EWP: EXPERIMENTAL Severe Thunderstorm Warning Based on UW-CTC and Environmental Parameters

Another thunderstorm was developing along an outflow boundary over southern Texas.  The NWS forecaster working the KCRP WFO made note of the UW-CTC  -20 K / 15 min at 2310 UTC 10 May 2012 on the newly developing thunderstorm.  Given the experiment is designed for out-of-routine thinking, he decided to issue a severe thunderstorm warning "a radar volume scan earlier" based upon the mesoscale environment, previous thunderstorm development along the boundary, and the fact the storm was exhibiting cooling rates in the strong category from the UW-CTC vs. NEXRAD study presented for training.

Figure 1.  Valid 2310 UTC 10 May 2012.  The UW-CTC rate of ~ -20 K / 15 min (top right panel) combined with the environmental conditions and previous thunderstorm development in the vicinity allowed for an experimental severe thunderstorm warning at EWP/HWT (bottom left panel).  **NOTE THIS IS AN EXPERIMENTAL WARNING**

We are continuing to monitor the storm via the KCRP radar for further intensification.
UPDATE 1:  2340 UTC 10 May 2012 - radar is estimating just over 1.00" hail (severe hail threshold); for a 30 minute lead-time for UW-CTC.

UPDATE 2:  2350 UTC 10 May 2012 - the NWS forecaster has upgraded the severe thunderstorm warning to an EXPERIMENTAL tornado warning, 40 minutes after the intense UW-CTC signal.   The radar estimated hail size has increased to 1.40".  The storm is highlighted in the image below.

Figure 2.  Valid 2350 UTC 10 May 2012.  The storm warned on in Figure 1, now upgraded to an EXPERIMENTAL tornado warning highlighted by the red circle.