We have been watching a line of storms that have continued redevelopment on the south side….

The south side keeps popping up new cells and actually the CI is picking up on that very well.. (the orange one towards the left).

I have been tracking this southern line and looking at radar and it is picking up on the new cell initiation.

This is at 2015Z.

Then here is the next image at 2030z.

And here is the line at 2044Z

Lauren13

Image 1.  AWIPS Time 1921Z.  5 Minute ENTLN Lightning Plot 1920Z.  Pulse Count (Upper left corner) 255.

Image 2.  AWIPS Time 1922Z.  5 Minute ENTLN Lightning Plot 1920Z.  Pulse Count (Upper left corner) 327.

Image 3.  AWIPS Time 1923Z.  5 Minute ENTLN Lightning Plot 1925Z.  Pulse Count (Upper left corner) 160.

Image 4.  AWIPS Time 1924Z.  5 Minute ENTLN Lightning Plot 1925Z.  Pulse Count (Upper left corner) 175.

Image 5.  AWIPS Time 1925Z.  5 Minute ENTLN Lightning Plot 1925Z.  Pulse Count (Upper left corner) 222.

Image 6.  AWIPS Time 1926Z.  5 Minute ENTLN Lightning Plot 1925Z.  Pulse Count (Upper left corner) 286.

Image 7.  AWIPS Time 1927Z.  5 Minute ENTLN Lightning Plot 1930Z.  Pulse Count (Upper left corner) 137.

Critical issue: The 5 Minute ENTLN Lightning Plot is adding new lightning data every minute and “resets” after 5 minutes.  It is NOT a 5 minute total based on the previous 5 minutes as it seems.  It is not a 5 minute running average (that could be updated every minute).  When the forecaster loads the most current frame they are getting data that is misleading.  In the case above it appears that the storm is strengthening from Image 1 to 2, then weakening from Image 2 to 3, then strengthening from Image 3 to 6, then weakening from Image 6 to 7.  In reality, it’s just the addition and reset of the 5 minute lightning data.  Not only is this misleading, but it is detrimental to forecasters trying decide whether to warn or not based on this data.  I certainly won’t use this data until it’s corrected and will pass this information on to others.  I don’t understand how someone in their right mind can find this current scheme above good.

Furthermore, the 5 Minute ENTLN Lightning Plot doesn’t match the AWIPS time.  In Image 3 the AWIPS Time is 1923Z, but the 5 Minute ENTLN Lightning Plot is 1925Z (in the future?).  Why???  In this case the 5 Minute ENTLN Lightning Plot should stay labeled as 1920Z and update to 1925Z after the AWIPS clock hits 1925Z.

What’s also worrisome is it appears other ENTLN Lightning minute products are “adding” new data every minute (i.e. the 5 and 15 Minute Lightning grids, etc.).  This needs to be looked into more and corrected.

How should this be fixed?  The 5 Minute ENTLN Lightning Plot needs to update AFTER it gets 5 minutes worth of added data.  In the example above it should work as…

AWIPS Time 1921Z.  5 Minute ENTLN Lightning Plot 1916Z.  Pulse Count (Upper left corner) NNNN where NNNN is the previous 5 minute total from 1911 to 1916Z.

AWIPS Time 1922Z.  5 Minute ENTLN Lightning Plot 1921Z.  Pulse Count (Upper left corner) 327.

AWIPS Time 1923Z.  5 Minute ENTLN Lightning Plot 1921Z.  Pulse Count (Upper left corner) 327.

AWIPS Time 1924Z.  5 Minute ENTLN Lightning Plot 1921Z.  Pulse Count (Upper left corner) 327.

AWIPS Time 1925Z.  5 Minute ENTLN Lightning Plot 1921Z.  Pulse Count (Upper left corner) 327.

AWIPS Time 1926Z.  5 Minute ENTLN Lightning Plot 1921Z.  Pulse Count (Upper left corner) 327.

AWIPS Time 1927Z.  5 Minute ENTLN Lightning Plot 1926Z.  Pulse Count (Upper left corner) 286.

This allows me to see the total trend every 5 minutes.  Going from a Pulse Count of 327 down to 286 is more informative.

Get the point?

-Champion

CI Prob continues to handle the developing line heading into western SJT cwa.  Visible satellite hints at outflow and developing clouds, but CI Prob helps confirm new storm initiations.  The 1930z 4 panel view shows the higher probability of thunderstorms developing along a line.

The larger view of the radar helps us verify the lengthening of the line into MAF cwa. These storms continue to move slowly SE. It should also be noted CI Prob is also indicating thunderstorm development ahead of the current line.  This area of convection will be contained in central SJT cwa. Will continue to monitor any possible development to see how CI Prob verifies in cloud/cirrus setting.

UFFSU

Here is an example where the convective initiation algorithm performed poorly (click to animate):

In this example, both instability and shear were very weak:

In contrast, here is an example where the convective initiation algorithm performed well (click to animate):

In this example, there was moderate instability, but shear was still weak:

From these examples, it appears the convective initiation algorithm (which uses environmental parameters) doesn’t do as good a job in poor environmental conditions. The algorithm especially seems sensitive to instability.

Polarimetric Researcher

Main issue for today is airmass recovery behind initial eastward propagating MCS now located at the eastern edge of our CWA. Our western half of the CWA more favored for SVR this afternoon due to a greater chance of recovery. Current CAPE profiles from the GOES sounder indicate ongoing airmass recovery along the western edge of our CWA, with CAPE values approaching 1000 J/K in the west and AOB 400 J/KG in the east. CIN is rather low/near zero over most of the area, so storm coverage could be high, which would limit overall severe potential.

However, model guidance suggests that afternoon CAPE profiles (~1000-1500 J/KG) and deep layer shear (~40 kts) will be favorable for organized convection, with potential for severe hail/wind and perhaps an isolated tornado with any supercell structures that could develop.

ERTEL

One good thing about these ENI alerts is using them in a large scale picture. This doesn’t help “too” much at the local WFO scale but looking at a swatch of tstorms over a large regional area, you can easily pinpoint the stronger storms. I see a lot of aviation impacts with this in terms of CAWS issuance and Convective Sigmets. They look at the entire country for convection and this can help draw their eyes to the strongest storms.

I can also see the ENI alerts being useful for storms coming from Mexico. It may not have good radar coverage but with the probsvr and the ENI, those offices can better see these storms coming into the area.

Lauren13

The CI product did a pretty good job of capturing the initiation of cells to our west over Mexico. The image below at 1630Z shows CI values over the center of the image at 31%. The next scan (1645Z) showed an increase to 53% and by the next scan (1715 Z) CI dropped out since the cell had initiated. It would have been interesting to see what CI trends would have provided if the satellite was in RSO or if there would have been a scan at 1700Z.

ERTEL

Here is an example of where ProbSvr can hurt and help. In a large swatch of rainfall and embedded thunderstorms, the ProbSvr picks up almost everything. This would be a situation where “turning off” the model under a certain percentage would hide these probs that are under 5-10%. It gets messy!

Lauren13

Dangerous Thunderstorm Alerts from ENI continue to be evaluated. In an environment with more isolated cells, the ENI displays are cleaner and more user friendly (decreased clutter). These cells are more long lived today, which reduces the DTA polygons from jumping all around with quickly developing storms that are short lived (Florida case observed yesterday). My concern with the DTA polygons today revolve around the storm movement indicated by these polygons. As the storm area increases lightning concentration will change, which seems to be throwing off storm direction. I am not sure what variables DTAs use to determine direction, but I have observed a few odd changes with polygon directions from minute to minute (1 minute update).

These following two images show the issue, they are one minute apart..the environment could not have changed that drastically…

UFFSU

I am noticing a trend that ENI Lightning Jumps are acting as a precursor in today’s environment to increased Prob Severe probabilities. The trend is developing after a few observations with early initiations in the far west part of our CWA border.  The first image is an example of an ENI jump, please focus on upper right panel (data point 2).

Prob Severe has been a very helpful tool through the week. As we analyze more discrete cells developing and moving east into the SJN CWA. In this cases, our data display from ENI has been much cleaner and seems to help guide the forecaster.  The correlation to lightning jumps and storm intensification will continue to be monitored in today’s environment. The image below demonstrates the increasing prob severe probability just minutes after our ENI lightning jump (bottom left panel, <70%)..

UFFSU