GOES-16 (GOES-East) Air Mass RGB images (above) displayed the characteristic pale yellow hues associated with cold arctic air that was moving southward behind a deep area of low pressure centered over Hudson Bay and northern Quebec, Canada on 12 February 2020.

A sequence of GOES-16 “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Day Snow-Fog RGB images (below) revealed north-to-south oriented horizontal convective rolls that highlighted areas where blowing snow was creating ground blizzard conditions across the Red River Valley of North Dakota/Minnesota (the strongest winds were being channeled southward through the lower terrain of the RRV).  The surface visibility was reduced to near zero in rural areas — and in eastern North Dakota, Interstate 29 was closed from the Canadian border to the South Dakota border. Toward the end of the day, conditions slowly began to improve in the northern portion of the Red River Valley — from Grand Forks (KGFK) northward — as surface winds decreased, horizontal convective rolls dissipated, and visibility started to increase. More information on this event is available from NWS Grand Forks and the Satellite Liaison Blog.

High res view of the ground blizzard over Fargo ND on Feb 12 as viewed by Sentinel-2’s 10 meter resolution (30ft!).

Notice tightly packed horizontal convective rolls organize blowing snow plumes (white) right over Fargo. Processed w/ @sentinel_hub @CopernicusEU #ndwx #mnwx #blsn pic.twitter.com/GwynOZITrh

— Carl Jones (@northflwx) February 13, 2020

Another feature of interest was the rapidly intensifying Hurricane Force low pressure system just south of the Canadian Maritime Provinces (surface analyses) — with a lowering tropopause along the western edge of the storm, a swath of the NOAA-20 Gridded NUCAPS Total Column Ozone product (below) showed a lobe of higher ozone extending southward behind the surface low (and along the axis of its 500 hPa trough). That region of higher ozone was also apparent the day before, on 11 February, as shown in this blog post.

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Gridded NOAA-Unique Combined Atmospheric Processing System fields in AWIPS (and elsewhere, such as this excellent site) include retrieved values of ozone (O3), an important gas.  In high concentrations in the upper troposphere, O3 is a marker for the presence of stratospheric air.  In the animation above, high concentrations of ozone are present over eastern Canada.  An earlier pass, shown below in a toggle with GOES-16 ABI Band 13 (10.3 µm, the “clean window”) and with a 6-h forecast of pressure on the 1.5 PVU surface (the forecast from the UK Met Office Global Model) shows a cold enhancement on the poleward side of the cold front draped across the North Atlantic, and a southward tropospheric intrusion of the stratosphere as visualized by the higher pressure on the 1.5 PVU surface.  That is to say, there is a dynamic response in the atmosphere to the intrusion of stratospheric air (with higher ozone) into the troposphere.

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Can you use the Ozone Band — Band 12 on the ABI, at 9.61 µm, to estimate where high ozone concentrations exist in the atmosphere?  The short answer to this is “No” — at least if you’re using just the 9.61 µm band.  Compare the retrieved and gridded values below from NUCAPS with the Band 12 brightness temperature;  it is difficult to make a claim that this single ABI band gives useable information in the detection of ozone.

At later overpass, over the western United States, leads to a similar conclusion:  Gridded NUCAPS Ozone values can highlight lower tropopauses upstream of developing storms (in this case on 11 February, over the southwestern United States);  Band 12 Ozone fields do not highlight stratospheric intrusions.

Some other examples from 11 February: over Southwestern Canada (toggle from 2016 UTC, Gridded NUCAPS Ozone, ABI Band 12); over the central United States (toggle from 1829 UTC, Gridded NUCAPS Ozone,  ABI Band 12).

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2.5-minute rapid scan JMA Himawari-8 “Clean” Infrared Window (10.4 µm) images (above) showed Cyclone Damien making landfall as a Category 2 storm in Western Australia on 08 February 2020. Well west of the storm center, winds gusted to 49 knots at Barrow Island (YBWX). The eye remained intact for several hours after Damien moved inland.

GCOM-W1 AMSR2 Microwave (85 GHz) imagery from the CIMSS Tropical Cyclones site (below) showed the eye at 1710 UTC.

Just prior to landfall. cloud-top gravity waves were evident in VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP, as viewed using RealEarth (below).

Wind speed, wind gusts and atmospheric pressure as Severe #CycloneDamien crossed the coast over our #Karratha Airport weather station.
This highlights the dramatic changes as the eye moves over an area.

Need more weather graphs? https://t.co/bOnuYRnTOV pic.twitter.com/rA4ITFAqQ5

— Bureau of Meteorology, Western Australia (@BOM_WA) February 9, 2020

Tropical Storm Damien was also seen in the first-light image from Russia’s Elecro-L3 satellite, a few hours before Damien reached Category 1 hurricane intensity.

??????????? ????????? #???????? ? 3 ? ?????? ?????? ????????? ???? ???????? ? ???????? ?????? ?????? ????? ? ??????? ? ??-?????????? — https://t.co/RBHtlQaTU9

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— ????????? (@roscosmos) February 7, 2020

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GOES-17 ABI Imagery on 6 February suggests the presence of a cold front over the Pacific Ocean northeast of Hawaii. The Clean Window imagery shows a flat region between 30º N and 40º N around 140º W. The Night Fog Brightness temperature difference shows a signal — cyan — in that region consistent with low stratus. The Night Microphysics RGB (shown here in a toggle with Night Fog Brightness Temperature) shows a strong signal there as well (with some noise that can be attributed to Loop Heat Pipe issues with the GOES-17 ABI).

NOAA-20 overflew this region around 1200 UTC on 6 February (Click this link to see all NOAA-20 orbit paths).  The Gridded NUCAPS field of the 900-700 mb Lapse Rate shows small values (around 2º for a temperature change, the darker cyan color in the enhancement), as might be expected over the stratus deck.  Note also how the air mass is less stable in the cold air behind the front (yellow and orange in the enhancement to the west west of the front, green to the east of the front).  Gridded NUCAPS data are created with all vertical retrievals.  The toggle with NUCAPS Vertical sounding points (here), shows how the profiles that failed to converge (i.e., red and yellow points) can affect the gridded fields.

 

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