Day 2 of week 3 kept us on the East Coast in the Raleigh and Columbia CWA's.
LAP
- GFS was underdoing CAPE values. Where we did have retrievals, values were higher, closer to what we expected.
- There was a CAPE gradient along which storms developed
- Looking at the Layer PW, it was good to note the drier air moving in aloft, while the low-layer stayed moist, increasing lapse rates.
CI
- It picked up a couple areas that gave 10-15 min lead time over cell development.
- It seemed like you had to be above 50% for future development yesterday.
- It did a good job of indicating that convection would develop along the boundary.
- Struggled in western portions of the Columbia CWA. We saw higher probs where convection never initiated.
- It did real well with a supercell that developed along a boundary in SE North Carolina, giving 10-15 min lead-time.
- The highest probabilities werein the south, and that's where storms developed later.
- We didn't see probabilities above 30% despite multiple severe storms developing.
ProbSevere
- The first storm I warned on was fluctuating, I warned as soon as it hit 76%. It then weakened, so I canceled the warning. Much later it strengthened again and produced severe. The next storm had a rapid increase in probabilities early in its development, but since the previous one did not produce right away, I did not warn based on my previous experience, which was the correct decision.
- Whenever I see a big jump in probs, it is an indicator that I should look at the storm further, and possibly issue a warning.
- I saw several storms where we had a jump in probsevere and LJ
- Not having the satellite with the one storm was a negative for probsevere; held the probs down.
- Losing 88d for Raleigh and having to use other radars was good practice to track just from higher elevations. It was nice to have probsevere during that time to kind of make up for it.
SRSOR
- With Parallax corrected imagery, the correction of a mature anvil blocked new development along the flanking line to the south. In the regular imagery, this new development was obvious - rapid development with OT in a few minutes. But in PC imagery, you could not see this. This is a key limitation of the PC imagery. See blog post
- The 1-min imagery allowed us to easily track the movement of the boundary.
- The boundary on which convection developed was very subtle, but the 1-min data allowed us to identify it.
- I cannot wait for GOES-R; we will see things we've never seen before.
- To keep my bearings between where I was looking in satellite and radar, I put warning polygons and counties on the 1-min imagery. I had never done this before.
- I overlayed 40+ base radar reflectivity on 1-min imagery, making it slightly transparent. It was helpful to see the relationships. This is where the PC imagery was useful.
Sat-derived winds
- There were multiple outflow boundaries in our area, and the winds did shift with the boundaries. It is nice to see that they picked up on this.
- When there were winds at multiple levels, I did a quick evaluation of deep layer shear. It was a nice, quick update on how shear was progressing.
Lightning Jump
- One storm had been trending downward, then had a 9-sigma jump, after which it strengthened again.
- Strong jumps (5+ sigma) seemed to typically be associated with the strongest storms.
- I made it transparent yesterday and that worked for me.
- I put Earth Networks point lightning data on top
- Between this and probsevere, we have two great warning decision tools, I really liked them.
NUCAPS
- After modifying the sfc/low-levels, I got CAPE of 1700 j/kg, similar to what I was seeing from other data sources
- I looked by an ASOS, SE of Raleigh. Compared mid-upper levels with that from the 12Z RAOB, 0C and -20C heights in particular, and they were very similar. Once I adjusted the low-levels, it gave a good estimate of CAPE and LR's. Knowing where the freezing level and -20C level is is helpful.
- I already view it in my office, it is quite useful now.
- Great for mesoscale analysis
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