HWT Archived Case #1: Example Images

VRot was around 50 knots at this time

Here are some example images from our first archived case, showing 0.3 base velocity, the AzShear and DivShear displays in AWIPS, and an MRMS four panel:

The ProbSevere product had a ProbTor value of 93%.
There was an issue in AWIPS with not displaying extreme values of Az and DivShear

Here is an image of the same storm using the PHI Tool:

An example of a TORP object in the PHI Tool Viewer. The trend shows TORP values are near 100%.

Here are a few more images from much later in the event. The first shows the MRMS 4 Panel with a strong low-level rotation track. The second shows the TORP values have remained right around 100% for the main object. A second object is being detected (pictured below), however on the next update these are merged into just the main object (not pictured).

MRMS product four panel at 0140z
TORP objects (circles) and probability trend with AzShear displayed at 0138z.

Finally, here is a look at a supercell in the eastern part of the JAN CWA. It is almost 95 miles from the DGX radar, but has a supercellular appearance and given the environment may be a candidate for a tornado warning. However, both ProbTOR (2%) and TORP (26%) are generally low values. TORP has largely been below 30% for the last 20-30 minutes, although this is near the edge of the typical TORP range.

An MRMS view of a storm in the eastern JAN CWA. ProbTor was just 2%.
DGX velocity with TORP object (and track) overlaid and a trend graph (left)

-Orange Lightning

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AzShear Indicates Threat as Velocity Strengthens

Excellent example of AzShear highlighting an area of rotation (western circle) before legacy velocity data indicated a significant threat. Subsequent velocity scans after the inserted example continued to indicate strengthening. If I was the warning forecaster, knowing the given atmospheric setup and mesoscale conditions, the AzShear would have resulted in me issuing a tornado warning 1 to 3 minutes earlier than I would have if basing the decision purely on the velocity data.

 

-Oppenheimer

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ProbSevere vs Torp

ProbSevere sometimes combines two areas of the storm into one overlay. This hides relevant info for one of the circulations. It’s nice to see Torp specifically highlight both of these regions separately.

Torp for the same storm showing distinct areas of rotation
ProbSevere- ProbTor overlaid in AWIPS

-Nimbus

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0155Z 032523 AzShear on Downstream Tornado Warning

A look at AzShear for the downstream tornado warning shows a signal but doesn’t appear quite as defined as it did previously. Notably, the storm behind it is starting to show a better signature. Torp probabilities remain very high (>90%). -Sidney Crosby

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AzShear highlighting new area for warning forecaster to focus on.

Another good example of where Az Shear would allow me, as a warning forecaster, quickly focus my attention towards part of a line of storms I may not have otherwise focused on.

In the reflectivity image, there is some enhancement in the southern portion of the line. Nothing that appears to be overly concerning at this time. However, taking a look at the AzShear, this data highlights an area of potential concern.  Sure enough, the velocity data shows some enhanced values. Despite the highlight in the AzShear, I would need to take a look at more than just the three shared images before making a warning decision…at least for this particular situation given some of the offsetting of the AzShear vs the higher velocity and reflectivity data placement.

-Oppenheimer

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032523 0146Z Spinup Torp Concerns

I am concerned for spinup tornadoes along this line given disappearing reflectivities and ocassional nubs. Reflectivity tags also moving up the line increasing confidence. Torp probabilities remain fairly low (generally less than 50%). -Sidney Crosby

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Az Trend Charts

Having a visual display such as in this example would be very beneficial to me as a warning forecast. The rapid increase and decrease in Az Shear trend charts would likely help a warning forecaster save time during warning operations. Ex: A notable downward trend could indicate to the forecaster that he/she/they could focus their attention to a different storm, and vice versa if there was a trend upwards.

-Oppenheimer

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Torp Sharkey County

Torp has consistently shown very high probabilities (<75%)  over the last 20 minutes. This object is colocated with a significant velocity couplet and TDS. -Sidney Crosby

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TORP and AZShear

A strong supercell storm developed northwest of Jackson with SRM data showing a tightening circulation between 00:44 and 00:48 UTC and the AZShear  also picked up this circulation with values moving into the high range on the trend graph. TORP also identified the circulation with a 69% probability at 00:49 UTC. This helped to add to my confidence that a tornado warning was needed and a warning was issued.

Flash

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