I utilized ProbSvr again today to help me to determine whether or not to let a warning expire or continue it. I also have the -20C MRMS height under this and that has also helped. My warning was supposed to expire at 2245z. I skipped a few screen captures for the sake of time/space.

2234Z ProbSvr was still at 90%

2238Z.. ProbSvr is down to 77%

At 2240Z…ProbSvr down to 75%

Here at 2244Z…probsvr is down to 74%

Although these probs are still fairly high.. the trend down was enough to let me expire it and the trend continued after expiration.

Lauren13

When using ENI data, forecasters must have a good handle on the “typical” amount of lightning displayed in “average” storms. There have been numerous severe storms in MAF cwa, but they have been low on lightning strikes. We opted to configure DTAs manually today triggering alerts for 75 strikes per minute. As a result of our new configured rate, we had very few DTAs and the DTAs that were triggered were accurate. However, this high threshold also missed a few severe thunderstorms in the southern portion of the cwa.  There must be local guidance given within each office on where DTAs should be set in order to be most productive with its use.

This photo shows DTAs in north part of MAF cwa, however it is actively missing severe thunderstorms producing hail that are ongoing in the southern portion of the cwa. UFFSU

At about 2128Z the ENI point lightning data for the storm in Reeves County TX dropped to zero and then started picking it up again (right image).  The algorithm appeared to split the cell in two and then combine it again.  (I wasn’t able to screenshot the image of this).  This was wrong because it was a lone cell that had a SVR warning with it and a TBSS earlier.  There was no redevelopment outside of the storm.  The algorithm should be able to handle these lone storms and it didn’t.

-Champion

Here is an example with Earth Networks Cell Lightning Cell tracking where there was a circle within a circle:

In this example, point 1 is in the interior circle and point 2 is in the outside circle. Note that the time series are the exact same for both circles. This situation would be confusing to a warning forecaster.

Polarimetric Researcher

Here is an interesting example of ProbSvr ramping up while looking at 4 storms.

2214Z. ProbSvr is picking up four cells. This is the first scan where the two right cells have pulsed. Earlier, this could be a situation where we weren’t sure which storms would pulse back up. Seeing this helped the LUB office issue the severe you see here.

2216 shows both right cells increasing some more.

2220 shows them combining so it’s hard to say which storm is stronger now.

2224 and we issued the southern severe.

At 2232 Z reported quarter size hail.

The ProbSvr showing the difference in the cells helped us see which ones needed the focus of attention. It caught the high probs on the southern storm before the warning went out with a higher lead time for the hail. Again, it is to note that when the two storms combined, that may be why it spiked up because the northern storm was stronger at an earlier point.

Lauren13/Polarimetric Researcher

Finally the storms are getting enough lightning to pull some higher ENI alerts. We have the configurable 1 set to 75 flashes/min and #2 set to 100/min. The light blue is #1 and dark blue is #2. Not really a point to it but you can see how the polygons can get a little confusing with 5 different colors. And this is without severe thunderstorm warnings overlaid.

Lauren13

Just wanted to show a difference between the circles and dots. The dots are on the top image and the circles on the bottoms. Don’t know about anyone else but I like the dots a lot better even just at first glance. The circles are a little annoying and the dots make more sense to me!

Lauren13

Here are four frames from a cluster of storms we have been watching and *trying* to track time series on but the cell tracks keep flip flopping.

2131Z and two are being tracked

2135Z and one circle inside another in the right storm is tracked.

2140 and we have three circles

2142 and now we have one big one!

Needless to say, the ENI tracking and timeseries was NOT very useful on these storms…

Lauren13/Polarimetric Researcher

Today we got a special sounding at 18Z from KMAF to compare with the 19 Z NUCAPS sounding at roughly the same location. The NUCAPS sounding was able to pick up on the stable layer above 850 mb, although the NUCAPS sounding did have it a little higher. Also, after modifying the boundary layer T/Td in the NUCAPS sounding, MUCAPE values were very comparable between the two.

Here is an example this morning of a clearly severe thunderstorm but with such little lightning that ENI only put a Level 1 Thunderstorm alert.

2055Z. Focusing on the southern most storm.

2059Z. The Thunderstorm alert has arrived but a TBSS is already evident at half degree. This is sampling about 10k ft AGL.

At 2105z, we issued the severe.

At 2111Z, the Significant Thunderstorm Alert was issued.

As of 2127Z, there is still not dangerous alert on the storm (or any that we have severes on…)

I think it just shows why DTA’s are not the “best” thing to wait for or look at for a severe thunderstorm.

Lauren13/Polarimetric Researcher