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Cyclone Freddy in the Indian Ocean continues to persist and is situated along the southwest coast of Madagascar. It is currently crossing the Mozambique channel for the third time. Freddy intensified to a Category 5 storm on 2023-02-15. It is now listed... Read More
Cyclone Freddy in the Indian Ocean continues to persist and is situated along the southwest coast of Madagascar. It is currently crossing the Mozambique channel for the third time. Freddy intensified to a Category 5 storm on 2023-02-15. It is now listed as a Category 2 storm.
Cyclone Freddy’s path across the Indian Ocean from 2023-02-14 to 2023-03-07 displayed in RealEarth.
A three-week animation made in RealEarth shows Cyclone Freddy’s long life and unusual path between Madagascar and Mozambique. The animation shows infrared satellite data every half day (every twelve hours) from 2023-02-14 to 2023-03-07. The storm first travels west across the Indian Ocean, changes in intensification once it makes landfall, and eventually gains its cyclonic structure back. The Global Infrared display product in RealEarth is archived quite far back compared to other display products, making it useful for tracking storms over multiple days or weeks. You can revisit this Cyclone Freddy animation in RealEarth and other weather data products.
The CSPP Geo project released (linux-based) Gridded GLM software version 1.0 (available for download here) in December of 2022 (This previous CIMSS Blog post discussed a beta version of that software). CSPPGeo Gridded GLM software (Documentation is available here) takes Lightning Cluster Filter Algorithm (LCFA) files and converts the Flash/Event/Group data therein to gridded fields that... Read More
GOES-16 GLM Observations of Flash Extent Density (FED), Minimum Flash Area (MFA) and Total Optical Energy (TOE), 1804-1805 UTC on 24 January 2023 (Click to enlarge)
The CSPP Geo project released (linux-based) Gridded GLM software version 1.0 (available for download here) in December of 2022 (This previous CIMSS Blog post discussed a beta version of that software). CSPPGeo Gridded GLM software (Documentation is available here) takes Lightning Cluster Filter Algorithm (LCFA) files and converts the Flash/Event/Group data therein to gridded fields that can be displayed with AWIPS, or with geo2grid, or with other display systems. The gridding algorithms use open-source software such as glmtools developed by Eric Bruning at Texas Tech and colleagues. Output gridded fields include Flash Extent Density, Total Optical Energy, Minimum Flash Area,
Where do the GLM L2+ (i.e., LCFA) files necessary for input into gridded GLM originate? They might come from the GOES Re-Broadcast (GRB) datastream: Direct broadcast users who receive the GOES-East or GOES-West GRB stream on an antenna can run the CSPPGeo GRB software package to generate GLM L2+ and other GOES-R series products in near real-time; any user can download LCFA files from NOAA CLASS by choosing ‘GOES-R Series GLM L2+ Data Product (GRGLMPROD)’; LCFA files are also available via Amazon Web Services, via this handy portal (for example). One could generate data from multiple sources to guard against a data outage in one or more GLM L2+ data feeds!
LCFA files typically have a time cadence of three per minute. For example, the first 12 LCFA files created from GOES-18 on 7 March 2023, that is, the 66th day of year 2023, are shown below. The first file name includes a string that indicates when the data within the file starts, ends, and when it was created s20230660000000_e20230660000200_c20230660000214. Data in that files starts on day 066 of 2023 at 00:00:00 and ends at 00:00:20; that data file was created at 00:00:21.4. The next file contains data between 00:00:20.0 and 00:00:40.0, then from 00:00:40.0 to 00:01.000, and so on.
Download the (gzipped and tared) gridded GLM software from here (free registration may be required). The call to create the gridded GLM data is straightforward, for example, as shown below using GOES-16 data from 24 January 2023:
sh ./cspp-geo-gglm.sh /path/to/LCFAfiles/accessible/by/your/machine/OR_GLM-L2-LCFA_G16_s20230241804*.nc
This will create the 1-minute aggregate GLM fields valid at 1804 UTC (that is, showing data from 1804 to 1805 UTC) on 24 January 2023, Fields created include Flash Extent Density (FED), Flash Centroid Density (FCD), Average Flash Area (AFA), Total Energy (TOE), Group Extent Density (GED), Group Centroid Density (GCD), Average Group Area (AGA) and Minimum Flash Area (MFA). Gridded GLM software expects that the unix wildcarding will match 3 LCFA files, in the case above from 18:04:00 to 18:04:20, 18:04:20 to 18:04:40 and 18:04:40 to 18:05:00. If one of the three files within the minute are missing, no gridded GLM output is produced, and an error message is produced. In the successful case above, the file created has this name: CG_GLM-L2-GLMF-M3_G16_s20230241804000_e20230241805000_c20230661822210.nc ; note the creation date is 1822 UTC on 7 March, the day I prepared this blog post. By default a Full Disk file is created. However, by adding a -t flag (or using –create-tiles), AWIPS-compatible “punctured” tiles are created, along with statistics files that describe the tiles fully. Amending the command above to include tile-generation
sh ./cspp-geo-gglm.sh -t /arcdata/goes_restricted/grb/goes16/2023/2023_01_24_024/glm/L2/LCFA/OR_GLM-L2-LCFA_G16_s20230241804*
still yields the same file as the first call (although it has a different creation date, so the file name is a bit different), but additional files are created, as listed below. These tiles can then be input into AWIPS and displayed as 1-minute aggregates of various GLM gridded products. The statistics file that describes the tiles is also created. The Global view from these tiled data are shown below, and the same data but zoomed in over Texas are shown above. Note that the data are timestamped in AWIPS as 1805 UTC, the time at which the GLM data ends.
GOES-16 GLM Observations of Flash Extent Density (FED), Minimum Flash Area (MFA) and Total Optical Energy (TOE), 1804-1805 UTC on 24 January 2023 (Click to enlarge)
Version 1.0 of gridded GLM allows a user to wildcard more than 1 minute of data at a time. For example, the command “sh ./cspp-geo-gglm.sh /pathToGLMdata/2023/2023_01_24_024/glm/L2/LCFA/OR_GLM-L2-LCFA_G16_s2023024180[4,5,6,7]*” created four 1-minute GLMF netcdf files.
Coming soon: How to display the gridded GLM data using geo2grid.
From the CIMSS Satellite Blog mailbag: This morning Lufthansa flight DLH469 AUS-IAD at FL370 0011Z at 34.9198N 89.5592W turbulence event, with 4 minor injuries. Your product (ed. note: The CIMSS Turbulence Product, available here) had highlighted the area up pretty well! The Flight Log for this Airbus A330, snipped from... Read More
From the CIMSS Satellite Blog mailbag:
This morning Lufthansa flight DLH469 AUS-IAD at FL370 0011Z at 34.9198N 89.5592W turbulence event, with 4 minor injuries. Your product (ed. note: The CIMSS Turbulence Product, available here) had highlighted the area up pretty well!
The Flight Log for this Airbus A330, snipped from the FlightAware website (direct link), below, shows the changes in speed/altitude that occurred with this event.
Flight Log of DLH469, 000817 – 001427 UTC on 2 March 2023 (Click to enlarge)
The CIMSS Turbulence product at 0000 UTC, just before that event is shown below. Note that 34.9198oN / 89.5592oW is very near the middle of the Mississippi/Tennessee border.
Probability of Moderate-or-Greater (MOG) Turbulence, Flight levels 36000 – 37000 feet, 0000 UTC on 2 March 2023 (click to enlarge)
The animation from 2300 UTC on 1 March through 0100 UTC on 2 March, below, shows a general expansion of the area with larger MOG Probabilities along the northern Mississippi border with Tennessee.
MOG Probability contours, 2300 UTC on 1 March through 0100 UTC 2 March 2023 (Click to enlarge)
Radar imagery from NQA, shown below (courtesy Don Eick, NTSB), shows the path of the plane into the observed convection.
WSR-88D Radar Imagery from KNQA, 0011/0012 UTC on 2 March 2023 for a scan angle of 9.98o (left) and 12.5o (right). White dots show the plane’s path into the convection (Click to enlarge)
What did the satellite imagery show for this event? Band 8 (Upper level water vapor, 6.19 µm) and Band 13 (Clean Window, 10.3 µm) infrared imagery, below, shows the plane flying through a region of developing convection. How adept are you at picking out the region of convection associated with this turbulence?
GOES-16 Band 8 (Upper Level Water Vapor, 6.19 µm) and Band 13 (Clean Window, 10.3 µm) infrared imagery, 2301 UTC on 1 March 2023 through 0101 UTC on 2 March 2023 (Click to enlarge)
The imagery below brackets the time of the convection, and the region of turbulence is circled. The satellite imagery shows multiple convective towers erupting.
GOES-16 Band 8 (Upper Level Water Vapor, 6.19 µm) and Band 13 (Clean Window, 10.3 µm) infrared imagery, 0006 UTC — 0016 UTC on 2 March 2023; the region where the aircraft encountered turbulence is circled (Click to enlarge)
The plane diverted to Dulles (KIAD) because of injuries on board. The screencapture below is from an Instagram user on board the plane. Flight information from FlightAware shows that the flight continued for about an hour after the turbulence before the diversion to Dulles.
Instagram imagery from Camila McConaughey (click to enlarge)
RADARSAT-2 overflew the Samoan Islands shortly after sunset on 4 March 2023, as shown above. The NRCS and derived wind fields show light winds over the entire region. The toggle below show Metop-B and Metop-C ASCAT winds between 0800 and 1000 UTC on 5 March. Those instruments also detect light winds.MIMIC Total Precipitable water fields, below,... Read More
Derived Winds and Normalized Radar Cross Section over the Samoan Islands, 0552 UTC on 5 March 2023 (Click to enlarge)
RADARSAT-2 overflew the Samoan Islands shortly after sunset on 4 March 2023, as shown above. The NRCS and derived wind fields show light winds over the entire region. The toggle below show Metop-B and Metop-C ASCAT winds between 0800 and 1000 UTC on 5 March. Those instruments also detect light winds.
Advanced Scatterometer (ASCAT) winds from the ascending pass of Metop C (0848 UTC) and Metop-B (0935 UTC) on 5 March 2023 (click to enlarge)
MIMIC Total Precipitable water fields, below, from 0000 UTC 04 March through 0000 UTC 06 March, show the Samoan islands north of an active storm path (cyclone Kevin moves from 170oE to 170oW during the animation, the remains of cyclone Judy move from 170oW to 150oW during the animation), and south of a region of moisture moving in slowly from the east.
MIMIC Total Precipitable Water fields, 0000 UTC 04 March – 0000 UTC 06 March 2023 (Click to enlarge)
