Last Impressions

 SZA

Love it! Can’t wait for it to be implemented. The amount of detail that can be ascertained both earlier in the morning and later in the evening is unbelievable. Main applications in my area would be for fog detection and snow squalls. While maybe a bit niche, the snow squall phenomenon is always a challenge. It’s a shallow feature that really ramps up in the afternoon and evening hours. If it’s too far out our radar really can’t pick up on it and the day cloud phase is often one of the best tools for tracking.

OCTANE

Continues to impress! The cloud top cooling tool remains a slam dunk for identifying cells that are quickly growing upscale. The example below shows further cooling after a decent anvil had already developed. 

Image below is from the same time above 2112Z

8 minutes later the storm looks to be producing hail

Lightning Cast

Another solid product. I didn’t notice too much difference between the two versions but the parallax fix is very welcome. I personally won’t use the dashboards as I like to see the data overlaid with satellite and radar. Just seeing a chart with numbers moving doesn’t work for me. However, if I would recommend adding a sound feature to the dashboard. The only other suggestion I have is using less contours. I prefer the 10, 25, 50, 75 that are already in AWIPS.

Lightning Stoplight

First time ever using this tool but it will definitely become a mainstay in my arsenal for helping with DSS. I really don’t have a lot of feedback to give. The tool is simple and easy to use. I like overlaying radar on top of it in my procedures and I’m neutral to the idea of changing green to blue.

Geoxo products

These were neat to look at over Africa and Europe, but I found myself really struggling to use them stateside. I may need more training to fully understand the benefits of the synthetic satellite data, but I can’t see myself using it. I already have a ton of different CAMs I can look at, so I’m not sure I understand the benefit of looking at the synthetic satellite. I do have high hopes for the WVT tool though. The color table is very difficult for me to tease out what I need from it though. I tried manipulating the ranges a few times and also changed dry to brown and moist to green, but it still seems pretty difficult to pick out features for myself. What I really want is something to help me track boundaries. Jason shared a really neat animation over Africa that highlighted boundaries very neatly, would love to see if that could be implemented somehow. My end goal is I want to see moisture boundaries from lake breezes, decayed thunderstorms, or different moisture fields such as evapotranspiration

IsthataTOR

Running with SZAs: Lessons to Carry Forward From the Spring 2026 SPG

 Today marks the final testing day of the 2026 Satellite Proving Ground. It has been an illuminating week for myself - a pun we’ll get back to in a second. But first, some serious business. The Satellite HWT has proven to be a beneficial experience for a multitude of reasons. Foremost of those is the opportunity to test and help shape development on a whole new generation of satellite-based forecaster tools. But one shouldn’t discount the benefit that comes from the process, the collaboration, and the chance to work with scientists one might not get to meet otherwise. For me at least, this collaboration has been the most satisfying part of the week. A sincere thanks to the organizers, developers, and other forecasters who have made this week such a treat.

Ok, now back to the pun. This has been an illuminating week testing out five different satellite-based tools. The one tool that I haven’t shared imagery from this week is the SZA azimuth-corrected imagery. There’s a simple reason for that: it is designed to increase the visibility of day-cloud satellite products in low light scenarios around daybreak and dusk. The actual experimental time for this project is from early-to-late afternoon across the CONUS. Not exactly an ideal time.

So with that in mind, one of the first things I did today was to check in on SZA imagery from off the coast this morning. This side-by-side comparison of Day Cloud Phase between SZA and non-corrected imagery shows how powerful of a tool this could be.

Figure 1: SZA-corrected Day Cloud Phase (left) and non-corrected imagery (right) over the Atlantic Ocean early this morning

It’s one thing for Day Cloud Phase to gain more definition in the updraft/anvil pinks right at daybreak. That is valuable, but only so much. We already kind of know what’s happening at that level. The forecaster can benefit so much more from increased brightness right by the surface, where dynamic processes and even the texture of the clouds can help us discern so much.

I spent most of today as the “warning operator” at the Topeka simulated WFO. This meant I wasn’t experimenting with satellite products as much as I was testing how they could be used in warning operations to increase confidence in severe impacts from a thunderstorm. Invariably, my real-life operations rely on Day Cloud Phase as just one of the best products to detect vertical motion trends within convection. There are multiple forms of Day Cloud Phase that one can use within this experiment. I am particularly intrigued by MesoAnywhere’s ability to level the playing field, so to speak, when Mesoscale sectors aren’t available for the GOES satellites. Unfortunately, I did not proof the gif pulled off of AWIPS to try and demonstrate that point, and it is not time-matched between different products.

Figure 2: A gif that I did not realize was going to be frame-unmatched showing the three different types of Day Cloud phase available without a meso sector

The products that we tested this week all have the potential to enhance operations in the NWS. I look forward to reviewing them with my colleagues in the weeks to come.

Sabrina Carpenter

Overview: Week 3, Day 4

The final operations day of the testbed began with our last daily debrief session, and we talked a bit about the applications sounding information with respect to the future GeoXO mission. The forecast for today was...meh? We had storms in the forecast, but the environment during our operations was marginal for severe weather overall. One office was localized to Billings, MT (BYZ) to capture developing thunderstorms closer to the jet streak, while a second office was localized to Topeka, KS (TOP) close to a remnant MCV that was kicking off convection already by 16 Z. Both offices got two mock-DSS events again today. If thunderstorms were looking unlikely to form in the Billings CWA by ~20Z we planned to move them to the Miami, FL office. Thank you Florida for being our safety net for thunderstorms.

Two MDs were issued by SPC during the afternoon for our forecast areas, with one resulting in a severe thunderstorm watch.

With Jonny's help I made a 'test RGB' from the Synthetic GXI imagery. There's no physical basis to the RGB (yet!), but it was a proof of concept that we could do it. An example and the recipe is shown below. What features can we pull from this new imagery relative to water vapor at low levels and through the entire column? Maybe we can figure it out in future testbeds!

During operations, I showed forecasters another example of SZA imagery over California with the impacts of the marine layer with low clouds and fog. Forecasters also compared this imagery against the Nighttime Microphysics to see how long the 'gap' was between the two, and what features you could identify with each product. Additionally I found a case from a fire from sunrise through the lens of the Day Fire RGB.

Kevin

LTG DSS with LTG Cast and Stoplight

 Upon starting the shift we had a supercell that was about 1 hr out from our first event. In operations our DSS forecaster would have immediately informed our partner that the cell (which had 1” hail report) is barreling in from the southwest.

Both versions of the LTG cast were providing a 70% chance of LTG within the next hour as well, with convection out ahead of the main supercell the heads up notification would also have included this information.

45minutes later we had our first lightning strike onsite ahead of the main supercell.

—---------------------------------------------------------------------------------------------------------------------------

Activity began to wind down by 2030Z

An all clear call would have been made at 2100Z with the stoplight product largely vacant of any lightning detection. MRMS-10C was also outside of the 8mile range ring with little build up expected upstream. Lightning cast had also dropped to around 10%.

IsthataTOR

Overview: Week 3, Day 3

Day 3 started with our debrief from Tuesday, along with a focus group activity for GeoXO lightning mapper capabilities. I showed forecasters SZA imagery near sunrise during a period of glare from the GOES-East perspective near sunset. Overall forecasters felt the cloud tops were more 'washed out' by the brighter visible channels, but mentioned the important feature from the Day Cloud Phase Distinction is often the cloud phase before the overspreading anvil cloud begins. 

Traditional Day Cloud Phase Distinction RGB

SZA Day Cloud Phase Distinction RGB

Wednesday targeted the Northern Plains again, with the cold front being are only source of lift and deep layer shear that we can pull from this week. We decided to localize the forecasters to NWS Grand Forks, ND (FGF) and Aberdeen, SD (ABR), and each had two DSS events so they could leverage the LightningCast SuperDashboards.

1PM

Storms were slow to develop early in the forecaster period with a bit of cloud cover making the Synthetic GXI imagery less usable, so the product developers took both offices on a 'tour of Europe' showing off the Water Vapor Transmittance product from the Meteosat-12 FCI. This led us back to the states where we talked more about colormaps for WVT and what forecasters preferred. I made a display as part of that discussion. Upper left is WVT with 'flipped' colormap, upper right is WVT with the origional colormap, lower left is WVT with a red-green colormap made by a forecaster in the previous week, and the lower right is PWATs from the most recent HRRR run (18Z).

 2 PM

Forecasters in both offices focused mostly on DSS tasks early in the forecast period, along with comparing OCTANE's CONUS and MESO products. Additional discussion centered around the Lightning Stoplight tool and debating the 'optimal' color table to convey the intended actions from those viewing the product.

As thunderstorms approached the mock-IDSS events forecasters interrogated LightningCast data and discussed its applications, along with the desire to have variable ranges for the dashboard web display. We did run into an interesting case where a thunderstorm initiated over a narrow band of cirrus clouds, which may have impacted signals from OCTANE and LightningCast.

To end the day, I spammed AWIPS looking for sunrise imagery to show off SZA (thanks Justin for turning on the feed so early!)

Fog and low clouds from the marine layer along the California coast from the Day Cloud Phase Distinction RGB (SZA left/traditional right)

Valley fog over the Appalachian Mountains in the morning from the Day Snow Fog RGB (SZA left/traditional right).

Kevin

Persistent Severe MCS and Downbursts in Southwestern South Dakota

 1. Convective Initiation & MCS Evolution (1900 UTC)

The early afternoon of 2 June 2026 was marked by the development of a persistent mesoscale convective system (MCS) over Fall River County, SD as shown in Figure 1 below.

Satellite Observations: The 1900 UTC composite satellite image shows the system advecting east-northeastward, exhibiting rapidly increasing ice-phase cloud tops and a significant rise in lightning flash rates.

Structural Signatures: At this stage, the MCS already exhibits a well-defined bow echo complex and a prominent rear-flank dry-air notch. These features indicate
that the system is efficiently processing dry mid-level air to generate strong surface outflows.

Figure 1: Composite SZA cloud phase distinction, MRMS reflectivity, and LightningCast probability product image at 1900 UTC 2 June 2026.

2. System Intensification and Dual Bow Echoes (2030 UTC)

By 2030 UTC, Figure 2 shows the convective complex underwent further intensification and expansion as it tracked across southwestern South Dakota.

Complex Organization: The system evolved into a more formidable MCS consisting of two distinct bow echo complexes.

Severe Potential: Each bow echo was accompanied by its own rear-flank dry-air notch. This dual-notch presentation signaled a marked increase in downburst potential, as the system became increasingly organized and capable of producing widespread damaging winds.

Figure 2: Composite SZA cloud phase distinction, MRMS reflectivity, and LightningCast probability product image at 2030 UTC 2 June 2026.

Figure 3. Comparison between the GOES-19 (G19) sounding retrieval 90 km SSE of Rapid City, SD (left) and the Rapid City (UNR) RAOB sounding at 1800 UTC 2 June 2026 (right).

3. Thermodynamic Environment: Rapid City (1800 UTC)

An analysis of the 1800 UTC environment in Figure 3 explains the high-end wind potential observed.

Sounding Profile: A comparison between the GOES-19 sounding retrieval and the Radiosonde observation (KUNR) at Rapid City, SD, reveals a textbook "hourglass-inverted-V" profile.

Instability & Wind Potential: The environment was characterized by large CAPE (1014 to 1584 J/kg). Correspondingly, the Wind Gust Potential (WGP) was calculated between 41 and 47 knots, providing strong evidence for the severe gusts that followed.

4. Regional Validation & Surface Verification

Regional sounding data further confirmed the widespread nature of this volatile environment.

NUCAPS Comparison: A NOAA-21 NUCAPS sounding retrieved at 1919 UTC approximately 150 km southeast of Rapid City showed excellent structural agreement with the UNR radiosonde (RAOB).

Key Ingredients: Both profiles highlighted favorable wet-bulb zero heights for evaporative cooling and robust downburst generation.

Ground Truth: This thermodynamic setup culminated in a significant surface event: a severe 55-knot downburst wind gust was recorded at Cactus Flats, SD, at 2043 UTC— aligning well with the high WGP and structural signatures identified earlier in the afternoon.

Figure 4. Comparison between the 1919 UTC NOAA-21 NUCAPS sounding retrieval 150 km SE of Rapid City, SD (left) and the Rapid City (UNR) RAOB sounding at 1800 UTC 2 June 2026 (right).

StormRangerWX

Overview: Week 3, Day 2

10 AM

Tuesday began with our morning discussion from Monday's operation/orientation day. Forecasters had plenty of storms to observe yesterday, which allowed everyone to get acquainted with OCTANE. Forecasters talked about the applications of OCTANE data, and one said it can be a 'super tool' for mesoanalysis but also needs 'super users'. For the Synthetic GXI WVT product, forecasters also showed early support for the 'flipped' color table but wanted to see it in action more this week before deciding. First impressions of the Lightning Stoplight and SZA Imagery were also positive, with forecasters finding the Stoplight tool easy to understand and message to partners.

I showed an example of some SZA imagery on CIRA-SLIDER from this morning of river valley fog in the Northeast US. When comparing with traditional imagery and the Nighttime Microphysics RGB, forecasters reacted positively to the 'brighter' SZA imagery and expressed the difficulties of transitioning from day to night when observing fog from their respective home CWAs.

SZA Day Cloud Phase Distinction RGB

Regular Day Cloud Phase Distinction RGB

Nighttime Microphysics RGB

After talking about the GeoXO GXI in our focus group, our forecast discussion for the day sent us back to the Cheyenne, WY (CYS) and Rapid City, SD (UNR) NWS offices to monitor developing storms along a cold front. Forecasters were also assigned mock-IDSS events in Fort Laramie, WY and Sturgis, SD.

1 PM

Similar to Monday, shortly after operations began SPC issued an MD for our area followed by a Severe Thunderstorm Watch.

In the CYS office (still without a radar), discussion focused on their mock-IDSS event and the timing of lightning activity within the event's range ring. With thunderstorms developing upstream of the site, timing dominated the conversation and the forecasters talked about how the LightningCast dashboard helped identify trends, especially if the partner needed more time to execute their safety plans.

The forecasters also looked at OCTANE, and noted that the the MESO Cloud-Top Cooling products showed a decreasing intensity trend while the CONUS CTC product appeared relatively steady.

3PM

The UNR office frequently viewed OCTANE products today, with several severe thunderstorm warnings issued today. Their mock-IDSS site appeared to 'miss' the storms today, but we'll see what they say tomorrow!

I plan to show this to the forecasters tomorrow to get their thoughts. Sorry for spamming the blog with SZA imagery.

-Kevin

Orographic Thunderstorms and Downbursts over Southeastern Wyoming

 Convective Initiation (1900 UTC)

The afternoon of 1 June 2026 has been convectively productive over and east of the Rocky Mountain Front Range of Wyoming and Colorado. The 1900 UTC composite satellite image in Figure 1 below captures the early afternoon development of a complex of strong, orographically-forced and high-based thunderstorms. These cells initially fired over the Rocky Mountain Front Range of southeastern Wyoming. As the system advected east-northeastward, satellite and MRMS data indicated rapid storm intensification, characterized by sharply cooling, ice-phase cloud tops and a significant surge in lightning flash rates. 

Figure 1: Composite SZA cloud phase distinction, MRMS reflectivity, and LightningCast probability product image at 1900 UTC 1 June 2026.

Linear Organization & Downburst Signatures (2006 UTC)

By 2006 UTC, the convection underwent a clear structural evolution into a downburst-producing thunderstorm system. The previously disorganized multicell clusters organized into a short-segment linear complex. Key Feature: The satellite presentation highlights a prominent rear-flank dry-air notch, which is a classic morphological signature of severe downburst potential as mid-level dry air is entrained into the storm's downdraft. Surface Observation: Validating this remote sensing presentation, a severe 52-knot downburst wind gust was recorded at the surface in Bordeaux, WY, at 1958 UTC, just minutes before this satellite scan.

Figure 2. Composite SZA cloud phase distinction, MRMS reflectivity, and LightningCast probability product image at 2006 UTC 1 June 2026.

Figure 3. Comparison between the GOES-19 (G19) sounding retrieval and the Rapid Refresh (RAP) model sounding at 1800 UTC 1 June 2026.

Thermodynamic Environment: Cheyenne Soundings (1800 UTC)

To understand the atmospheric mechanics driving these downbursts, we can analyze the 1800 UTC thermodynamic environment over Cheyenne, WY in Figures 3 and 4. A comparison between the GOES-19 (G19) sounding retrieval and the Rapid Refresh (RAP) model sounding reveals a prominent "hourglass-inverted-V" profile in the lower and mid-troposphere—a textbook thermodynamic setup for evaporatively cooled, severe convective wind gusts.

The associated Wind Gust Potential (WGP) derived from these profiles showed values ranging from 39.2 knots (G19) to 44.5 knots (RAP), which closely aligns with the observed severe gusts in the region.

Regional Corroboration: Denver ACARS Profile (1647 UTC)

Further corroborating the regional environmental setup is an ACARS vertical sounding profile retrieved at 1647 UTC from Denver, CO  (Denver International Airport). When compared to the Cheyenne RAP model sounding, the Denver ACARS data demonstrates excellent structural agreement across the Front Range boundary layer. Specifically, the profile highlights highly favorable wet-bulb zero heights and substantial Downdraft CAPE (DCAPE), confirming a widespread optimal thermodynamic environment for the robust downburst generation observed throughout the afternoon.

Figure 4. Comparison between the Denver, CO ACARS sounding profile at 1647 UTC and the Cheyenne, WY Rapid Refresh (RAP) model sounding at 1800 UTC 1 June 2026.

StormRangerWX

Overview: Week 3, Day 1

 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

Overview: Week 2, Day 4

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!