The image above (credit to Rick Kohrs from SSEC/CIMSS) shows Advanced Baseline Imager (ABI) data from GOES-17 (West), GOES-18 (Central, Preliminary/Non-Operational), and GOES-16 (East) on 15 May 2022. This “Local Noon CIMSS Natural Color” image is created by blending vertical strips of true-color imagery at local noon, starting in the east and proceeding westward. This was a rare opportunity for the GOES-R Series as GOES-18 was only at the central location (89.5W) for a limited time. A larger (5509×4207) version of this image is also available.

Other CIMSS Blog entries have introduced GOES-18, the latest in the GOES-R series. NOAA and NASA recently released the first ABI (Advanced Baseline Imager) imagery from GOES-18 (including this 2-min video). GOES-T was launched on 1 March 2022. Currently GOES-18 is “drifting” out west to be near the “West” position. GOES-18 is slated to become NOAA’s operational GOES-West in early 2023 (GOES-18 Post Launch Test and Transition Plan) after a thorough post-launch test period.

SSEC/CIMSS scientists (notably Rick Kohrs) create daily imagery that blends vertical strips of true-color imagery at local Noon, starting near the dateline and proceeding westward. Recent images are available at this website and include data from 5 geostationary satellites: Himawari, GOES-West, GOES-East, Meteosat-Prime, and Meteosat-IODC. There are multiple other blog posts featuring and explaining the local-noon composite.

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The hourly animation above shows the GOES-17 Night time Microsphysics RGB over and surrounding the Aleutian Islands, from 0800 – 1300 UTC on 18 May 2022. Yellowish features are low clouds in this RGB; low clouds at warmer temperatures have a blue/cyan tint because the inclusion of Band 13 infrared (10.3 µm) brightness temperatures in the ‘blue’ part of the RGB will change the color representation of low clouds. High clouds — red in the RGB — are also present along the western edge of the domain, over the Bering Sea — and are apparent as thin clouds over the low clouds over the Aleutians, visible as purple streaks.

Are the low clouds shown above fog — that is, are the clouds touching the surface? That’s hard to tell with certainty over Marine Environments. The single surface observation — at St Paul Island (PASN) in the Bering Sea, does show fog/low stratus present, and IFR conditions. An inference from that observation might be extended into the entire region. Real-time webcams and ship observations can also help with the determination of whether low clouds are actually banks of fog.

IFR Probability fields, below, for the same 6 observation times, incorporate model-derived estimates of low-level saturation, suggesting more low-level variability to the low clouds/fog over the Bering Sea (and in the Gulf of Alaska south of the Aleutians); that’s shown more clearly in this toggle between the two fields at 1200 UTC. Note also that a useful signal is produced underneath the high clouds at the western edge of the domain: even though the satellite gives no direct observations of the low-level clouds there, model estimates can nevertheless give information on low-level saturation.

When the sun is above the horizon, the Night time Brightness temperature difference field (10.3 µm – 3.9 µm) signal flips sign because of the large amounts of 3.9 µm solar reflectance; thus the Nighttime Microphysics RGB is less useful in low-cloud detection. The toggle below compares the Night Time Microphysics RGB and the IFR Probability field at 0400 UTC. Note that the observation at St Paul Island at this time does not show IFR conditions — and IFR Probabilities there are not quite so large as later, as displayed in the animations above.

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The imagery above were all captured using a National Weather Service AWIPS machine, with dataflow over the Satellite Broadcast Network (SBN) that supplies data products to the offices. What if you don’t have that resource? RealEarth contains Full-Disk IFR and Low IFR Probability fields from GOES-16 and GOES-17 (search for IFR within the search box at the RealEarth website). An animation of IFR Probability from GOES-17, from 1000 UTC – 1250 UTC, at 10-minute steps (the scanning cadence of GOES-17 Full Disk imagery) is below.

GOES-17 Full-Disk Nighttime microphysics RGB imagery is available from a variety of sources. For example, it’s at the NOAA/NESDIS Imagery viewer (link); at the CIRA Slider ; the mp4 animation below is taken from a coming upgrade to the CSPP Geosphere site that shows Night time Microphysics RGB imagery at night (and true color imagery during the day).

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Preliminary / non-operational GOES-18 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed that the Calf Canyon Fire/Hermits Peak Fire in northern New Mexico produced another another pyrocumulonimbus (pyroCb) cloud on 14 May 2022 — following 2 previous pyroCb events on 10 May and 01 May. This particular pyroCb first exhibited cloud-top infrared brightness temperature (IR BT) values of -40C and colder (shades of blue in the bottom panel) at 2211 UTC, and later attained IR BTs in the -50s C (shades of red in the bottom panel).

A comparison of Suomi-NPP VIIRS True Color RGB, False Color RGB, Infrared Window and Shortwave Infrared images valid at 2032 UTC is shown below. These VIIRS images were acquired and processed using the Direct Broadcast ground station at SSEC/CIMSS.

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A narrow ribbon of Slight RIsk was forecast for parts of the midwest on 13 Friday 2022, as shown below, and a few severe weather events occurred (SPC Storm Reports); they were well forecast. How did the Polar Hyperspectral Sounding forecast system perform on this day? The toggle above shows a 7-h forecast of CAPE (initialized at 1600 UTC and valid at 2300 UTC). It’s noteworthy that the forecast also shows a narrow corridor of instability. A similar toggle, but starting with the 0-h initial field of PHSnABI derived CAPE from the model at 2200 UTC, is here.

The toggle below shows the 7-h forecast compared to the GOES-16 ABI Derived CAPE. A similar toggle, here, compares the 1-h forecast (initialized at 2200 UTC, valid at 2300 UTC) with the 2300 UTC Derived CAPE observed from GOES. The 7-h forecast below might be too far to the east; however, the developing convection associated with ribbon of instability is removed from the leading edge of the CAPE.

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Precipitation forecasts from this event (available at this website) are shown below, starting with two forecasts valid at 2300 UTC: a 3-h forecast from 2000 UTC and a 1-h forecast from 2200 UTC. They both show strongest convection over western IL, as observed. The 2000 UTC forecast also shows the break in convection over southern WI, also as observed.

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The PHSnABI modeling system accurately showed the corridor of instability over the Great Lakes, and convection did develop with this instability as observed. (Note: forecasts initialized before 1700 UTC did not produce precipitation; observations from the afternoon overpasses of NOAA-20 and Suomi-NPP perhaps supplied the necessary information leading to a better prediction of precipitation). Radar imagery over WI at 0054 UTC on 14 May 2022 is shown below. The initial (very narrow) line of convection did produce precipitation over Madison, but precipitation moved over Madison from the south after 0100 UTC.

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