1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the evolution of the eye of Hurricane Darby as it moved westward across the East Pacific Ocean on 11 July 2022. Mesovortices were evident within the eye, along with a stadium effect eye structure —... Read More
GOES-17 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.35 µm, bottom) images [click to play animated GIF | MP4]
A NOAA-20 VIIRS Infrared Window (11.45 µm) image from RealEarth (below) revealed an arc of slightly colder cloud tops (shades of white within dark black) in the northern portion of the eyewall.
NOAA-20 VIIRS Infrared Window (11.45 µm ) image at 2129 UTC [click to enlarge]
NOAA-20 ATMS Microwave (183 GHz) image at 2129 UTC [click to enlarge]
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This NOAA/NESDIS website shows small footprints where SAR observations of ice and wind (from the RADARSAT Constellation Mission — RCM — satellites and from Sentinel) are available. AWIPS-ready data are also available from an ftp site. Consider the animation of GOES-17 Band 13 imagery above, just south to the Equator, and to... Read More
This NOAA/NESDIS website shows small footprints where SAR observations of ice and wind (from the RADARSAT Constellation Mission — RCM — satellites and from Sentinel) are available. AWIPS-ready data are also available from an ftp site. Consider the animation of GOES-17 Band 13 imagery above, just south to the Equator, and to the west of 160oW longitude. The slightly cooler brightness temperatures at the eastern edge of the arc of clouds moving to the west is associated with two patches of strong surface winds. The toggle below zooms in on the region of winds. Surface wind speeds are close to 15 m s-1 with this weak line of tropical convection.
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GOES-18 images in this blog post are preliminary and non-operational Overlapping 1-minute Mesoscale Domain Sectors provided GOES-18 “Red” Visible (0.64 µm) images at 30-second intervals (above), which include time-matched SPC Storm Reports. This imagery showed widespread thunderstorms that moved eastward across Montana on 09 July 2022, which produced damaging straight-line winds as strong as 78... Read More
GOES-18 “Red” Visible (0.64 µm) images, with time-matched SPC Storm Reports plotted in red [click to play animated GIF | MP4]
GOES-18 images in this blog post are preliminary and non-operational
Overlapping 1-minute Mesoscale Domain Sectors provided GOES-18 “Red” Visible (0.64 µm) images at 30-second intervals (above), which include time-matched SPC Storm Reports. This imagery showed widespread thunderstorms that moved eastward across Montana on 09 July 2022, which produced damaging straight-line winds as strong as 78 mph and hail as large as 2.00 inches.
30-second GOES-18 “Clean” Infrared Window (10.35 µm) images (below) extended for several hours past sunset, and indicated that the coldest overshooting tops exhibited infrared brightness temperatures around -70ºC (darker black enhancement). Given that the radar at NWS Glasgow was out of service (due to a lightning strike the previous night), this type of 30-second GOES imagery could have served as a valuable source of information to help monitor thunderstorm evolution.
GOES-18 “Clean” Infrared Window (10.35 µm) images, with time-matched SPC Storm Reports plotted in blue [click to play animated GIF | MP4]
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An animation from the CSPP Geosphere site, above (link), shows a quiescent period in/around Samoa and American Samoa. Low clouds (purple and pink) occasionally developed overnight into showers (dark red) that then dissipated.NOAA-20 overflew the Samoan islands at around 1200 UTC on 8 July, as shown in the toggle below... Read More
An animation from the CSPP Geosphere site, above (link), shows a quiescent period in/around Samoa and American Samoa. Low clouds (purple and pink) occasionally developed overnight into showers (dark red) that then dissipated.
NOAA-20 overflew the Samoan islands at around 1200 UTC on 8 July, as shown in the toggle below with GOES-17’s clean window imagery (10.3 µm). The clean window imagery (as well as NOAA-20’s Day Night Band visible imagery) show no organized or large areas of precipitation, although some cold cloud tops suggest a few showers to the west of Samoa at 1230 UTC. The location of NUCAPS profiles are shown. These profiles can be used to create gridded horizontal fields of thermodynamic variables (available in AWIPS, and also at this site).
The Samoan islands are within a narrow band of enhanced total precipitable water, as shown in the MIMIC Total Precipitable Water fields below (current data; archive data). As noted above, no organized shower activity is associated with this moist band.
The Cross-Section lines J-J’ and E-E’ are represented in the GOES-17 imagery, and cross-sections of equivalent potential temperature from gridded NUCAPS Fields and from the 1-degree Global GFS model are shown below. The J-J’ cross-sections are similar: Strong low-level Potential Instability at the edges with a weaker low-level potential instability in the center of the cross-section. The 1200 UTC Sounding from Pago Pago is shown here, from this site. The atmosphere is moist up to 550 mb.
Use Cross Sections of gridded NUCAPS fields (accessible as shown in this blog post) to make comparisons to numerical models in regions where conventional data are sparse — such as over the Pacific Ocean.
This blog post used imagery from the NOAA/NESDIS TOWR-S cloud instance of AWIPS. Thank you!
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