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Tropical Disturbance south of Guam

MIMIC (Morphed Integrated Microwave Imagery at CIMSS) estimates of Total Precipitable Water, above, and available in real time here, and archived here, show two cyclonic rotations on the poleward side of the deep moisture of the Intertropical Convergence Zone in the western Pacific. These two circulations are areas of interest... Read More

MIMIC Total Precipitable Water, 0000 UTC 01 April – 1200 UTC 04 April 2022 (Click to enlarge)

MIMIC (Morphed Integrated Microwave Imagery at CIMSS) estimates of Total Precipitable Water, above, and available in real time here, and archived here, show two cyclonic rotations on the poleward side of the deep moisture of the Intertropical Convergence Zone in the western Pacific. These two circulations are areas of interest to the Joint Typhoon Warning Center, as shown below. At the end of the animation, one circulation (tropical invest 94W) is about to move over the Phillippines. A second feature at the end of the animation is near 10o N, 150o E.

JTWC analysis valid at 1000 UTC on 4 April 2022 (Click to enlarge)

You can also view assessments of total column precipitable water (and TPW in pre-defined layers) as measured by NOAA-20 CrIS/ATMS sensors and produced by HEAP software that produces NUCAPS profiles. This SPoRT site displays gridded swaths of precipitable water, and they’re aggregated below in a loop. The latest esimates of layer Relative Humidity are shown below that. The middle-/upper-troposphere over Guam is quite dry!

Gridded Total Precipitable Water at 1213, 1355 and 1536 UTC on 03 April 2022 and at 0145 and 0326 UTC on 04 April 2022 (Click to enlarge)
Gridded NUCAPS estimates of Relative Humidity at 850, 700, 500 and 300 mb, 0326 UTC on 4 April 2022 (Click to enlarge)

What does Himawari-8 show over the region? As noted in this blog post, it’s a straightforward task to automatically acquire Himawari data via cron on any unix machine. Daily animations can then be produced, and strung together as shown below in an mp4 (Click here for the animated gif) spanning 01 through 03 April 2022. The convection associated with Invest 94W is obvious early in the animation before its convection collapses. The rotation associated with Invest 95W is apparent to the southeast of Guam at the end of the animation, but the system is poorly organized.

Himawari-8 Sandwich Product (daytime) and Band 13 along (nighttime), 0000 UTC on 1 April – 2350 UTC 3 April 2022

Why have these systems not developed further? The toggle below shows a mapping of shear and SSTs centered on Invest 95W (click here for a basin-wide analysis of Shear, taken from the SSEC Tropical Weather Website). Given that the atmosphere has low shear, and sea-surface temperatures are warm, it’s possible that dry air to the north has helped prevent organization. The low latitude — between 5o and 10o N — might also be a factor.

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Satellite signatures of a SpaceX rocket launch

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Shortwave Infrared (3.9 µm), Upper-level Water Vapor (6.2 µm), Split Water Vapor BTD (6.2 – 7.3 µm) and Day Convection RGB images (above) showed that the launch of a SpaceX Falcon 9 rocket (for the Transporter-4 Mission) on 01 April 2022 created a short-lived shock wave that propagated northward through the clouds just... Read More

GOES-16 Shortwave Infrared (3.9 µm), Upper-level Water Vapor (6.2 µm), Split Water Vapor BTD (6.2 – 7.3 µm) and Day Convection RGB images [click to play animated GIF | MP4]  

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Shortwave Infrared (3.9 µm), Upper-level Water Vapor (6.2 µm), Split Water Vapor BTD (6.2 – 7.3 µm) and Day Convection RGB images (above) showed that the launch of a SpaceX Falcon 9 rocket (for the Transporter-4 Mission) on 01 April 2022 created a short-lived shock wave that propagated northward through the clouds just off the Florida coast.

A sequence of GOES-16 images from ABI Infrared spectral bands 07-16 at 16:25:55 UTC (below) displayed the Falcon 9 rocket booster’s thermal signature at that time (when the rocket was well above the clouds, at an altitude around 30 km).

GOES-16 images from ABI Bands 07-16 at 1626 UTC [click to enlarge]

A plot of rawinsonde data (source) from Cocoa Beach, Florida (below) indicated that the entire tropospheric column was nearly saturated, supporting the presence of dense layered cloudiness. There was an isothermal 600-650 hPa layer, which could have enhanced horizontal ducting of these shock waves (although it’s curious as to why the direction of wave propagation was primarily northward in the GOES-16 imagery).

Plot of rawinsonde data from Cocoa Beach, Florida [click to enlarge]

Kudos to Todd Beltracchi (The Aerospace Corporation) for bringing this interesting rocket signature to our attention!

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Using Polar2Grid and NOAA CLASS VIIRS data to create imagery

Previous blog posts (example) have documented how to create imagery from the VIIRS instrument, and this one is another example. For example, if you receive a request for VIIRS imagery such as this one: “If you have time to try a case, you could pick Feb 1, 2022 near North... Read More

NOAA-20 I05 (11.45 µm) imagery over the Arctic Ocean, 1455-1510 UTC on 1 February 2022 (Click to — greatly!! — enlarge)

Previous blog posts (example) have documented how to create imagery from the VIIRS instrument, and this one is another example. For example, if you receive a request for VIIRS imagery such as this one: “If you have time to try a case, you could pick Feb 1, 2022 near North Pole Point for 11 um channel” — how do you proceed? A first step is to determine the day/time of the data, and that’s achieved by looking at orbits over the Arctic, at this website. That website also has an archive, and the archive for Arctic passes on 1 February 2022 is here. The image shows NOAA-20 passing over Greenland, the Arctic Ocean, and then moving over eastern Russia between 1455 and 1510 UTC on 1 February 2022. Now you know the times to request.

NOAA CLASS is the data repository that stores VIIRS imagery from NOAA-20 and Suomi-NPP. Go to the website, an log in (register if you have not already), and choose JPSS VIIRS SDRs (Operational Sensor Data Records) as shown below. Choosing those data and clicking >>GO to the right of the drop-down menu bar will move you to a new data-selection menu, where you will select the day/time of the data (1 February 2022, 14:55 Start time, 15:10 end time), and the band (I chose SVI05 — the 11.45 µm Imager channel, with 375-m resolution, that is: VIIRS Imagery Band 05 SDR (SVI05) (public 02/07/2012) ), and the satellite (NOAA-20). Geolocation data must also be selected, and Polar2Grid will expect the GITCO files. Choose them ( VIIRS Image Bands SDR Ellipsoid Terrain Corrected Geolocation (GITCO) (public 02/07/2012)) as well. It is very important, however, that your User Preferences are configured so that the data are disaggregated! Click on User Preferences, and make that selection. The User Preferences page should include information as shown here.

NOAA CLASS front page showing the VIIRS data to select (Click to enlarge)

The steps above will produce 12 matches — 6 files of SVI05 and 6 GITCO files. Submit your order and wait for the email notification that the files are ready. While you are waiting, if you’ve not done so already, download the Polar2Grid software from CIMSS CSPP Site (CSPP: Community Satellite Processing Package; note that a free registration might be required). Expand the downloaded (compressed tar) file into an empty directory, and enter this unix command: export POLAR2GRID_HOME=/directory/where/the/expanded/file/sits.

NOAA CLASS will send an email once the data are staged and ready for you. Download those data, and then enter this command:

sh ./polar2grid.sh viirs_sdr gtiff -p i05 -g polar_canada -f /directory/holding/downloaded/SVI05Data/SVI05* /directory/holding/downloaded/GITCOdata/GITCO*

That code takes the viirs_sdr and GITCO data pointed to by the -f flag and creates a geotiff of i05 (11.45) imagery. Because these data are near the Pole, I’ve specified a grid (‘-g polar_canada’) to be used (a full list of pre-defined grids is here, part of the Polar2Grid online documentation). The command will stitch together the data in the 6 different files, and you’ll see an image at full resolution, as shown above. I also used software to add coastlines and lat/lon (‘grid’) lines.

sh ./add_coastlines.sh --add-grid --grid-D 10 10 --grid-d 10 10 --add-coastlines noaa20_viirs_i05_20220201_145336_polar_canada.tif

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Widespread severe weather across the Mid-South and Deep South

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) include time-matched SPC Storm Reports — and showed the widespread severe weather produced by thunderstorms (many of which were associated with a squall line that developed ahead of a cold front) moving eastward across the Mid-South and Deep South on 30 March 2022.The corresponding 1-minute GOES-16 “Red”... Read More

GOES-16 “Clean” Infrared Window (10.35 µm) images, with time-matched SPC Storm Reports plotted in blue [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) include time-matched SPC Storm Reports — and showed the widespread severe weather produced by thunderstorms (many of which were associated with a squall line that developed ahead of a cold front) moving eastward across the Mid-South and Deep South on 30 March 2022.

The corresponding 1-minute GOES-16 “Red” Visible (0.64µm) images (below) showed these storms during the period leading up to sunset on 30 March.

GOES-16 “Red” Visible (0.64 µm) images, with time-matched SPC Storm Reports plotted in red [click to play animated GIF | MP4]

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