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Nicole to the east of Florida

Day Night Band imagery from NOAA’s AOML Direct Broadcast site, above, shows a low-level circulation with deep convection over the center at 0719 UTC. GOES-16 Low-Level water vapor (Band 10, 7.3 µm) mesoscale sector one imagery, below, (from this website) shows abundant mid-level dry air to the south of the Nicole. Nicole is near... Read More

NOAA-20 (0540 and 0719 UTC) and Suomi NPP (0630 UTC) Day Night Band visible (0.7 µm) imagery centered on Tropical Storm Nicole (Click to enlarge)

Day Night Band imagery from NOAA’s AOML Direct Broadcast site, above, shows a low-level circulation with deep convection over the center at 0719 UTC. GOES-16 Low-Level water vapor (Band 10, 7.3 µm) mesoscale sector one imagery, below, (from this website) shows abundant mid-level dry air to the south of the Nicole. Nicole is near a dry environment.

GOES-16 Band 10 (low level water vapor) infrared (7.3 µm) imagery, 1350-1449 UTC on 9 November 2022

Nicole’s path, shown below, (from this website), is along a corridor of low shear, and towards the warm waters of the Gulf Stream.

Nicoles’s path on top of an SST analysis. Also shown: 1400 UTC 200-850mb Shear (Click to enlarge)

A true-color visible mp4 animation, below, from the CSPP Geosphere site, (direct link to animation) shows the center of Nicole very close to dryer air to the south. This proximity to dry air argues against rapid intensification.

GOES_16 True-color animation, 1216 – 1531 UTC on 9 November 2022

Nicole does have a very large windfield. HY-2C scatterometery, above, (from this website), show the very large region of tropical storm-force winds over much of the South Atlantic Bight, from the Bahamas up to Cape Hatteras! Coastal erosion and flooding from the wind and generated waves (in addition to storm surge) is likely, and residents along the coast should heed advisories/warnings.

HY2C Scatterometer winds, 0430 UTC on 9 November 2022 (Click to enlarge)

For more information on Nicole, refer to the National Hurricane Center website.

10 November Update: Hurricane Nicole made landfall along the coast of Florida around 0800 UTC on 10 November, producing wind gusts as high as 75 mph.

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Lunar Eclipse of 8 November 2022 and the Day Night Band

The Day Night band on Suomi NPP and on NOAA-20 (and on the soon-to-be-launched JPSS-2 that will become NOAA-21) rely on reflected moonlight to provide crisp imagery of clouds. When a lunar eclipse occurs, as happened early on 8 November 2022, lunar illumination is lost. The lunar eclipse of 8 November started at 0803 UTC,... Read More

Suomi NPP and NOAA-20 Day Night Band images, 8 November 2022 (click to enlarge)

The Day Night band on Suomi NPP and on NOAA-20 (and on the soon-to-be-launched JPSS-2 that will become NOAA-21) rely on reflected moonlight to provide crisp imagery of clouds. When a lunar eclipse occurs, as happened early on 8 November 2022, lunar illumination is lost. The lunar eclipse of 8 November started at 0803 UTC, with totality from 1017 to 1142 UTC, and the eclipse ended 1249 UTC. (Details are here.)

The toggle above shows Suomi NPP and NOAA-20 imagery (from the VIIRS Today website); when Suomi NPP overflew the east coast (at around 0700 UTC, viewing Tropical Storm Nicole to the east of Florida) and the midwest (around 0830 UTC), the lunar eclipse had not yet started, or its effects were minimal (here is a map of Suomi NPP orbital paths). NOAA-20 overflew the midwest 90 minutes after Suomi NPP when the Lunar Eclipse was starting to reduce illumination. For both satellites, the overflights over the western US occurred during totality; lunar illumination was minimal.

Previous lunar eclipses are discussed here, here and here.

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SAR data over Guam (part II and III)

Synthetic Aperture Radar (SAR) data retrievals continue over Guam, with 10 planned for November. The toggle above compares the 2009 UTC SAR footprint (from RADARSAT-2) with Himawari-8 Clean Window (10.41) infrared imagery at 2010 UTC (on 5 November 2022). These data are also available online at this NOAA/STAR Website; there are also... Read More

Himawari-8 Clean Window infrared (Channel 13, 10.4 µm) and SAR Winds, 2010 UTC on 5 November 2022 (Click to enlarge)

Synthetic Aperture Radar (SAR) data retrievals continue over Guam, with 10 planned for November. The toggle above compares the 2009 UTC SAR footprint (from RADARSAT-2) with Himawari-8 Clean Window (10.41) infrared imagery at 2010 UTC (on 5 November 2022). These data are also available online at this NOAA/STAR Website; there are also direct links to wind analyses and Normalized Radar Cross Section (NRCS) data. MetOp-B Scatterometer winds for this time (from the manati website), show light southeasterly winds over the Guam and islands to its northeast: Rota, the very small Aquipan, Tinian and Saipan.

The SAR Wind observations show several things. Each of the islands has a wind shadow, with lighter winds downwind of the islands (that is, to their north and west given the prevailing southeasterlies). The strongest winds — 30 to 40 knots — are most likely a result of cloud ice causing a much greater SAR return, and this can be verified by viewing the Normalized Radar Cross Section, shown below, from this link. Feathery features that occur in the NRCS imagery are most likely cloud ice, and the enhanced reflection from that cloud ice results in an analysis that shows stronger surface winds than may be present. So an analyst who sees very strong winds in/near deep convection should verify what kind of hydrometeors might be in the cloud.

Normalized Radar Cross Section, 2009 UTC on 5 November 2022 (Click to enlarge)

SAR Winds just to the west of the island of Saipan show 5 separate strong maxima in a region where Himawari-8 data show little evidence of cloudiness. This image of Saipan from the International Space Station suggests a possible reason: ships at anchor in Saipan’s harbor! Such ships are highly reflective in C-band frequencies as used on RADARSAT-2.

SAR WInds around Saipan, 2009 UTC on 5 November 2022 (Click to enlarge)

Thanks to Brandon Aydlett, SOO at WFO Guam, for pointing out the artifacts near Saipan!


Another RADARSAT-2 pass occurred at 0823 UTC on 7 November. The toggle with Himawari-8 infrared imagery is shown below. Again, weaker winds are shown downwind of the islands (in this case, to the west of the islands as winds have shifted to a more easterly direction; click here to see the wind analysis and the NRCS analysis, both from this website) To the east of Guam are numerous dipoles of strong/weak winds associated with showers.

Himawari-8 Clean Window infrared (Channel 13, 10.4 µm) and SAR Winds, 0820 UTC on 7 November 2022 (Click to enlarge)

The toggle below zooms in on the shower activity near 13.5oN, 147.75oE, to the east of Guam. Stronger winds (10-15 knots, yellow and brown in the enhancement) are apparent to the east of the cooler clouds that are mostly likely tradewind cumulus showers. The strongest winds, 20+ knots might be associated with ice in clouds. Himawari-8 Band 13 brightness temperatures over the showers are in general not sub-freezing (the exception being the cyan and blue enhancements where brightness temperatures are from -5o to -8o C. The small NRCS image underneath the toggle (snipped from here), however, shows some bright feathered regions that suggest ice is present in small (perhaps smaller than the Himawari-8 infrared resolution) regions within the clouds (this image references NRCS features with the zoomed-in SAR wind image shown below)

Himawari-8 Clean Window infrared (Channel 13, 10.4 µm) and SAR Winds, 0820 UTC on 7 November 2022, centered on 13.5 N, 147.75 E (Click to enlarge)
NRCS imagery for a small region centered near 13.5 N, 147.75 E (Click to enlarge)

Note that the very large signals persist just to the west of Saipan — and there’s one more ship, apparently!

SAR WInds around Saipan, 0823 UTC on 7 November 2022 (Click to enlarge)

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Grassland fire in South Dakota

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Power derived product and Fire Temperature derived product images (above) showed the thermal signatures associated with a wind-driven grassland fire in north-central South Dakota on 06 November 2022. The Fire Temperature and Fire Power derived products are components of... Read More

GOES-16 Fire Temperature RGB (top left), Shortwave Infrared (3.9 µm, top right), Fire Power (bottom left) and Fire Temperature (bottom right) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Power derived product and Fire Temperature derived product images (above) showed the thermal signatures associated with a wind-driven grassland fire in north-central South Dakota on 06 November 2022. The Fire Temperature and Fire Power derived products are components of the GOES Fire Detection and Characterization Algorithm FDCA. The earliest unambiguous fire signature was seen in the 3.9 µm imagery at 1720 UTC, as infrared brightness temperatures began to increase. The first Fire Power pixel then appeared at 1724 UTC, with the first Fire Temperature RGB pixel appearing at 1727 UTC. At 1743 UTC, the hottest 3.9 µm brightness temperature occurred (9.78ºC) along with the peak Fire Power value of 1459.1 MW.

GOES-16 True Color RGB images from the CSPP GeoSphere site (below) displayed the smoke plume as it drifted southeastward and eventually crossed the South Dakota / Minnesota border — and a dark burn scar became apparent at the fire source region.

GOES-16 True Color RGB images [click to play MP4 animation]

NOAA-20 VIIRS True Color and False Color RGB images valid at 1944 UTC (below) provided a higher spatial resolution view of the smoke plume; on the False Color RGB image, pink pixels highlighted the hottest portions of the wind-driven fire at that time. The VIIRS data used to create these images were acquired and processed by the SSEC/CIMSS Direct Broadcast ground station.

VIIRS True Color and False Color RGB images, valid at 1944 UTC [click to enlarge]

===== 07 November Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images valid at 0759 UTC, along with the GOES-16 Shortwave Infrared (3.9 µm) image at 0756 UTC [click to enlarge]

During the subsequent nighttime hours, a comparison of NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images valid at 0759 UTC (above) showed the bright glow and warm thermal signature associated with a small remnant fire near the northwestern end of the burn scar — but the small thermal signature was not apparent in lower spatial resolution GOES-16 Shortwave Infrared (3.9 µm) imagery at 0756 UTC.

This small fire was not evident in a later Suomi-NPP VIIRS Day/Night Band image valid at 0852 UTC (below) — but the 7-8 mile long dark burn scar was easily seen between Bowdle and Loyalton.

Suomi-NPP VIIRS Day/Night Band (0.7 µm) image, valid at 0852 UTC [click to enlarge]

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