EWP Blog

Convective Initiation product (CI) correctly showed increasing values just south of the Denver Boulder area from 1600 to 1800 UTC 11 June 2015.  Values increase from 36 to near 60% in the general vicinity of the storms that developed  in the Pueblo, CO area.  This gave about 30 minutes of lead time to the first lightning strikes around 1715Z.  It would be nice to get CI output at 1-5 minute temporal resolution to match RSO/SRSO.  We had outflow boundaries evident in the SRSO imagery but had to wait 15 minutes for CI updates.  Below are a series of images as the storms were developing showing the CI, the MRMS Composite Reflectivity, Visible satellite, PGLM 6min summary, 0-200km Lighting Jump, 15minute ENI 8km interpolated lighting grid and cloud to ground strikes.  The lightning jump showed up to 2 sigma jumps at 1729 UTC.  MrSnow/Shasta.

– CI is/was available with RSO! – BL

Prob Severe jumped as storm developed just west of my warning area. Should nicely move into my warning polygon.

Had a lightning jump on this cell with higher reflectivity aloft as well.  Issued a short warning for southeast Page county.  ProbSevere was up as well as CG strikes and DVIL.

…we didn’t warn. Despite ProbSevere jumping to 75% and decent looking reflectivities, we decided not to warn on the cell in Jackson Co, KS. The MESH estimates were only up to .7″. 

But the bigger deciding factor was unimpressive lightning data (seen below).

-BT

Purple DTA box headed back into our CWA if correct…for now keeping the box further southeast.

ProbSevere had a 69% chance, but highest dbZ still in the low 20 kft range.  DVILs from neighboring radars all low, lightning data coming down.

This cell continues to move into an area that had a window of clear skies, and SRS imagery still shows a fairly good updraft, but not overshooting.  Thus we still have not issued a SVR.

In our northeast CWA as well as south of the Johnson county previously warned storm.

Cell in Pawnee county showed some rotation again , but DVILs are coming down as well as lightning data. Highest dbZ’s are in the low 20 kft range, so decided against issuing a downstream SVR.

As an experiment…issuing the Severe Thunderstorm Warning based on several severe probability values of +90%.

We’ll see what happens…

-Shasta

Had an earlier signal on a rotating cell that lasted only one frame in our southeast and did not receive reports from it.  Had another signal in Gage county, also did not last too long.  Area already under a SVR warning.

Here’s an earlier snapshot when rotation was stronger, but not in an area where reflectivity was high, especially given how high up we were in the storm.

Also, we have some local office research using RAP parameters for when we issued TOR warnings.  They looked at warnings that verified and those that didn’t and what the parameters were.  In this case, the 0-1 km shear was low, 10-15 knots, where the storm was, so it likely was just a rotating cell.