Swan Lake Fire in Alaska

August 17th, 2019 |

GOES-17

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

1-minute Mesoscale Domain Sector GOES-17 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) revealed thick smoke and a pronounced thermal anomaly associated with the Swan Lake Fire which was burning on the Kenai Peninsula in south-central Alaska on 17 August 2019. Later in the day, a few pyrocumulus jumps could be seen in Visible imagery over the fire source region.

Strong northwesterly winds were transporting smoke from the Swan Lake Fire across the Kenai Peninsula and the Seward area — a time series of surface report data from Seward (below) showed that this smoke reduced the visibility to 1-2 miles at times.

Time series of surface reports from Seward, Alaska [click to enlarge]

Time series of surface report data from Seward, Alaska [click to enlarge]

The Air Quality Index reached 410 at Copper Landing and 358 at Seward (below).

Air Quality Index at Copper Landing and Seward [click to enlarge]

Air Quality Index at Copper Landing and Seward [click to enlarge]

The southward transport of smoke across the Seward area and out across the adjacent offshore waters of the Gulf of Alaska was evident in VIIRS True Color Red-Green-Blue (RGB) images from NOAA-20 and Suomi NPP, as viewed using RealEarth (below).

VIIRS True Color RGB images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS True Color RGB images from NOAA-20 and Suomi NPP [click to enlarge]

Super Typhoon Lekima in the West Pacific Ocean

August 8th, 2019 |

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.4 µm, right) images [click to play animation | MP4]

JMA 2.5-minute rapid scan Himawari-8 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.4 µm) images (above) showed the eye and eyewall region of Category 4 Super Typhoon Lekima on 07-08 August 2019. Features of interest included surface mesovortices within the eye, eyewall cloud-top gravity waves, and a quasi-stationary “cloud cliff” notch extending northwestward from the eye (infrared brightness temperature contours). This cloud cliff feature has been observed with other intense tropical cyclones (for example, Typhoon Neoguri in 2014).

VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 as viewed using RealEarth are shown below.

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

The trochoidal motion (or wobble) of the eye of Lekima became very pronounced as it crossed the Ryukyu Islands, as seen in an animation of 2.5-minute rapid scan Himawari-8  Infrared images (below). The center of the tropical cyclone moved between Miyakojima (ROMY) and Ishigakijima (ROIG), which reported wind gusts to 67 knots and 64 knots respectively.

Himawari-8 Infrared (10.4 µm) images [click to play animation| MP4]

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

Himawari-8 Infrared images with contours and streamlines of deep-layer wind shear at 15 UTC from the CIMSS Tropical Cyclones site (below) indicated that Lekima was moving through an environment of very low shear, which was a factor aiding its intensification.

Himawari-8 "Clean" Infrared Window (10.4 µm) images, with contours and streamlines of deep-layer wind shear at 15 UTC [click to play animation]

Himawari-8 “Clean” Infrared Window (10.4 µm) images, with contours and streamlines of deep-layer wind shear at 15 UTC [click to play animation]

Milepost 97 Fire in southwestern Oregon

July 26th, 2019 |

GOES-17 Fire Temperature RGB,

GOES-17 Fire Temperature RGB, “Red” Visible (0.64 µm), CIMSS Natural Color RGB and Day Cloud Phase Distinction RGB images [click to play animation | MP4]

An animation that cycles through GOES-17 (GOES-West) Fire Temperature Red-Green-Blue (RGB), “Red” Visible (0.64 µm), CIMSS Natural Color RGB and Day Cloud Phase Distinction RGB images (above) showed the thermal anomaly (darker red pixels) and smoke associated with the Milepost 97 Fire in southwestern Oregon on 26 July 2019. In this particular case, dense smoke appeared as darker shades of green in the Day Cloud Phase Distinction RGB images.

A time series of surface data from Sexton Summit (immediately downwind of the fire) indicated that smoke reduced the surface visibility at that location to 1/4 mile at times; farther from the fire, the visibility was in the 2-3 mile range at times in Medford (below).

Time series of surface data from Sexton Summit [click to enlarge]

Time series of surface data from Sexton Summit [click to enlarge]

Time series of surface data from Rogue Valley International Airport in Medford [click to enlarge]

Time series of surface data from Rogue Valley International Airport in Medford [click to enlarge]

===== 27 July Update =====

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images from the AOS site (above) showed the increased coverage of smoke from the Milepost 97 Fire, spreading across southern Oregon and into Northern California on 27 July. Some of the smoke had been lofted to higher altitudes, being transported as far northeastward as Montana.

Later in the day, GOES-17 True Color RGB images showed that the smoke had moved a significant distance southward along and just off the California coast (below).

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

Severe weather in Minnesota and Wisconsin

July 19th, 2019 |

GOES-16 "Red" Visible (0.64 µm) images, with SPC Storm Reports plotted in red [click to play MP4 animation]

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

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the development and propagation of a Mesoscale Convective System (MCS) that produced hail up to 3.0 inches in diameter in Minnesota and wind gusts to 84 mph and a few tornadoes in Wisconsin (SPC Storm Reports | NWS Twin Cities | MN DNR | NWS Green Bay) on 19 July 2019. Numerous overshooting tops and widespread storm-top gravity waves were evident in the imagery, along with a few Above-Anvil Cirrus Plume features extending northeastward from some of the overshooting tops around sunset. Also notable were the inflow feeder bands that were streaming northward into the southern flank of the MCS across Minnesota.

A comparison of GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (below) revealed cloud-top infrared brightness temperatures as cold as -86ºC over northwestern Wisconsin.

GOES-16

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play MP4 animation]

As the MCS persisted into the subsequent nighttime hours, GOES-16 Infrared images (below) showed the large canopy of cold cloud tops, with infrared brightness temperatures of -80ºC or colder (violet pixels).  Some of the embedded storms exhibited well-defined Enhanced-V storm top signatures (for example, at 2219 UTC).

GOES-16

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

===== 22 July Update =====

Terra MODIS True Color RGB images, 11 July vs 22 July [click to enlarge]

Terra MODIS True Color RGB images, 11 July vs 22 July [click to enlarge]

A comparison of Terra MODIS True Color Red-Green-Blue (RGB) images from 11 July and 22 July (above) showed the subtle NW-SE oriented swath of downed trees across northeastern Wisconsin. A 14 July vs 22 July comparison as viewed using RealEarth is shown below — the swath extended from approximately Pickerel to Mountain.

14 July and 22 July Terra MODIS True Color RGB images [click to enlarge]

Terra MODIS True Color RGB images, 14 July vs 22 July [click to enlarge]

In 22 July Terra MODIS images displayed using AWIPS (below), the swath of downed trees was brighter (more reflective) in the Near-Infrared “Snow/Ice” (1.61 µm), warmer (darker shades of orange to red) in the Shortwave Infrared (3.7 µm) and Land Surface Temperature, and lighter shades of green in the Normalized Difference Vegetation Index.

Terra MODIS Visible (0.65 µm), Near-Infrared "Snow/Ice" (1.61 µm), Shortwave Infrared (3.7 µm), Land Surface Temperature and Normalized Difference Vegetation Index images on 22 July [click to enlarge]

Terra MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.7 µm), Land Surface Temperature and Normalized Difference Vegetation Index images on 22 July [click to enlarge]

The swath of downed trees was also seen in GOES-16 Normalized Difference Vegetation Index images (below), showing up as a darker shade of green with that product’s default enhancement.

GOES-16 Normalized Difference Vegetation Index images [click to play animation]

GOES-16 Normalized Difference Vegetation Index images on 22 July [click to play animation]