GOES-16 Derived CAPE

Here's an example where convection developed along a corridor of high instability:

Though the values of CAPE appear too low (by about 50% when compared to SPC Mesoanalysis), it is a great situational awareness tool to find the location of the greatest instability. 

Baseline Derived Products Not Useful within area of Convective Complex

The baseline derived products are not useful to get an update on the mesoscale environment where a deep convective complex is ongoing. NUCAPS data also came in several hours ago, so this will not be useful to reassess the current environment.

-Ironman

GLM During Large Cluster of Convection near DDC

In this example below, it was a bit difficult to use GLM to assess trends in convection since there was a large complex of storms with lightning being observed well away from the actual updrafts. New flashes were detected where new updrafts were developing to the SW of the main complex, but within the complex trends were difficult to assess.

NUCAPS Sounding added to Chicago environmental analysis

Later, Bill Line pointed out we had NUCAPS data in FROM 19Z, including Experimental.

The un-modified sounding looked wasn't very threatening with CAPE 0.  See attached NUCAPS.

The modified version gave SB CAPE of 290, and FCST Parcel 653. See attached NUCAPS EXPERIMENTAL.

Environment according to NUCAPS sounding not overly unstable. 

Storms were to our north at the time, Marginal Risk.

QUESTION: The Experimental DP didn't just modify the surface, but also the sounding up to around 870mb.  It seems strange, but I am told it must be portraying a mixed layer.  Is that closer to reality?

Davis Nolan
WKRN Meteorologist

RGB Sampling

Old RGBs (such as the Daytime Composite) included information such as radiance and cloud top temperature when sampling:
 

Newer RGBs only include the color components when sampling, as shown below:

These values have no operational utility. 

It would include beneficial for all RGBs to include radiance and cloud top temperature.

-Lost Met

Prob Severe vs All Tilts

One aspect of Prob Severe I noted today in the DDC region was its usefulness in a broader scale to pick out the strongest cells with large hail. There were several cells with high Prob Hail values all in a similar environment supportive of large hail. It may be quite difficult to do all tilts on each cell and be able to keep up with the fast changes in each one. Prob Severe would help in this case to issue timely warnings and potentially improve wording for hail size.

I do not want say Prob Severe should replace our typical radar interrogation, but I think it can help in an environment with many cells nearby all showing similar characteristics and structure.

I issued several warnings based on continuous high probabilities with Prob Hail. 

-Ironman

Analysis of environtment Chicago CWA ahead of storms with derived products and

Derived CAPE at 1902Z:  Only in the 100s  See: attached DERIVEDCAPE1902

Derived TPW at 1902Z:  Only 1-1.3"  See attached: TPW1902

Neither looked very menacing.

We had a METOPS pass at 1526Z (10:26AM Chicago time).  Sounding in the area.  It showed DP 48F, Temp 70.  All CAPE was zero and a stable environment.  See attached METOPSCHI1026 

I edited it to a DP of 54F and a temp of 86F.  It gave me a SB CAPE of 950.  See attached METOPSSCHIEDITED

A little more unstable, but nothing drastic.  

SPC had Marginal Risk as storms were moving in from the NNW.

Davis Nolan
WKRN Meteorologist

GOES-16 ABI Raw Imagery vs. RGB

The example below compares the GOES-16 Raw Imagery vs. Day Land Convection RGB:

In the example, the GOES-16 raw imagery is visible imagery with semi-transparent IR overlay. This combination of raw imagery provides similar and even more information than the dry land convection RGB.

Both examples provide information about the texture of the clouds; however, there is greater contrast with the colder cloud tops in the raw imagery when compared to the dry land convection.

-Lost Met

CG lead time

CG lead time with GLM:

Looked at two cases of initial convective activity of the day to see if GLM could provide some lead-time to a CG strike. In this case the GLM Event bump (orange) appear at the same time as a CG strike in both NLDN and Earth Networks. Zero lead-time in these cases.   --Tahoe

Shifting Severe Threat Focus

Main Points:

•  GOES-16 derived stability: No changes to southern CWA, still not expecting deep convective growth.
• Main focus is dry sub-cloud layers and convective outflow threat. Surface obs/msas were main data used to have confidence in outflow threat

After inspecting GOES16 derived stability plots, have not seen any changes to the environment in the southern CWA ahead of the line of storms. Basically low instability and lack of Cu field development in VIS. MSAS dewpoint depression shows 30+ degrees of dew point depression, so this piece of information was used to continue to monitor threat for outflows. Think usefulness in lightning and Prob-severe is of limited use at this stage since not looking at renewed deep convection due to low instability and overall low lightning amounts due to the lack of deep convection as well. --Tahoe.