It’s pretty clear to me that both the GOES-west and GOES-east are having a lot of trouble detecting lightning (GLM) in the northwest U.S. with accuracy of location or frequency due to parallax, spatial resolution, and GOES tilt sampling of storms. Below is an animation specifically over southwest Montana where the GLM displaces the FED significantly (side note: TOE was very similar for these, so FED is shown for best example), and also has trouble picking up in-cloud pulses. The ENTI is overlaid in pink to show the differences in GLM vs ENTI. If you watch closely, the first frame depicts an ENTI in-cloud lightning flash & pulse in the far southwest portion of the screen, where no GLM FED (or TOE; not shown here) was even detected. There is also some instances where the GLM places lightning pixels where the ENTI or NLDN does not show anything in the same time frame (also making it hard to verify both products).

Below is a separate example where the FED does not show what I would expect it to show for a central Wyoming storm (differentiating intensity as well as location and timing). The GOES-east is the first to detect, then the GOES-west detects thereafter. GOES-east and GOES-west did not detect at the same time in any frame. Both products are loaded as a 5min-1min update.

Now here’s a case farther south in New Mexico where a storm cell is of comparable intensity as the northern examples. The GLM detection seems more accurate than the MT case, but the last frames here show that the GLM also has trouble with keeping FED on the cell core of interest.

Interestingly enough, the TOE (shown below) does a better job here  in NM with spatial coverage than it did up north in MT, but still has displacement issues comparing to ENTI and MRMS storm cores. I find that the TOE (especially with GOES-west) does a better job at recognizing the spatial extent of a flash here than the FED product did. (See above vs. below).

Now the question is, is the parallex better in the south-central U.S.?  And what if we look at higher resolution products like the group centroid density GLM product? While comparing the satellite GLM, with Day-Land-Cloud-Convection RGB, and with the ENTI/GLD/NLDN strikes (overlaid in pink) in SE Missouri…..it’s clear that a forecaster should not solely rely on GLM for core lightning locations (below). -shearluck

A great example of GLM usability is over the Gulf of Mexico (or any open bodies of water) where radar coverage and ENTI lightning sources diminish. Here’s an example of how a system moves eastward over the Gulf: radar disappears, but GLM (and some NLDN/ENTI) lightning data still lets you know where the strongest storm updrafts are located. Not only that, but the spatial extent of lightning is better known now that you have GLM alone. Below is displaying radar and satellite with FED GLM data, and NLDN/ENTI lightning detection. ProbSevere also becomes less relevant. The separate updrafts are easily distinguishable toward the end of the animation using FED.

Next animation is the same, but with FED on top of radar making it easier to see its evolution and usability:

Now with the same scenario, comparing the Minimum Flash Area (MFA) GLM product with the Average Flash Area (AFA) GLM product, it is MUCH easier to differentiate new convection with the MFA product. Notice all of the yellow spots in NM and Mexico that make it easily detectable with the human eye as you watch your SA monitor. This may be a product of color scale for the AFA, but this tells me that the MFA would be more useful in convective initiation. I have not gotten much value out of the AFA  as I would with just simply using the FED (Flash Extend Density GLM product) or TOE (Total Optical Energy). -shearluck

TOP IMAGE: MFA       ;     BOTTOM IMAGE: AFA