Official websites use .gov
A
.gov website belongs to an official government
organization in the United States.
Secure .gov websites use HTTPS
A
lock (
) or https:// means you’ve safely connected to
the .gov website. Share sensitive information only on official,
secure websites.
The storm in Reagan County, depending on the data you look at, looked like they may merge! When looking at OCTANE/Visible satellite, the cell moving out of Reagan actually seemed like it was moving fairly rapidly eastward towards the stronger cell in Tom Green County. But, when viewing radar data, it wasn’t moving quite that quickly. Interestingly, GREMLIN has been hinting that these may merge (or is this a smoothing effect?).
 |
| OCTANE |
 |
| KMAF (left) and GREMLIN (right) |
Forecaster Cumulus
On the warning desk today, I’ve noticed that I have been using OCTANE the most out of the newer tools (besides an adjacent radar). It has really helped with confidence with warning decisions – are the storms maintaining strength… are newer ones growing? The storm in the eastern portion of this loop (below) has been going and going for a handful of hours (originally SVR in our area). OCTANE has kept right along with it and showing its evolution aloft (in both IR and Visible).
These products have aided in confidence in warning ops, especially with lack of primary radar.
Forecaster Cumulus
The distribution characteristic of the derived cloud top divergence product has been helpful in highlighting potentially severe thundretsorms. Here the purple/pink colors are fairly consistent compared to the more “broken” distribution of colors to the east. Additionally, cloud top cooling is appearing as an overshooting top (and continued to reappear after this animation ended). Even if radar data was absent the severity of the thunderstorm would be apparant. A warning was issued on this storm (shown below).
-Joaq
Severe thunderstorm and tornado warnings were issued partially driven by the increasing intensity of GLM FED. With the indication of a strengthening updraft due to increasing lightning activity atop the convergence signature on radar, a warning decision was made for both damaging winds and a tornado threat.
-Joaq
Developing convection along a surface front in eastern Kansas was producing signals in the OCTANE storm top divergence product, signs of glaciation, in the day cloud phase product, and increasing LightningCast probabilities. Along northern areas of the surface boundary, the divergence product and visible characteristics were stronger, while updrafts further south still struggled to sustain themselves. This may be due to residual convective inhibition evident on MCI ACARS soundings. Even about 20 minutes after these screen shots were taken, the GLM activity was fairly weak, while the storm top divergence only really showed showed up on storms near and north of the KC metro. While severe convection is still likely downstream, the OCTANE divergence product definitely highlights where better synoptic forcing is overcoming any convective inhibition.
-Joaq
It was interesting when comparing the Warning side of the house today versus the DSS side. When we (Cumulus and Kadic) were discussing this and picked two of the tools we used the most, there were similarities and differences:
For Warning Ops: OCTANE and LightningCast
OCTANE proved very useful in interrogating convection. LightningCast was also a helpful diagnostic tool in highlighting the potential for and track of intense convection when used with ProbSevere.
OCTANE:
Here’s a look at 2 particular instances from OCTANE:
A combination of cloud top cooling in OCTANE and subsequent divergence aloft was a helpful clue in assessing the potential of a storm that was distant from the radar. It was caught a little later in analysis, but OCTANE proved helpful in diagnosing the storm and deciding to pull the trigger.
This next instance was a warning that was issued solely using OCTANE and seeing how well it lined up with radar. The warning targeted the center of where the maximum storm top divergence was taking place, and then stretched down towards the south to account for parallax. The warning decision was made for the impressive cloud top cooling and pronounced divergence that appeared in the scans leading up to the warning. The panel on the top left shows the OCTANE speed, and it transitioned to a blue color leading up to the event.
LightningCast and Radar:
Below is the example of what MRMS looked like the moment DMXSVR005 was issued solely based on OCTANE. Much of the SVR encompassed the highest LightningCast values with a probability of 10 flashes of 70% in yellow and the various ProbSevere contours. Again, this highlights how useful these tools can be in performing storm interrogation. However, when thunderstorms are numerous, this may be a lot to run through. They are definitely useful tools in the tool belt, though.
For DSS: LightingCast (especially the Dashboard) and GREMLIN/GLM.
– LightingCast: I REALLY like the form and Dashboard. It helps focus on the DSS site specifically and organizes the data really well to where I would feel comfortable explaining/showing an EM the graph of lightning probabilities. Honestly, I could bring this back to my home WFO right now and use this for DSS events this summer. A couple things that could be added to make it even more awesome: adding more options for ranges (right now there is only 10 miles, perhaps adding 15 and/or 20 miles). Folks could then choose which to display in the graph. The other thing (fairly minor), perhaps reversing the size of the bubbles for the GLM data (smaller range, smaller bubble). But, this is personal preference – maybe if this could be customized by the user like the colors?
– GREMLIN/GLM: GREMLIN followed the storms a lot better today (seems to do better with more intense storms versus run of the mill/sub-severe ones). I used a two panel display with GREMLIN on the left and MRMS on the right with GLM and LightningCast and compared the two. I used time of arrival for the storms to 10 miles outside the DSS event and also at the site itself. GREMLIN was able to keep up with MRMS really well! I am becoming more and more convinced that this could be a really great product to help if a radar goes down or there is a radar hole (in data).
Overall, it seems as though OCTANE was used more for warning ops versus DSS, but LightningCast was used by both the warning operator and DSS forecaster.
Forecasters Cumulus and Kadic
Day 2 has featured more convection, and has been a helpful day testing these products and how they help in warning operations. Although I might not feel confident making warning decisions solely based on any of these tools, I think that each tool provides a valuable piece of information.
Pre-Storm
To keep things short here with all the observations, PHS was very helpful today in showing how the QLCS situation would evolved with several areas of embedded rotation. Having CAPE with SRH together showed how these came together, and in conjunction with velocity highlighted rotation updrafts within PHS. This proved to be a helpful pre-storm evaluation. A few storms began rotating, and then everything began rotating as the PHS model indicated.
The developing squall had a linear appearance at first. As time progressed with more embedded areas of rotation, this became a lot less neatly organized.
One thing to note early was that the PHS forecast had a lot of convective debris lingering in Iowa that was not present in reality. This does not appear to have impacted the instability parameters very much.
We’d mentioned looking at the dewpoints for the tendency for aggressive convection. But it only seemed slightly high compared to reality.
We did have a blob near Sioux City on Gremlin that didn’t really correspond with any signal on radar, and it didn’t seem to have satellite signal to go with it. Not sure where it came from, but we were able to see it was erroneous.
Here’s a look at GREMLIN with waves and wobbles following the GLM lightning.
Kadic
Examining the qualitative appearance of OCTANE Cloud Top Divergence (CTD) and Cloud Top Cooling (CTC) products with storms near St Joseph MO.
First image: 2001Z. A series of updrafts is noted, several with mature CTD signals in blue/purple/red. Most notably is the signal over Leavenworth/Platte counties (largest CTD signal, near the bottom). The CTD signal here is large and mature, which implies a very strong updraft relative to the other storms in the area. The size of this feature does matter, as it implies the updraft (and thus the outspreading of the anvil) is very strong relative to the others. To add on to this, there is a CTC signal (green dot) associated with an overshooting top. This indicates that even though this storm has already produced a significant updraft, it continues to produce an overshooting top, implying the updraft is still strong and mature.
–Insolation
