Category: SZA Imagery

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
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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

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DSS: Max Road Fire

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

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

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

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

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

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

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

Hurricane Specialist

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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
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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

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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Final Ops Day – LCH

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

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

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Thursday HWT …the last operational day…

Posted in Lightning Stoplight, LightningCast, SPG2026, SZA Imagery on by Kevin Thiel.

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

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Overview: Week 1, Day 4

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

10 AM

Day 4 kicked off with another debrief session, with considerable focus on LightningCast and Lightning Stoplight for decision support. Near the end of the operations period yesterday we got the Lightning Stoplight tool into the HWT’s AWIPS-II instances (thanks to Justin, Jonny, Roger, Kris, and the rest of the Stoplight team for the hard work to get that done!). We talked about what products in AWIPS-II you could display with it, and some forecasters preferred to have the lightning information (GLM, ENTLN) while others didn’t. I’m hoping another day with DSS will better inform forecasters of these products, and using OCTANE and Synthetic GXI imagery in marginal/messy environments.

Picking our WFO locations was a bit easier today, but it was unfortunately from how limited the areas for convection were. A cold front had washed out much of the moisture and instability down to the Gulf Coast, leaving us with marginal convection from the 13 Z SPC outlook. You know it’s a meager setup when we had to request an ABI MESO domain for our area, and we were glad the SAB approved. We settled for Lake Charles, LA (LCH) and returned to San Antonio (EWX) in hopes of getting some semi-discrete convection in each. Both offices were again given two DSS events and encouraged to use the LightningCast Super Dashboards.

1PM

Operations kicked off and forecasters spent a good bit of time playing with LightningCast and the Lightning Stoplight tool together, and providing feedback to both sets of developers. Working with forecasters and developers, we made a few ‘flavors’ of the Stoplight tool in AWIPS by modifying the colorbar. Here’s the descriptions from the animation below:

  • Top left is default
  • Top right colors the flashes in the last minute as dark red
  • Bottom left changes the green to blue
  • Bottom right colors the flashes in the last minute as pink followed by a red, orange, yellow scheme

Forecasters had a positive response to the top right panel, and said that coloring the 0-1 minute flashes from GLM and ENTLN dark red in some ways removed the need to overlay those products in AWIPS, simplifying their display. I saved this display off as a procedure and hope to show future weeks and get their feedback too.

3 PM

The Synthetic GXI folks decided to show the forecasters WVT data from the METEOSAT-12 FCI, since it has the 0.91 µm band that GXI plans to add. Features such as fronts and low level moisture boundaries were identified and discussed.

4PM

We found an interesting case of CI near the Lake Charles, LA CWA, with anvil debris from upstream convection obscuring the convection from visible and infrared satellite imagery. The OCTANE cloud top cooling product had a hard time showing cooling until the updraft produced its first lightning. LightningCast v2 and v1 were also compared for their performance in this challenging scenario.

5PM
To end the day I went back and made another animation of the SZA product. This time I got sunrise over the CONUS (thanks Justin!) and showed some early morning convection across central TX, with a different cloud types and layers.

Even in the MRGL, we still had a full day!

-Kevin

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