Tornado at Denver International Airport
Suomi NPP VIIRS 0.64 um visible image and 11.45 um IR channel image (with overlay of METAR surface reports)
A tornado touched down just east of the Denver International Airport concourses at 20:21 UTC on 18 June 2013, producing a peak wind gust of 97 mph (before the wind instrumentation stopped transmitting data). AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel data at 20:03 UTC (above) showed the storm about 20 minutes before it produced the tornado. The minimum cloud-top IR brightness temperature was -68º C (darker red color enhancement), which was significantly colder that the tropopause temperature of -56º C on the 12 UTC Denver rawinsonde data.
The corresponding Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image (viewed using the SSEC Web Map Server) is shown below.
Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image
The series of METAR surface reports from Denver (KDEN) during the period from 20:20 to 20:37 UTC:
KDEN 182037Z 09026KT 9SM -TSRA FEW050 BKN080CB BKN180 24/04 A3002 RMK FUNNEL CLOUD B18 FUNNEL CLOUD E20 TORNADO B21 TORNADO E36 AO2 LTG DSNT NE-S RAB03 TORNADO 2 SE MOV N P0005
KDEN 182032Z 09026KT 7SM +FC -TSRA FEW050 BKN080CB BKN180 22/08 A3001 RMK FUNNEL CLOUD B18 FUNNEL CLOUD E20 TORNADO B21 AO2 LTG DSNT NE-S RAB03 TORNADO 2 SE MOV N P0005
KDEN 182022Z 06021G28KT 5SM +FC TSRA FEW050 BKN080CB BKN180 21/07 A3002 RMK FUNNEL CLOUD B18 FUNNEL CLOUD E20 TORNADO B21 AO2 PK WND 07028/2020 LTG DSNT E-S RAB03 OCNL LTGICCG VC E TS OHD MOV E VIRGA SW P0005
KDEN 182021Z 06022G28KT 5SM +FC TSRA FEW050 BKN080CB BKN180 21/06 A3003 RMK FUNNEL CLOUD B18 FUNNEL CLOUD E20 TORNADO B21 AO2 PK WND 07028/2020 LTG DSNT E-S RAB03 OCNL LTGICCG VC E TS OHD MOV E VIRGA SW P0005
KDEN 182020Z 07020G28KT 5SM FC +TSRA FEW050 BKN080CB BKN180 21/07 A3003 RMK FUNNEL CLOUD B18 AO2 PK WND 07028/2020 LTG DSNT E-S RAB03 OCNL LTGICCG VC E TS OHD MOV E VIRGA SW P000
McIDAS images of GOES-13 0.63 µm visible channel data (below; click image to play animation) showed the development of the thunderstorms over the region
GOES-15 0.63 µm visible channel images (click image to play animation)