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.

CIMSS Satellite Blog

MENU

Leeside cold frontal gravity wave across the central and southern Plains

By Scott Bachmeier •

GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) (above) and Mid-level Water Vapor (6.9 µm) images (below) displayed a well defined leeside cold frontal gravity wave (reference) as it began to propagate southward from Colorado/Kansas late in the day on 11 October 2020. A bore structure eventually developed near the leading edge of the cold... Read More

GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of hourly surface wind barbs and gusts [click to play animation | MP4]

GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of hourly surface wind barbs and gusts [click to play animation | MP4]

GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) (above) and Mid-level Water Vapor (6.9 µm) images (below) displayed a well defined leeside cold frontal gravity wave (reference) as it began to propagate southward from Colorado/Kansas late in the day on 11 October 2020. A bore structure eventually developed near the leading edge of the cold frontal gravity wave as it continued moving south over New Mexico/Texas/Oklahoma during the subsequent overnight hours.

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

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

As the surface cold front moved southward across the drought-impacted plains of eastern Colorado, 1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) and CIMSS Natural Color Red-Green-Blue (RGB) images (below) revealed the hazy signature of blowing dust lofted by post-frontal northerly winds with peak gusts in the 60-80 knot range. Blowing dust reduced the surface visibility to 1-2 miles at several reporting stations, falling to near zero at some locations (causing a multi-vehicle accident along Interstate 70 in Kansas).

GOES-16 “Red” Visible (0.64 µm) and CIMSS Natural Color RGB images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and CIMSS Natural Color RGB images [click to play animation | MP4]

GOES-16 True Color images created using Geo2Grid (below) provided a clearer view of the blowing dust along and immediately behind the cold front across the Colorado/Kansas border region.

GOES-16 True Color images [click to play animation | MP4]

GOES-16 True Color images [click to play animation | MP4]

View only this post Read Less

Typhoon Chanhom south of Japan

By Scott Lindstrom •

Multi-spectral views from Himawari-8’s “Target Sector” that provides 2-minute imagery, above, show weakening Typhoon Chan-hom south of Japan. The Typhoon shows a sheared structure, with the surface circulation southwest of the main convection, a shift that is especially evident in the Band 5 1.61 µm channel that differentiates between low... Read More

Himawari-8 Target Sector over Typhoon Chanhom, 2314 UTC 8 October to 0532 UTC 9 October (Click to animate). Band 2, Visible (0.64 µm, upper left); Band 5 “Snow/Ice” (1.61 µm, upper right); Band 10, Low-level Water Vapor (7.3 µm, lower left); Band 13, Clean Window (10.4 µm, lower right)

Multi-spectral views from Himawari-8’s “Target Sector” that provides 2-minute imagery, above, show weakening Typhoon Chan-hom south of Japan. The Typhoon shows a sheared structure, with the surface circulation southwest of the main convection, a shift that is especially evident in the Band 5 1.61 µm channel that differentiates between low clouds containing water droplets and upper clouds containing ice crystals. (Himawari data courtesy of the Japan Meteorological Agency.)  A 24-hour animation (ending at 0500 UTC on 9 October) of Mimic Total Precipitable water (from this site) shows that the storm is surrounded by dry air to the north and west.

An analysis of Advanced Microwave Sounder Unit (AMSU) Channel 7 (54.94 GHz), below, (from this site) shows a warm anomaly over the storm.  Atmospheric shear (200-850 mb) is also shown in this figure, and the storm is approaching a region of high shear.

AMSU Channel 7 temperatures, 0058 UTC on 9 October 2020; Wind shear (contoured in green, yellow and red) from 850-200 mb, 0300 UTC on 9 October 2020 (Click to enlarge)

 

View only this post Read Less

Hurricane Delta in the Gulf of Mexico

By Scott Bachmeier •

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images — with and without an overlay of GLM Flash Extent Density — and “Red” Visible (0.64 µm) images (above) showed showed Hurricane Delta as it intensified from a Category 2 to a Category 3 storm over the Gulf of Mexico during the daytime hours on 08 October 2020. Cloud-top infrared brightness temperatures of... Read More

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images — with and without an overlay of GLM Flash Extent Density — and “Red” Visible (0.64 µm) images (above) showed showed Hurricane Delta as it intensified from a Category 2 to a Category 3 storm over the Gulf of Mexico during the daytime hours on 08 October 2020. Cloud-top infrared brightness temperatures of -90ºC and colder  (yellow pixels embedded within the darker shades of purple) were occasionally seen within the eyewall region of Delta, along with intermittent bursts of lightning activity.

A toggle between Suomi NPP VIIRS Infrared Window (11.45 µm) and Visible (0.64 µm) images of Hurricane Delta shortly before it intensified to a Category 3 storm are shown below; the coldest cloud-top infrared brightness temperature at that time was -93.0ºC.

Suomi NPP VIIRS Infrared Window (11.45 µm) and Visible (0.64 µm) images [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) and Visible (0.64 µm) images [click to enlarge]

In a time-matched comparison of Infrared images from Suomi NPP and GOES-16 (below), the coldest cloud-top infrared brightness temperature sensed by GOES-16 was 5.6ºC warmer (-87.4ºC); note the small northwestward parallax displacement that is inherent with GOES-16 imagery over the Gulf of Mexico. The same color enhancement is applied to both images.

Infrared images from Suomi NPP and GOES-16 [click to enlarge]

Infrared images from Suomi NPP (11.45 µm) and GOES-16 (10.35 µm) [click to enlarge]

===== 09 October Update =====

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

In a toggle between Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images at 0734 UTC or 2:34 am CDT on 09 October (above), the coldest cloud-top infrared brightness temperature was -93.8ºC (just northwest of the storm center).

1-minute GOES-16 Infrared and Visible images (below) showed Category 2 Hurricane Delta making landfall in southwestern Louisiana at 2300 UTC, producing wind gusts as high as 100 mph at Texas Point, Texas.

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

The MIMIC Total Precipitable Water product (below) indicated that Hurricane Delta was transporting a large amount of moisture northward across the Gulf of Mexico — rainfall totals included 15.64 inches at Evangeline Gardner, Louisiana.

MIMIC Total Precipitable Water product [click to enlarge]

MIMIC Total Precipitable Water product [click to enlarge]

The MIMIC-TC product (below) showed the deterioration of the eye and eyewall structure as Delta approached the Gulf Coast.

MIMIC-TC product

MIMIC-TC product [click to enlarge]

===== 10 October Update =====

Suomi NPP VIIRS True Color RGB images from 04 and 10 October [click to enlarge]

Suomi NPP VIIRS True Color RGB images from 04 October and 10 October [click to enlarge]

A before (04 October) / after (10 October) comparison of Suomi NPP VIIRS True Color RGB images from the VIIRS Today site (above) revealed a marked increase of turbidity within the more shallow shelf waters of Texas and Louisiana, due to extensive mixing from the wind field associated with Delta. A comparison of VIIRS False Color images from those 2 days (below) highlighted inland areas with significant flooding that resulted from heavy rainfall and/or storm surge (darker shades of blue).

Suomi NPP VIIRS False Color RGB images from 04 October and 10 October [click to enlarge]

Suomi NPP VIIRS False Color RGB images from 04 October and 10 October [click to enlarge]

A GOES-16 River Flood Detection product viewed using RealEarth (below) helped to quantify the severity of flooding resulting from the landfall of Delta.

GOES-16 River Flood product [click to enlarge]

GOES-16 River Flood Detection product valid at 1900 UTC on 10 October [click to enlarge]

View only this post Read Less

Tropical Storm Delta becomes a Hurricane over the Caribbean Sea

By Scott Bachmeier •

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images — with and without an overlay of GLM Flash Extent Density — and “Red” Visible (0.64 µm) images (above) showed showed an impressive convective burst near the center of Tropical Storm Delta, which developed a couple of hours before the storm reached Category 1 Hurricane intensity at 0000 UTC on 06 October over the Caribbean Sea.... Read More

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density)and

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images — with and without an overlay of GLM Flash Extent Density — and “Red” Visible (0.64 µm) images (above) showed showed an impressive convective burst near the center of Tropical Storm Delta, which developed a couple of hours before the storm reached Category 1 Hurricane intensity at 0000 UTC on 06 October over the Caribbean Sea. There was no GLM-detected lightning activity near the center of Delta during this 2100-0100 UTC time period.

A toggle between GOES-16 Infrared and Visible images at 2156 UTC (below) revealed a small tropical overshooting top near the center of the developing convective burst — which exhibited a cloud-top infrared brightness temperature as cold as -93.2ºC (yellow pixels embedded within the darker shades of purple).

GOES-16 “Clean” Infrared Window (10.35 µm) images (with an overlay of GLM Flash Extent Density) and "Red" Visible (0.64 µm) images at 2156 UTC [click to enlarge]

GOES-16 “Clean” Infrared Window (10.35 µm) images (with an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images at 2156 UTC [click to enlarge]

===== 06 October Update =====

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

Hurricane Delta rapidly intensified to a Category 4 storm at 1520 UTC on 06 October — with 1-minute GOES-16 Infrared and Visible images (above) showing evidence of a more organized eye and eyewall structure, including a notable amount of lightning activity near the core of the storm.

GOES-16 Infrared Window (11.2 µm) images from the CIMSS Tropical Cyclones site (below) indicated that Delta was moving through an environment of low deep-layer wind shear as the hurricane was moving over water possessing very high ocean heat content.

GOES-16 Infrared Window (11.2 µm) images, with an overlay of deep-layer wind shear [click to enlarge]

GOES-16 Infrared Window (11.2 µm) images, with an overlay of deep-layer wind shear [click to enlarge]

===== 07 October Update =====

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

A comparison Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images (above) revealed a small area with cloud-top infrared brightness temperatures as cold as -100.9ºC (within the small cluster of red pixels) just east of the island of Cozumel, Mexico. Even though Delta was still moving over water possessing very high ocean heat content, its intensity was reduced from Category 4 to Category 3 around this time.

A time-matched comparison of Infrared images from Suomi NPP and GOES-16 is shown below; a cloud-top infrared brightness temperature of -95.8ºC was sensed by GOES-16. There was significant parallax associated with the Suomi NPP image, since Hurricane Delta was located along the far western edge of the descending overpass swath. The same color enhancement is applied to both images.

Infrared images from Suomi NPP and GOES-16 [click to enlarge]

Infrared images from Suomi NPP and GOES-16 [click to enlarge]

View only this post Read Less

  • last_page First
  • Last last_page

Search blog