ProbSevere from west of MLB

ProbSevere jumped to 69% for hail with a storm west of the MLB CWA. 55 dBz was noted at the -20C level and 50 dBz to 33 kft. A  hail threat this high still seems a little ambitious for central Florida in July given the marginal mid level lapse rates and tropical environment. 

-64BoggsLites

Day Cloud Phase loop from MLB this afternoon.

An example of a line of cumulus along an outflow boundary growing deeper and eventually glaciating to the west of MLB late this afternoon.

Along with a loop of the GLM interpolated flash product. Lightning seemed to remain focused with the strongest updraft in this case.

-64BoggsLites

FL storm development along boundary

Not much going on over the last few hours across the CWA. However, the IR overlaid atop vis imagery shows a storm strengthening along an outflow boundary just to the west of our CWA border. Lightning increase was seen in this storm as well. This "sandwich" image proved to be very useful in identifying the outflow boundary itself while also showing how a thunderstorm developed along it with cooling cloud tops

Storm IR comparison

Intense storm diving south out of FSD area into Boyd and Holt counties. Coldest temperatures got around -79.5 C for a time and area of subsidence/warming noted around periphery of overshooting top. 

Interesting to compare the GOES-16 IR imagery to GOES-13 data. (Images below) Aside from the differences in spatial resolution, the latency in GOES-13 data results in what appears to be a shift in position of the overshooting top.  This position closely resembled where feature was located about 7 minutes prior. So not only does GOES 16 provide higher resolution and more frequent images, its data can also be used to more accurately position features (although paralax remains a potential positional error)

-JRM

MLB update

A convergence of several boundaries into an area of ongoing convection south of  Palm Bay showed a considerable increase in deep convection.

IR shows cloud tops as cold as -77C (the Equilibrium level is near -80C) with this convection.

As this boundary interaction occurred, a considerable increase in lightning occurred in this area, as shown in the 2 images below

ProbSevere came up to 19% for wind with this band of convection, the strongest of the day so far.

-64BoggsLites

First Lightning Along in south Central SD

By 1951 storms have initiated over the area of interest with the first GLM flash occuring at 1951 UTC,  coinciding with first 50dbz echo from FSD at 1952 UTC.

First CG strike was detected at 1957 UTC with the GLM giving 6 minute lead time before the first strike.  Note that the parallax error causes the data to be shifted east of the CG location, which could cause some misinterpretation of the data.

-JRM

Montoring for Convective Initation - Using NUCAPS and GOES 16

By 19z shifted attention to possibility of new convective development along what appears to be outflow boundary across southwest corner of FSD CWA. Area of concern highlighted below:

First concern is how strong capping inversion is in this area. RAP analysis fields indicate H7 temps around 14-15C in area of interest. This is well supported by NUCAPS soundings around 18z which showed a large area of H7 temps in the 13-14C range.

Despite the warm temps aloft, persistent convergence and sustained cumulus provides some potential for storm initiation in this area in the next hour or so. Watching the 1 minute imagery of the Day cloud phase RBG, you can see glaciation begin in the towering CU field (increasing color). The following three images show an increase in ice starting around 1918 UTC through 1945 UTC. First 50 dbz echo appeared at 1952 UTC half degree KFSD scan.

GLM grid comparison

I thought I'd try comparing different resolutions of GLM data with radar/ENTLN data to see if something stood out in the GLM data. Below is a 4-panel with radar (top left, 5 minute flash density at 9km (top right), 5 minute group density (bottom left), ENTLN cloud and flash obs (bottom right).

Next is a 4-panel of GLM flash data at 5km (top right), 8km (top left), 9km (bottom left), and 10 km (bottom right)

...followed by a 4-panel of GLM group data at 5km (top right), 8km (top left), 9km (bottom left), and 10 km (bottom right)

It seemed the flash plots (second image) better represented the location and captured attention to a more specific area where lightning was occurring (although slightly displaced east), while the group data focused the bullseyes even further east and were a little more spread out/dispersed.  The 8km flash plot seemed to be the favorite.

-64BoggsLites

FL lightning compare

Tried to compare several different lightning plots associated our strongest cell along the coast. 5min Total ENT 1 min data is in the top left, 5min GLM  1 min 10km upper right, 5 min GLM 1 min 8km lower left, and 5 min GLM 1 min 5km in the lower right:

I still like how the ENT is placed over top of the storm, so that still tends to be my favorite. Comparing the GLM products, I was most quickly drawn to the 10km trend with the notable increase in lightning. However, 5km look most realistic. Since i tend to use lightning data at this point more for situational awareness, I kind of like the 10km data the best.

Northeast FSD Area- Satellite/Lightning Trends on

One of main concerns for period will be if severe MCS in southwest MN will continue on. The 1 minute GOES 16 IR window continues to show new cold cloud tops developing with no large scale warming of cloud tops. GLM data showing lightning increasing again as well which would would support storms continuing as it moves through instability axis. Loops approx 1834 UTC through 1904 UTC.

-JRM