Starting off as WFO IWX

Az Shear steadily increased in Berrien County, Michigan around 2010z but did not get a TORP object. Increasing AzShear in close vicinity to the warm front prompted the SVR issuance.

Interesting how “nothing” convection over the lake gets the TORP probs, but the supercell in Berrien County with strong AzShear does not. (see below)

Example below of ground clutter high V values giving bad AzShear and DivShear data

One side note: Noticed it is harder to look for SVR wind and hail because TOPR, AzShear, and DivShear has me looking at the tornado threat more than anything else. Wondering, if products like this in future go operational, if you need to seperate tornado warning operator from a wind/hail one for the work load…

Below, TORP went way up to 57% as this got close to the warm front, div shear went up. Still waiting to see how Az Shear responds, and then SRM for Vrot

AzShear goes up, crosses the warm front, start to see Vrot organize, TORP comes in at 57%, tornado warning issued.

Storm fell apart, looks like cold pool ejected from forward flank, SRM never tightened up with respect to Vrot, TORP probs also dropped

Still no confirmed no tornado. Looked like it was dying, then took a right turn. GRR TORP remained high as the 0.5 deg scan was getting the persistent mid-level meso. IWX radar was up and down as the 0.5 low-level meso was “sloppy”. However, a right turn and potential cell merger with GRR TORP still high, decided to reissued downstream with a tornado warning.

KIWX has spurious outbounds behind the higher reflectivity that do not appear to be associated with organized storm-scale rotation, given it’s placement and also very high spectrum width. 33% prob TORP seems to be associated with this artifact. 

-dryadiabat

Noticed that two TORPs along the leading edge of the line jumped to a common circulation but did not merge. One was from KMKX and the other was from KLOT. Ideally, these would have merged and the TORP from the closest range radar would have taken over.

UPDATE: Found “Display Overlapping Options” filtering option, which when turned off shows objects from all radars. Curious how this filtering decides which to display when turned on? Higher probability? Closer range? Longest track duration?

-dryadiabat

Although insignificant and not worthy of a Tornado Warning at this time, it’s noteworthy that TORP did call my attention to an area of a storm cluster where I would not have heavily interrogated the velocity. Rotation is weak but is present and TORP flagged this, calling my attention to it. This demonstrates at the very least the situational awareness utility of TORP.  Noticed this in AvShear, too.

-dryadiabat

The difference in the rotation between KGRR and KIWX doesn’t seem to necessitate that difference in probabilities for the objects associated with each radar. 48% vs 90%. Upon going back to look at this again, I only see GRR and not IWX. So filtering must have purged IWX, although in real time they were both visible. 

A sudden yet steady increase in DivShear helped lead to an earlier lead time on a tornado warning when rotation in velocity was apparent but still generally weak.

AzShear was medium leading up to the tornado reports and only jumped up after reports started coming in around 12:20z.

Spectrum width, which I would generally rely more on in the absence of these new tools, had a general positive trend through this period, but plateaued in the minutes leading up to the tornado reports.

The absolute maximum of velocity trend was low leading up to the tornado reports and only suddenly increase afterwords. Essentially, just relying on strong rotational velocities in this case would have resulted in no lead time for the initial reports.

TORP, while sometimes slow to update in AWIPS compared to the online tool, helped highlight an area of weak vrot where a tornado was likely ongoing based on storm reports at the time. (If not a tornado, there were at least several TSTM WND DMG reports.

While TORP only remained around 50%, both AvShear and DivShear highlighted an area of strengthening rotation that may have been associated with a brief tornado, including a clover pattern present in the DivShear. Neither of these features prompted a tornado warning, but confirmed suspicions immediately after the warning was issued based on the velocity pattern.

TORP does a good job here of identifying a developing QLCS meso and tracks it well as it gradually tightens, with a TORP max of 56% occurring at the time the circulation is strongest and a tornado possibly occurring. TORP was a high as 50% several scans before the circulation was strongest, which could have been an indication that it was an object to keep an eye on, though probabilities drop to <30% for the following two scans before the  eventual spike to 56% and possible tornado.

The object in question is the southernmost one that begins east of Heflin and tracks through Dumfries.

– Mr. Peanut

Just wanted to show a case of weak rotation that TORP and AzShear handled well. This was also in a broken line, which I have seen TORP struggle in. Not sure why it handled this situation as well as it did.

Here you can see how this weak rotation in velocity can be overlooked at first if there is a lot going on on radar. You can also see though how there is  a TORP object and it has been tracking it for a bit, all while the rotation is very weak:

Here is AzShear at the same time:

As you can see it may get your attention more than the velocity signature would.

Now stepping forward in time, you can see a better couplet in velocity along with a bright AzShear signature and a clover signature in DivShear. This is when we decided to warn. Probably would have warned with just seeing the velocity signature, but AzShear, DivShear and TORP definitely helped nudge us and get the warning out quicker.

-Gary

TORP seems to struggle a bit when there are gaps in between lines on reflectivity. Noticed that several areas of low probabilities existed in gaps throughout the event. Can be a bit distracting as it is eye catching and takes time away from other areas that may need more attention.

Nice clover signature on DivShear. This appeared about 3 minutes after the original tornado report, so did not provide a lead time. However, it is good to see this signature verify.

-FujitaReno

TORP had an issue handling the tracking of objects along a linear AzShear maximum where a weak tornadic circulation was also developing. Initially, an object with ID 340 was identified with low probabilities (27%) along a linear AzShear feature associated with a region of convergence northwest of LWX.

Note: Ignore the trend on the left throughout this post – it was slow to update on objects being clicked in the PHI Tool and doesn’t necessarily represent the actual trend in objects being discussed.

On the next scan, ID340 continues to track the same part of the linear AzShear feature, still with low probabilities, while a new object (ID171) appears with a 95% probability just to the south where a circulation is rapidly strengthening and a tornado is ongoing or forms shortly thereafter.

In the next scan, ID340  jumps south to the tornadic circulation, where ID171 is still tracking the circulation for its second scan in a row.

ID171  then drops off on the next scan and ID340 becomes the primary object tracking the tornadic circulation for the next several scans.

– Mr. Peanut

Issued a tornado warning on the cell just east of Philmont. There was a long broken line (hard to see here as I zoomed in quite a bit) and one cell can be seen broken off,  looks like an embedded weak supercell.  Issued the warning based off of the line break, weak but tight couplet and a very slight CC drop aligned with the couplet. Was watching this thing for a few scans and the rotation slowly wrapped up and the CC drop even had some vertical continuation. At this time, there was no TORP object over the rotation. I have noticed TORP struggles in QLCS type events. When TORP did eventually put an object over this rotation, its trend line came down from the north, which makes no sense in this case. I noticed this a few other times with this simulation and another simulation. It will make huge jumps along a line and not realize that they are two different circulations. This storm did eventually have damage reports,  5 mins after the warning and 3 mins after the TORP object.

First pic shows the storm I warned on just east of Philmont (no warning showed here).

The second picture shows no TORP object over the storm I warned.

The third picture shows the TORP object a few scans later, with the “line history” coming down from the north.

-Gary

Noted a difference in TORP and PHI regarding the reported tornado. Forgot to turn on the setting in PHI that allows for near radar imagery to be seen. However, after I turned this on I noticed that PHI had a 95% ring, while TORP at the same time showed nothing.

I noticed that as the northern end of the line of convection became more parallel to the radar beam, several low-probability TORP objects occurred (see below):

However, when I go back to the 30% threshold the one that is left is correlated to a deeper area of rotation using a traditional All-Tilts analysis (see below the 1.8 deg elevation angle of SRM). This was encouraging that TORP was able to identify the most legit circulation with highest probabilities.

-dryadiabat

Just re-worked every procedure to simplify my view in order to take in the TORP, Az/Div-Shear products more easily. There were time match issues, and missing data and this seems to have helped some. I’m running a simple 0.5 Z/SRM w/ TORP and 4-panel Z/SRM/Az/Div now and it seems to have helped.

Had several issues with thresholds and various settings that resulted in only seeing the TORP for the tornadic circulation after it developed with 95% prob, and no history using the PHI tool to display.

-dryadiabat

Even with the reset of procedures and time matching to TORP,  still having trouble displaying TORP in AWIPS.

Unsure what all elements in the readout for TORP are. 

-dryadiabat

The AzShear product is useful for UDCZ identification. Curious to see its use in the more difficult cases where the UDCZ location can be ambiguous. Will be watching for such examples in this experiment.

-dryadiabat

Really difficult with time match issues. Concerned I’m not getting timely velocity data if time matched to TORP.

Noticed a 25% TORP well west within the stratiform area to the west of the deeper convection, where I would’ve discounted from my manual analysis of radar data.

The Az and Div stood out with the mesovort/possible brief tornado in eastern Prince Williams County. 

Noticed a very distant TORP object from KLWX in southern Pennsylvania. Obviously there are beam height issues and the velocity is relatively low compared to earlier circulations closer to the radar. So, this is encouraging as it seems to account for the beam broadening issue with greater range.

More brainstorming, exploring, and unfiltered blogging. Noticed that once the convection moved east and the beam is more perpendicular that for the UDCZ the DivShear product really shows a strong signal, as would be expected given beam orientation. See earlier post above about AzShear showing a stronger signal when the beam was more parallel to the UDCZ.

Good example of the contrast of radar perspective, KILX vs KDOX.

Similar beam height but a stronger rotation on KDOX. Shows the value of having multiple radar TORP overlaid onto a single radar display, for situational awareness.

Monitoring another area where the line orientation should be favorable for QLCS mesovort/tornado concerns. There are areas within this segment of rotation and a slight upward trend in the latest scan as I type this. TORP has identified this area with 33% prob.

Was curious to see if anticyclonic rotation would have a TORP object. It did not in this example east of D.C.

A TORP detection along the cold front, from KDOX which is much further than KIWX. Reflectivity thresholds must have been just enough. 33% is higher than I would’ve considered from my manual assessment.