This forum supports Geostationary Lightning Mapper (GLM) implementation and training.  The page provides a vehicle for learning about the GLM capabilities and limitations, exploring applications, understanding data quality, and addressing inquiries.

The GLM continuously observes lightning throughout a near hemispheric field of view, capturing spatiotemporal variability on unprecedented scales (Rudlosky et al. 2019). As a high-frame-rate camera that detects light pulses at cloud tops, the GLM differs from the ground-based lightning detection networks most familiar to NWS forecasters. Thus, focused research, development, and training efforts are required to guide the operational application of these new data. A gridded product suite (Bruning et al. 2019) and associated AWIPS configurations were implemented to provide GLM information to forecasters (Sima 2020).

The first product (flash extent density; FED) is available to all NWS weather forecast offices (WFOs) via experimental channels (i.e., the Operations Proving Ground, OPG), with a ‘full disk’ version rolling out during 2020.  Additional gridded products (presently average flash area and total optical energy, AFA and TOE) are undergoing a limited demonstration at ~60 WFOs.  Work continues on refining display specifications for these and other gridded GLM products.  The OPG and Hazardous Weather Testbed (HWT) help develop and test new versions before broader dissemination.  These efforts leverage forecaster feedback to improve the gridded products and the ability for forecasters to both interpret and apply them.

The FED is awaiting formal SBN distribution, and a nationwide demonstration during 2020 aims to determine whether the total optical energy (TOE), average flash area (AFA), and/or minimum flash area (MFA) should be distributed via the SBN.  Gridded GLM products cannot advance past RL7 without migration to NESDIS generation and distribution.  Thus, the NWS is working with NESDIS to shift product generation and distribution to more robust channels.  Present plans aim to provide GLM gridded products via official NESDIS channels by Summer/Fall 2022.

Please follow the tabs above to explore training documents, daily GLM status information, product descriptions, and imagery examples.

Archive GLM Grids are available at https://lightning.umd.edu/glm/archive/

Near real time imagery is available at https://lightning.umd.edu/glm/http://col.st/haYgj, and http://col.st/WtVLp

Example GLM Imagery - Click the drop down menu in the top right for lots more options!



What's New

Optical Extinction Example

There appeared to be a good case of optical extinction with a severe warned storm near the Hughes/McIntosh county line in southeast Oklahoma on 10 October, 2019. ENI data showed a tight...

When the GLM detects Lightning that isn't Lightning

Because the GLM is an optical detector and looks for changes in brightness over a certain time interval, there will be times that sun glint off of various objects will result in a false...

GLM and Public Safety: An Important Caveat

As great as is to use data from the Geostationary Lightning Mapper, there is an important caveat forecasters have to consider when using the data. During the afternoon of July 11,...

Lone Left-moving Supercell

On 19 July 2018 a lone, left-moving supercell was observed with GLM moving from eastern Kansas into western Missouri. The loop below has 1-min GLM Flash Extent Density with IR...

Periphery, single, small, dim flashes on central Great Plains storms 

While monitoring GLM across the central Great Plains on 19 Jun 2018 it was noted that several storm clusters showed single, small, dim flashes along their trailing edges. These...