Storms With Lots of Lightning

A line of storms near Santa Claus, Indiana to southwest of Owensboro continues to maintain its intensity as it progresses eastward. Lightning counts have been increasing over the past hour.

Will it hold together long enough to reach us here in Louisville?

We'll see. Typically storms begin to fizzle this time of day after lasting for several hours. Even if they do begin to weaken, I still expect precipitation here in Jefferson County by the two o'clock hour.

Right now, I am more concerned with the lightning count than anything else. But, if the line begins to collapse, strong winds often accompany such a feature. Otherwise, winds up to 40 mph along with pea-size hail and intense lightning should be expected.

MS

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UPDATE 2:30 pm
Strong storm pushes through Valley Station...Wind gusts of 40 mph and very heavy rainfall with a decreasing lightning count came through the area.

Over the past 3 days, I have recorded 0.4", 0.38", and now 0.38" respectively. Consistency indeed.

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Severe Weather and SQUALCON

After analyzing latest data, I have given our region of southern Indiana to central Kentucky from Owensboro to Lexington a 2.8 out of 5 using my exclusive SQUALCON Index. Top 5- ranked analogs for our region average 9.6 / 13, fairly low for widespread severe weather (range of 3 highest to 13 lowest).

The last time I used this experimental index, I assigned a 3.3 to the region with Louisville being the regional center. Most of the severe weather reports occurred east of Louisville. Any value above 3 signifies an increasing likelihood for severe weather associated with any form of a line of thunderstorms or non-thunderstorms.

While I do expect some severe weather reports regionally, I still believe that the strongest storms will reside mostly north of our region. Using Indianapolis as the center of its region, I am assigning a higher value of 3.3.

You can see the SQUALCON descriptors here on my blog. Remember, this is still experimental. Additional modifications are expected as I tweak possibly several variables.

An average value of 3 for a particular region means there is a 50 percent chance for severe weather reports within the assigned center's region.

MS

Storm Outlook

Good Sunday morning. Brief thoughts about our upcoming storm chances.

First, some parts of the state got in on some hefty rain totals yesterday. In western Kentucky, some amounts were over 2". My house in Valley Station received 0.34".

Now, severe weather chances appear meager at best. Nonetheless, there will be a chance especially just ahead of an approaching cold front.

Best chances exist in far west Kentucky today into the overnight. Then for northeast Kentucky tomorrow. But again, low chances.

Then, more beautiful weather for the week ahead. Enjoy it.

😊 MS

***NEW*** SQUALCON Index

Here is something new I developed exclusively for my blog, the SQUALCON Index. You have already heard of The Weather Channel's Dr. Greg Forbes and his TORCON Index. Well, this experimental index will help assign a numerical value for determining the strength of an expected squall line of thunderstorms (or non-thunderstorms).

There are many sources and references I use to establish the new index. Forecasts from numerical models like GFS and NAM, analogs, Storm Prediction Center, and other National Weather Service products are a few of the samples.

The SQUALCON Index is experimental because various challenges exist. For example, what defines a squall line? Does a derecho count or its cousins, the MCS and MCC, the cluster of storms that are defined as such based on size and shape?

Other questions and challenges may include whether to assign a value to the entire squall line or to a regional/local focus.

Below is the table with associated values and descriptors....

Scale of 1-5.

1 - Winds of 25 to 35 mph; scattered small twigs.
2 - Winds of 35 to 45 mph; numerous twigs and scattered small limbs.
3 - Winds of 45 to 55 mph; numerous small to medium-size limbs, isolated power outages.
4 - Winds of 55 to 65 mph; large limbs, susceptible trees uproot, widespread power outages.
5 - Winds > 65 mph; widespread damage to trees, power outages, shingles affected.

Applying this table to a regional focus, for later today, I've assigned a value of 3.3.

Therefore, I would expect a few severe reports, but this is not expected to be a widespread event, at least in our region.

Winds just above the surface should register between 44 and 62 mph. How much of that will translate to the surface? Not all of it, but we should expect winds of at least 40 - 50 mph on average with higher gusts. Also, the foliage will add extra weight to limbs, making them more prone to damage if wet.

MS