A toggle between Terra MODIS and Suomi NPP VIIRS Red-Green-Blue (RGB) images, viewed using RealEarth (above), revealed the well-defined eye structure of Cyclone Numa over the Ionian Sea (between Italy and Greece) on 18 November 2017. Tracing its origin back to the remnants of Tropical Storm Rina (track), Cyclone Numa had acquired subtropical characteristics, making it a relatively rare Medicane.

EUMETSAT Meteosat-10 High Resolution Visible (0.8 µm) images (below) showed the evolution of the storm on 18 November. Plots of hourly surface reports (in metric units) are plotted on the images.

Meteosat-10 Infrared Window (10.8 µm) images (below) showed cloud-top infrared brightness temperatures around -60ºC (darker red enhancement) associated with some of the convective bursts during the 18-19 November period, as the system eventually moved inland across Greece.

Personal analysis of Tropical Storm #Numa's track and evolution. No official agency has classified this as a tropical storm; however, all data is in agreement with it being such. Phase diagrams depicted a deep warm core and strong convection was present around the center. pic.twitter.com/XNV5cyCXmw

— Brenden Moses (@Cyclonebiskit) November 22, 2017

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Alaska’s first (official) surface air temperature of -40º or colder for the 2017-2018 winter season was reported by the Cooperative Observer at Chicken (-43ºF) on 19 November 2017. A NOAA-18 Infrared Window (10.8 µm) image at 0320 UTC (above) showed cold air drainage into river valleys, with the coldest infrared brightness temperatures around -40ºC/-40ºF (darker blue color enhancement). Chicken is located about midway between Eagle (PAEG) and Northway (PAOR), where 03 UTC surface air temperatures were -17ºF and -24ºF, respectively. However, PAEG reached their minimum temperature around 11 UTC after additional hours of cloud-free radiational cooling.

An automated RAWS site at Chicken reached a minimum temperature of -34ºF at 1120 UTC — the dew point at that time was -42ºF. However, a MesoWest map (below) shows that the RAWS tower is located on a small hill (at an elevation of 2060 feet) — and the Cooperative Observer instrument shelter was likely located in the lower elevations of the settlement.

For comparison, note the 2011-2012 and 2010-2011 winter seasons.

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The JPSS-1 satellite was successfully launched at 0947 UTC (1:47 AM local time) on 18 November 2017 from Vandenberg Air Force Base, California (Spaceflight Now). A Suomi NPP VIIRS Day/Night Band (0.7 µm) image about 22 minutes prior to launch (above; courtesy of William Straka, CIMSS) showed light emitted by the launch facility as well as nearby cites and offshore buoys.

A comparison of 3 consecutive images of GOES-16 Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 mm) data (below) revealed the thermal signature of the launch rocket booster engines at 0947 UTC (just west of the California coast). The hot thermal signature is brighter white on the Near-Infrared images, and darker gray on the Shortwave Infrared image. Nearby 09 UTC surface observations are also plotted (KVBG = Vandenberg AFB).

Since the GOES-16 Water Vapor bands — Lower-level 7.3 µm, Mid-level 6.9 µm and Upper-level 6.2 µm —  are essentially Infrared bands (which sense the mean temperature of a layer of moisture), a warm thermal signature was evident on all three of the 0947 UTC images (below).

Read about SSEC scientists’ efforts to calibrate and validate CrIS and VIIRS on JPSS-1 here.

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing *

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* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing *

GOES-16 “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Shortwave Infrared (3.9 µm) images (above) revealed the presence of ship tracks across Lake Superior on 16 November 2017. Aerosols from the exhaust of ships cause a “cloud seeding effect”, which results in a higher concentration of smaller cloud droplets compared to the surrounding unperturbed clouds. These smaller cloud droplets are more effective reflectors of sunlight, resulting in a brighter white signature on the Snow/Ice imagery and a warmer (darker gray) signature on the Shortwave Infrared imagery.

A view of the entire lake — using similar Visible, Snow/Ice and Shortwave Infrared images from the Terra MODIS instrument — is shown below. In addition to the ship tracks, plumes from power plants and/or industrial sites can be seen in southern Ontario, streaming southward near Thunder Bay (station identifier CYQT) and southwestward near Upsala (CWDV); another plume was evident in northeastern Wisconsin, to the southeast of Eagle River (KEGV).

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