This website works best with a newer web browser such as Chrome, Firefox, Safari or Microsoft Edge. Internet Explorer is not supported by this website.

Halos due to the presence of ice crystal clouds

Photos taken by SSEC scientist Claire Pettersen at 1615 UTC (above) and 1623 UTC (below) revealed several examples of ice crystal cloud optics over Madison, Wisconsin on 14 November 2016.  More information on the various types of ice cloud halos can be found here and here.1650 UTC Terra MODIS Visible (0.65 µm),... Read More

Photo showing an Upper Tangent Arc, a Parhelia (Sun Dog), a Parhelic Circle segment and a faint 46 degree segment (upper right).

Photo showing an Upper Tangent Arc, a Parhelia (Sun Dog), a Parhelic Circle segment and a faint 46 degree segment (upper right).

Photos taken by SSEC scientist Claire Pettersen at 1615 UTC (above) and 1623 UTC (below) revealed several examples of ice crystal cloud optics over Madison, Wisconsin on 14 November 2016.  More information on the various types of ice cloud halos can be found here and here.

Photo showing a Circumzenithal Arc with a Supralateral Arc, in addition to an Upper Tangent Arc.

Photo showing a Circumzenithal Arc with a Supralateral Arc, in addition to an Upper Tangent Arc.

1650 UTC Terra MODIS Visible (0.65 µm), near-infrared Cirrus (1.375 µm) and Infrared Window (11.0 µm) images (below) showed the patches of cirrus clouds that were over southern Wisconsin not long after the photos above were taken. Many of the cirrus cloud features over the Madison (KMSN) area appeared very thin and nearly transparent on the Visible image; they also exhibited very warm Infrared Window brightness temperature values (warmer than -20ºC), since a great deal of radiation from the warmer surface of the Earth was reaching the MODIS detectors through the thin clouds. The 1.375 µm Cirrus band is able to detect the presence of airborne particles that are efficient scatterers of light — such as cirrus cloud ice crystals, dust, volcanic ash, smoke, haze — so the thin cirrus clouds exhibited a good signature on that image.

Terra MODIS Visible (0.65 µm), Cirrus (1.375 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Terra MODIS Visible (0.65 µm), Cirrus (1.375 µm) and Infrared Window (11.0 µm) images [click to enlarge]

A similar 1.37 µm Cirrus Band will be on the ABI instrument aboard GOES-R.

View only this post Read Less

Fires in the southeast United States

Persistent moderate to severe drought (shown here, from this site) over the southeastern United States has supported the development of fires in and around the Great Smoky Mountains on 7 November 2016. True-color imagery from Terra MODIS, above, (source: MODIS Today) showed the active fires and plumes of smoke spreading northward into the Ohio... Read More

terramodis_truecolor_7nov2016

Terra MODIS True-Color Imagery over the Smoky Mountains, 7 November 2016 (Click to enlarge)

Persistent moderate to severe drought (shown here, from this site) over the southeastern United States has supported the development of fires in and around the Great Smoky Mountains on 7 November 2016. True-color imagery from Terra MODIS, above, (source: MODIS Today) showed the active fires and plumes of smoke spreading northward into the Ohio River Valley.

Suomi NPP VIIRS true-color imagery also captured the smoke emanating from the active fires, and the Aerosol Optical Depth product, toggled below (data sources: RealEarth) showed the extent of the thickest smoke layer (click here for an animation that does not include the RealEarth framing).

Suomi NPP VIIRS true-color image with fire detection locations (red dots), and VIIRS Aerosol Optical Depth product [click to enlarge]

Suomi NPP VIIRS true-color image with fire detection locations (red dots), and VIIRS Aerosol Optical Depth product [click to enlarge]

A sequence of true-color Red/Green/Blue (RGB) images from Terra MODIS (1643 UTC), Suomi NPP VIIRS (1809 UTC) and Aqua MODIS (1824 UTC) is shown below.

Terra MODIS, Suomi NPP VIIRS and Aqua MODIS true-color images [click to enlarge]

Terra MODIS, Suomi NPP VIIRS and Aqua MODIS true-color images [click to enlarge]

The temporal evolution of the smoke was captured on GOES-13 Visible (0.63 µm) images (below; also available as an MP4 animation). Smoke reduced the surface visibility to 2.5 – 3.0 miles at some locations in Kentucky (KJKL | KLOZ) and Tennessee (KOQT), leading to EPA Air Quality Index values in the “Unhealthy” category.

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

===== 10 November Update =====

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

In the wake of a cold frontal passage on 09 November, northerly to northeasterly winds were transporting the smoke south-southwestward as the fires continued to burn on 10 November. GOES-13 Visible (0.63 µm) images, above, showed the dense smoke plumes — some of which were briefly reducing the surface visibility to less than 1 statute mile in far western North Carolina (Andrews | Franklin). In Georgia, smoke restricted the visibility to 2.5 miles as far south as Columbus.

A Pilot Report (PIREP) in northern Georgia at 1530 UTC, below, indicated that the top of the smoke layer was around 3500 feet (where the Flight Visibility was 4 miles).  Surface reports in the vicinity of that PIREP indicated a ceiling of 1500 to 1700 feet, suggesting that the dense smoke layer aloft was about 1800-2000 feet thick over northern Georgia.

GOES-13 Visible (0.63 µm) image, with cloud ceiling (hundreds of feet above ground level) and visibility (statute miles) plotted in cyan and a Pilot Report in yellow [click to enlarge]

GOES-13 Visible (0.63 µm) image, with cloud ceiling (hundreds of feet above ground level) and visibility (statute miles) plotted in cyan and a Pilot Report in yellow [click to enlarge]

The smoke plumes showed up very well on an Aqua MODIS true-color RGB image from the MODIS Today site, below.

Aqua MODIS true-color image [click to enlarge]

Aqua MODIS true-color image [click to enlarge]

The 1858 UTC Suomi NPP VIIRS true-color image (with fire detections) and the Aerosol Optical Depth product, below, depicted the aerial coverage of the smoke.

Suomi NPP VIIRS true-color image (with fire detection locations in red) and Aerosol Optical Depth product [click to enlarge]

Suomi NPP VIIRS true-color image (with fire detection locations in red) and Aerosol Optical Depth product [click to enlarge]

View only this post Read Less

Himawari-9 Launches

Japan successfully launched the Himawari-9 satellite from the Tanegashima Space Center (near the southern tip of Tanegashima in the Osumi Islands south of Kyushu), a back-up to Himawari-8, shortly after 3:20 PM local time (0620 UTC) on 2 November 2016 (News Link 1, 2, 3, 4). Images showing all 16... Read More

Himawari-8 imagery of all 16 AHI Channels, as indicated, bracketing the launch time of Himawari-9 (Click to enlarge)

Himawari-8 imagery of all 16 AHI Bands, as indicated, bracketing the launch time of Himawari-9 (Click to enlarge)

Japan successfully launched the Himawari-9 satellite from the Tanegashima Space Center (near the southern tip of Tanegashima in the Osumi Islands south of Kyushu), a back-up to Himawari-8, shortly after 3:20 PM local time (0620 UTC) on 2 November 2016 (News Link 1, 2, 3, 4). Images showing all 16 Himawari-8 AHI spectral bands bracketing the 0620 UTC launch time are shown above; signatures of the warm thermal anomaly (from the burning of the solid rocket boosters) as well as the moisture of the rocket condensation cloud plume were evident in the Shortwave Infrared (3.9 µm) and Water Vapor (6.2 µm, 6.9 µm and 7.3 µm) bands, but a signal was also detectable in the Infrared 8.6 µm, 12.2 µm and 13.3 µm bands. The Himawari-8/9 AHI instrument is nearly identical to the ABI instrument on GOES-R — so similar imagery will be routinely available once GOES-R becomes operational in 2017.

h8_band4_0617_0625_h9launchanim

Himawari-8 Band 4 (0.86 µm) Visible Imagery for times bracketing the launch of Himawari-9 on 2 November 2016 (Click to enlarge)

The animation above shows the rocket plume in the Band 4 (0.86 µm) imagery (Band 4, the so-called “Veggie Band”, better discriminates between land and water so that the island of Tanegashima is more distinct) from Himawari-8, in the image at 0622 UTC. (Annotated 0622 UTC Image is here). The plume appears north of the launch site (which is located at the southern tip of the island).

A true-color image, below, that includes the three visible channels from Himawari-8 (Band 1 at 0.47 µm, Band 2 at 0.51 µm and Band 3 at 0.64 µm, with the Band 2 “Green Band” boosted by information in the Veggie Band at 0.86 µm) shows a plume, perhaps, emerging from the cloud field at the southern tip of the island.

h8_band4_0617_0625_h9launchanim

True-color imagery from Himawari-8 at 0620 UTC on 2 November, 2016 (Click to enlarge)

Another view of the 3.9 µm Shortwave Infrared imagery, below, shows a short-lived hot-spot near where the Band 4 imagery shows the plume. Note: due to parallax, the location of the high-altitude hot spot appears farther north than its actual location.

h8_band4_0617_0625_h9launchanim

Himawari-8 Band 7 (3.9 µm) Shortwave Infrared Imagery for times bracketing the launch of Himawari-9 on 2 November 2016 (Click to enlarge)

Visible Imagery for the same three times, below, suggests a plume may be present (toggle between Visible and Shortwave Infrared images).

h8_band4_0617_0625_h9launchanim

Himawari-8 Band 3 (0.64 µm) Imagery for times bracketing the launch of Himawari-9 on 2 November 2016 (Click to enlarge)

As mentioned above, signatures of the warm thermal anomaly and the moisture of the rocket condensation cloud plume were also evident on the three Himawari-8 Water Vapor bands, shown below — strong westerly winds aloft (satellite | model) quickly transported the high-altitude portion of the rocket plume eastward.

Himawari-8 6.2 µm (top), 6.9 µm (middle) and 7.3 µm (bottom) Water Vapor images (Click to enlarge)

Himawari-8 6.2 µm (top), 6.9 µm (middle) and 7.3 µm (bottom) Water Vapor images [click to enlarge]

A video of the launch is here, with the launch itself at 44 minutes.

View only this post Read Less

“Medicane” in the Mediterranean Sea

A compact tropical-like cyclone (often referred to as a “medicane“) moved across the Mediterranean Sea during the 28-31 October 2016 period. EUMETSAT Meteosat-10 Infrared Window (10.8 um) images (above; also available as a 71 Mbyte animated GIF) showed the system as it developed over the Ionian Sea between Italy and Greece,... Read More

EUMETSAT Meteosat-10 Infrared Window (10.8 um) images [click to play MP4 animation]

EUMETSAT Meteosat-10 Infrared Window (10.8 um) images [click to play MP4 animation]

A compact tropical-like cyclone (often referred to as a “medicane“) moved across the Mediterranean Sea during the 28-31 October 2016 period. EUMETSAT Meteosat-10 Infrared Window (10.8 um) images (above; also available as a 71 Mbyte animated GIF) showed the system as it developed over the Ionian Sea between Italy and Greece, initially moved southwestward, and then turned to the east where it eventually passed near the Greek island of Crete on 31 October (producing a wind gust to 52 knots at Chania’s Souda Airport LGSA and causing some wind and water damage: media story 1 | media story 2). In addition, a wind gust to 50 knots was seen on a ship report at 12 UTC on 28 October, just to the west of the storm center.

The corresponding EUMETSAT Meteosat-10 Visible (0.64 um) images (below; also available as a 17 Mbyte animated GIF) provided a more detailed look at the structure of the storm during the daylight hours of those 4 days.

EUMETSAT Meteosat-10 Visible (0.64um) images [click to play MP4 animation]

EUMETSAT Meteosat-10 Visible (0.64um) images [click to play MP4 animation]

Daily snapshots of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images viewed using RealEarth are shown below. The hazy signature of blowing dust/sand from northern Africa could be seen within the broad southeast quadrant of the storm circulation.

Suomi NPP VIIRS true-color images [click to enlarge]

Suomi NPP VIIRS true-color images [click to enlarge]

There was ample moisture available to fuel convection around the storm, as seen in the MIMIC Total Precipitable Water product (below).

MIMIC Total Precipitable Water product [click to play animation]

MIMIC Total Precipitable Water product [click to play animation]

The surface wind circulation of the medicane was well-sampled on a variety of Metop-A and Metop-B overpasses, using ASCAT plots (below) from this site.

Metop-A and Metop-B ASCAT surface scatterometer winds, 28-31 October [click to play animation]

Metop-A and Metop-B ASCAT surface scatterometer winds, 28-31 October [click to play animation]

Suomi NPP ATMS images (below; courtesy of Derrick Herndon, CIMSS) revealed the areal coverage of the small “warm core” on Channel 8 (54.94 GHz) and Channel 7 (53.596 GHz); a north-to-south oriented vertical cross section showed the depth of the thermal anomaly associated with the medicane.

Suomi NPP ATMS Channel 8 (54.94 GHz) image, 31 October at 0037 UTC [click to enlarge]

Suomi NPP ATMS Channel 8 (54.94 GHz) image, 31 October at 0037 UTC [click to enlarge]

Suomi NPP ATMS Channel 7 (53.596 GHz) image, 31 October at 0037 UTC [click to enlarge]

Suomi NPP ATMS Channel 7 (53.596 GHz) image, 31 October at 0037 UTC [click to enlarge]

 

North-to-south vertical cross section of Suomi NPP ATMS brightness temperature anomaly [click to enlarge]

North-to-south vertical cross section of Suomi NPP ATMS brightness temperature anomaly [click to enlarge]

For additional information, see this blog post from the Capital Weather Gang.

 

View only this post Read Less