Category: Synthetic GXI

SPG Blog Post Day 4

Posted in LightningCast, OCTANE Speed Sandwich, SPG2026, Synthetic GXI on 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

Tags: None

Overview: Week 2, Day 4

Posted in Daily Summaries, SPG2026, Synthetic GXI, SZA Imagery on by Kevin Thiel.

10AM

Thursday began with another group discussion, focusing on the following topics:

  • When to give the ‘all clear’ using the Lightning Stoplight tool
  • The limitations of satellite imagery and OCTANE-CONUS products on days with lots of convective anvil debris overtop developing convection, obscuring signals of stronger updrafts.
  • Playing with the color bars for the WVT product and finding what ‘works’ for showing different moisture boundaries like dry lines and sea breezes.
We played another round of ‘When does the satellite imagery become useful/useless?’ with the SZA imagery. This time we viewed a sunrise over the Mid-Atlantic with the 0.64 µm (ABI Channel 2) visible band, and forecasters stated when the imagery became useful. Here’s the results…
  • SZA Imagery: 0956 Z (x3), 1006 Z
  • Traditional Imagery: 1026 Z (x4)
SZA Imagery

Traditional Imagery

After a full week of MRGL and SLGT events, we were rewarded with…another SLGT! Surface moisture and instability was difficult to come by over nearly the full CONUS, and we relied on moisture transport from the Pacific front and sub tropical jet. Oddly enough this was positioned behind the dry line, which led to some large inverted-V forecast soundings and downburst potential from elevated thunderstorms. The 1630Z SPC convective outlook had a Slight Risk in the Central and Southern Plains, driven by a 15% CIG1 risk in SW KS and the TX panhandle. We decided to localize to the Goodland, KS (GLD) and Dodge City, KS (DDC) NWS offices today (Note: Later GLD office moved to Amarillo).

1 PM

Early on forecasters sent DSS messages to their mock events and waited for convection to develop. In the GLD office some convection tried to form in far-eastern CO, but dissipated and was unable to sustain itself. OCTANE-CONUS CTC showed low cooling values (<10C) and LightningCast was showing lower probabilities. Conversation moved to the Synthetic GXI imagery, and observing the moisture from the mid-level jet across the Southern and Central Plains. The group compared the 5.15µm Synthetic GXI band with the ABI 7.34 µm (Channel 10) IR band designed for ‘Low Level’ water vapor.

3PM

Decided to move the GLD office to Amarillo (AMA) after observing minimal instability in their CWA, and a more agitated cu field on the western edge of the AMA CWA. SPC also issued an MD and subsequent severe thunderstorm watch for the DDC and AMA forecast areas, which reinforced our thinking that convection would be focused further south during our forecast period.
4PM
After some discussion with the DDC forecasters and some developers, we made vis-IR sandwich procedure that mimicked the ‘oops all Day Cloud Phase Distinction RGB’ procedure. The motivation was that once convection gets going, forecaster may liked to transition away from the DCPD RGB and to imagery with more direct visible and infrared information.

5PM

At the very end of the day, we talked about the SZA imagery some more and its applications for OCONUS users in places like Alaska. While roaming the CONUS comparing SZA and traditional imagery, a developer pointed out a large blowing dust event in ND, which was evident even in the DCPD RGB, along with the Channel-2 visible imagery.

That’s a wrap for week 2!

-Kevin
Tags: None

SPG Blog Post Day 3

Posted in DSS, Lightning Stoplight, LightningCast, SPG2026, Synthetic GXI on 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
Tags: None

Overview: Week 2, Day 3

Posted in Daily Summaries, OCTANE Speed Sandwich, SPG2026, Synthetic GXI, SZA Imagery on by Kevin Thiel.

10 AM

Wednesday presented a ‘7-10 split’ of severe potential, with thunderstorms expected in the Great Basin and Mid-Atlantic regions. Most of this was driven by a Slight Risk from the 13 Z SPC Convective outlook, driven by 15% CIG1 wind probabilities. Timing and moisture were a little less certain out west, while convection was more certain in the east but had limited deep instability and subsequent severe weather potential. After some discussion, we localized to the Pittsburgh, PA (PBZ) and Pocatello, ID (PIH) offices.

During the morning discussion we played the same comparison game between the SZA and traditional imagery, but this time for the upper great lakes region around sunset on Tuesday, using archived imagery from CIRA-SLIDER. Forecasters were asked when the imagery no longer became useful to them, and here’s their reported times when looking at the same loop between 21 Z and 02 Z.

  • Traditional: 2156 Z, 0001 Z, 0001 Z, 0021 Z
  • SZA: 0111 Z, 0111 Z, 0111 Z, 0111 Z

Here’s the loops so you can play along at home! (Sorry these are really big GIFs, the blog didn’t like the when I converted them to MP4 format)

Traditional Day Cloud Phase Distinction RGB

SZZ Day Cloud Phase Distinction RGB

1 PM

Forecasters in the PBZ office were thrown into a situation where convection was already developing in the western side of their CWA, and they began issuing warnings, investigating OCTANE, and sending DSS messages to their mock-events.

In the PIH office storms were slow to get going, so we looked at some imagery from the FCI and the synthetic GXI imagery from the HRRR. One target we casually watched throughout the day was a dry line in the TX panhandle, and we compared them to moisture boundaries in Europe and north Africa.

3 PM

PIH was issuing warnings by this time, and frequently relied on radar imagery and knowledge of the environment when making warning decisions. When looking at the OCTANE CTC product and other satellite imagery, the presentation of most storms were not impressive.
In the PBZ office, the forecasters noted that the OCTANE CTC product was limited in its application due to dense cirrus and anvil debris obscuring cooling signals in the ABI infrared bands. In the OCTANE Speed Sandwich however, the forecasters found the speed values and textures from visible imagery easier to view new and intensifying updrafts. This resulted in some discussion about how to ‘train’ for this.

By the end of the day, a number of severe wind reports appeared across the PIH CWA from their mesonet, while in PBZ a single hail report was featured. More reports may come in tonight or tomorrow?

-Kevin

Tags: None

SPG Blog Post Day 2

Posted in OCTANE Speed Sandwich, SPG2026, Synthetic GXI, SZA Imagery on by Kevin Thiel.

Today, forecasters were located over the MLB and TBW CWAs for a marginal risk over the FL peninsula. Stationary frontal boundary right over the peninsula, with some sea breeze boundaries right along the coastline. Today, I was simulating a forecaster at the MLB office.

Figure 1: SZA Comparison ECONUS Product

  • Around 18Z, I noticed the SZA product had better resolution for analyzing cloud top structure, and picking out some finer details.
    • The SZA and RGB product became more similar later in the afternoon, which is expected. Resolution began to improve on SZA compared to RGB closer to sunset.
Figure 2: OCTANE CTC
  • The CTC product was great for identifying rapidly developing storms during this event. There was one impressive cell that developed by Kissimmee, and the CTC product highlighted these cloud tops very well.
    • From a forecaster perspective, it helped me to pinpoint an area that needed further analysis, and my team and I decided quickly afterwards that a warning needed to be issued for this storm.
    • The speed product was also helpful for visualizing storm motion. Rescaling the product back out to the CONUS scale helped put into perspective where faster moving storms were located.
  • Additionally for the OCTANE suite, I paired the MesoAnywhere, LightningCast spotlight, and MRMS data in a perspective. In this perspective, I had the “red” 0-10 minute values flashing, and semi-transparent, so you could see the data below the stoplight.
    • Stoplight was very helpful in the DSS realm. I used it for a quick guide to respond to partners about event precautions.
Figure 3: WV/WVT/IRob/VISob Compare 4 panel
  • Something very interesting that was noticed on the WVT imagery, was sea breeze moisture moving in on the FL east coast. I toggled with the colormap a little bit, making the minimum be 0.2, and the maximum be 1. This makes it a little easier to watch the darker colors, representing the moisture, move in from the ocean. Very interesting feature to capture on the simulated satellite imagery!
    • The 5.15 imagery did not seem to capture this as well, which makes sense as the sea breeze was probably a very shallow feature.
Kelvin-Helm
Tags: None

Overview: Week 2, Day 2

Posted in Daily Summaries, OCTANE Speed Sandwich, SPG2026, Synthetic GXI, SZA Imagery on by Kevin Thiel.

10 AM

Tuesday began with a group discussion and first impressions for the five experimental products. Topics included how forecasters applied LightningCast and the Lightning Stoplight, OCTANE Cloud-Top Cooling for monitoring updraft strength, and the value of SZA imagery near sunrise to observe low clouds and fog. I showed an example of the SZA Day Cloud Phase Distinction RGB on CIRA-SLIDER, with clouds and storms across Florida around sunrise. I asked the forecasters to identify what time the imagery became ‘usable’ for them, and compared it against the traditional imagery of the same scene. Here were the results:

  • Traditional imagery: 1131 Z, 1141 Z, 1151 Z, 1206 Z
  • SZA imagery: 1051 Z (x3), 1101 Z

I’m hoping to run a similar experiment with SZA imagery near sunset tomorrow. Here’s the imagery I showed today. When do you think each imagery becomes ‘usable’?

Traditional Day Cloud Phase Distinction RGB

SZA Day Cloud Phase Distinction RGB

We jumped into our forecast discussion, which asked the question ‘Can we avoid going back to Florida again?’ Unfortunately that answer was NO, so we localized to NWS Melbourne, FL and NWS Miami, FL.

 

 

1 PM

Shortly after ops started SPC issued an MD for the Florida peninsula.

Forecasters in the MFL office talked about providing DSS with LightningCast and Lightning Stoplight, and noticed in the OCTANE MesoAnywhere product how cirrus motions aloft cloud interfere with low cloud motions. MesoAnywhere is on the left, ABI MESO imagery is on the right.

Forecasters in the MLB office issued a handful of warnings, and we had a discussion about the OCTANE-CONUS Cloud-Top Cooling product. While the OCTANE MESO products showed more information, forecasters still found the OCTANE-CONUS products useful if a MESO wasn’t availalble in this case.

Late in the day we viewed the frontal boundary in KS where storms might initiate this evening through the Synthetic GXI products, namely the 5.15 µm and WVT products. We compared them with the ABI split window moisture field (10.3-12.2 bands) and the ALPW from JPSS. In talking with another developer, we got the idea to create a ‘sandwich’ product that meshes the WVT and ABI Split Window products.

-Kevin

Tags: None

SPG Blog Post Florida Convection 05-11-2026

Posted in OCTANE Speed Sandwich, SPG2026, Synthetic GXI on by Kevin Thiel.

Deep convection was hard to come by in Florida on May 11th, 2026 but a weakening storm did move over a land breeze boundary along the coast during the late afternoon and into the evening. The land breeze was visible on the GeoXO viewer and can be seen as a buildup of moisture along the coast which then dissipates around 2200z. Figure 1 shows this buildup of moisture very well.

Figure 1: Land breeze moisture build up along the East Coast of Florida.

As a weakening thunderstorm traversed over the boundary, it was reinvigorated and strengthened rapidly. This can be seen below on Figure 2. A thunderstorm moved over the boundary, seemingly absorbed the moisture at the boundary and developed deep convection over the ocean.

Figure 2: A thunderstorm moved over a land breeze boundary and restrengthened.

Batman

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Florida Convection – May 11 2026

Posted in SPG2026, Synthetic GXI on by Kevin Thiel.

Today we examined several experimental satellite products, LightningCast V2, Synthetic GXI, and Solar Zenith Angle – Adjusted (SZA) Imagery, OCTANE, and Lightning Stoplight over north central Florida. It was a relatively quiet convective day across the CONUS, especially for mid May with the only area of significant convection over north central Florida.

While I was already very familiar with the LightningCast V2, the Stoplight and the SZA imagery, the product that sparked the most interest to me or was most excited about its future capabilities  was the synthetic GXI imagery, which uses the 0.91 µm and the Water Vapor Transmittance (WVT) or the ratio of the 0.91 µm/0.86 µm channels.  Once these two new channels become available on the Next Generation of GOES satellites, GeoXO, I believe these two new products will become extremely useful in determining moisture gradients or moisture pooling and it would be of greater utility than the current Split Window Difference (SWD) product available from the current GOES Advanced Baseline Imager (ABI). In particular, the WVT image below (top right panel) clearly showed a moisture gradient (darker colors representing higher TPW vs brighter color colors representing lower TPW) associated with a cold front sinking into the Gulf Coast states.

Figure 1 (above): Four Panel Display of GeoXO imagery showing the 5.5 µm and the WVT products at the top left and right respectively, and the “Clean” Window IR and VIS channels at the bottom left and right respectively.

Figure 2. WPC Surface Analysis valid 18 UTC Mon May 11 2026 showing cold front extending from the Carolinas southwestward to the Gulf Coast states to along the U.S.- Mexico border.

Hurricane Specialist

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Overview: Week 2, Day 1

Posted in Daily Summaries, Lightning Stoplight, LightningCast, OCTANE Speed Sandwich, SPG2026, Synthetic GXI, SZA Imagery on 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
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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 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

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