Stereoscopic Views of Convection every minute in Mesoscale Domains

August 29th, 2018 |

GOES-17 and GOES-16 Mesoscale Domains at 1616 UTC on 29 August 2018 (Click to enlarge)

GOES-17 images shown here are preliminary and non-operational

The presence of GOES-17 data means that 4 mesoscale sectors, each taking 1-minute imagery, are over the United States. In the example above, from 1616 UTC on 29 August 2018, there is no overlap. (Note: Three of the Four are in their default locations; the Mesoscale sector over the northeast United States has been shifted north to monitor convection over New England).

On 28 August 2018, however, two mesoscale sectors overlapped over the central United States, and sampled convection developing over Oklahoma (that subsequently caused wind damage in Roger Mills County in western Oklahoma). The Stereoscopic View of that convection is shown below. To view the convection in three dimensions, cross your eyes until you see 3 images, and focus on the image in the center. An animated gif (215 Megabytes!!) is available here.

GOES-16 (Left) and GOES-17 (right) Visible (0.64) stereoscopic views of convection developing over western Oklahoma, 2000 UTC 28 August – 0118 UTC 29 August 2018 (Click image to play mp4 animation)

GOES-17 Data are flowing in GRB

August 28th, 2018 |

GOES-17 0.86 µm Near-Infrared and 3.9 µm Infrared imagery, 1607 UTC on 28 August 2018 (Click to enlarge)

GOES-17 images shown here are preliminary and non-operational

The GOES Rebroadcast (GRB) is now transmitting GOES-17 data that remain Preliminary and non-operational.  The first data sent were at 1530 UTC on 28 August. The toggle above shows Bands 3 (“Veggie Band”, 0.86 µm) and Band 7 (“Shortwave Infrared”, 3.9 µm) from the Meso-1 sector that was positioned over the West Coast at 1607 UTC on 28 August 2018.  Band 13 (“Clean Window”, 10.3 µm), below, from the Meso-2 sector is over the High Plains.

GOES-17 10.3 µm Infrared imagery, 1613 UTC on 28 August 2018 (Click to enlarge)

Visible (Band 2, 0.64 µm) Imagery from 1531 UTC, below, was produced using CSPP Geo, a software package that reads the GRB signal and produces imagery. (Image courtesy Graeme Martin, CIMSS)

GOES-17 Visible (0.64) Imagery at 1531 UTC on 28 August 2018 (Click to enlarge)

The Geo2Grid Software Package can be used with GRB output to produce True-Color imagery, as shown below. The full-disk image was created in about 8 minutes using a centOS server, and it is corrected for atmospheric and solar zenith angle effects. Green Band information is simulated from other ABI channels.

Geo2Grid True Color Imagery, 1700 UTC on 28 August 2018 (Click to enlarge)

Full Disk examples of imagery from all 16 ABI bands (in addition to a Natural Color RGB image) are shown below (courtesy Mat Gunshor, CIMSS).

GOES-17 Natural Color RGB and individual ABI band images (Click to animate)

GOES-17 Natural Color RGB and individual ABI band images (Click to animate)

Typhoon Soulik in the northwest Pacific Ocean

August 20th, 2018 |

Himawari-8 AHI Band 13 Clean Window (10.4 µm) imagery, 0900-1400 UTC on 18 August 2018 (Click to animate)

Typhoon Soulik, south of Japan and moving westward, has acquired a very large eye — almost 100 miles across! Himawari-8 imagery, above (courtesy JMA), shows the evolution and enlargement of the eye between 0900 and 1400 UTC on 20 August 2018.

GCOM, Suomi NPP and NOAA-20 all passed over Soulik between 1600 and 1715 UTC on 18 August. The Infrared Toggle, below, from NOAA-20 (1608 UTC) and Suomi NPP (1658 UTC) also shows a large eye.

NOAA-20 (1608 UTC) and Suomi NPP (1658 UTC) 11.45 µm Infrared Imagery of Soulik on 18 August 2018 (Click to enlarge)

Day Night Band Imagery from Suomi NPP, below, also shows a large eye. There was little lunar illumination occurring at the time because the moon was below the horizon.

Suomi NPP Day Night Band Visible (0.70 µm) Imagery over Soulik, 1658 UTC on 18 August 2018 (Click to enlarge)

GCOM overflew Soulik at 1702 UTC, and the AMSR-2 instrument on board gave estimates of rain rate, both convective and a the surface. Those are toggled below.

GCOM AMSR-2 Microwave estimates of Precipitation over Soulik, 1702 UTC on 18 August 2018 (Click to enlarge)

(Suomi NPP, NOAA-20 and GCOM imagery courtesy William Straka, CIMSS)

Soulik’s eye was wide enough that a NUCAPS soundings retrieval (Click here for more information on NUCAPS soundings) could be made from data collected during a Suomi-NPP overpass at 0350 UTC on 21 August 2018.  Note the green sounding location within Soulik’s eye — Green dots denote regions where the infrared retrieval was successful.  The sounding at that point is shown below. (NUCAPS imagery courtesy Landon Aydlett, WFO Guam).

Suomi NPP NUCAPS sounding locations at 0350 UTC on 21 August 2018 on top of AHI 10.4 µm Clean Window imagery (Click to enlarge)

Suomi NPP NUCAPS Sounding within the eye of Soulik at 0350 UTC on 21 August 2018 (Click to enlarge)

You can use NUCAPS Soundings to diagnose the difference between the environment in the storm eye, and in the surrounding environment. The animation below shows locations of 5 soundings, one in the Eye, and one north, east, south and west of the CDO.  The five selected soundings are shown at the bottom, with insets showing which sounding is which.  The sounding in the eye shows remarkable warmth, as expected:  at 555 hPa, for example, eye temperatures are around 8º C;  values at the 4 outside points range from 0.4º to 2.9º C.  Sounding parameters as viewed in AWIPS can be seen here.

Suomi NPP NUCAPS Sounding Points overlain on a Day Night Band Image, ~0350 UTC on 21 August 2018 (Click to enlarge). Sounding locations are indicated.

NUCAPS Soundings in and around Typhoon Soulik at the locations indicated, ~0350 UTC on 21 August 2018 (Click to enlarge)

Soulik’s path is projected to remain south of Japan and approach the Korean Peninsula by mid-week. For more information on Soulik, consult the CIMSS/SSEC Tropical Weather Website, or the Joint Typhoon Warning Center.

Hurricane Lane in the eastern Pacific Ocean

August 17th, 2018 |

NOAA-20 VIIRS Imagery at 1023 UTC on 17 August 2018. Day Night Band Visible (0.7 µm) and I05 Infrared (11.45 µm) imagery are shown (Click to enlarge)

The active eastern Pacific Hurricane season continues, as Lane has formed. Suomi NPP and NOAA-20 overflew the system early on 17 August 2018. The toggle above, from NOAA-20’s VIIRS Instrument, shows both the Day Night Band 0.70 µm visible Image and the 11.45 µm infrared channels. Lack of lunar illumination means that only Earthglow is making clouds visible; a distinct eye is not present. The step animation below between the NOAA-20 11.45 µm infrared and, 50 minutes later, Suomi NPP’s 11.45 µm Infrared, right at the limb of the scan, also show no distinct eye.

VIIRS I05 11.45 µm Infrared Imagery from NOAA-20 (1023 UTC) and Suomi NPP (1113 UTC) on 17 August 2018 (Click to enlarge)

In fact, however, an eye was likely present at this time. As noted in the National Hurricane Center’s 0900 UTC Discussion (Link), “Recent microwave images show a well-defined low-level eye, but this feature is not yet apparent in geostationary satellite images.”  AMSR-2 (Advanced Microwave Scanning Radiometer 2) estimates of Convective Precipitation and Surface Rainfall in the toggle below (data from 1003 UTC) show a distinct eye.  AMSR-2 is a microwave instrument that flies on JAXA’s GCOM satellite;  microwave views of tropical cyclones are able to penetrate the cirrus shield that is commonly present, revealing important information about the low-level structure of a developing system.

GCOM AMSR-2 estimates of convective precipitation and surface rainfall rates at 1003 UTC on 17 August 2018 (Click to enlarge)

Polar Orbit tracks are available here. For the latest information on Hurricane Lane, refer to the National Hurricane Center or to the CIMSS/SSEC Tropical Weather Website. Imagery from Polar Orbiters are available at this site that shows data from an antenna in Honolulu.

Thank you to William Straka, CIMSS, for the imagery.