Have noticed several instances through the day today of the GOES LAP CAPE values looking very blocky across central Texas. This leads to very low CAPE values transitioning to a quick jump up to more realistic CAPE values. While this has been annoying, it was easy to interpolate between the lower values to get a better idea of the CAPE values in that area. -SRF

In the AMA area today, a double centroid was observed at 2203Z with one of the centroids going above 40 flashes/min, prompting the level 3 DTA, though probably erroneously as the before (2159Z) and after (2208Z) centroids were 20 flashes or less. Also, why did the algorithm produce two centroids of similar size at 2208Z?

Brick Tamland

While monitoring the storms just to the northwest of the SJT area, noticed a limitation of the ProbSevere tool, largely due to the processing time. At 2139Z on the KSJT radar, a TBSS was noted on several levels of the radar. With the time lag on the ProbSevere, it was still only outputting a 26% severe probability. But looking at the details below, you can see that the satellite growth around the same time was indicating both moderate and strong and leading to increased confidence in the strengthening storm.

Jumping ahead 2 minutes to 2141Z, the ProbSevere has jumped to 58% with the radar data being processed.

Now moving ahead to the next scan at 2144Z, the TBSS has moved closer to the surface and the ProbSevere has quickly jumped up to 94%.

While this jump has increased confidence, I felt that looking closely at the radar data I would have issued the warning (if it was in our area) before the ProbSevere had made the jump to 94% (would have probably been issued at the same time as the jump).

Finally, looking at the Lightning Cell Time Series data for that cell, a significant jump in the Total Lightning and Cell Area was seen around 2140Z, which matches the significant increase in the radar reflectivity data.

While our group is unable to use the lightning jump algorithm today, I find my self both wishing I was able to use that data but also glad it was able to utilize the time series data to pick up on the significant jump manually. -SRF

The Convective initiation product showed an area of 51% probability in the south central part of Parmer county in the far northwestern part of the LBB CWA at 2015 UTC after showing some 10% probabilities at 2000 UTC.  By 2030 UTC the convective initiation probability increased to over 60% and also identified another area with a 74% probability.

Looking back at the radar data in the loop below the first 10+ dbz reflectivity values appeared at 2037 UTC.

The first 35 dbz value occurred at 2048 UTC in the west central part of Parmer county.

I think the CI product successfully identified this initiation with over 30 minutes of lead time again highlighting it’s situational awareness value.

Jack Bauer

We moved over to SJT where we’re covered in pretty thick stratus. There was a promising looking boundary to the west of the CWA. The GOES CI showed 90% at the northern most part on this line. I was hoping this would be the beginning of a nice storm that would move into our CWA.

Apparently the environment did not agree…

The tiny little shower never amounted to anything and dissipated quickly. Fail.

-V. Darkbloom

At 2045Z, noticed a delay in gridded total lightning. Staff found out there is a 10 minute delay on the SBN.

Lynford

With scattered thunderstorms and limited severe threat in the ABQ area, we have been moved to SJT to hopefully capture convection moving northeast into the area from the dry line and leftover outflow from last nights convection.

Taking a look back at the visible satellite and convective initiation product, it highlighted the development of convection to the southwest of KBPG very well at 2000Z, with an area of 91% prob of development (and 67% to the south-southwest of that area).

Moving forward 30 minutes, you can see that area developed experienced development in several locations along that line.

-SRF

I didn’t get a chance to look at the NUCAPS soundings on Day 1 but as soon as the pass occurred today we looked at a sounding that was about 60 miles east of the storm of interest that we have been following in the northern portion of the MAF CWA.  The NUCAPS availability point was located in a brief area of clearing within the cumulus field but we were a little uncertain whether or not clouds interfered or not.

However, the data did look reasonable as the temp was close to surrounding obs, though the dewpoint appeared to be low compared to surrounding observations.  The SBCAPE in the NUCAPS sounding was about 245 J/kg which was significantly lower than the GOES-R LAP CAPE observation which was around 1000 J/kg.

We modified the sounding to increase the dewpoint to 59 degrees to be better in line and this resulted in SBCAPE of just under 1000 J/kg and lined up well with the GOES-R CAPE.

Jack Bauer

An area of convection (70% probability in GOES CI) continued to develop around 1900 UTC.  Between 1922 and 1928 UTC, the Prob Severe increased from 18% to 63%, and by 1935 was up to 86%.  The lightning jump increased to 2 sigma during this time.  The 1 minutes lightning density increased over a 2 minute time span from 1 to about 4 flashes/gridbox.   By 1945, the lightning density was up to 9 flashes/gridbox.  All of this evidence points to convection which is increasing in intensity.

Evidence from the NUCAPS sounding as well as the GOES LAP CAPE suggest the storm is in an environment with around 1000 J/kg of CAPE.  By 20:06, the storm is a well-organized supercell with a hook echo and well defined rotational velocity.

The combination of lightning data, Severe Prob, NUCAPS and GOES LAPE CAPE were good indicators of strengthening storm worth watching.  The storm produces a tornado.

Since I didn’t have time to test out the Lightning Cell Tracking and Time Series data yesterday, it was nice to have an opportunity to use it today. Overall, I think the lightning time series data can be really useful, especially the multiple color version.

One thing that was pointed out to me by one of the trainers was to keep an eye on the cell area (blue dashed line above), as significant drops/rises can indicate cell splits/mergers.  That was definitely the case with the image in the upper left of the four panel above, as the cell tracking was splitting/merging the lightning areas. That can be seen in the two images below, where the the first image shows the combined lightning cell with 39 flashes (2005Z lightning cell). Then the next minute (2006Z lightning cell), the detection split it into several different cells and lowered the total flash rates.

Knowing that information can help eliminate false interpretations of lightning jumps on the time series. -SRF