Category: SPG2024

Consitency with Lightning Cast

Posted in LightningCast, SPG2024 on by Kevin Thiel.

As a QLCS moved through Tennessee and the threat for severe dropped, we were thinking of a way to message the persistent lightning threat that would still be present. We leaned on the Lightning Cast tool to message this threat.

 

 Image one: SPC risk categories with colors.

 

 

Before we made the image though, the idea came up to re-do the contours such that they better aligned with the style guide the NWS, or SPC more specifically uses (img. 1). Image two shows how we added two contours and realigned the colors to add consistency with other operational areas of the NWS.

Image two: Lightning Cast with a new 5 and 90 percent contour added and colors of the contours aligned with the risk colors used elsewhere in the NWS. In the background is channel 2- Red Visible satellite.

 

We compared this with the base style from the lightning cast tool and we felt that our updated style better captured our eyes and made it simpler to interpret by us. We also felt that the public would have a better chance of understanding the product if the colors were more consistent.

Lake Charles Radar Confirmed Tornado

Posted in OCTANE Speed Sandwich, SPG2024 on by Kevin Thiel.

 An MCS resulted in a number of TDS and TVS signatures on radar near Lake Charles today.

This one was capture to the WNW of Sulphur LA as an MCS surged east in an atmosphere that had 5000J/KG of SBCAPE. In addition to a TDS a LSR was submitted to the Lake Charles office regarding significant damage to the Walmart in Sulphur downstream of where these stills were taken. Radar was primarily used to determine that a tornado was on the ground. Looking at some of the Octane data, it was noted that this tornado formed on the leading edge of a speed minimum on the EMESO-1 Octane Speed Display.

As the storm moved toward Lake Charles, the line segment began to bow out. Numerous reports of wind damage came in with an Semi being flipped on I-10 and a 60MPH wind gust reported by the Lake Charles ASOS. Velocity data showed a strong signal for damaging winds, and the Octane Speed Sat Display again gave us a significant gradient between speeds as the storm passed over Lake Charles. This data could be useful in verifying the potential for damaging winds, especially when storms are close to the radar.

The Octane Sandwich display seems to be an upgrade to the Day Cloud Phase Distinction although both displays could serve different purposes, with Day Cloud being useful in watching storms develop, while Octane is useful once storms become more organized in identifying more distinct elements of the storm.

-Charmander

Gremlins are dismantling the nebula!

Posted in GREMLIN, LightningCast, SPG2024 on by Kevin Thiel.

Hi everyone!

First blog post for the Satellite Convective Applications Experiment – Week 1, let’s go!

The loop below shows an example of this from the Corpus Christi, Texas. Notice the convection moving out of the frame to the northeast is bounded by prob-lightning contours (Gif 1). My desire would be to have these better matched to the storms. Right now, the contours are too nebulous.

GIF one: MRMS reflectivity at -10 C overlaid with lightning cast 60-min probability.
Why do I care about it’s nebulousness? When I am providing decision support to an event, I want to know which cell is driving the highest probability, which is building and be able to anticipate the lightning threat based on the cells movement.
As my partner in the testbed pointed out, the anvil(s) (see image one below) were merging and this was likely causing the nebulousness.
   Image one: GOES East Day Cloud Phase RBG channel.
Our discussion began to expand to others in the testbed and an idea emerged to try and reduce the nebulousness. The idea was to use the GREMLIN Radar Emulation product to further train the lightning cast dataset so that the probabilities become anchored by the emulated MRMS product.
Below is a GIF of the GREMLIN and MRMS product. With the GREMLIN product using some of the same satellite features as the lightning cast; the two products have some base level of compatibility. And so my challenge to the developers of these products is, an these two be combined such that lightning cast is mapped to the convective feature causing the probability.
GIF Two: GREMLIN Emulated Radar on the left, and MRMS composite reflectivity on the right.

-Kilometers

Using PHS to analyze an area of surface based convective potential

Posted in PHSnMWnABI, SPG2024 on by Kevin Thiel.

The potential for surface based convection will be important for the severe weather coverage in the CYS CWA this afternoon/evening. The 19Z PHS model is forecasting a northwesterly push of instability which is depicted above in the left panel moving into the far southwest counties of the CWA. To the north of that instability axis the PHS is depicting still elevated convection that is going on this afternoon. Additionally it is depicting surface based convection in northern Colorado, which may impact the moisture feed further north into the CYS CWA. I would highlight the far southeastern portion of the CYS CWA for a severe thunderstorm potential in my DSS/public messaging, with more uncertainty further north.

-Joaq