GOES-16 GLM Lightning detection over Minnesota

May 12th, 2022 |

Wednesday, 05-11-2022, brought storm damage and copious amounts of lightning over Minnesota and parts of South Dakota, Iowa, and Wisconsin. The GOES-16 Geostationary Lightning Mapper (GLM) detected the flash extent density over these areas. A NEXRAD radar composite shows a large bow echo signature around 05-12-2022 01:25Z that spanned the entire lower half of Minnesota. Storms are still currently pushing through eastern Minnesota and northern Wisconsin and forecast to bring severe thunderstorms throughout the afternoon. There are also continuing threats of flooding in the Twin Cities and surrounding areas.

GOES-16 GLM Flash Extent Density and Band 13 reflectance on 05-12-2022 from 00:03 UTC to 16:43 UTC.
GOES-16 Band 13 reflectance with NEXRAD Reflectivity on 05-12-2022 from 00:05 UTC to 16:45 UTC.

The GOES-16 GLM Flash Extent Density product is available on RealEarth here. Near-real-time GLM visualizations are available as well as archived visualizations of GLM going back 3-4 days.

Using the Night Microphysics RGB and LightningCast probabilities to anticipate nighttime convection and Lightning

May 11th, 2022 |
Nighttime MIcrophysics RGB, 0616 – 0811 UTC on 11 May 2022 (click to enlarge)

The Nighttime Microphysics RGB, above, over central Wisconsin (that’s Green Bay at the northeastern edge, and southeast Minnesota/northeast Iowa over the southwestern part, of the animation), shows a field of low clouds stretching west-southwest to east-northeast. Note however, the occasional appearance of redder pixels within the field (as shown in this annotated image from 0806 UTC), especially in Wood and Portage counties (Click here for a map of Wisconsin counties). That kind of signal suggests that vertical cloud growth is occurring. Do you think convection will occur shortly? What about lightning?


NOAA-20 overflew this region shortly after 0730 UTC, and NUCAPS profiles would have become available in AWIPS at about the time of the end of the animation. What do they show? The image below shows 850-mb Temperature and the 850-500 mb lapse rates computed from gridded NUCAPS fields. The steepest lapse rates and strongest instability is centered on a NUCAPS profiles in central WI (in Adams County) which is just south of the band of clouds identifiable in the Night Microphysics RGB shown above: NUCAPS profiles show ample instability just south of this line (and winds are southerly: 0000 UTC Green Bay sounding).

850-mb Temperatures, 850-500 mb Lapse Rate, and Total Totals Index, 0730 UTC on 11 May 2022 (click to enlage)

The individual NUCAPS soundings in Adams County and Green Lake County, below, show very steep mid-level lapse rates.

NUCAPS Profiles in Adams County (left) and Green Lake County (right) at 0735 UTC on 11 May 2022 (Click to enlarge)

The GOES animation of Nighttime Microphysics above ended at 0811 UTC. What happened in the next 15 minutes? Note a continued development in the amount of reddish pixels! During these 15 minutes, radar is also showing increasing returns.

Nighttime Microphsyics RGB, 0811-0826 UTC on 11 May 2022 (Click to enlarge)

If convection is expected, lightning might also occur. Lightning Cast is a product in the NOAA/CIMSS ProbSevere portfolio, and it’s available online here, and a short training video is here. LightningCast probabilities for the same 15-minute span as above are shown below. Low probabilites are present until 0826 UTC. When do you think lightning might occur with this developing line?

LightningCast probabilities, 0811-0826 UTC on 11 May 2022 (click to enlarge)

The animation below follows the developing cells through the next 15 minutes — from 0826 to 0841 UTC. Nighttime Microphysics (overlain by radar: note the parallax shift, and also note the continued reddening of pixels in the RGB where convection is occurring) is on the left, and LightningCast Probabilities are on the right. Do you think lightning is imminent?

Nighttime Microphysics RGB overlain with 0.5 Base Reflectivity (left) and LIghtningCast Probability (right), 0826 – 0841 UTC (Click to enlarge)

The first GLM observations (with a CONUS time cadence of every 5 minutes) of lightning occurred at 0846 UTC, as shown in the animation of the Nighttime Microphysics RGB below. (Here is LightningCast at 0846 UTC).

Nighttime Microphysics RGB and GLM Flash Extent Density (FED), 0616 – 0851 UTC on 11 May 2022 (click to enlarge)

The animation below shows the NightMicrophysics RGB overlain with LightningCast Probabilities, from 0816 to 0846 UTC.

GOES-16 Nighttime Microphysics RGB with LightningCast Probabilities and GLM FED observations, 0816 – 0846 UTC on 11 May 2022 (click to enlarge)

Gridded NUCAPS fields for this blog post were created using the NOAA/TOWR-S Cloud Instance of AWIPS. Thank you! And here is a link to a presentation detailing how the Nighttime Microphysics RGB can be used in winter!

Comparisons of LIS and GLM Lightning observations

May 4th, 2022 |
GOES-16 5-minute Flash Extent Density (updated every minute) and ISS LIS Flash Events, 1318-1320 UTC on 4 May 2022 (Click to enlarge)

The Geostationary Lightning Mapper (GLM) on GOES-16 and the Lightning Imaging Sensor (LIS, additional information here) on the International Space Station (ISS) both observe lightning. The GLM has nadir resolution of approximately 8 km, and is in geostationary orbit, about 36000 km above the Earth’s surface. In contrast, the LIS has a resolution of approximately 4 km, and it’s on the ISS, only 400 km above the Earth’s surface. Both sensors detect the optical signal of the lightning. The animation above shows 2 minutes of LIS Flash Events plotted (in yellow) on top of 5-minute aggregates of GLM Flash Extent Density (updated at 1-minute time-steps). The animation below shows the same LIS observations, but plotted in black, on top of GOES-16 ABI Band 13 imagery. Many of the LIS flash events are colocated with cold cloud top as defined by the GOES-16 Band 13 (10.3 µm) brightness temperatures — meaning that the optical signal is strongest there. That’s not always the case though, as shown in this image with LIS data from 13:19:48.

GOES-16 Band 13 Infrared (10.3 µm) imagery and LIS Flash Events, 1318-1320 UTC on 4 May 2022 (Click to enlarge)

Severe weather in South Carolina

April 5th, 2022 |
ProbSevere (version 2) over South Carolina, 1902-2012 UTC on 5 April 2022 (click to enlarge)

SPC Storm Reports from 5 April 2022 note a Tornado hit Allendale SC shortly before 2000 UTC. The animation above shows the ProbSevere (version 2 — available online here) display prior to and just after the tornado. NOAA/CIMSS ProbSevere identifies and tracks the radar feature associated with this tornadic storm. ProbSevere is designed to give forecasters more confidence in warning issuance. ProbSevere in this case highlights the radar object associated with model fields and satellite/radar observations that are most suggestive of a storm supporting tornadogenesis — note that ProbSevere values in adjacent cells are smaller. A meteorogram of this radar object, shown below (and available here), shows the ProbSevere components, and also ProbHail/ProbWind/ProbTor/Probsevere values, for both versions 2 and 3. ProbSevere values increased at around 1930 UTC. ProbSevere v3 values generally are smaller than ProbSevere v2 values; ProbSevere v3 will be demonstrated this year at the Hazardous Weather Testbed (HWT) this year. (Click here to view the Charleston, SC (KCLX) radar at 1958 UTC; a pronounced hook is apparent)

ProbSevere readout meteogram, Object Number 653760, 5 April 2022 (Click to enlarge). For the ProbSevere readout (top row), ProbTor values are in red, ProbHail values are in green, ProbWind values are in blue. (Click to enlarge)

This tornadic cell stood out in the visible imagery. GOES-16 Mesoscale Sector #2 on 5 April included portions of South Carolina. The mp4 animation below, from the CSPP Geosphere site, (this direct link to the animation will be valid for a bit less than a week) shows the tornadic cell erupting at around 1930 UTC near the Georgia/South Carolina border.

GOES-16 Visible Imagery (Band 2, at 0.64 µm) from Mesoscale Sector 2, 1900-2005 UTC 2022

Observations — satellite and radar — both showed the obvious storm. How did short-range guidance perform? A Polar Hyperspectral modeling system — also to be demonstrated at the Hazardous Weather Testbed — produces hourly 18-hour forecasts with initial fields influenced by Sounder Data from the Polar Orbiting satellites Suomi-NPP, NOAA-20, Metop-B and Metop-C. Infrared sounder (CrIS on Suomi/NPP and IASI on Metop) and Microwave sounder (ATMS on Suomi/NPP, AMSU/MHS on Metop) data can produce a more accurate initialization of the moisture distribution in atmosphere. The forecast initialized at 1200 UTC for Lifted Index and Significant Tornado Parameter, valid at 18, 19 and 20 UTC — that is, 6-h, 7-h and 8-h forecasts, below, shows increasing instability before the tornado in Allendale.

Lifted Index (left) and Significant Tornado Parameter (right) at 1800, 1900 and 2000 UTC on 5 April 2022 (Click to enlarge). Forecast initialized at 1200 UTC on 5 April 2022

The model runs initialized at 1700, 1800 and 1900 UTC, showing fields from initialization through 0000 UTC on 6 April 2022, are shown below. Note that the area with a Significant Tornado Parameter signal is mostly confined to southeastern South Carolina — that is, near the coast. Storm reports show that severe weather was mostly near the coast as well.

Lifted Index (left) and Significant Tornado Parameter (right) hourly from at 1700 UTC on 5 April 2022 through 0000 UTC on 6 April 2022 (Click to enlarge). Forecast initialized at 1700 UTC on 5 April 2022
Lifted Index (left) and Significant Tornado Parameter (right) hourly from at 1800 UTC on 5 April 2022 through 0000 UTC on 6 April 2022 (Click to enlarge). Forecast initialized at 1800 UTC on 5 April 2022
Lifted Index (left) and Significant Tornado Parameter (right) hourly from at 1900 UTC on 5 April 2022 through 0000 UTC on 6 April 2022 (Click to enlarge). Forecast initialized at 1900 UTC on 5 April 2022

These fields are also available in AWIPS via an LDM feed (in preparation for HWT). The 3 images below show changes in the 2000 UTC forecast (from the model initialized at 1400, 1600 and 1700 UTC). The trend towards higher Significant Tornado Parameter over southeastern South Carolina is obvious. Note that Allendale’s location is shown.

Significant Tornado Parameter valid at 2000 UTC on 5 April 2022 from forecasts initialized at 1400, 1600 and 1700 UTC (Click to enlarge)

Added: the GLM on GOES-16 saw a dramatic increase in Flash Extent Density with the tornadic storm starting around 1925 UTC on 5 April. (Click here to see a slower animation from 1920 – 1930 UTC)

GOES-16 GLM Flash Extent Density, 1900-2029 UTC on 5 April 2022 (Click to enlarge)