EWP Blog

AzShear showed an interesting streak of both cyclonic and anit-cyclonic shear exactly down radial from the radar KDVN at 2025z. Just looking at that, it look like an artifact from the base velocity data down radial from the radar.

Looking at the reflectivity and velocity data, the issue seems to be beam blocking to the northwest of KDVN causing the erroneous AzShear values. Good to see that TORP is not influenced by this artifact.

-Stormy Surge

A LP supercell produced a tornado in Calhoun County, IA, on the radar scan shown in a very low Z region with little rotation evident on velocity. TORP got as high as 43% but did not have a notable quick increase as recent tornadic storms did. AzShear increased but with a quick, minimal jump. This is a tough case and, considering that the TORP ingests radar data, without a defined signature on radar it will be tough for TORP to detect anything either. -newt

Trending up, not reports at this time, but V would suggest meso at 7kft to match – Wildcat

Not obvious – Wildcat

During the slow portion of our CWA being in three tornado watches (for a much longer time than one might think), we noticed a TORP object along a meager looking meso. Probabilities were relatively low sitting around 25% which we tended to agree with due to the lack of promising features among base radar products. And then we decided to entertain a look at the ProbTor model and found an estimate of 58% for the same meso. This was clearly blowing the probabilities out of the water and TORP was able to give us confidence in disregarding ProbTor’s input in this case.

It’s nice to see even just one example of TORP trumping the aged ProbTor model.

-Wx Warlock

Maybe a wind farm? – Wildcat 

NW Mercer county had some higher values of AZshear appear, but not flagged as an area with TOR potential I’m guessing because it’s in a an area where there is no reflectivity. 

Beam blockage in velocity data makes it easy to discount AZshear. Screen capture of similar time and blockage – Wildcat