Wildfire in Alaska

May 1st, 2019 |

GOES-17 Shortwave Infrared (3.9 µm) and "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 Shortwave Infrared (3.9 µm) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

On 01 May, GOES-17 (GOES-West) Shortwave Infrared (3.9 µm) and “Red” Visible (0.64 µm) images (above) showed the thermal anomaly (or fire “hot spot”) and dispersion of smoke from the first moderate-size wildfire of 2019 in the Interior of Alaska — the Oregon Lakes Impact Area Fire about 7 miles southwest of Fort Greely. This fire grew from 30 acres to 4000 acres in a 24-hour period, aided by warm daytime temperatures with low relative humidity values and southwest winds late in the day on 30 April (surface data). The Oregon Lakes Impact Area Fire was burning in a remote area just west of the Delta River which was previously burned by the 2013 Mississippi Fire; that area also contained unexploded ordnance dropped by military aircraft during training exercises.

A toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 1216 UTC or 4:16 am local time (below) revealed the nighttime glow of the fire, along with a more accurate depiction of the size and location of the thermal anomaly.

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]

Although the color enhancements were different, a comparison of Shortwave Infrared images from Suomi NPP (3.74 µm) at 1216 UTC and GOES-17 (3.9 µm) at 1220 UTC (below) demonstrated the advantage of imagery from polar-orbiting satellites at high latitudes. In this example, the 375-meter resolution VIIRS image showed 2 distinct fire hot spots that were not apparent in the lower spatial resolution — 2 km at nadir, decreasing to about 4 km over Alaska — GOES-17 image.

Shortwave Infrared images from Suomi NPP (3.74 µm) and GOES-17 (3.9 µm) [click to enlarge]

Shortwave Infrared images from Suomi NPP (3.74 µm) and GOES-17 (3.9 µm) [click to enlarge]

A larger-scale view of GOES-17 Shortwave Infrared and Visible images from 02-04 UTC on 02 May (below) showed the fire as it exhibited its peak 3.9 µm infrared brightness temperature (51.3ºC or 324.5 K at 0210 UTC) and the smoke plume had drifted over 100 miles to the southeast, moving over Beaver Creek, Yukon (CYXQ). While most of the smoke was apparently lofted above the boundary layer, the surface visibility at Fort Greely PABI was briefly reduced to 6 miles at 09 UTC or 1am local time on 02 May. Note the lack of “false cold pixels” adjacent to the warmest 3.9 µm pixels — this is due to a recent change to the GOES-R ABI Band 7 resampler, as detailed in this blog post.

GOES-17 Shortwave Infrared (3.9 µm) and "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 Shortwave Infrared (3.9 µm) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

A comparison of Visible and Shortwave Infrared images from GOES-17 and GOES-15 (below) highlighted the improved fire detection and monitoring capability of the new GOES-R series. The higher spatial resolution (0.5 km vs 1.0 km at nadir for Visible, and 2 km vs 4 km at nadir for Shortwave Infrared) and more frequent image scans (10 minutes for GOES-17 Full Disk vs 15-30 minutes for GOES-15 CONUS sector) along with better Image Navigation and Registration (INR) were especially valuable at the higher latitudes of Alaska. For example, the subtle behavior of the fire’s smoke column vertical jump at 2350 UTC was only apparent in the GOES-17 Visible imagery.

GOES-17 Visible (0.64 µm, top left), GOES-15 Visible (0.63 µm, top right), GOES-17 Shortwave Infrared (3.9 µm, bottom left) and GOES-15 Shortwave Infrared (3.9 µm, bottom right) images [click to play animation | MP4]

GOES-17 Visible (0.64 µm, top left), GOES-15 Visible (0.63 µm, top right), GOES-17 Shortwave Infrared (3.9 µm, bottom left) and GOES-15 Shortwave Infrared (3.9 µm, bottom right) images [click to play animation | MP4]

Since the fire was also located within the GOES-17 Mesoscale Domain Sector #2, 1-minute imagery provided an even better depiction of the fire’s smoke column vertical jump and downstream smoke transport (below).

GOES-17 Visible (0.64 µm, top left), GOES-15 Visible (0.63 µm, top right), GOES-17 Shortwave Infrared (3.9 µm, bottom left) and GOES-15 Shortwave Infrared (3.9 µm, bottom right) images [click to play animation | MP4]

GOES-17 Visible (0.64 µm, top left), GOES-15 Visible (0.63 µm, top right), GOES-17 Shortwave Infrared (3.9 µm, bottom left) and GOES-15 Shortwave Infrared (3.9 µm, bottom right) images [click to play animation | MP4]

Strong jet streak over the Lower 48 states

February 17th, 2019 |


GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of Derived Motion Winds [click to play animation | MP4]

GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of Derived Motion Winds [click to play animation | MP4]

An unusually strong jet streak was located over the Lower 48 states on 17 February 2019. GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) images with plots of 6.2 µm Derived Motion Winds (above) showed numerous tracked targets along and south of the jet axis — within the jet streak exit region over the Mid-Atlantic states, some velocity values were as high as 181 knots (below).

GOES-16 Upper-level Water Vapor (6.2 µm) image, with plots of Derived Motion Winds at 0002 UTC [click to enlarge]

GOES-16 Upper-level Water Vapor (6.2 µm) image, with plots of Derived Motion Winds at 0002 UTC [click to enlarge]

A plot of rawinsonde data from Lincoln, Illinois at 00 UTC (below) showed wind speeds as high as 190 knots at a pressure of 231 hPa. The 250 hPa wind speed of 184.7 knots set both a daily and an all-time record speed for that pressure level (the old all-time record was 175 knots for a sounding on 10 Dec at 00 UTC).

Plot of 00 UTC rawinsonde data from Lincoln, Illinois [click to enlarge]

Plot of 00 UTC rawinsonde data from Lincoln, Illinois [click to enlarge]

GOES-16 Air Mass RGB images from the AOS site (below) provided a classic portrayal of the green hues of warm/moist tropical air south of and the orange/red hues of cold/dry polar air north of this strong jet stream.

GOES-16 Air Mass RGB images [click to play animation | MP4]

GOES-16 Air Mass RGB images [click to play animation | MP4]

===== 18 February Update =====

GOES-17 "Red" Visible (0.64 µm) and Near-Infrared "Snow/Ice (1.61 µm) images [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice (1.61 µm) images [click to play animation | MP4]

The large southward dip of the polar jet stream — evident in the GOES-16 Air Mass RGB images from the previous day — brought cold air into the Desert Southwest, resulting in snowfall at lower-elevation locations such as Las Vegas, Nevada. GOES-17 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice (1.61 µm) images (above) revealed snow on the ground in the Las Vegas area — much of which quickly melted with increased surface heating after sunrise. Snow cover is a good absorber of radiation at the 1.61 µm wavelength, so it appeared as darker shades of gray on the Snow/Ice images; the distribution of the heavier snowfall amounts (which naturally melted more slowly) was influenced by the topography of the area. This snowfall forced the closure of Interstate 15 from Las Vegas to the Nevada/California border for several hours due to icy pavement and multiple traffic accidents.

The snow cover was apparent in Visible imagery from 4 GOES (below) — GOES-17 (GOES-West), GOES-15 (the backup GOES-West), GOES-16 (GOES-East) and GOES-13 (the backup GOES-East, which had been brought out of storage for annual maintenance activities).

Visible images from GOES-17, GOES-15, GOES-15 and GOES-13 [click to play animation | MP4]

Visible images from GOES-17, GOES-15, GOES-15 and GOES-13 [click to play animation | MP4]


Seattle, Washington as viewed by 4 GOES

February 13th, 2019 |

Visible images, centered at Seattle, from (left to right) GOES-17, GOES-15, GOES-16 and GOES-13 [click to play animation | MP4]

Visible images, centered at Seattle, from (left to right) GOES-17, GOES-15, GOES-16 and GOES-13 [click to play animation | MP4]

The GOES-13 satellite was brought out of storage for annual maintenance activities on 13 February 2019 — allowing for a unique view of the Seattle, Washington area from that satellite as well as GOES-15, GOES-16 (GOES-East) and GOES-17 (GOES-West). After receiving significant snowfall during the previous several days, snowcover was abundant across that region. The brighter-white snow-covered mountain peaks south and southeast of Seattle (especially that of Mount Rainier) were also apparent on visible imagery from all 4 satellites.

Note that visible images from the older GOES-13/GOES-15 are not as bright as those from the newer GOES-16/GOES-17 — performance of visible detectors on the previous generation of satellites degraded over time, while the new GOES-R series benefits from on-orbit calibration of the visible detectors to mitigate this effect.

Using a spare rooftop antenna, staff at the SSEC Data Center were able to ingest and process this data from GOES-13 (in addition to the other 3 GOES satellites). GOES-13 will be placed back into storage on 25 February 2019.

A toggle between larger-scale images using the 5 spectral bands of the GOES-13 Imager are shown below.

GOES-13 Visible (0.63 µm), Shortwave Infrared (3.9 µm), Water Vapor (6.5 µm), Infrared Window (10.7 µm) and Infrared CO2 Absorption (13.3 µm) images at 2015 UTC [click to enlarge]

GOES-13 Visible (0.63 µm), Shortwave Infrared (3.9 µm), Water Vapor (6.5 µm), Infrared Window (10.7 µm) and Infrared CO2 Absorption (13.3 µm) images at 2015 UTC [click to enlarge]

Strong midlatitude cyclone north of Hawai’i

February 10th, 2019 |
GOES-17

GOES-17 “Red” Visible (0.64 µm) images [click to play MP4 animation]

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

1-minute Mesoscale Domain Sector GOES-17 “Red” Visible (0.64 µm) images from the AOS site (above) showed the distinct circulation of a strong midlatitude cyclone (surface analyses) that was centered just north of Hawai’i on 10 February 2019. The pressure gradient associated with this storm produced strong winds across the island chain. Wave heights to 38.4 feet were recorded at Buoy 51208 near Kaua’i, with wind gusts to 57 knots at Buoy 51001 northwest of Kauwa’i.



GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below) revealed the presence of numerous lee waves which extended hundreds of miles downwind of the islands — most notable were those emanating from Kauwa’i.

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) images [click to play animation | MP4]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play animation | MP4]

Derived Motion Winds calculated using GOES-15 (GOES-West) Water Vapor (6.5 µm) imagery from the CIMSS Tropical Cyclones site (below) showed targets with velocites of 150-160 knots just north of Hawai’i at 09 UTC and 12 UTC.

Derived Motion Winds calculated using GOES-15 Water Vapor (6.5 µm) imagery [click to enlarge]

Derived Motion Winds calculated using GOES-15 Water Vapor (6.5 µm) imagery [click to enlarge]

GOES-17 Air Mass RGB images (below) showed the orange to red hues signifying a lowered tropopause and increased stratospheric ozone within the atmospheric column as the storm evolved during the 09-10 February time period.

GOES-17 Air Mass RGB images [click to play MP4 animation]

GOES-17 Air Mass RGB images [click to play MP4 animation]

Suomi NPP VIIRS True Color and Infrared Window (11.45 µm) images at 23 UTC as viewed using RealEarth are shown below.

Suomi NPP VIIRS True Color and Infrared Window (11.45 µm) images at 23 UTC [click to enlarge]

Suomi NPP VIIRS True Color and Infrared Window (11.45 µm) images at 23 UTC [click to enlarge]