LightningCast – Page 2

Overview: Week 3, Day 1

Posted in Daily Summaries, LightningCast, SPG2026, Synthetic GXI, SZA Imagery on June 1, 2026 by Kevin Thiel.

Week 3 kicks off today and the ridge that stymied us in week two is….still there! Thankfully we’ve recovered a good bit of moisture across the plains and southeast for convection to work with. We began today with product introductions and an orientation session, followed by our forecast discussion to decide where we would target today. The forecast was pretty clean cut, with two options of elevated convection in NE Colorado/SE Wyoming and additional convection from a remnant MCS across Mississippi/Arkansas. Based on timing of CI, instability in the high plains, and the size of the MesoAnywhere domain, we decided to localized to the NWS offices of Cheyenne, WY (CYS) and Boulder, CO (BOU).

1 PM

SPC issued an MD just before operations began for our area, citing thunderstorm development and a high chance for a watch to be issued later. And by 2pm we had a watch!

In the CYS office, forecasters looked at synthetic GXI imagery and identifying the moisture advection northward into their CWA later in the forecast period. This also led to the discovery that a few of the procedures had ‘inverted’ color maps for WVT. While not intended, we did compare how they looked from each color map. Which is better? You decide!

Original colormap. Dry air/clouds are white, moisture is dark.

‘Flipped’ color map. Dry air/clouds are black, moisture is light.

First impressions of SZA from this morning’s imagery was positive with forecasters in both the CYS and BOU offices. A forecaster with experience in AK said they regularly adjust brightness of visible imagery on the fly, especially in lower light seasons. A forecaster with more experience in the central plains said they rarely adjust the brightness. Some of the areas we examined included over Colorado and Montana. Forecasters mentioned using the DCPD RGB frequently, and having more time with that imagery would be welcome. Additionally, one mentioned liking that the colors stayed more consistent throughout the day.

Forecasters in the CYS office compared LightningCast v1 and v2 from GOES-East and GOES-West along with the timing of the first lightning flash. V2 introduced more heterogenety in the bands, while V1 appeared fairly uniofrm and more widespread. Also LightningCast v2 seemed to be ahead of v1 for thunderstorm growth over the Denver metro.

3 PM

Both offices issued severe thunderstorm warnings for severe wind and hail hazards. Looking ahead, we have a steady stream of SLGTs this week, so we should stay fairly active. Also wanted to noted the CYS radar was out today, so some questions about using Sat data (especially things like OCTANE) for warnings are of interest for the morning discussion tomorrow.

-Kevin

LightningCast and Stoplight Chart Comparison

Posted in Lightning Stoplight, LightningCast, SPG2026 on May 14, 2026 by Kevin Thiel.

Today I tried to focus on the LightningCast and Stoplight Charts by comparing them. I noticed that in the case of lightning approaching, the probabilities on the dashboard went up. While version 2 in Figure 1 shows a blip around 20:15z, this was validated by a storm up to the north of the Airport which had lightning near 10 miles of the site. Version 1 had more of a persistent gradual increase which began sooner than Version 2. Version 1 would have most likely given more of a lead time than a quick ramp up.

Figure 2 represents the same timestamp as Figure 1 and shows the lightning increasing in coverage as storms approach. Figure 3 is a screenshot of the current lightning and LightningCast probabilities. The Stoplight Chart did very well with the area that the lightning was occurring.

Figures 4-6 show similar images but this time as the storms passed by. One thing I noticed was the LightningCast probabilities dropped off dramatically while lightning was still around the area. The lightning Stoplight Chart, in my opinion, handled the ramp down better with a more gradual end to the lightning.

So, it was interesting to see that both of them did fairly well ramping up lightning probabilities which increases confidence in forecasting and giving lead time for lightning DSS. However, there was a noticeable difference with the end time since the Stoplight Chart kept showing red over the area, meaning lightning was either nearby or occurring whereas the LightningCast rapidly dropped probabilities.

Overall, they both did well and they were both useful with lead/end times of lightning.

Figure 1: KAMA LightningCast ramped up the probabilities before lightning occurred.

Figure 2: Lightning Stoplight red boxes approached the 10 mile ring as lightning was approaching.

Figure 3: LightningCast showed the probabilities of lightning pretty well as lightning was occurring and approaching the site.

Figure 4: LightningCast ramped down the chances for lightning very quickly as storms passed.

Figure 5: Lightning Stoplight Chart kept lightning within the ring as storms passed.

Figure 6: LightningCast on AWIPS ramped down lightning very quickly as storms passed.

-Batman

SPG Blog Post Day 4

Posted in LightningCast, OCTANE Speed Sandwich, SPG2026, Synthetic GXI on May 14, 2026 by Kevin Thiel.

Today’s Set-up: Strong low pressure system moves through the region, with associated cold front. Slight risk over northern Texas, Oklahoma panhandle, and western Kansas. I was simulating the Dodge City office today. Their primary threats were severe wind gusts from an incredibly deep inverted V sounding, and some possible small hail.

Figure 1: LightningCast Viewer

Got more experience with the LightningCast dashboards. I got the events pulled up fine, and I found myself pulling the dashboards up to get a quick visual on trends, and which site was more at threat.
- This helps me, as a forecaster, get an idea on which event needs to be notified before the other. AKA – which event is the priority, based on the ongoing weather.
I explored some of the options that you can overlay on LightningCast viewer
- Having METARs pulled up is VERY helpful for getting some ground truth to what I am looking at on satellite and radar.
- I also appreciated having the SPC outlooks overlaid in the back, to have a quick guide for where is favorable for severe weather.

Figure 2: GXI-ALL Procedure

On a day like today, with a pretty strong frontal system and dry air in a lot of places, the GXI products worked well at highlighting the moisture ahead of the front. You can pretty clearly see the boundary moving through the CONUS.
- I did not get much help when looking at the CWA level view, but looking at the “big picture” CONUS view was significantly more useful for me in operations today.

Figure 3: CONUS Octane Speed Product

This image was earlier in the operations period, and I thought it was interesting to see that the speed was all relatively uniform. We’re used to looking for plenty of speed and directional shear in severe weather, but here most systems were moving around 30kts or so.

Figure 4: CONUS OCTANE CTC

I took a peek at cloud top cooling for some of these storms, and they were very cold (~-55C).
- I saw that the office to the south issued warnings based on that (shoutout!) and I looked into it a bit more, and realized we had even colder cloudtops. After radar analysis and further satellite, along with trying to find some ground truth, I put a warning out for the eastern portion of the CWA.

-Kelvin-Helm

High-based convection over western Kansas Blog Post

Posted in Lightning Stoplight, LightningCast, SPG2026 on May 14, 2026 by Kevin Thiel.

On the last full day of the Hazardous Weather Testbed, we monitored convection over the Dodge City (DDC), KS County Warning Area (CWA). We were responsible for issuing convective warnings and providing IDSS to two mock DSS events, the Sunflower Balloon Festival near Dodge City, and the Emerald City Oz Festival in Liberal, KS.

The near thermodynamic environment over the Dodge City, KS CWA was characterized by moist mid-levels atop deep, well-mixed boundary layer profiles and steep low-level lapse rates as sampled by the special 18Z DDC sounding. The sounding revealed modest CAPE values around 766 J/kg, but also significant CINH values of over 400 J/kg. See image below.

Figure 1 above: 18Z DDC RAOB showing a classic inverted-V sounding.

While numerous thunderstorms developed across southwest KS, most of the storms remained below severe levels with several wind reports between 38 and 47 kt, likely due to the combination of the inverted-V thermodynamic environment and gradient winds. See Figure 2 below.

Figure 2 above: LightningCast V2 & Stoplight combined procedure showing numerous thunderstorms affecting southwest and south central KS.

Figure 3 above: shows the Fire channel (left) and the Fire Temperature RGB (right). Around 2016 UTC, GOES-East CONUS 5-minute imagery detected a fire south of Richfield in Morton County in southwest KS. The Fire Temperature RGB showed some white pixels at times indicating that this fire was having a strong heat signal in all of the three channels in this RGB indicating a very hot intense fire, this despite being obscured intermittently by mid-high level clouds.

Figure 4. A VIIRS pass around 2021 UTC also indicated an intense fire in southwest KS with energy being emitted in the 101 to 350 Mega Watts range.

Overall, this was a day of dangerous fire weather conditions with dry thunderstorms producing marginally severe wind gusts. It is possible that this fire was ignited by lightning. Red Flag Warnings were in effect for southwest KS and the OK and TX panhandles.

-Hurricane Specialist

Severe Weather over western Pennsylvania

Posted in DSS, Lightning Stoplight, LightningCast, SPG2026 on May 13, 2026 by Kevin Thiel.

On Day 3 Wednesday of the Hazardous Weather Testbed, we monitored weather for the Pittsburgh CWA (PBZ), and in particular lightning and severe weather that could affect the Pittsburgh Mimosa Festival and the Allegheny Caribbean Carnival. We issued several SVRs that ended up verifying with multiple hail reports of 1.0” in diameter (quarter size) and a few damaging wind reports in northern WV. See SPC reports further below.

The main radar products that were used for severe weather decision making were the 0.5° Base Reflectivity and Base Velocity products, the MRMS @-20C, Vertically Integrated Ice, and MESH. LightningCast V2 and Stoplight V2 were also used to support DSS activities at the two festivals mentioned above. At the beginning of the event at 18Z, thunderstorms were already impacting the two festivals as seen on the Time-Series plot of LightningCast with observed GLM flash counts and near 100% lightning probability at the exact locations.

Figure 1 above shows the probability of lightning at the location of the Allegheny Caribbean Carnival from LightninCast V2 (green line) and the observed flash counts from the Geostationary Lightning Mapper (GLM) instrument. Notice that the second spike in lightning probabilities did not result in lightning activity detected at the exact location as shown by the lack of GLM flash counts. In this second spike in lightning probability, the LightningCast V2 had a small false alarm than the V1 product.

Figure 2 above shows the Pittsburgh Mimosa Festival experienced two rounds of thunderstorms, one between 18Z and 19Z and a second round between 1945Z and 20Z.

We also monitored the Stoplight V2 product to give the all clear message that the lightning threat had ceased.

Figure 3 above shows the Stoplight product indicating the cessation of lightning and when it was good to give the all clear message that activities could be resumed.

Figure 4 above shows the MRMS Isothermal Reflectivity product @-20C which often shows the most significant storms and the storms that might contain hail alongside the Vertically Integrated Ice. SVRs polygons are also shown to indicate where SVRs were issued.

Figure 5 above shows the SPC’s Severe Weather reports from Wed May 13 2026. Four hail reports of quarter size were reported in western Pennsylvania and three wind damage reports in northern WV.

-Hurricane Specialist

SPG Blog Post Day 3

Posted in DSS, Lightning Stoplight, LightningCast, SPG2026, Synthetic GXI on May 13, 2026 by Kevin Thiel.

Disclaimer: I had alot of internet and AWIPS issues today :-(. So I mostly got experience with DSS procedures. After IT helped me (Thank you!!) I was able to get some warnings out. I’m sorry for the issues!

Today, we looked at a slight risk out in Idaho. A relatively strong low pressure system with an associated cold front moved through, providing decent parameters for wind concerns in the PIH CWA. This event featured some initially shallow pop-up convection, that quickly blew up to storms that were producing 70-85mph winds over eastern Idaho! Very interesting setup, because the only really notable instability initially noticed was the impressive DCAPE (1000-2000 J/kg), and decent lapse rates. Was hard to notice before reports rolled in, since the storms really did not look impressive on satellite or radar.

Figure 1: WVT (left: colored color map, right: greyscale)

During the quiet period of the event in Idaho, after sending out Slack messages and a briefing slide to partners, I played around with the color maps for the WVT product. This one is based off of a WV map product that SLC uses. You can see the seabreeze move in pretty well during this time frame (lighter green = moisture).
- I sent this color map in the Slack group!

Figure 2: LightningCast Stoplight over PIH

LightningCast was great today for having multiple DSS events!
- This is an image where I made the colormap slightly transparent so you can see the imagery underneath the stoplight colors a bit more clearly.
- What isn’t visible here, was that I had the “0-10” range blinking, to help grab attention quickly.
- I also used the SuperDashboard today! I really liked it – especially when I had AWIPS issued and had to rely on desktop products more than AWIPS.
  - I oddly enough couldn’t get both events on the dashboard at the same time? Both events existed and had links. At first, it was because they started at different times because I had entered the wrong time zone. But, when both events should have been active, only one appeared. The links themselves sent to my email, however, worked just fine!

-Kelvin-Helm

DSS: Max Road Fire

Posted in DSS, Lightning Stoplight, LightningCast, SPG2026, SZA Imagery on May 12, 2026 by Kevin Thiel.

During Day 2 of the Hazardous Weather Testbed, we provided mock-DSS to the Max Road Fire located in South FL along the Broward and Miami-Dade county line. Since this was a DSS event, we evaluated the two most important products related to lightning onset and cessation, LightningCast V1 vs V2 and the Stoplight product, at the fire location making sure firefighters had ample lead to time to seek shelter before lightning struck the area. We also requested an on-demand dashboard display of LightningCast V1 and V2 at the exact fire location to help monitor probability trends of lightning activity.

Figure 1 (above): shows an animation of LightningCast V1 (images on the left) vs Lightning V2 (images of the right). Notice the higher probabilities indicated by V2 on the right of up to 70% vs 50% on the left. It turned out that LC V2 provided a much longer lead time of lightning onset just outside the range ring over the fire location.

Figure 2 (above): shows the Spotlight V2 product (GLM FED + ENTLN combined) confirming lightning activity at 1921Z outside of the 8-mile radius from the fire location.

Figure 3 (above): shows a time series plot showing the probability trends of lightning at the exact location of the fire and also the maximum probability of lightning within the 8-mile radius of the fire location. Lightning was detected by the GLM instrument around 2041Z (image below) when the LightningCast probability trends showed a rapid upward trend in probabilities (image above)

Lastly, the Solar Zenith Angle imagery below provided a clearer view of the texture of the clouds right on the coast just north of Miami roughly an hour before sunset when compared to the traditional imagery on the right.

Figure 1: Solar Zenith Angle imagery at 606 PM EDT, almost two hours before sunset. Sunset at Miami (MIA) was at 7: 58 PM as shown on the Climate Daily Report (CLI) from NWS MFL.

Hurricane Specialist

SPG Blog Post Day 1

Posted in LightningCast, OCTANE Speed Sandwich, SPG2026 on May 11, 2026 by Kevin Thiel.

Today, the group learned about the suite of satellite products that we will be testing. Below I will include some notes on two of the products we learned about during the operations portion of the day.

Figure 1: LightningCast-ECONUS-compare product

During this exercise, we were placed into two different CWAs: MLB and JAX. I was in the MLB CWA, monitoring developing convection over the FL peninsula, as a frontal boundary moves through to the north. There was a marginal risk, per SPC guidance.
Above is the LightningCast ECONUS comparison product. The top two panels used GOES-19 satellite imagery, while the bottom two panels used MRMS data. The left panels are V1 of LightningCast, and the right panels are V2.
- I noticed that V2 improved on noise reduction, with low percent chances of lightning being more confined to developing storms. V1 seemed to have some low percentages over clouds that looked like low level cumulus, but V2 fixed that.
I really liked how this product highlights areas of active storms, and where the best chances of thunder are next. I find the extent of the LightningCast product to help for DSS purposes, as I have an idea on what areas ahead of the storm should prepare to see lightning.
- The color scale, following SPC categories, works nicely and is easy to interpret, from a forecaster point of view.

Figure 2: Octane CTC

Figure 2 shows the OCTANE Cloud Top Cooling product.
This suite of products became helpful as I began to understand their use.
- The CTC product seems to be very informative on convection development, and differentiating between the various thunderstorm phases. The color scale changes from green, yellow, to red to indicate cloud tops beginning to cool, and are colored at the rate at which they cool every 5 minutes. This way, the user can see where cloud tops are rapidly cooling, and thus where convection is developing/strengthening.
The colormap is relatively easy to understand, from my perspective.
Playing around with the color scale may help to really hone in on developing storms, as from looking around the CONUS, there is a lot of blues and greens. If someone wanted to narrow the scale a little, to reduce the amount of data to sift through, that could help make things a little easier to navigate. I personally don’t mind it, because I think it’s a good way to see general cloud coverage and cloud types.

Kelvin-Helm

Overview: Week 2, Day 1

Posted in Daily Summaries, Lightning Stoplight, LightningCast, OCTANE Speed Sandwich, SPG2026, Synthetic GXI, SZA Imagery on May 11, 2026 by Kevin Thiel.

10 AM

Week 2 of the Satellite Experiment kicked off this morning, with a fresh batch of forecasters and a recharged group of developers. Convection was difficult to find unless you were along the Gulf or Atlantic coasts, and with marginal deep layer shear the potential for severe weather was also also categorized as Marginal from SPC in its 13Z outlook. After our orientation session, the forecast discussion today was focused on western Louisiana, Florida, and the Carolinas. Ultimately we decided to localize to the NWS offices in Jacksonville, FL (JAX) and Melbourne, FL (MLB) with the expectation that upstream convection and land-sea breeze interactions could initiate and sustain convection throughout our operations window (18-22 Z).

1 PM

Operations kicked off with the developers providing hands-on demonstrations and walk-throughs with the forecasters. With a slower severe weather pattern on the first day, we encouraged everyone to think of today as a ‘training day’. Forecasters asked several questions about the synthetic GXI imagery, such as the heights sampled by the 0.91 and 5.15 µm bands, the impacts of snow cover, and how the synthetic products compare to the real 0.91 µm imagery from FCI. We also talked about making RGB products from the synthetic imagery, and realized that the imagery specialists at CIRA had taken the liberty of remapping the products to the ABI 2km grids (kudos!). I’m hoping to create some RGBs this week that we can play with and improve on. What would forecasters like to see in an RGB? Moisture by height? Low level boundaries?

2 PM

We got an MD from SPC! Not a great chance for a watch, but good to know some severe risk exists in our CWAs.

4 PM

The rest of the operations day was pretty slow, so I spent some time working (arguing?) with AWIPS to make an RGB for the Synthetic GXI data. It’s a work in progress…

Found an interesting case of dissipating and initiating convection form the perspective of LightningCast v2 and Lightning Stoplight v2 further west near the Alabama coast. You can watch the probabilities drop and the stoplight transitions from red to green for the dissipating storm, while probabilities increase shortly before the first lightning flashes. Lots of anvil debris to obscure the signal of initiating convection in this example, but there appeared to be at least some lead time by LightningCast before the first lightning flashes appeared from the Lightning Stoplight.

A nice thunderstorm went up east of Jacksonville, with a notable cooling signature from the OCTANE-CONUS Cloud-Top Cooling product. I compared that with the OCTANE-MESO product, and may encourage forecasters to do the same later this week.

To wrap up, I decided to explore all the flavors of the Day Cloud Phase Distinction RGB with a procedure I called ‘oops-all-dcpd’.

Upper Left: GOES-19 CONUS
Upper Right: OCTANE MesoAnywhere (from GOES-19 CONUS)
Lower Left: SZA (from GOES-19 CONUS)
Lower Right: GOES-19 MESO

Kevin

Cirrus over I-10 Cold Front, Cirrus, Anvils: Lake Charles, LA

Posted in Lightning Stoplight, LightningCast, OCTANE Speed Sandwich, SPG2026, Synthetic GXI, SZA Imagery on April 30, 2026 by Kevin Thiel.

Today was a very marginal day as a majority of the CWA was covered in cirrus and then later anvils from nearby thunderstorms. This inhibited much of the solar heating potential with the exception of a small corridor from Lake Charles to Lafayette along I-10. The thermodynamics was not impressive across the area with only 1000 to 2000 j/kg of CAPE. Much of the convective initiation relied on a weak cold front and a sea breeze. There were some thunderstorm complexes that had moved through the area which brought lightning concerns to our two DSS points. Towards the end of the afternoon we were finally seeing convective initiation along the cold front.

With clouds contaminating many of the satellite products, today was mainly focused on lightning cast, lightning stoplight, and seeing how they interact with each other. We found some issues with the stoplight product today. The stoplight product was putting an active grid box that was not co-located with the lightning strike that reported from the lightning detection system. In the image below there is a small purple cross outside of the lone red box.

Final thoughts:

Every product we worked with this week has potential to make an impact. From extending daylight rgb products using a solar zenith adjustment, to using lightning cast and lightning stoplight to help make DSS decisions. OCTANE is a massive improvement for helping to forecast the state of convection. While there are limiting factors like clouds, overall the product could quickly make an impact diagnosing convection and being able to see how correct the models are handling the shear profile. The 0.91 and 5.95 products when operational could be used as ground truth in order to identify the boundaries, and being able to compare that with the models will help with getting those first few storms correct.

-Blizzard

EWP Blog

Spring Experiments & Beyond

Category: LightningCast