This is not normal.

-Champion

Today wins the distance award as we split up across the country to diagnose convective initiation in various environmental regimes. In the morning, forecasters started in Sterling, VA (LWX), Tampa Bay (TBW), and Pocatello, ID (PIH). Our LWX team used a suite of the GOES-R LAP and CI products to diagnose the near-storm environment and convective potential along/ahead of the cold front across the Appalachian mountains today. With minimal convection in the late afternoon hours, they were moved to Denver/Boulder, CO (BOU) to evaluation the pGLM color curves of some very marginal convection . Out PIH team also spent a good part of the day diagnosing CI and evaluating ENTLN tools and trends as a region of instability on the westward side of the upper-level ridge moved into the area. Our TBW team stayed quite busy with sub-severe seabreeze thunderstorms occurring across most of central FL throughout the day. ProbSevere and the suite of GOES-R products were used actively to target and prioritize regions with promising CI potential throughout the day.

-Darrel Kingfield, CIMMS/NSSL Research Associate & Week 2 EWP Coordinator

The GOES-R Convective Initiation seems to have issues at nighttime. This even occurs with the use of infrared satellite data in the algorithm.

Here are a couple images from the transition from day to night:

From these images, it seems the convective initiation algorithm is probably more useful during the day. The coarser resolution of the infrared satellite data could possibly explain this problem.

Polarimetric Researcher

As expected, the max value on gridded lightning data will likely need to be location specific and might even need to be adjusted based on time of year or even type of storm to better visualize storm trends. I can see how this would quickly become complex and would require local research that might only be done at offices with someone interested in ltg data. Regardless, as has been discussed ad nauseam, changing the max value needs to be easier for forecasters. Simply adjusting the color map is not a long term fix!

Finally got a cell to exceed 25 flashes/min (only lasted for a minute or two), which triggered a DTA (since there is a lower threshold in the west).

At the same time, ProbSevere was near the highest we had seen all day at ~36% with MESH of 0.83 in.

The OT algorithm also began to indicate a possible OT with the storm at roughly the same time.

Hard to say which of these products was the first to key in on the intensification as they all started showing signs at approximately the same time. However, the lightning time series does show a rapid increase just prior to 2245 (lightning jump?).

Issued a SPS based on the experimental products and base radar data.

Ertel

Monitoring the ongoing thunderstorms, Earth Networks continue to supply helpful lightning data.  This is a good supplement to watch indicating future thunderstorm growth or at least some pulsing. The lightning flash data drops out, much like a missed satellite frame. Interestingly enough, there are a couple other troubling notes. Multiple lightning lines (streamers of history) are located in the same circled area. What exactly does this mean to the forecaster? Additionally, four areas inside the circle are showing flash rates above 25 strikes per minute. It is confusing to an operational forecaster and takes time to interpret data that should be straightforward. The display has to be massaged to increase ease and usability. At 2315z there is a circle inside a circle…. and a dangerous thunderstorm alert inside a thunderstorm alerts.

UFFSU

Looking at some slow moving multicell storms over the Gulf (near Houston) and the cell polygons jump around as new cells merge/develop around the original cell polygon. The end result is a pretty interesting storm track!

Ertel

A few rounds of storms have moved through Tampa Bay this afternoon and evening. I have been monitoring another round of development on a 4 panel showing Prob Severe, reflectivity, and Earth Networks alert data with lightning track. While Earth Networks has had issues with over-alerting, this product was the first to alert to a developing strong storm. The boxes from Earth Networks are overlapping and confusing as it appears lightning data is being pulled from the same storm, but parsed into separate tracks. These alerts were posted at least 45 minutes before Prob Severe indicated 77% probability of going severe in the next 60 minutes.  Reflectivity did a better job that prob severe hinting, at least, at the chance for thunderstorm growth.

UFFSU

Storms continue to move through the Tampa Bay area.  Storms continue to display a high degree of electrical charge. Alerts from the Earth Networks lightning guidance remains on. As these storms move slowly to the west, one notices a tremendous amount of alerts. The photos below show dangerous and significant thunderstorm alerts in the bottom right page. You can see that there are a number of alert boxes present at 2100z.  The times associated with these boxes all expire after 2115z.  Yet, these boxes come and go so rapidly that they are really useless, disappearing when lightning ramps down it appears. It just lacks reliability with its current display.

UFFSU

2100z

2115z 

ProbSevere prompted a third significant weather advisory. In this example, the probability increased from 13% to 74% in 10 minutes:

The base data confirmed strong winds and small hail would be possible with this storm.

Cape Coral Police reported several trees and power lines down in Cape Coral and South Cape Coral areas. They estimated the damage occurred between 3:40 PM and 3:55 PM.

This is another example where the trends in ProbSevere can be extremely useful to warning forecasters to find storms that need further integration (“all-tilts without looking at all-tilts”).

Polarimetric Researcher