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.

SnOMG! Detailed list of snow reports: https://t.co/TLWHOeEyWr. Thanks to everyone who has submitted measurements! #wawx #wasnow pic.twitter.com/TXAkRUf2cu

— NWS Seattle (@NWSSeattle) February 12, 2019

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

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A strong storm system affecting the western third of the United States on 13 February 2019 was responsible for turbulence that caused damage and injuries and forced an ERJ-170 aircraft flying from John Wayne Airport (in Orange County CA) to Seattle WA to make an unscheduled stop in Reno NV (News report). (Flight Aware information on the flight) Three passengers were hospitalized.

The water vapor imagery animation above, annotated so that the departure airport (SNA) and Reno (RNO) are shown in the first frame. During the second run-through of the animation, the approximate location of the turbulence is noted with a red square (Flight Aware data suggests it occurred very near 2030 UTC — Flight Aware times are EST), and the animation slows. Water Vapor imagery suggests that the aircraft encountered a convective element that likely was associated with the Sierra Nevada. A stepped animation between 2027 and 2032 UTC is shown below.

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GOES-S (named GOES-17 once it reached geostationary orbit) was launched on 01 March 2018. Beginning at 1800 UTC on 12 February 2019, it became the operational GOES-West satellite (replacing GOES-15, which was launched in March 2010). The period of transition to operational status is shown on Full Disk images of “Red” Visible (0.64 µm) and Mid-level Water Vapor (6.9 µm) images (above).

In an animation of GOES-17 images from the 16 ABI spectral bands, centered on the Big Island of Hawai’i (below), an increase in cumulus clouds was evident in the Visible and Near-Infrared bands (1-6) along with a warming signature of the island summits (Mauna Kea and Mauna Loa) in the Infrared bands (7-16) as daytime heating increased during the morning hours. Weighting functions for all of the Infrared bands which are not strongly affected by water vapor absorption (7, and 11-16) have peaks at/near the surface — and the presence of dry air within the middle troposphere shifted the three Water Vapor band (8-10) weighting functions downward to allow some of the island summit thermal signature to be sensed. This dry air aloft (and a lack of cirrus clouds over the island) also enabled the summits to be sensed by the 1.37 µm Near-Infrared “Cirrus” band (4).

A comparison of all 16 ABI bands from GOES-17 covering most of Alaska and the adjacent Bering Sea is shown below.

In the animation below (source), GOES-17 and GOES-16 (GOES-East) Longwave Infrared (11.2 µm) images have been combined and displayed in a Mollweide projection. This shows the broad area of coverage provided by the current GOES constellation, which reaches from far eastern Australia to far western Europe and Africa.

Although the GOES-17 ABI instrument experiences a nocturnal Loop Heat Pipe (LHP) cooling problem (also discussed here) — which increases around the time of the Spring and Autumn equinox —  the issue only affects the emitted Longwave Infrared spectral bands (bands 08-16), and only for periods lasting as long as a few hours (peaking daily around 1300-1330 UTC). Trends of the Focal Plane Module (FPM) temperature of the ABI instrument can be monitored at this site — and examples of Band 09 (6.9 µm Water Vapor) imagery from 11 February are shown below. Note how the images return to normal after the peak FPM temperatures cool from around 97 K to around 80 K. More information on the daily variation of FPM temperatures throughout the year is available here, here and here.

The LHP cooling issue affects various ABI spectral bands to differing degrees, with the Band 14 (11.2 µm Longwave Infrared) imagery being the least impacted — this can be seen in a Full Disk animation covering the same time period (below).

GOES-17 and GOES-15 will operate in tandem from their respective locations of 137.2º West and 128º West longitude through early July 2019 — so GOES-15 imagery can be used during times when GOES-17 is adversely affected by the LHP cooling issue.

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* 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.

Here's a brief overview of some of the highest wind speeds and other impacts we experience over the weekend. Unsettled weather looks to stick around though the rest of the week with breezy trades. See https://t.co/fUefWa9aTA for the full forecast #hiwx pic.twitter.com/24Qi1fnxAJ

— NWSHonolulu (@NWSHonolulu) February 13, 2019

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.

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.

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.

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

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