Seattle, Washington as viewed by 4 GOES

February 13th, 2019 |

Visible images, centered at Seattle, from (left to right) GOES-17, GOES-15, GOES-16 and GOES-13 [click to play animation | MP4]

Visible images, centered at Seattle, from (left to right) GOES-17, GOES-15, GOES-16 and GOES-13 [click to play animation | MP4]

The GOES-13 satellite was brought out of storage for annual maintenance activities on 13 February 2019 — allowing for a unique view of the Seattle, Washington area from that satellite as well as GOES-15, GOES-16 (GOES-East) and GOES-17 (GOES-West). After receiving significant snowfall during the previous several days, snowcover was abundant across that region. The brighter-white snow-covered mountain peaks south and southeast of Seattle (especially that of Mount Rainier) were also apparent on visible imagery from all 4 satellites.

Note that visible images from the older GOES-13/GOES-15 are not as bright as those from the newer GOES-16/GOES-17 — performance of visible detectors on the previous generation of satellites degraded over time, while the new GOES-R series benefits from on-orbit calibration of the visible detectors to mitigate this effect.

Using a spare rooftop antenna, staff at the SSEC Data Center were able to ingest and process this data from GOES-13 (in addition to the other 3 GOES satellites). GOES-13 will be placed back into storage on 25 February 2019.

A toggle between larger-scale images using the 5 spectral bands of the GOES-13 Imager are shown below.

GOES-13 Visible (0.63 µm), Shortwave Infrared (3.9 µm), Water Vapor (6.5 µm), Infrared Window (10.7 µm) and Infrared CO2 Absorption (13.3 µm) images at 2015 UTC [click to enlarge]

GOES-13 Visible (0.63 µm), Shortwave Infrared (3.9 µm), Water Vapor (6.5 µm), Infrared Window (10.7 µm) and Infrared CO2 Absorption (13.3 µm) images at 2015 UTC [click to enlarge]

Strong midlatitude cyclone north of Hawai’i

February 10th, 2019 |
GOES-17

GOES-17 “Red” Visible (0.64 µm) images [click to play MP4 animation]

* GOES-17 images shown here are preliminary and non-operational *

1-minute Mesoscale Domain Sector GOES-17 “Red” Visible (0.64 µm) images from the AOS site (above) showed the distinct circulation of a strong midlatitude cyclone (surface analyses) that was centered just north of Hawai’i on 10 February 2019. The pressure gradient associated with this storm produced strong winds across the island chain. Wave heights to 38.4 feet were recorded at Buoy 51208 near Kaua’i, with wind gusts to 57 knots at Buoy 51001 northwest of Kauwa’i.



GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below) revealed the presence of numerous lee waves which extended hundreds of miles downwind of the islands — most notable were those emanating from Kauwa’i.

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) images [click to play animation | MP4]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images [click to play animation | MP4]

Derived Motion Winds calculated using GOES-15 (GOES-West) Water Vapor (6.5 µm) imagery from the CIMSS Tropical Cyclones site (below) showed targets with velocites of 150-160 knots just north of Hawai’i at 09 UTC and 12 UTC.

Derived Motion Winds calculated using GOES-15 Water Vapor (6.5 µm) imagery [click to enlarge]

Derived Motion Winds calculated using GOES-15 Water Vapor (6.5 µm) imagery [click to enlarge]

GOES-17 Air Mass RGB images (below) showed the orange to red hues signifying a lowered tropopause and increased stratospheric ozone within the atmospheric column as the storm evolved during the 09-10 February time period.

GOES-17 Air Mass RGB images [click to play MP4 animation]

GOES-17 Air Mass RGB images [click to play MP4 animation]

Suomi NPP VIIRS True Color and Infrared Window (11.45 µm) images at 23 UTC as viewed using RealEarth are shown below.

Suomi NPP VIIRS True Color and Infrared Window (11.45 µm) images at 23 UTC [click to enlarge]

Suomi NPP VIIRS True Color and Infrared Window (11.45 µm) images at 23 UTC [click to enlarge]

Strong jet stream over the North Pacific Ocean

January 2nd, 2019 |
GOES-17 Mid-level Water Vapor (6.9 µm) images, with 250 hPa wind isotachs [click to play animation | MP4]

GOES-17 Mid-level Water Vapor (6.9 µm) images, with 250 hPa wind isotachs [click to play animation | MP4]

* GOES-17 images shown here are preliminary and non-operational *

GOES-17 Mid-level Water Vapor (6.9 µm) images with an overlay of 250 hPa wind isotachs from the GFS90 model (above) showed a string of disturbances (surface analysis) along the axis of a 180-knot “Japan Jet” across the North Pacific Ocean on 02 January 2019.

GOES-17 Split Ozone (9.6 µm10.3 µm) Brightness Temperature Difference images (below) include an overlay of PV1.5 pressure (an indicator of the height of the “dynamic tropopause”) — they showed the difference between cold polar air having a low tropopause (shades of cyan to blue) north of the jet stream and warm tropical air having a much higher tropopause (shades of yellow). The Split Ozone BTD is the Green component of the Air Mass Red-Green-Blue (RGB) product.

GOES-17 Split Ozone (9.6 - 10.3 µm) images, with contours of PV1.5 pressure [click to play animation | MP4]

GOES-17 Split Ozone (9.6 – 10.3 µm) images, with contours of PV1.5 pressure [click to play animation | MP4]

Rawinsonde data also showed the significant difference in tropopause height between St. Paul Island, Alaska (pressure=314 hPa, height=8.1 km) in the polar air of the Bering Sea and Lihue, Hawai’i (pressure=82 hPa, height=17.9 km) in the tropical air of the central Pacific (below).

Plots of rawinsonde data from St. Paul Island, Alaska [click to enlarge]

Plots of rawinsonde data from St. Paul Island, Alaska [click to enlarge]

Plots of rawinsonde data from Lihue, Hawai'i [click to enlarge]

Plots of rawinsonde data from Lihue, Hawai’i [click to enlarge]

GOES-17 Air Mass RGB images from the UW-AOS site (below) further illustrated the sharp contrast between the cold/dry polar air to the north and warm/moist tropical air to the south of the strong jet stream. The purple hues along the northwestern edge of the scan are a result of the “limb cooling” effect, as the satellite’s infrared detectors sense radiation from colder upper levels of the atmosphere at large viewing angles.

GOES-17 Air Mass RGB images [click to play animation | MP4]

GOES-17 Air Mass RGB images [click to play animation | MP4]

In addition to the series of larger disturbances along the jet stream axis, there were also some smaller-scale storms apparent in the Bering Sea (surface analyses). Better detail of these high-latitude features could be seen using Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images separated by 10 hours (below).

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1427 UTC and 0022 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1427 UTC and 0022 UTC [click to enlarge]

Regarding the strong Japan Jet, GOES-15 (GOES-West) Derived Motion Winds (source) tracked targets having velocities as high as 200 knots at 03 UTC (below).

GOES-15 Water Vapor (6.5 µm) Derived Motion Winds [click to enlarge]

GOES-15 Water Vapor (6.5 µm) Derived Motion Winds [click to enlarge]

Hurricane-Force low over the Aleutian Islands

December 29th, 2018 |
Water Vapor images from GOES-17 (6.9 µm, left) and GOES-15 (6.5 µm, right) [click to play animation | MP4]

Water Vapor images from GOES-17 (6.9 µm, left) and GOES-15 (6.5 µm, right) [click to play animation | MP4]

* GOES-17 images shown here are preliminary and non-operational *

A mid-latitude cyclone moved northward over the far western Aleutian Islands late in the day on 28 December 2018, intensifying to a Hurricane Force low pressure system by 06 UTC on 29 December (surface analyses). A comparison of GOES-17 and GOES-15 (GOES-West) Water Vapor images (above) highlighted the improved spatial resolution of the GOES-17 data (2 km at satellite sub-point, vs 4 km for GOES-15). The view from GOES-15 was more oblique, since it was positioned at 128º W longitude (compared to 137.2º W longitude for GOES-17). GOES-17 is scheduled to become the operational GOES-West satellite in January 2019.

A toggle between GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images at 1100 UTC is shown below. Although the satellite viewing angle was large, good detail could still be seen.

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images at 1100 UTC [click to enlarge]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images at 1100 UTC [click to enlarge]

A sequence of Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (below) showed the storm as it was intensifying — the peak surface wind gust at Shemya Eareckson Air Station (PASY) was 66 knots at 1024 UTC. Since the Moon was in the Waning Gibbous phase (at 60% of Full), there was ample illumination to provide a useful “visible image at night” with the VIIRS Day/Night Band at 1403 UTC (4:03 AM local time).

Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

A time series plot of hourly surface weather data from Shemya during the time period of the GOES-17/15 Water Vapor image comparison is shown below, along with a more detailed time series that included Special Reports in addition to the standard Hourly Reports..

Time series plot of surface weather data from Shemya Eareckson Air Station [click to enlarge]

Time series plot of Hourly surface weather data from Shemya Eareckson Air Station [click to enlarge]

Time series plot of Hourly and Special surface weather data from Shemya Eareckson Air Station [click to enlarge]

Time series plot of Hourly and Special surface weather data from Shemya Eareckson Air Station [click to enlarge]