appeared much warmer (darker shades of red)  in the Shortwave Infrared image — this is due to enhanced solar reflectance off the small dust particles. Since airborne dust is generally transparent at longer infrared wavelengths, only the thickest portion of the plume exhibited a subtle signature on the 11.45 µm image.

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

The surface visibility briefly dropped to 3 miles at Middleton Island (PAMD) around the time of the Suomi NPP VIIRS images. as gusty north-northeasterly winds carried the plume over that location (below). Although Cordova (station identifier PACV) is only about 20 miles northwest of the Copper River Delta, the localized gap winds did not affect that site (where wind speeds were 3 knots or less the entire day).

Time series plot of surface observations at Middleton Island [click to enlarge]

Time series of surface observations at Middleton Island [click to enlarge]

ASCAT surface scatterometer winds (source) from Metop-A and Metop-B (below) showed speeds in the 25-30 knot range where the gap winds were exiting the Copper River Delta.

Metop-A and Metop-B ASCAT surface scatterometer winds [click to enlarge]

Metop-A and Metop-B ASCAT surface scatterometer winds [click to enlarge]

A toggle between Suomi NPP VIIRS Visible (0.64 µm) and Infrared Brightness Temperature Difference (11-12 µm) images (source) at 2204 UTC on 01 November (below) showed a subtle BTD signal within the more dense center portion of the plume, due to the silicate composition of some of the airborne particulate matter.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Brightness Temperature Difference (11-12 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Brightness Temperature Difference (11-12 µm) images [click to enlarge]

VIIRS Aerosol Optical Thickness (AOT) products from the eIDEA site (below) revealed larger AOT values on 01 November.

VIIRS Aerosol Optical Thickness product [click to enlarge]

VIIRS Aerosol Optical Thickness product [click to enlarge]

The gap winds were caused by a strong gradient between cold high pressure over Interior Alaska/Yukon and an occluding gale force low pressure system in the Gulf of Alaska (surface analyses: WPC)| OPC). GOES-15 (GOES-West) Visible (0.63 µm) images (below) showed the circulation of the low, and surface observations highlighted the cold air over snow-covered inland areas. While the dust plume was faintly apparent, it did not show up as well with the lower spatial resolution and large viewing angle of GOES-15.

GOES-15 Visible (0.63 µm) images [click to play animation]

GOES-15 Visible (0.63 µm) images [click to play animation]

A similar — though more prolonged and intense — event was noted in October 2016.

NUCAPS views Saharan Air over the Atlantic

September 20th, 2018 |

Saharan Air Layer Analysis over the Tropical Atlantic, 0600 UTC on 20 September 2018 (Click to enlarge)

There have been many episodes of Saharan Air over the tropical Atlantic within the past months, and another episode is in progress on 20 September. The Saharan Air Layer (SAL) analysis, above, from the CIMSS Tropical Weather website (Direct Link), shows dry air north and east of the Caribbean. The Clean Window ABI Band 13 (10.3 µm) Full-Disk ABI infrared imagery, below, from 0500 UTC, overlain with NUCAPS sounding points, shows where data were available from that morning overpass of Suomi NPP.

GOES-16 ABI 10.3 µm Infrared Imagery at 0500 UTC along with NUCAPS Sounding Points at approximately the same time (Click to enlarge)

The stepping animation below shows NUCAPS Soundings at a selection of points that starts north of the Saharan Air Layer and ends up within the SAL. The underlying figure is the Dust RGB from AWIPS, an RGB that combines the Split Window Difference (12.3 µm -10.3 µm; Red Component), Split Cloud Top Phase Brightness Temperature Difference (11.2 µm – 8.5 µm; Green Component) and 10.3 µm Infrared Imagery (Blue Component). Typically, regions with dust as might accompany a SAL have a pink tinge. The soundings are annotated to include Total Precipitable Water measurements, and mid-level Relative humidity. NUCAPS soundings identify the region where the SAL is present.

Dust RGB at 0433 UTC north and east of the Caribbean, and NUCAPS Soundings at selected points along a transect (Click to enlarge)

The SAL air continued its movement west during the day on 20 September.  The toggle below shows the Dust RGB, ABI Band 3 (0.86 µm) and the Baseline Aerosol Detection Product (in blue) at about the same time as the afternoon NUCAPS Sounding overpass (from Suomi NPP).  Suomi NPP overflew the eastern half of the SAL air (the overpass from NOAA-20 was more centered on the SAL air approaching the Caribbean, but NOAA-20 NUCAPS soundings are not yet in AWIPS;  they should be by the end of the year).

GOES-16 ABI Dust RGB, “Veggie Band” (Near-Infrared at 0.86 µm), and Baseline Aerosol Detection Product (Blue points), 1615 UTC on 20 September 2018 (Click to enlarge)

NUCAPS Soundings at 3 points (North of the SAL, within the SAL, and south of the SAL), below, show much different thermodynamics within the SAL.

NUCAPS Profiles at ~1600 UTC on 20 September 2018 at three locations as noted (Click to enlarge)

NOAA’s G-IV flew through this outbreak, deploying dropsondes to sample the event. The path of the aircraft (with the dropsonde locations) is here. Sonde #26, below, in the heart of the SAL, is shown below, with a nearby NOAA-20 NUCAPS sounding. (Flight path and Sonde imagery courtesy Chris Barnet, STC/NOAA) Refer to the caption for details.  Recall that the Dropsonde shows values at a point.  The NUCAPS profile is sampling a volume that is approximately a 50-km cylinder!  There is nevertheless excellent agreement.

Dropsonde #26 data (raw data in light grey; values averaged into the 100 NUCAPS vertical layers in black); GFS sounding in magenta. NUCAPS Microwave-only sounding in green; NUCAPS Microwave and infrared retrieval (as might be seen in AWIPS) in Red. Time offset from the Dropsonde is noted (Click to enlarge)

SAL outbreaks cause a significant deterioration in air quality over the Caribbean. The image below, courtesy Ernesto Rodriguez, SOO for the National Weather Service office in San Juan, Puerto Rico, compares Air Quality before and during a SAL outbreak in July, and during the current outbreak.

The view outside of the National Weather Service office in San Juan on 20 September and 13 July 2018 (during SAL outbreaks) and on 12 July 2018 (before a SAL outbreak). Imagery courtesy Ernesto Rodriguez, NWS SJU.

Wildfires in British Columbia

August 17th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

A 2-panel comparison of GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the smoke plumes and thermal anomalies or “hot spots” (darker black to red pixels) associated with a flare-up of wildfires in western British Columbia on 17 August 2018.

A sequence of Shortwave Infrared (3.7 µm) images from Terra / Aqua MODIS and Suomi NPP / NOAA-20 VIIRS (below) revealed the diurnal changes in areal coverage and intensity of the thermal signature of the fires.

Shortwave Infrared (3.7 µm) images from Terra / Aqua MODIS and Suomi NPP / NOAA-20 VIIRS [click to enlarge]

Shortwave Infrared (3.7 µm) images from Terra / Aqua MODIS and Suomi NPP / NOAA-20 VIIRS [click to enlarge]

Toggles between Visible and Shortwave Infrared images from Terra MODIS (1912 UTC), NOAA-20 VIIRS (1950 UTC) ans Suomi NPP VIIRS (2129 UTC) are shown below (note: the NOAA-20 images are incorrectly labeled as Suomi NPP). It is interesting to note the impact that the smoke plume had on the air temperature at Quesnel (CYQZ) — because the smoke layer was optically dense enough (VIIRS True Color image) to significantly reduce incoming solar radiation, the temperature was as much as 14-18ºF (8-10ºC) cooler than Prince George (CYXS) to the north and Williams Lake (CYWL) to the south.

Terra MODIS Visible (0.65 µm) and Shortwave Infrared (3.7 µm) images [click to enlarge]

Terra MODIS Visible (0.65 µm) and Shortwave Infrared (3.7 µm) images at 1912 UTC [click to enlarge]

NOAA-20 VIIRS Visible (0.64 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

NOAA-20 VIIRS Visible (0.64 µm) and Shortwave Infrared (3.74 µm) images at 1950 UTC [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Shortwave Infrared (3.74 µm) images at 2129 UTC [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Shortwave Infrared (3.74 µm) images at 2129 UTC [click to enlarge]

Farther to the east in Alberta, thick smoke caused very poor air quality in cities like Edmonton and Grande Prairie (photo 1 | photo 2). Daily composites of Suomi NPP VIIRS True Color RGB images from 11 August to 17 August (below) revealed the transport of smoke across British Columbia, Alberta and Saskatchewan.

Daily composites of Suomi NPP VIIRS True Color RGB images (with VIIRS fire detections in red), 11-17 August [click to play MP4 | Animated GIF]

Daily composites of Suomi NPP VIIRS True Color RGB images (with VIIRS fire detections in red), 11-17 August [click to play MP4 | Animated GIF]

A time series of surface reports from Edmonton, Alberta covering the period 14-17 August (below) showed that smoke restricted the surface visibility there to 1.5 miles on 15 August and 17 August.

Time series of surface reports from Edmonton, Alberta during the period 14-17 August [click to enlarge]

Time series of surface reports from Edmonton, Alberta during the period 14-17 August [click to enlarge]

===== 19 August Update =====

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

GOES-17 Near-Infrared

GOES-17 Near-Infrared “Cloud Particle Size” (2.24 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play 81 Mbyte MP4 animation]

A 2-panel comparison of GOES-17 Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images during the 7-day period of 13-19 August (above) showed the diurnal changes in thermal signatures of the ongoing British Columbia wildfires. The nighttime thermal signatures seen on the 2.24 µm images (brighter white pixels) result from the fact that this spectral band is located close to the peak emitted radiance of very hot features such as active volcanoes or large fires (below).

Plots of Spectral Response Functions for ABI Bands 5, 6 and 7 [click to enlarge]

Plots of Spectral Response Functions for ABI Bands 5, 6 and 7 [click to enlarge]