Monitoring Downburst-Producing Thunderstorm Development in Southwestern Kansas

 Convective Initiation and Multi-Sensor Signatures

Our analysis begins with a compelling multi-sensor perspective of a vigorous, multicellular, high-based thunderstorm cluster rapidly organizing over southwestern Kansas as depicted in Figure 1. By analyzing a composite of the GOES-19 Cloud Phase Distinction product, LightningCast probabilities, and MRMS base reflectivity, several severe storm signatures become immediately evident. The imagery highlights expansive, cold ice-bearing cloud tops and high localized reflectivity cores, which are strongly correlated with high lightning probabilities. Together, these features highlight an environment highly favorable for robust precipitation loading and subsequent severe downburst generation, specifically targeting the communities of Liberal and Meade, Kansas.

Figure 1: Composite image of GOES-19 SZA Day Cloud Phase Distinction, LightningCast lightning probability, and MRMS radar reflectivity at 1951 UTC 14 May 2026.

Cloud Convection and Downburst Validation

Building upon the initial analysis, the Figure 2 shifts focus to a composite view utilizing the GOES-19 Cloud Convection product alongside LightningCast and MRMS reflectivity. This specific combination provides a clear view of the intense convective cores and robust updrafts associated with the cluster. The impressive convective depth and structural characteristics identified in this imagery directly foreshadowed the surface wind impacts. Validating these satellite and radar signatures, sub-severe downburst wind gusts were recorded shortly near 2000 UTC, with a 44-knot gust observed at Liberal, KS, and a 47-knot gust recorded at Meade, KS.

Figure 2: Composite image of GOES-19 SZA Day Cloud Convection, LightningCast lightning probability, and MRMS radar reflectivity at 2001 UTC 14 May 2026.

Thermodynamic Analysis (GOES-19 & RAP Model)

To understand the thermodynamic drivers behind these severe downbursts, we evaluate the 1900 UTC sounding profiles near Liberal, Kansas. A comparison between GOES-19 derived soundings and the RAP model output in Figure 3 reveals excellent agreement, with both platforms depicting a classic 'inverted-V' thermodynamic profile. This signature, characterized by a deep, dry sub-cloud layer beneath a moist convective layer, is a textbook indicator for evaporatively generated downbursts. Additionally, both profiles show wet-bulb zero heights near the 650-mb level. The integration of these parameters via the Microburst Windspeed Potential Index (MWPI) yielded a calculated Wind Gust Potential (WGP) of 60 to 64 knots, accurately emphasizing the high downburst wind threat.

Figure 3. GOES-19 and RAP model sounding profiles retrieved near Liberal, KS at 1900 UTC 14 May 2026.

Observational Ground-Truth (Dodge City RAOB)

Further solidifying the thermodynamic assessment, the 1800 UTC radiosonde observation (RAOB) launched from nearby Dodge City, Kansas, and shown in Figure 4, serves as critical observational ground-truth. The RAOB data supports the signatures identified in the GOES-19 and RAP model soundings from Figure 3. Featuring the same pronounced inverted-V profile and substantial sub-cloud dry air, the Dodge City sounding confirmed that the regional atmospheric environment across southwestern Kansas was broadly primed for high-based convection and efficient, momentum transfer and severe downburst wind generation.

Figure 4. RAOB sounding profile retrieved at Dodge City, KS at 1800 UTC 14 May 2026.

-StormRangerWX

Dry Signal East of Developing Dry Line?

 An interesting signal developed in the GeoXO synthetic Water Vapor Transmittance (WVT) imagery today across Texas. Higher reflectance values (brighter colors in the WVT) were sandwiched between lower values, both to the west and east, in Central TX.

Figure 1: 4-panel with GeoXO synthetic imagery (5.15 band - top left, WVT - top right) and GOES-19 imagery (IR - bottom left, VIS - bottom right) at ~1800 UTC 14 May 2026.

At first, this signal seemed a bit counterintuitive, as the dry line was expected to develop in western TX, based on today’s briefing and the SPC Convective Outlook. However, when taking a look at the Advected Layered Precipitable Water (ALPW) product at nearly the same time (1800 UTC 14 May 2026), there’s noticeably higher moisture in the 850-700 and 700-500 hPa layers across West TX and New Mexico, and to the east near the TX/LA border.

Figure 2: 4-panel CIRA ALPW at 1800 UTC 14 May 2026.

A 1700 UTC HRRR forecast run, valid for 1800 UTC, just southeast of the TX Panhandle, showed this sharp reduction in moisture in its sounding near 850 hPa. Farther west, this sharp reduction is not evident. Perhaps the dry air around 850 hPa resulted in this counterintuitive WVT signal in TX.

Figure 3: HRRR sounding over North-Central TX at 1800 UTC 14 May 2026.

Figure 4: HRRR sounding over the Texas Panhandle at 1800 UTC 14 May 2026.

-csmith70

SPG Blog Post Day 4

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

LightningCast and Stoplight Chart Comparison

 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

High-based convection over western Kansas Blog Post

 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

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!

Squall Line Development over western Pennsylvania

 The issuance of Mesoscale Discussion #708 by NWS/Storm Prediction Center at 1641 UTC established the main area of focus for thunderstorm downburst wind generation as the plateau and Allegheny Mountain region of western Pennsylvania and northern West Virginia. The latest multi-sensor analysis in Figure 1 captures the rapid development of a squall line along an eastward-advancing cold front in western Pennsylvania. This convective system consists of vigorous multicellular storm clusters that appear prominently in both MRMS reflectivity and GOES-19 cloud convection imagery. A significant diagnostic feature is the high lightning probability within the storm cores. This enhanced electrical activity underscores the robust updraft strength and high liquid- and ice-phase water content, creating a highly favorable environment for severe downburst generation as these convective cells mature.

Figure 1. GOES-19 day cloud convection, LightningCast lightning probability, and MRMS radar reflectivity at 2000 UTC 13 May 2026.

Atmospheric profiling from Pittsburgh (PIT) area ACARS and RAP model soundings (1700–1800 UTC) in Figure 2 show strong consensus for severe wind potential. Both platforms exhibit classic "hourglass" profiles, characterized by dry air in the low-to-mid levels flanking a moist convective layer. Wet-Bulb Zero (WBZ): Positioned near the 750-mb level, enhanced melting-induced cooling and downdraft acceleration. WGP: MWPI-derived Wind Gust Potential ranging from 38 to 44 knots. This thermodynamic environment directly supports the concurrent GOES-19 Microburst Risk (MBR) imagery, which indicates moderate downburst potential over southwestern PA. Shortly after 2000 UTC, thunderstorm downburst wind damage was observed in the Morgantown-Fairmont, WV area near the southern terminus of the squall line.

Figure 2. ACARS and RAP model sounding profiles near Pittsburgh, PA compared to an eastern U.S. sector IR BTD product image during the afternoon of 13 May 2026.

-StormRangerWX

SPG Blog Post Template Day 3

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

OCTANE Cloud Top Cooling with Shallow Convection

 Convection over the PIH CWA was fairly shallow today due to the limited instability. That being said, strong DCAPE developed, owing to pronounced Inverted-V profiles. The line of storms that developed was able to produce significant wind gusts, with multiple reports of 70 to 80 mph winds.

Satellite products were not particularly helpful in knowing what storms to issue warnings on due to the shallow nature of the convection. The loop below shows visible, IR, and water vapor imagery for the area of interest around the time we issued our first warning.

Figure 1 - Satellite imagery over the PIH forecast area around the time of warning issuance.

The thing that really stands out is that everything looks about the same. No single storm stands out as being particularly tall or possibly severe. The same is true when we look at the OCTANE Cloud Top Cooling product.

Figure 2 - Cloud Top Cooling around the time of warning issuance.

There was never a value of more than 3°C per 5 minutes over any of the developing convection, indicating the weak instability present. This doesn’t help much in figuring out what storms we need to focus on.

So we turned to radar. The KSFX radar showed an area of 50 knots inbounds associated with an area of higher reflectivity. This led to us issuing the first severe thunderstorm warning of the day.

Figure 3 - KSFX radar loop showing base velocity around the time of warning issuance.

After this, it became clear that almost any shower in the area was capable of producing severe wind gusts due to the favorable low-level thermodynamics and we began looking for similar looking signals in the satellite and radar products. We then issued several more severe thunderstorm warnings as the line progressed eastward.

-ei2018

Severe Weather over western Pennsylvania

 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

Cloud Obstruction with Octane Products

 A cold front swept across Western Pennsylvania and Northern West Virginia with a line of strong to severe thunderstorms that produced hail and wind damage. One thing to note about the Octane Cloud Top Cooling (CTC) imagery is that the anvil cirrus masked other storms in its wake. This might be a limiting factor for the Octane imagery, especially in linear storm events.

Figure 1: Anvil Cirrus was blown over other storms to the northeast and masked some overshooting tops/cloud top temperatures.

Shortly after, we noticed a similar problem so we then looked at the Octane Speed and Direction products in the mesosector. It is easier to make out the individual updrafts in these products as they appear less washed out and more defined. In this case, you can see 2 separate storms, one near Hundred, and one near Blacksville. These produced wind damage in northern West Virginia.

Figure 2: Octane Direction imagery in the mesosector.

Figure 3: Octane Speed imagery in the mesosector.

After seeing the initial problem, we changed the color table slightly in order to see if we can mitigate the masking issue. I personally like this color table more than the original but it still has the issue of masking other storms under the anvils. It is definitely easier to see individual storms but not as easy as the Octane Direction/Speed products.

Figure 4: New color table for the Octane CTC product.

-Batman

Overview: Week 2, Day 3

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