This short tutorial will explain how Polar2Grid can show individual isobaric levels, and also lapse rates (dT/dp) between two isobaric levels.

Polar2Grid is CSPP software designed to process files either from the NOAA NODD (EDR files for NOAA-20 are here; EDR files for NOAA-21 are here) or from Direct Broadcast antenna data streams. Polar2grid creates reprojected imagery. In this example, I decided to work with data over the western United States. The NOAA-20 orbits on 18 December (here, from this website), show a descending pass over the Rockies, from the USA-Canada border at 0938 UTC to Los Angeles at about 0943 UTC. The data for this were downloaded from the AWS Cloud for NOAA-20, and a list of the files is shown below. Times for the granules listed start at 09:37:22.9 and end at 09:43:44.7.

(base) [scottl@machine NUCAPSData]$ ls -1
NUCAPS-EDR_v3r2_j01_s202412180937229_e202412180937527_c202412181021100.nc
NUCAPS-EDR_v3r2_j01_s202412180937549_e202412180938247_c202412181022030.nc
NUCAPS-EDR_v3r2_j01_s202412180938269_e202412180938567_c202412181021170.nc
NUCAPS-EDR_v3r2_j01_s202412180938589_e202412180939287_c202412181022310.nc
NUCAPS-EDR_v3r2_j01_s202412180939309_e202412180940007_c202412181021180.nc
NUCAPS-EDR_v3r2_j01_s202412180940029_e202412180940327_c202412181021580.nc
NUCAPS-EDR_v3r2_j01_s202412180940349_e202412180941047_c202412181023480.nc
NUCAPS-EDR_v3r2_j01_s202412180941069_e202412180941367_c202412181023040.nc
NUCAPS-EDR_v3r2_j01_s202412180941389_e202412180942087_c202412181023430.nc
NUCAPS-EDR_v3r2_j01_s202412180942109_e202412180942407_c202412181023470.nc
NUCAPS-EDR_v3r2_j01_s202412180942429_e202412180943127_c202412181023120.nc
NUCAPS-EDR_v3r2_j01_s202412180943149_e202412180943447_c202412181023480.nc
(base) [scottl@machine NUCAPSData]$ 

The variables that can be displayed using polar2grid and those files is quite long. If you were to download the files, and run the following command: ./polar2grid.sh -r nucaps -w geotiff --list-products-all -f /path_to_files/NUCAPS*.nc , you would see the many possibilities. For this blog post, I’m choosing Temperature_802mb and Temperature_596mb.

By default, polar2grid will rescale the plotted temperatures based on the range it finds. I want to have the same scale used for both levels here, and to do that, I have to tell polar2grid. This is done by adding a cris.yaml file into the directory polar2grid_v_3_1/etc/polar2grid/enhancements/, which directory is created as part of the polar2grid install process. The contents of the cris.yaml file that I created are below. I’ve mandated that both 802-mb temperatures and 596-mb temperatures be scaled from 240 to 300 K.

I also want to display these data on a map of my choosing (rather than the native NOAA-20 orbital map). Polar2grid allows a user to define a map with the p2g_grid_helper.sh shell script below; the script expects a grid name (CANucaps), a center longitude and latitude (115 W, 35 N), grid spacings in m (4000/-4000) and grid sizes (960×720). The output here is put into a yaml file.

./p2g_grid_helper.sh CANucaps -115.0 35.0 4000 -4000 960 720 > CANucaps.yaml

Next, I call polar2grid to make imagery, color-enhance it, and add coastlines and a colorbar, shown below.

../polar2grid.sh -r nucaps -w geotiff -p Temperature_802mb Temperature_596mb -g CANucaps --grid-configs ./CANucaps.yaml -f /path_to_NUCAPSData/*
./add_colormap.sh ../../colormaps/p2g_sst_palette.txt j01_atms-cris_Temperature_802mb_20241218_093722_CANucaps.tif
./add_colormap.sh ../../colormaps/p2g_sst_palette.txt j01_atms-cris_Temperature_596mb_20241218_093722_CANucaps.tif
./add_coastlines.sh --add-coastlines --add-colorbar --colorbar-text-size 16 j01_atms-cris_Temperature_802mb_20241218_093722_CANucaps.tif
./add_coastlines.sh --add-coastlines --add-colorbar --colorbar-text-size 16 j01_atms-cris_Temperature_596mb_20241218_093722_CANucaps.tif

The resultant imagery is shown in a toggle below. I didn’t label the imagery, but I hope you can tell which field is 802mb, and which is 596mb! The colorbar automatically scales to the values specified in the cris.yaml file.

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Next, I decided I wanted to compute and plot the temperature difference between 802 and 596 mb. That requires additions to two files within the polar2grid distribution. A cris.yaml file is needed in (polar2grid_v_3_1/etc/polar2grid/composites/), with contents as shown below. I defined the parameter (lapse802_596) as using the DifferenceCompositor that requires two fields. Then, in the enhancements directory (polar2grid_v_3_1/etc/polar2grid/enhancements/) I scaled the field to be between 4 and 25K.

If I ran polar2grid now, and pointed to the NUCAPS data directory, and asked it to –list-products-all — I would see a new possibility! lapse802_596. The three polar2grid calls below,

./polar2grid.sh -r nucaps -w geotiff -p lapse802_596 -g CANucaps –grid-config ./CANucaps.yaml -f /path_to_NUCAPSData/*

./add_colormap.sh ../../colormaps/p2g_sst_palette.txt j01_atms-cris_lapse802_596_20241218_093722_CANucaps.tif

./add_coastlines.sh –add-coastlines –add-colorbar –colorbar-text-size 16 j01_atms-cris_lapse802_596_20241218_093722_CANucaps.tif

The result of those three calls is shown below. The steepest lapse rates are off the coast of California and in northwestern Mexico.

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Thanks to Dave Hoese, CIMSS, for helping me figure this out!

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10-minute Full Disk scan GOES-16 (GOES-East) daytime True Color RGB + Nighttime Microphysics RGB images from the CSPP GeoSphere site (above) depicted the cyclonic (clockwise in the Southern Hemisphere) circulation associated with the formation of Subtropical Storm Biguá just off the coast of Rio Grande do Sul state in far southern Brazil during the 14th-16th December 2024 period.

12-hourly surface analyses shown below (source) indicated that this subtropical storm developed as an area of low pressure (denoted by a red “B”) moved southeast across Rio Grande do Sul on 14th December, becoming classified as Subtropical Storm (“Tempestade Subtropical”) Biguá shortly after it moved offshore at 0000 UTC on 15th December. 24 hours later, Biguá was downgraded to a Subtropical Depression (“Depressao Subtropical”) at 0000 UTC on 16th December.

A sequence of ASCAT surface scatterometer winds (source) from Metop-B and Metop-C (below) showed that the compact low-level circulation center of Subtropical Storm Biguá remained just off the Brazilian coast on 15th December. The strongest winds were generally within the southern semicircle of the storm.

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A selection of several GOES ABI loops during 2022 and 2023 showcased the diverse range of features observed, which included volcanic ash plumes, hurricanes, convection, fog, smoke, fires, dust and ice.

It’s very hard to choose just one event from every month of the year, but the goal here is to show a variety of phenomena and locations that NOAA‘s GOES ABI routinely monitors, in this case during 2024. Most loops generated are from the University of Wisconsin-Madison CIMSS Satellite Blog, which is linked to in the titles at the top of each monthly entry. Imagery from GOES-16 and -18 (and -19) are showcased, along with the ABI’s sectors: Full Disk (10-min intervals), Contiguous U.S. (5-min intervals) and Mesoscale sectors (30-sec to 1-min intervals).

January Single-banded snow squall along the length of Lake Michigan

The mesovortices were also well forecast and observed by radar.

February The Smokehouse Creek Fire

GOES-16 Fire Temperature RGB over north Texas 15:06 UTC 27 February 2024 – 03:31 UTC 28 February 2024 as shown in AWIPS

The above animation (and as an animated gif).

March SpaceX Starship Test Flight 3

Note that each of the ABI spectral bands could see a signal of the SpaceX rocket launch.

Bonus material: A SUVI Animation when the Sun was being eclipsed.

The sun eclipsed by the moon as seen in a mp4 animation. Near realtime SUVI images: SSEC and SWPC.

April Time Composite Imagery of the Total Solar Eclipse

The Moon’s shadow during the total solar eclipse was observed by many ABI spectral bands.

Bonus material: 1-min Mesoscale Sector (with 5-min CONUS sectors) of an enhanced ABI band 3 (0.86 um) following the shadow:

May Hail swath across the Texas Panhandle

GOES-16 (GOES-East) Nighttime Microphysics RGB images showed a thunderstorm that moved southeast from the New Mexico / Texas border across the southern Texas Panhandle Plains on 29 May 2024. A narrow northwest-to-southeast oriented hail swath produced by this storm  — from south of Clovis, New Mexico to south of Lubbock, Texas — showed up as pale shades of beige. The Land Surface Temperature derived product showed cooling in the hail swath of more than 10F.

Bonus material: River valley fog in Wisconsin, Minnesota and Iowa

Similar to the long forgotten fog in many river valleys in BAMS (1989) observed by GOES-7, GOES-16 showed narrow tendrils of river valley fog — along a portion of the Mississippi River and a few of its tributaries in Wisconsin, Minnesota and Iowa. The derived fog and low stratus product also monitored the fog, while showing the need for improved spatial resolutions.

June GOES-U Rocket Launch

The GOES-U rocket launch was monitored by both GOES-18 ABI (30-sec) and GOES-16 (1-min), these were research Mesoscale Sector requests. Note that not only was the launch and rocket separation seen, but also the booster rockets re-burn when returning to land at the Kennedy Space Center! GOES-U became GOES-19 after successfully reaching geostationary orbit.

Bonus material: Haboob in New Mexico

Double Bonus: SUVI (Solar) Imagery

July Hurricane Beryl in the central Caribbean as a Category 5 storm

The earliest Cat 5 Atlantic basin hurricane as seen with 1-min GOES-16 imagery.

Bonus material: Mesovortices seen within the eye in the ABI high resolution visible band.

August Tornado in Buffalo New York

The storms associated with a weak tornado (at 16:49 UTC) in Buffalo New York were monitored by GOES. The Day Cloud Phase Distinction RGB is shown, demonstrating the glaciation of the clouds.

Bonus – Gravity waves in the Midwest.

September Early (Preliminary / Non-operational) GOES-19 Imagery

During September, GOES-19 ABI continued to collect imagery from it’s location at approximately 90W and the equator. The ABI has 2 visible, 4 near-IR (or near-visible) and 10 IR bands.

Bonus – Mesoscale imagery of Helene.

October Annular Eclipse Shadow in the Southern Hemisphere

On October 2, 2024 several of the geostationary imagers observed the Moon’s shadow in the Southern Hemisphere. An example from the ABI on GOES-19 is below. A CIMSS true color loop doesn’t create the artificial colors that can happen in Raleigh-corrected composite imagery.

November Prolonged eruptive period of Popocatépetl in Mexico

A prolonged eruptive period of Popocatépetl occurred during 22 October – 4 November 2024. Ash RGB images showed the periodic pulses of ash from Popocatépetl.

A number of derived products, such as a radiometrically-retrieved Ash Height product from the NOAA/CIMSS Volcanic Cloud Monitoring site showed that the volcanic plume occasionally reached altitudes of 12 km or greater.

Bonus – Power Plant Plume Produces Precipitation

According to Scott Bachmeier, CIMSS “The Nighttime Microphysics RGB did a good job of highlighting the industrial plume — then after sunrise, True Color RGB imagery showed that the plume had seeded the cloud layer enough to cause it to dissipate as it produced the snowfall (sort of like the aircraft-induced “fall streak” effect).”

December Combined GOES West and East IR images

While the animation below does not start in the month of December, it does end in that month. This is a combined GOES-West and East ABI band 13 composite image, in a Mollweide projection. This loop shows hourly data, as does this near realtime web page.

Similar animations as above, from June 1 to December 13, but with playback durations of 1 and 2 minutes. The location of 7-day (hourly) animations for a few of the ABI bands.

Bonus – Blowing Snow RGB from GOES-19 ABI (by Bill Line) — CIMSS Satellite Blog post on Blowing Snow

Double Bonus – Severe weather across the Bay Area of California

H/T

Thanks to all who make the GOES imagery possible, the ingest and software to display the imagery (including, but not limited to McIDAS-X, geo2grid, geosphere, Real Earth and AWIPS) and all who generated CIMSS Satellite Blog entries, especially Scott Lindstrom and Scott Bachmeier. Special thanks to Mat Gunshor and Jim Nelson of the UW/CIMSS AWG Imagery Team. T. Schmit works for NOAA/NESDIS/STAR, is stationed in Madison WI, and will be retiring from federal service at the end of 2024.

A similar ‘Year in Review’ for 2021; 2022 by NOAA Satellites.

Also, some “top 25” GOES-16 and GOES-17 ABI loops. Also see the Satellite Liaison Blog.

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EUMETSAT Meteosat-9 Infrared Window (10.8 µm) images (above) showed Category 4 Cyclone Chido as its eye moved across the small island of Mayotte (airport identifier FMCZ) in the Mozambique Channel around 0730 UTC on 14th December 2024 — and went on to make landfall just south of Penba, Mozambique (airport identifier MQPB) around 0400 UTC on 15th December. Chido traversed increasingly warmer sea surface temperatures (source) as it approached Mozambique.

As Cyclone Chido passed over Mayotte, the airport reported wind gusts of 92 kts (106 mph) as the eye approached and 91 kts (105 mph) as the eye departed (below).

Shortly before Chido made landfall in Mozambique, a Synthetic Aperture Radar (SAR) image at 0253 UTC (below) indicated that a derived maximum wind speed of 123.84 knots was present in the SE quadrant of the eyewall (source).

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