GOES-16 Views of Tornadic Thunderstorms over Louisiana

February 7th, 2017

Severe Weather hit Louisiana on Tuesday 7 February 2017, and the ABI on GOES-16 viewed the convective development. This website includes an animation (also available on YouTube) of the visible imagery (Band 2, 0.64 µm with 0.5-km resolution at the subsatellite point) from ABI during the time period of the strongest tornadoes in and near New Orleans. Click here for an animation that includes views of all 16 ABI Bands.

A comparison of GOES-13 (GOES-East) Visible (0.63 µm) and Infrared Window (10.7 µm) images is shown below, with hourly surface reports and locations of the tornado reports.

GOES-13 0.63 µm Visible (top) and 10.7 µm Infrared Window images (bottom), with hourly surface reports and locations of the tornado reports.

GOES-13 0.63 µm Visible (top) and 10.7 µm Infrared Window images (bottom), with hourly surface reports in yellow and locations of the tornado reports in cyan.

Suomi NPP overflew the convection shortly after the tornadoes were on the ground in Louisiana, and images from the three spectral bands shown below, 11.45 µm, 0.64 µm and 1.61 µm show a mature convective system with overshooting tops over the Gulf Coast states and the Gulf of Mexico. The 1.61 µm Snow Ice band helps in the discrimination between cloud tops comprised of water droplets (bright white) vs. cloud tops comprised of ice crystals (grey); the ABI on GOES-16 has a similar band.

Suomi NPP VIIRS Imagery from 1924 UTC on 07 February 2017. Infrared Window (11.45 µm), Visible (0.64 µm) and Snow/Ice (1.61 µm) bands are shown. (Click to enlarge)

Sequential NUCAPS Profiles at Higher Latitudes

October 20th, 2016
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Suomi NPP Day/Night Band (0.70 µm) and NUCAPS Sounding Locations, 0538 and 0724 UTC on 20 October 2016. Green Dots represent soundings that have passed quality control; Yellow Dots represent soundings for which the infrared retrieval failed; Red dots represent soundings for which both infrared and microwave retrievals failed (Click to enlarge)

The orbital geometry of Suomi NPP is such that regions north of about 43º N latitude can occasionally receive NUCAPS (NOAA-Unique Combined Atmospheric Processing System) Vertical Profiles of moisture and temperature on sequential orbital passes, meaning a given location could have vertical profiles separated by less than 2 hours. This occurred early on 20 October 2016 over Maine and Cape Cod, as shown above: Suomi NPP NUCAPS Vertical Profile locations are indicated over Day/Night Band Visible imagery. Two soundings at approximately the same location are circled in cyan in this small image and are shown below. There are two sequential profiles over Cape Cod, and then the two sequential profiles north of Maine. The atmosphere over Cape Cod was quiescent on this date, and little change between soundings is evident. In contrast, slight cold air advection was occurring north of Maine (Surface analysis from 0900 UTC, 500-mb analysis from 00 UTC), and the NUCAPS Sounding shows mid-level cooling.

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NSharp depictions of NUCAPS Vertical Profiles near 42N, 70W at 0500 and 0700 UTC on 20 October 2016 (Click to enlarge)

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NSharp Depictions of NUCAPS Vertical Profiles near 48 N, 68 W at 0500 and 0700 UTC on 20 October 2016 (Click to enlarge)

For stations in the northern Plains, or in Canada, sequential soundings overnight or perhaps more importantly in the mid-afternoon (Suomi NPP typically overflies the Plains a bit after Noon local time) could give important information about destabilization.

Previous CIMSS Satellite Blog Entries referencing NUCAPS Vertical Profiles are available here.


=============== Added 2100 UTC on 20 October 2016 ===============
The toggle below shows two soundings, from 1700 and 1800 UTC in central Pennsylvania in the region between Harrisburg and Williamsport (click here to see the Sounding Locations), just east of a slight risk issued by the Storm Prediction Center. The time evolution suggests upward motion (the top of the inversion rises) and a weakening in the cap. Severe Thunderstorm Watch #499 was issued 1945 UTC on 20 October for counties just to the west of these NUCAPS Profile locations — and damaging winds were reported in central Pennsylvania beginning at 2154 UTC.

NSharp depictions of NUCAPS Vertical Profiles near 41N, 77W at 1700 and 1800 UTC on 20 October 2016 (Click to enlarge)

Hurricane Hermine

September 1st, 2016

GOES-13 Visible (0.63 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

GOES-13 Visible (0.63 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

Hermine was upgraded to a Hurricane over the Gulf of Mexico around 20 UTC on 01 September 2016. GOES-13 (GOES-East) Visible (0.63 µm) images (above) showed improvement in the appearance of curved banding structures around the eye late in the day. The GOES-13 satellite had been placed into Rapid Scan Operations (RSO) mode, providing images as frequently as every 5-7 minutes. Note that Hurricane Hermine developed from Tropical Invest 99L, which was sampled by 1-minute GOES-14 imagery beginning on 25 August; unfortunately, the 1-minute Super Rapid Scan Operations for GOES-R (SRSO-R) test period ended at 1115 UTC on 29 August (however, imaging of the evolution of Tropical Depression 9 to Hurricane Hermine continued at 15-minute intervals).

The corresponding GOES-13 Infrared Window (10.7 µm) images (below) revealed the eventual formation of a distinct eye, with bursts of convection exhibiting cloud-top IR brightness temperatures in the -75º to -80º C range (shades of white to violet pixels) in the western and southern semicircles of the eyewall region. Hermine became the first hurricane to make landfall in Florida since Wilma in 2005.

GOES-13 Infrared Window (10.7 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

GOES-13 Infrared Window (10.7 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

A Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image visualized using RealEarth (below) provided a detailed view of the curved banding around the western and southern portion of the eye.

Suomi NPP VIIRS true-color image [click to enlarge]

Suomi NPP VIIRS true-color image [click to enlarge]

A comparison of DMSP-17 SSMIS Microwave (85 GHz) and GOES-13 Infrared Window (10.7 µm) images around 2315 UTC (below) depicted a much larger eye presentation on microwave vs infrared — the microwave image showed the curved banding structure around an eye that was still not well-organized.

DMSP-17 SSMIS Microwave (85 GHz) and GOES-13 Infrared Window (10.7 µm) images [click to enlarge]

DMSP-17 SSMIS Microwave (85 GHz) and GOES-13 Infrared Window (10.7 µm) images [click to enlarge]

While Hermine passed over waters exhibiting warm Sea Surface Temperature values in the eastern Gulf of Mexico, the Ocean Heat Content values were only modest (below).

Sea Surface Temperature and Ocean Heat Content values [click to enlarge]

Sea Surface Temperature and Ocean Heat Content values [click to enlarge]

The high values of Total Precipitable Water (TPW) associated with Hermine were evident on hourly composites of morphed TPW from MIRS sensors (below). Rainfall amounts exceeded 22 inches in Florida (WPC storm summary)

Morphed Total Precipitable Water derived from MIRS sensors [click to play animation]

Morphed Total Precipitable Water derived from MIRS sensors [click to play animation]


===== Post-landfall Update, 02 September =====
 

Suomi-NPP overflew Hermine shortly after 0700 UTC on 02 September, after its 0530 UTC landfall near St. Mars FL. The toggle below shows the VIIRS 0.7 µm Day/Night Band and the 11.45 µm Infrared Window imagery. Both show the asymmetric nature of the storm. Rain and clouds extend quite a distance to the south and east of the storm, but not far to the west. The infrared imagery shows cold cloud tops surrounding the storm center southeast of Tallahassee, with very cold cloud tops also over Tampa FL and near Savannah GA with bands associated with the storm. Cloud detail is missing in the Day/Night Band image because of the lack of lunar illumination — a New Moon occurred early on 01 September — however, high-altitude mesospheric airglow waves (references: 1 | 2 | 3) can be seen off the east coast of Florida and Georgia, excited by Hermine’s bands of strong thunderstorms.

Suomi NPP Day/Night Band Visible (0.70 µm) and Infrared Window (11.45 µm) images at 0723 UTC on 2 September [click to enlarge]

Suomi NPP Day/Night Band Visible (0.70 µm) and Infrared Window (11.45 µm) images at 0723 UTC on 2 September [click to enlarge]

A toggle between before-landfall (0319 UTC Terra MODIS) and after-landfall (0814 UTC POES AVHRR) Infrared images, below, shows the expected trend of warming cloud-top IR brightness temperatures and a consolidation into a more compact storm circulation.

11.0 µm Terra MODIS (0319 UTC) and 12.0 µm POES AVHRR (0814 UTC) Infrared images [click to enlarge]

11.0 µm Terra MODIS (0319 UTC) and 12.0 µm POES AVHRR (0814 UTC) Infrared images [click to enlarge]

===== 03 September Update =====

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

A toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0707 UTC on 03 September (above; courtesy of William Straka, SSEC) showed that Hermine — still being classified as a Tropical Storm — continued to produce mesospheric airglow waves as it moved off the East Coast of the US. Numerous bright white streaks were also evident on the Day/Night Band image, due to cloud illumination from intense lightning activity.

During the following daylight hours of 03 September, GOES-13 (GOES-East) Visible (0.63 µm) images (below: also available as an MP4 animation) showed the circulation of post-tropical cyclone Hermine. In eastern North Carolina, winds gusts as high as 80 mph were recorded, with rainfall amounts as great as 8.54 inches (NWS Newport/Morehead City); the storm also produced a few tornadoes (SPC Storm Reports). In southeastern Virginia, winds gusted to 73 mph (NWS Wakefield). A few of the heavier rainfall amounts for individual states are listed here.

GOES-13 Visible (0.63 µm) images, with surface and buoy wind barbs plotted in yellow and wind gusts (knots) plotted in red [click to play animation]

GOES-13 Visible (0.63 µm) images, with surface and buoy wind barbs plotted in yellow and wind gusts (knots) plotted in red [click to play animation]

A Suomi NPP VIIRS true-color image visualized using RealEarth (below) showed the clouds associated with Hermine at 1827 UTC.

Suomi NPP VIIRS true-color image [click to enlarge]

Suomi NPP VIIRS true-color image [click to enlarge]

323 reindeer killed by lightning in Norway

August 26th, 2016

GFS model fields of surface pressure, 6-hour precipitation, 850 hPa temperature, and 10-m wind [click to play animation]

GFS model fields of surface pressure, 6-hour precipitation, 850 hPa temperature, and 10-m wind [click to play animation]

GFS model fields from this site (above) showed a relatively compact storm that was deepening as it moved northeastward across southern and central Norway on 26 August 2016.

EUMETSAT Meteosat-10 Visible (0.75 µm) and Infrared Window (10.8 µm) images (below; also available as an MP4 animation) revealed the development of thunderstorms over southern Norway during the 0900-1300 UTC period. Cloud-to-ground lightning from one of these storms is believed to have killed 323 reindeer near the southeastern corner of the Hardangervidda National Park (which is located in the center of the visible and infrared satellite images).

Meteosat-10 Visible (0.75 µm, top) and Infrared Window (10.8 µm, bottom) images, with surface reports plotted in cyan [click to play animation]

Meteosat-10 Visible (0.75 µm, top) and Infrared Window (10.8 µm, bottom) images, with surface reports plotted in cyan [click to play animation]

The coldest cloud-top infrared brightness temperatures of the thunderstorms on the 1100 UTC image was -51º C, which corresponded to an altitude of around 10.5 km on the 1200 UTC Ørland rawinsonde report (below) — looking at the individual sounding profiles, Ørland to the north of Hardangervidda was still in the moist convective environment near the center of the storm system, while Stavanger to the south began to show the drier air aloft in the wake of the northeastward-moving storm.

Rawinsonde data from Stavanger and Orland, Norway [click to enlarge]

Rawinsonde data from Stavanger and Orland, Norway [click to enlarge]

A composite of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image swaths as viewed using RealEarth (below) showed the widespread thunderstorms across southern Norway on the earlier (eastern) 1103 UTC overpass, while the later (western) 1243 UTC overpass showed the effects of the mid-level drier air that was beginning to overspread the region as the center of the parent storm system moved northeast.

Suomi NPP VIIRS true-color image swaths [click to enlarge]

Suomi NPP VIIRS true-color image swaths [click to enlarge]