GOES-16 and Tropical Depression #4 in the Atlantic Ocean

July 6th, 2017 |

GOES-16 “Cirrus Channel” (1.38 µm) near-infrared imagery, 0900-2100 UTC on 6 July 2017 (Click to play animated gif)

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

Tropical Depression #4 formed in the tropical Atlantic on 5 July 2017 (Click here for National Hurricane Center advisories on the system). The Depression is not forecast to strengthen, and two GOES-16 products give evidence to its weakened state. The animation of GOES-16 Band 4 (1.38 µm “Cirrus Channel”), above, shows a general decrease in the high clouds associated with this system (located north of 10º North Latitude and between 40º and 50º West Longitude), meaning convection is not strong. A closer view reveals intricate cirrus transverse banding around the periphery of the system during the early part of the day. In addition, the 10.3 µm “Clean Window” image, below, overlain on top of the GOES-16 Baseline Total Precipitable Water (TPW) Product, shows dry air west of the circulation. A Saharan Air Layer (SAL) analysis from here that uses Meteosat data, shows dry air moving towards the system from the east as well (Link). A toggle between GOES-13 Infrared Window, Meteosat-10 SAL product, and MIMIC TPW imagery can be seen here.

Refer to the National Hurricane Center website, or the CIMSS Tropical Weather website, for more information on this sytem.

GOES-16 “Clean Window” Band (10.33 µm) and GOES-16 Total Precipitable Water, 2100 UTC on 6 July 2017 (Click to enlarge)

Deadly Fire in Portugal

June 18th, 2017 |

Suomi NPP VIIRS Day/Night Band Visible Imagery (0.70 µm) at 0240 UTC on 18 June 2017 (Click to enlarge)

(Images in this blog post were created by William Straka, SSEC. Thanks William!!)

Parts of Pedrogao Grande in central Portugal (northeast of Lisbon) burned over the weekend in a massive forest fire. At least 62 people were killed (News Link; Youtube Video 1, 2). Suomi NPP overflew the region shortly after the fire started, and annotated VIIRS (Visible Infrared Imaging Radiometer Suite) Day/Night Band imagery is shown above (Click here for an image without annotation).  The size of the bright light signature from the fire (overlain with thin clouds) rivals that of Lisbon.

Suomi NPP VIIRS Shortwave Infrared imagery ( 3.75 µm) at 0240 UTC on 18 June 2017 (Click to enlarge)

Shortwave Infrared channels on Suomi NPP also testify to the intensity of the fire. The 3.75 µm above (Click here for an image with no labels) shows a saturated pixel (exceeding 367 K) over the hottest part of the fire.  The 1.61 µm channel in the near infrared also had a strong signal.   The 4.05 µm imagery (Click here for an image without annotation) shown below had a maximum brightness temperature exceeding 550 K! (This channel was specifically designed for fire detection).

Suomi NPP VIIRS Shortwave Infrared Imagery (4.05 µm) at 0240 UTC on 18 June 2017 (Click to enlarge)

Meteosat-10 Severi Infrared Imagery (3.9 µm) from 0000 to 0400 UTC on 18 June 2017 (click to enlarge)

The SEVERI Instrument on Meteosat-10 also detected this fire, and because Meteosat is geostationary, it provided better temporal coverage vs. the single snapshot from Suomi NPP. The animation above shows considerable cloud cover over Portugal, but very warm pixels are present starting after 0145 UTC. The toggle below compares 3.9 µm SEVIRI at 0245 UTC with 3.75 µm Suomi NPP VIIRS at 0240 UTC. The better spatial resolution of the VIIRS instrument is apparent, as are much warmer temperatures as expected given the smaller pixel size on VIIRS.  Note also a slight parallax shift.

Shortwave Infrared Imagery (3.9 µm from Meteosat-10 SEVIRI at 0245 UTC and 3.75 µm from Suomi NPP VIIRS at 0240 UTC) over Portugal (Click to enlarge)


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Suomi NPP VIIRS Day/Night Band visible (0.70 µm) imagery at 0145 UTC on 19 June 2017 (Click to enlarge)

Data from the 0145 UTC 19 June overpass on Suomi NPP show that the fire continues, although with less intensity. The Day/Night Band (above) and the 3.75 µm Shortwave Infrared (below) show the fire locations.

Suomi NPP VIIRS Shortwave Infrared (3.75 µm) imagery at 0145 UTC on 19 June 2017 (Click to enlarge)

 

High wind event in Moscow, Russia

May 29th, 2017 |

Meteosat-10 Visible (0.8 µm, left) and Infrared Window (10.8 µm, right) images [click to play animation]

Meteosat-10 Visible (0.8 µm, left) and Infrared Window (10.8 µm, right) images [click to play animation]

High winds associated with a strong cold frontal passage were responsible for 16 fatalities and 168 injuries in Moscow, Russia on 29 May 2017 (CNN | BBC). EUMETSAT Meteosat-10 High Resolution Visible (0.8 µm) and Infrared Window (10.8 µm) images (above; MP4 ) showed the cluster of thunderstorms that moved through the region. Plotted in yellow are 4-letter station identifiers of the three principal Moscow airports (UUEE, UUWW and UUDD). The cloud-top Infrared brightness temperatures of the thunderstorm cluster exhibited a distinct bowing structure on Infrared imagery around the time of the highest winds (1230 UTC).

On the corresponding Meteosat-10 Water Vapor (6.25 µm) images (below; MP4), the well-defined signature of a middle-tropospheric vorticity center could be seen.

Meteosat-10 Water Vapor (6.25 µm) images [click to play animation]

Meteosat-10 Water Vapor (6.25 µm) images [click to play animation]

Time series plots of surface observations from the 3 major Moscow airports (below) showed that Sheremetyevo International Airport (UUEE) recorded a wind gust of 54 knots (62 mph) at 1230 UTC — also note the sharp drop in air temperature as the cold front passed.

Time series of surface observations at Sheremetyevo International Airport UUEE [click to enlarge]

Time series of surface observations at Sheremetyevo International Airport UUEE [click to enlarge]

Time series of surface observations at Vnukovo International Airport UUWW [click to enlarge]

Time series of surface observations at Vnukovo International Airport UUWW [click to enlarge]

Time series of surface observations at Domodedovo International Airport UUDD [click to enlarge]

Time series of surface observations at Domodedovo International Airport UUDD [click to enlarge]

Thermal signature of missile strikes at Shayrat Air Base in Syria

April 7th, 2017 |

EUMETSAT Meteosat-10 Shortwave Infrared (3.9 µm) images, with hourly surface reports; Shayrat Air Base is located at the center of the cyan circle [click to play animation]

EUMETSAT Meteosat-10 Shortwave Infrared (3.9 µm) images, with hourly surface reports; Shayrat Air Base is located at the center of the cyan circle [click to play animation]

EUMETSAT Meteosat-10 Shortwave Infrared (3.9 µm) images (above) showed the thermal signature or “hot spot” (darker black pixels) of fires resulting from US missile strikes at Syria’s Shayrat Air Base on 07 April 2017. The warmest infrared brightness temperature was 300.22 K on the 0030 UTC image (the SEVIRI instrument was scanning the Shayrat region at 00:40 UTC), which was about 25 K warmer than the surrounding background temperatures; though the fires were much smaller than the nominal 3 km spatial resolution of the 3.9 µm detector, the sub-pixel effect enables a signal of the fire radiative power to be registered.

A toggle between the 0015 and 0030 UTC images displayed using McIDAS-V (below; courtesy of William Straka, SSEC) highlights the appearance of the thermal signature at Shayrat Air Base. Two persistent hot spots located northeast of Palmyra could have been due to refinery or mining activities.

EUMETSAT Meteosat-10 Shortwave Infrared (3.9 µm) images at 0015 and 0030 UTC [click to enlarge]

EUMETSAT Meteosat-10 Shortwave Infrared (3.9 µm) images at 0015 and 0030 UTC [click to enlarge]