GOES-R IFR Probability Fields at 1230 UTC on 6 March 2017 (Click to enlarge)

Note: GOES-16 data shown on this page are preliminary, non-operational data and are undergoing on-orbit testing.

Here is what this blog post will show: It is vital to tweak the supplied default AWIPS Enhancements so that important atmospheric information is better highlighted.

GOES-R IFR Probability fields (Click here for a website that shows many examples), shown above, use present GOES Data and Rapid Refresh Data to forecast the probability that IFR conditions exist. (There are also Low IFR Probability fields and Marginal VFR Probability fields as well, data from this site). The inclusion of surface information via the Rapid Refresh Model output (that details low-level saturation) is vital to screen out false fog detection (regions where mid-level stratus does not extend to the surface) and to highlight IFR conditions that exist under cirrus that block the satellite detection of low clouds.

GOES-16 data in AWIPS includes pre-defined channel differences judged to have utility in Decision Support Services. One of these is Fog detection (the infrared Brightness Temperature Difference between 3.9 µm and 11.2 µm) that extracts information at night based on emissivity differences from water-based clouds at those two wavelengths. This is a product that can detect stratus clouds at night, if cirrus clouds do not block the satellite’s view. If those stratus clouds extend to the surface, then fog is a result. A GOES-16 Channel Difference field, shown below with the default AWIPS enhancement, contains information about the fog/low clouds that are present over North Dakota, and over Texas (click here for a graphic from the Aviation Weather Center that highlights regions of IFR conditions — Dense Fog Advisories were issued on 6 March over North Dakota).

The Fog signal in the Brightness Temperature Difference field at night occurs when the value is negative; the default color enhancement, below, contains a lot of color gradations that grab the eye in regions where the Brightness Temperature Difference is positive; for Fog Detection, those extra colors in regions of positive difference are needless visual clutter.

Brightness Temperature Difference fields (3.9 µm – 11.2 µm) over the United States, 1227 UTC on 6 March 2017 (Click to enlarge)

To get useful information from this field, alter the Brightness Temperature Difference enhancement to highlight negative values. That has been done in the toggle below with the IFR Probability field. Fog regions over North Dakota and Texas are apparent.  (Note that the scale for the Brightness Temperature Difference field here has also been flipped — click here to toggle between the two Brightness Temperature Difference field enhancements).

GOES-R IFR Probability fields and GOES-16 Brightness Temperature Difference fields, ~1230 UTC on 6 March 2017 (Click to enlarge)

It is vital to tweak the supplied default AWIPS Enhancements so that important atmospheric information is better highlighted.

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GOES-16 ABI Radiance Quicklooks for all 16 bands at 1925 UTC on 3 March 2017 (Click to enlarge)

Note: GOES-16 data shown on this page are preliminary, non-operational data and are undergoing on-orbit testing.

CSPP (Community Satellite Processing Package) Geo software developed at SSEC/CIMSS is designed to allow a user to process data from a GRB (GOES ReBroadcast) antenna, producing useful imagery. Development Snapshot Releases have been ongoing as actual GRB GOES-16 signal has become available to shake out any issues, and Quicklook ABI images are now being processed, as shown in the animation above. Grey-scale value ranges for these images are not now configurable; different values are used for each band (which explains, for example, why Band 8, 9 and 10 — the three water vapor channels at 6.2 µm, 6.95 µm and 7.3 µm do not appear to be progressively warmer).

More information on CSPP Geo is available here.

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GOES-16 Visible (0.64 µm) Imagery, every minute from 1427-2000 UTC on 3 March 2017 (Click to play mp4 animation)

Note: GOES-16 data shown on this page are preliminary, non-operational data and are undergoing on-orbit testing.

Heavy snow squalls led to multiple vehicle crashes that shut down both I-80 and I-99 in central Pennsylvania on Friday 3 March (link 1 | link 2). A Mesoscale sector over Pennsylvania today provided 1-minute imagery, enabling forecasters to view the event as it happened (Click image above for an mp4 animation, or here for a 300-megabyte animated gif). The excellent temporal sampling of the mesoscale sectors — which data typically shows up in AWIPS within two minutes — is key to monitoring the progression of the snow bands across Pennsylvania. ‘Clean Infrared Window’ (that is, 10.3 µm) animations for this event are available here (mp4, animated gif). These infrared animations end at 1845 UTC. Note that State College PA (KUNV) had 1/8th mile visibility in snow at 1835 UTC. DuBois (KDUJ) had 1/4-mile visibility at the start of both animations.

CIRA also has animations of this event: (mp4, animated gif).

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GOES-16 ABI Default Mesoscale Domains, shown with Band 1 Visible (0.47 µm) and Band 5 Snow/Ice (1.61 µm) data (Click to enlarge)

Note: GOES-16 data shown on this page are preliminary, non-operational data and are undergoing on-orbit testing.

GOES-16 ABI Flex Mode (Mode 3) scanning affords the opportunity of two moveable mesoscale sectors that are 1000×1000 km in size at the sub-satellite point. These sectors are scanned every 60 seconds. After post-launch testing is complete this summer, a National Weather Service (NWS) Weather Forecast Office (WFO) or a National Center (SPC, or NHC, for example), can request that the Mesoscale domain be moved to sample a region or feature of interest. If no requests are active, then default positions, shown above for GOES-16 in the Test Position at 89.5º W, are used. These defaults were selected because they overlay major air corridors.

When GOES-16 and GOES-S (operating as GOES-17) are operational, four different Mesoscale Sectors will be available. The Default positions for Mesoscale Sectors are shown below.

Dashed red Boxes indicate the default positions of Mesoscale Domains when GOES-16 and GOES-17 are operational. Blue shading shows approximate infrared pixel sizes. (Click to enlarge)

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