Blowing Dust in Kansas

March 6th, 2018 |

GOES-16 Band 1 (“Blue Visible”) 0.47 µm Imagery, 1502 – 2132 UTC on 6 March 2018 along with surface METAR observation plots (Click to animate)

Strong northwesterly winds over the Great Plains to the west of a storm system over the mid-Mississippi River Valley have resulted in Red Flag Warnings over Oklahoma, and High Wind Warning and Dust Storm Warnings — including the closing of I-70 over Kansas. Visible Imagery in the “Blue Band”, above, shows little indication of the blowing dust (Click here for an animation without surface observations); dust is difficult to observe when sun angle are high. The higher-(spatial) resolution “Red Visible” animation, shown below, similarly struggles to identify with clarity where the dust is occurring.

The ‘Blue Band’ does detect plumes of smoke that develop over southern Kansas during this animation, plumes that originate over ‘hot spots’ in the 3.9 µm shortwave infrared imagery (not shown).

GOES-16 Band 2 (“Red Visible”) 0.64 µm Imagery, 1502 – 2132 UTC on 6 March 2018 along with surface METAR observation plots (Click to animate)

Infrared Imagery can be used to detect dust, both during the day and at night. This is because dust selectively absorbs energy. For example, energy at 10.3 µm that is emitted by the surface, and destined to be observed by the satellite, will be absorbed (and re-emitted from a higher, cooler level in the atmosphere) as it passes through the dust layer. Energy with a longer wavelength (12.3 µm), passes through dust mostly unaffected. Thus, a difference field between the two — the so-called Split Window Difference — will show negative values in regions where lofted dust is present in the atmosphere. An animation is shown below. As with imagery in this blog post, the colormap in the AWIPS display was changed to “Grid/Lowrange Enhanced”; dust regions are highlighted in yellow.  Dust is first detected in central Nebraska before it shows up in central and western Kansas. A closer view of the area where Interstate 70 was closed (between Goodland and Colby in northwestern Kansas) can be seen here.

GOES-16 Split Window Difference Field (10.3 µm – 12.3 µm) Imagery, 1502 – 2132 UTC on 6 March 2018 along with surface METAR observation plots (Click to animate)

The Cloud Phase Channel Difference field in AWIPS (Currently 10.3 µm – 8.5 µm, shortly to transition in AWIPS to 11.2 µm – 8.5 µm) can also detect dust (as was shown in this blog post), and that animation is shown below. Blowing Dust in this field is a bright green — and this Difference field (compared to the Split Window Difference) better identifies sources of plumes over western Kansas.

GOES-16 Cloud Phase Brightness Temperature Difference Field (10.3 µm – 8.5 µm) Imagery, 1502 – 2132 UTC on 6 March 2018 (Click to animate)

The Dust RGB, below, combines both the Split Window Differerence (the ‘Red Gun’) and the Cloud Phase Brightness Temperature Difference (the ‘Green Gun’), as well as the Clean Window (10.3 µm, ‘Blue Gun’, not shown). Dust in this RGB is typically bright pink, and its presence is notable over western Kansas.

GOES-16 Dust Red-Green-Blue (RGB) Composite Imagery, 1502 – 2132 UTC on 6 March 2018 (Click to animate)

Closer to sunset, at 2252 UTC on 6 March, the Dust Plume is readily apparent in the Band 1 and Band 2 imagery, shown below in a toggle with infrared channel differences and the Dust RGB.

GOES-16 Band 1 (“Blue Visible”) 0.47 µm Imagery, Band 2 (“Red Visible”) 0.64 µm Imagery, Split Window Difference (10.3 µm – 12.3 µm), Cloud Phase (10.3 µm – 8.5 µm) Brightness Temperature Difference and Dust RGB, all at 2252 UTC on 6 March 2018 (Click to enlarge)

Hat tip to Jeremy Martin, the SOO in the Goodland KS National Weather Service Office, for alerting us to this case!

Summary of the 02-03 March Nor’Easter

March 3rd, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with plots of hourly wind gusts [click to play MP4 animation]

A strong Nor’easter affected much of northeastern portion of the US during 02 March and 03 March 2018. As noted in the previous blog post, the storm produced very strong winds which led to widespread wind damage and power outages. A GOES-16 (GOES-East) Mesoscale Sector was positioned over the storm on 02 March, and “Red” Visible (0.64 µm) images (above) provided a detailed view of the center of circulation over the western Atlantic.

A 2-day animation of GOES-16 Mid-level Water Vapor (6.9 µm) images (below) showed the evolution of the storm as it moved from the Great Lakes to the Atlantic Ocean (surface analyses). A summary of the peak wind gusts and highest snowfall/rainfall totals can be seen here and here.

GOES-16 Mid-level (6.9 µm) images, with plots of hourly wind gusts [click to play MP4 animation]

GOES-16 Mid-level Water Vapor (6.9 µm) images, with plots of hourly wind gusts [click to play MP4 animation]

On 03 March, a vortex was seen to develop in GOES-16 “Red” Visible (0.64 µm) images, just behind the occluded frontal boundary — about 30 minutes after a burst of stronger northeasterly winds (with speeds as high as 58 knots) was analyzed in that region by the Metop ASCAT instrument.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with surface fronts and Metop ASCAT surface scatterometer winds [click to play MP4 animation]

A signature of this vortex was also evident in GOES-16 Low-level Water Vapor (7.3 µm) images (below). A toggle between Visible and Water Vapor images at 1605 UTC is available here.

GOES-16 Mid-level (6.9 µm) images, with surface fronts and Metop ASCAT surface scatterometer winds [click to play animation]

GOES-16 Low-level Water Vapor (7.3 µm) images, with surface fronts and Metop ASCAT surface scatterometer winds [click to play MP4 animation]

Finally, a NOAA-20 VIIRS True-color Red-Green-Blue (RGB) image centered over Lake Erie at 1839 UTC on 03 March (below) showed the fresh snow cover left by the storm as it moved across the Great Lakes on 02 March. Snow can be seen across parts of Lower Michigan, southern Ontario, northern Ohio, and far northwestern Pennsylvania. NOAA-20 is the first of the JPSS series of satellites (note: the data are still considered preliminary and non-operational as the instruments and products are being evaluated and tested).

NOAA-20 True-color RGB image, centered of Lake Erie [click to enlarge]

NOAA-20 VIIRS True-color RGB image, centered of Lake Erie [click to enlarge]

Flooding in the Midwest and lower Ohio River Valley

February 26th, 2018 |

GOES-16 0.86 µm “Veggie” Band Imagery at 1902 UTC on 12 and 26 February 2018 (Click to enlarge)

Solar radiation at 0.86 µm is strongly absorbed by water on the surface, but reflected by land. There is therefore a big contrast in GOES-16 “Veggie” Band imagery between rivers and adjacent land, and that contrast difference can easily identify regions of inundation. The toggle above compares imagery from 26 February 2018 and from 12 February 2018 over the lower Ohio River Valley. Significant widening of many waterways is apparent in the 0.86 µm imagery on 26 February, especially over southern Indiana, a result of both snow melt and abundant precipitation in the past 7 days, shown below (from this link). This has caused many stream gauges to show Moderate (Red gauges) to Major (Purple Gauges) flooding (image from this link), also shown below.  A zoomed-in image over northern Indiana, at bottom, shows the major flooding along the Kankakee River.

Observed precipitation for the 7 days ending at 1200 UTC on 26 February 2018 (Click to enlarge)

Stream Gauge Observations at 1200 UTC on 26 February 2018 (Click to enlarge)

GOES-16 0.86 µm “Veggie” Band Imagery at 1902 UTC on 26 February 2018 (Click to enlarge). Green Arrows highlight the Kankakee River, in flood.


=============== Added, 27 February 2018 ===================
Suomi NPP’s Flood Product, produced via CSPP using data from a Direct Broadcast site (at UW-Madison) is shown below. Flooded regions in the lower Ohio River/Mississippi River Valley and surroundings are indicated by shading in yellow to red.

Suomi NPP Flood Product, 1923 UTC on 26 February 2018 (Click to enlarge)

Some of these areas of river flooding could also be seen in a comparison of Suomi NPP VIIRS True-color and False-color Red-Green-Blue RGB images (below) — the False-color image uses the Near-Infrared 2.2 µm and 0.86 µm bands for the Red and Green contributions, and highlights water as shades of blue.

Suomi NPP VIIRS True-color and False-color images [click to enlarge]

Suomi NPP VIIRS True-color and False-color RGB images [click to enlarge]

Eruption of Mount Sinabung volcano

February 19th, 2018 |

Himawari-8 RGB images [click to play animation]

Himawari-8 RGB images [click to play animation]

An explosive eruption of Mount Sinabung began at 0153 UTC on 19 February 2018. Himawari-8 False-color Red-Green-Blue (RGB) images from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) showed the primary plume of high-altitude ash moving northwestward, with ash at lower altitudes spreading out to the south and southeast of the volcano.

Mutli-spectral retrievals of Ash Cloud Height (below) indicated that the explosive eruption injected volcanic ash to altitudes generally within the 12-18 km range, possibly reaching heights of 18-20 km. Advisories issued by the Darwin VAAC listed the ash height at 45,000 feet (13.7 km).

Himawari-8 Ash Height product [click to play animation]

Himawari-8 Ash Height product [click to play animation]

Ash Loading values (below) were also very high within the high-altitude portion of the plume.

Himawari-8 Ash Loading product [click to play animation]

Himawari-8 Ash Loading product [click to play animation]

The Ash Effective Radius product (below) indicated that very large particles were present in the portion of the plume immediately downwind of the eruption site.

Himawari-8 Ash Effective Radius product [click to play animation]

Himawari-8 Ash Effective Radius product [click to play animation]

In a comparison of Himawari-8 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.4 µm) images (below), note the very pronounced warm thermal anomaly or “hot spot” (large cluster of red pixels) on the 0150 UTC image — Himawari-8 was actually scanning that location at 01:54:31 UTC, just after the 0153 UTC eruption. Prior to the main eruption (beginning at 0120 UTC), a very narrow volcanic cloud — likely composed primarily of condensed steam — was seen streaming rapidly southward from the volcano summit.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, left), Shortwave Infrared (3.9 µm, center) and “Clean” Infrared Window (10.4 µm, right) images [click to play Animated GIF | MP4 also available]

The coldest Himawari-8 cloud-top infrared brightness temperature was -73 ºC at 0300 UTC, which roughly corresponded to an altitude of 15 km on nearby WIMM (Medan) rawinsonde data at 00 UTC (below).

Medan, Indonesia rawinsonde data at 00 UTC on 19 February [click to enlarge]

Medan, Indonesia rawinsonde data at 00 UTC on 19 February [click to enlarge]

A Terra MODIS True-color RGB image viewed using RealEarth is shown below. The actual time of the Terra satellite overpass was 0410 UTC.

Terra MODIS True-color RGB image [click to enlarge]

Terra MODIS True-color RGB image [click to enlarge]

An animation of Himawari-8 True-color RGB images can be seen here.