MAF - SVR issued based on increase in lightning activity

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

Warning issued same time as office

We were diagnosing a storm in the northwest portion of the IWX forecast area. I did use NSEA HRRR hail readout to diagnose the hail environment in conjunction with the other plan view all sky LAPS and NAM12/HRRR model. The ProbWind product had about 30-45% while ProbHail was much lower around 7%. However, dual pol and Z/V products are showing a deep developing core with a very tall (35-40 kft) updraft and 45-50 kts of low level velocity.  GLM wasn't really helping with the warning decision process on this at the time I issued. Was looking at other data. However, in hindcast we did see an uptick in the event density and total energy. Perhaps I'm still trying to learn how to use it and incorporate it into the warning decision process. We actually did issue a warning at exactly the same time (2230Z) as the IWX office (saw this in their chatroom).

Here's what the GLM data showed at same time.

 Here's the NSEA Hail readout from what I was seeing there:

More to come...

Supercell/Jack Swigert