2300Z: I decided to try & get a jump on the storm east of the already warned one in eastern Jeff Davis county. GLM was my primary tool used in deciding to issue a warning based on an increasing trend I began to notice around 2230Z. between 2230 & 2250 Flash density increased from 10 to 30 & total energy from 50 to over 100. The animation below I could have issued a warning even earlier when I first noticed this increase in lightning activity but waited until I saw more of an increasing trend in prob severe. ProbHail was at 6% when I first noticed the increased lightning trend & I waited until I saw an increase to 14% & MESH increasing from 0.5" to 0.74". At the same time I noticed a cooling trend on cloud tops on the GOES 16 clean window IR which added even more confidence to the lightning data that this storm would continue to intensify. Unfortunately I fumbled around with WarnGen a bit so my warning wasn't actually out until 2051Z but I made up my mind on issuance & began the warning process around 2040Z
GLM 4 Panel animation:
Around 2300Z the storm became more obviously severe with ProbHail of 84%, ProbWind of 68%, & MESH of 1.38". I'm not anticipating receiving any reports out of this storm given the sparse population in that part of TX but given those numbers I would certainly consider this storm a severe candidate. Taking a look only at "conventional" storm interrogation products such as 50 dBZ height for 1" hail & isothermal reflectivity at -20C I don't think I would have made a decision on warning the storm until the 2255Z scan. Shortly after 2300Z the storm even took on supercell characteristics & began a turn to the right which certainly would have resulted in a warning. GLM products & ProbHail/ProbSevere without a doubt added value to my warning decision making in this case.
Of note is how the GLM fields actually decreased towards the end of the above loop despite the storm seemingly reaching it's peak intensity. I noticed similar trends yesterday watching storms in ABQ so this may be unique to GLM & storms out west.
UPDATE (2045Z): decided to reissue on this storm given a steady trend in high GLM Flash Density Values, Prob Hail over 60%, & MESH near 1.5". Below is a 4 panel animation of the GLM fields/ProbSevere/& a MRMS 1km RALA over the whole period I was actively watching it.
Peter Sunday
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