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
Tags: None

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

Tags: None

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
Tags: None

SPG Blog Post 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
Tags: None

DSS: Max Road Fire

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

Tags: None

Overview: Week 2, Day 1

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
Tags: None

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

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

Tags: None

Final Ops Day – LCH

Started off the day with a cold front moving north towards the Louisiana coast. As discussed previously, GeoXO products don’t do as well with an already cloudy area, however we were able to clearly pick out where the cold front was over the gulf using the 5.15 imagery. Beyond this, I did not use this product again for ops.

Figure 1: GeoXI Imagery on top, GOES imagery on bottom

When looking at the Day Cloud Phase Distinction around 1830Z, I noticed the SZA imagery was much easier to view in terms of picking out cloud top textures vs the MesoAnywhere imagery. On the same topic of SZA, we got to see SZA really shine by looking at an area of bubbling convection that occurred around sunrise. The difference SZA made was just remarkable. In real time operations, I would’ve viewed the SZA imagery for at least 45 minutes, maybe longer, compared to what we typically use.

Figure 2: MesoAnywhere (left), SZA added (right)

Applied the Stoplight product in AWIPS today, really enjoyed using that with the Earth Networks lightning and GLM. I did observe some spatial difference between the desktop version and the version in AWIPS. I realize this could be because I approximated the range ring in the desktop viewer since there is no lat/lon input option.

 

 

Figure 3: Stoplight Desktop (left), Stoplight AWIPS (right) – 1 minute apart timestamped 18:49 and 18:50 Z, respectively

I also observed that the Stoplight expanded in coverage once storms got stronger, which increased my confidence in using this product to assist decision markers. There was a substantial jump in lightning activity highlighted by all of the lightning products, and Stoplight’s footprint expanded in response.

Figure 4: 18:41Z (left), 19:11Z (right)

LightningCast also did a great job picking up lightning potential before seeing evidence of cloud top cooling.

Figure 5: LightningCast probabilities

Finally, there were numerous cirrus clouds/anvil debris over our CWA, so we did have a more difficult timing utilizing some of the OCTANE products, but I did want to highlight that the CTC product detected areas of cooling along a boundary that was pushing away from the complex of storms into an area not obscured with anvil debris. CTC also showed the core areas of the storm where more rapid cooling was occurring.

Figure 6: OCTANE CONUS Cloud Top Cooling

-simoom

Tags: None

Lightning Stoplight in AWIPS

While utilizing stoplight for IDSS activities. I noticed a few mapping errors in the AWIPs version. The first example comes from a lightning strike detected by ground-based networks underneath the anvil ahead of the storm. Stoplight correctly highlighted this strike, however on the AWIPS display it highlighted the adjacent grid (Figure 1). The strike occurred just northwest of McDade.

 

Figure 1: ENTLN lightning plot with lightning stoplight and lightningcast (contoured).

While comparing the CAVE lightning stoplight with the webviewer, it appeared as if they did not match one another. Below is an example of what was seen while viewing the CAVE version (figure 2) versus what was seen on the web viewer (figure 3). The webviewer indicated that the radius of concern had been lightning free for 30 minutes, whereas the cave version held on to some for longer.

Figure 2) AWIPS lightning stoplight valid at 2018z.

Figure 3) Lightning stoplight webviewer at 2018z.

-WxBoi

Tags: None

Thursday HWT …the last operational day…

FYI: The image above shows my LightningCast forecast setup on my AWIPS workstation at NWS Pueblo. All Ltg data plots in the upper left, and the lightningcast is in the upper right. I prefer lightningcast as an image (vs contours), as the image shows ALL of the probabilities.

Today we are tasked with both IDSS and Warnings for the Austin TX area. I have been doing warnings while my colleague Nick has been doing DSS (2 sites). Once again Lena picked two excellent sites as the strongest of the day went right over the 2 DSS sites. As the storm approached the first DSS site, it intensified, and I decided to issue a warning based on subtle cloud top cooling, the gradient with the storm and the MRMS trends in hail size. At the time I issued the warning a 1 inch hail report came in.

Late yesterday, Kevin was able to put Stoplight in the AWIPS instances. During luchbreak today, I was able to create a procedure which married the ltg stoplight product with LightngCast. We used this today for our DSS. As mentioned earlier, Nick was taking care of the IDSS so I did not look at the ltg data as much as I wanted to. Below is a loop of the data and the storm we were warning for….

Image above…the married “ltg cast” and “ltg stoplight” (upper left panel).The marginal severe storm (vcnty Austin)  is in the lower right image. I really like the fact that we can marry the two lightning products into one (unfortunately, this can only be done cleanly with AWIPS, although it may be doable within the GR environment (but would be really cluttered))

Just some thoughts…A lot of the ltg data above is based primarily off of the GLM. The GLM has an exaggerated footprint of 8 x 8 km. Hopefully, with the new ltg mapper which will eventually come on line in several years will have a smaller footprint. Based on the way things are now, We are likely “overwarning” for the lightning threat when we do DSS based off of  ltg stoplight and LightningCast.

Some more thoughts, with the HWT ending tomorrow, the most obvious product that needs to be put into operations in the SZA sat pix products. THE SZA has the biggest bang for the buck and should be easily do-able (but I am no AWIPS software expert). The lightning products (Ltgcast and Stoplight) are also very valuable tools, but need to be simplified as these tools are not ready for public consumption (even though they are public facing). The OCTANE products are impressive, but need alot of work before they are placed into AWIPS (The OCTANE site on the CIRA website is the place to go to see this data the best.

Here are some suggestions on making things a bit easier for the forecasters for the next HWT:

Have IDSS parameters defined ahead of time, i.e., ‘For IDSS point A, wind criteria is 40 mph, any lightning, any hail. Let us know if any of these parameters get within 10 miles of my IDSS Site. Once the weather threat is 10 miles outside my circle, let me know”. In a nutshell, pretend you are the emergency manager for that site.

Set up AWIPS so it defaults with the maps of the CWAs, cities, county names already plotted. Make sure the density and magnifications are appropriate.

A 4 panel radar display of R/SRM would help. Set this up for all radars that will be used on this day. See below for a good display setup

I think it would be better if the teams were either doing IDSS or Warnings, but not both at once. That way we can work together and learn (bounce ideas off each other in realtime). If one is doing IDSS and the other is doing warnings we really can’t share knowledge amongst ourselves (we are too focused on our separate responsibilities).

Some last second things….we noticed that ltg cast was having issues of not detecting lightning in Colorado….

 

-Mesovortex

Tags: None