Landsat-8 images of Washington State landslide site

March 23rd, 2014
Landsat-8 0.59 µm panochromatic visible image of the Washington State landslide site

Landsat-8 0.59 µm panochromatic visible image of the Washington State landslide site

Kudos to Russ Dengel of the SSEC RealEarth web map server development team for spotting this: a relatively cloud-free overpass of the Landsat-8 satellite which revealed the site of the massive landslide/mudslide near the small town of Oso in northwestern Washington State (north of Seattle). The animation shown above was made using RealEarth to zoom in with the Google Maps base layer, and then toggle between the base map and an overlay of 15-meter resolution Landsat-8 0.59 µm (Band 8) panochromatic visible imagery at 19:03 UTC or 12:03 PM local time on 23 March 2014. It can be seen that debris from the landslide — which occurred a day earlier — covered one mile of State Road 530, cutting off access to the town of Darlington (located east of the landslide site); it also blocked the North Fork of the Stillaguamish River, leading to fears of localized flooding both upstream and downstream of the landslide site.

The Landsat-8 visible image is shown below. The landslide was blamed on ground saturation due to heavy rainfall in the region over the past month (30-day total rainfall | depature from normal).

Landsat-8 0.59 µm panochromatic visible image

Landsat-8 0.59 µm panochromatic visible image

===== 01 April Update =====

Landsat-8 0.59 µm panochromatic visible image on 01 April

Landsat-8 0.59 µm panochromatic visible image on 01 April

14 days later, there was another overpass of the Landsat-8 satellite; it could be seen on the 0.59 µm panochromatic visible image (above) that the mudslide still covered a significant portion of State Road 530. The 1.61 µm near-IR image (below) revealed that the mudslide had altered the course of the North Fork of the Stillaguamish River, and highlighted areas where some localized flooding was occurring due to a widening of the river (water is a strong absorber at the 1.61 µm wavelength, so it appears dark on the near-IR image).

Landsat-8 1.61 µm near-IR image on 01 April

Landsat-8 1.61 µm near-IR image on 01 April

Strong Storm in the Mediterranean

November 19th, 2013
Meteosat-10 10.8 µm infrared channel images (click to play animation)

Meteosat-10 10.8 µm infrared channel images (click to play animation)

Cyclone Cleopatra moved through the central Mediterranean Sea, causing flooding in Italy and Sardinia (BBC News Link) with northeastern Sardinia particularly hard hit. The infrared imagery from Meteosat-10, above, and the water vapor imagery, below, shows the slow movement of the entire system within the Mediterranean basin, as well as the strong thunderstorms over Sardinia later in the day on 18 November. Note in the Infrared animation that the minor eruption of Etna, on Sicily, is apparent (as documented here).

Meteosat-10 6.2 µm water vapor channel images (click to play animation)

Meteosat-10 6.2 µm water vapor channel images (click to play animation)

A higher-resolution view centered on Sardinia, below, shows the redevelopment of strong thunderstorms (inferred by cold cloud tops on the IR imagery) over Sardinia ending after 1800 UTC on 18 November as dry air swept north. The visible imagery (bottom) is also testimony to the training aspect of this convection. (Hat tip to Byron Grisham at NOAA/OSPO for alerting us about this noteworthy storm)

Meteosat-10 10.8 µm infrared channel images (click to play animation)

Meteosat-10 10.8 µm infrared channel images (click to play animation)

Meteosat-10 0.7 µm visible channel images (click to play animation)

Meteosat-10 0.7 µm visible channel images (click to play animation)

Typhoon Wipha

October 15th, 2013
MTSAT-2 10.8 µm IR channel images (click to play animation)

MTSAT-2 10.8 µm IR channel images (click to play animation)

McIDAS images of MTSAT-2 10.8 µm IR channel data (above; click image to play animation) showed the center of Typhoon Wipha moving just southeast of Japan on 15 October 2013. The asterisk at the center of the images denotes the location of Tokyo Narita International Airport — many areas in the Tokyo region received very heavy rainfall which caused flooding and mudslides. At Izu Oshima island just south of Tokyo, rainfall rates were as high as 11.8 mm (4.7 inches) per hour, with a 24-hour rainfall total of 824.9 mm (32.5 inches).

AWIPS images of the MIMIC Total Precipitable Water (TPW) product (below; click image to play animation) revealed the large amount of tropical moisture that was transported northward toward Japan as Wipha began its poleward recurvature. At the end of the animation Wipha began its extratropical transition as it merged with a cold front that was exiting Asia and beginning to move southeastward across the North Pacific Ocean.

MIMIC Total Precipitable Water product, with surface analyses (click to play animation)

MIMIC Total Precipitable Water product, with surface analyses (click to play animation)

Flooding rains in southern Texas

October 14th, 2013
GOES-15/GOES-13 6.5 µm water vapor channel images (click to play animation)

GOES-15/GOES-13 6.5 µm water vapor channel images (click to play animation)

Flooding rains have occurred over south Texas during the past two days, and the animation of GOES water vapor imagery, above, and of MIMIC Total Precipitable Water, below, shows two airstreams moving moisture into that region. The GOES-15/GOES-13 Water Vapor image animation, above, shows upper-level moisture moving in from the tropical Pacific south of Mexico (much of it likely outflow from Tropical Storm Octave). MIMIC Total Precipitable Water animation (available from this site), below, shows a concomitant lower-level moisture source, the Gulf of Mexico. Plots at 925 mb, and 850 mb, show moist, easterly flow around a High centered over the mid-Mississippi valley. As a result, total precipitable water values exceeded 200% of normal over a wide region. (Blended Total Precipitable Water products are available here). The high values of Total Precipitable Water persist into the day on 14 October. (Link, analysis from SPC).

MIMIC Total Precipitable Water (click to play animation)

MIMIC Total Precipitable Water (click to play animation)

VIIRS 11.45 µm IR image (click to enlarge)

VIIRS 11.45 µm IR image (click to enlarge)

A Suomi-NPP VIIRS 11.45 µm IR image from late in the day on 13 October (above) showed strong convection near Laredo, TX, with very cold cloud tops (brightness temperature values over Mexico are as cold as -92º C!). Applying a different color enhancement, a comparison of this 1-km resolution VIIRS IR image at 20:11 UTC with the corresponding 4-km resolution GOES-13 10.7 µm IR image (below) highlights two advantages of polar orbiter imagery over geostationary imagery: (1) with the higher spatial resolution, the magnitude of the coldest overshooting cloud tops can be assessed: the -92º C minimum cloud-top IR brightness temperature on the VIIRS image was 14º C colder than the -78º C value seen on the GOES-13 image, and (2) with the minimal parallax error of polar orbiter imagery, the exact location of such cloud-top features can be more accurately determined.

Suomi NPP VIIRS 11.45 µm IR and GOES-13 10.7 µm IR channel images

Suomi NPP VIIRS 11.45 µm IR and GOES-13 10.7 µm IR channel images

The result of the strong convection near 2100 UTC, and from other convection apparent in the water vapor animation at top, was a broad region of heavy rains, (obtained from this site) shown below. Some of these rains fell over regions of Texas in drought (as shown here), so where damage was minimal, the heavy rains could be considered beneficial.

24-hour precipitation over Texas valid 1200 UTC 14 October (click to enlarge)

24-hour precipitation over Texas valid 1200 UTC 14 October from this site (click to enlarge)