Tornado Watch...Why?

A low-end Tornado Watch is now in effect for locations primarily along and east of Interstate 65. I have not heard any rumbles of thunder with a couple of these small cells.

Hail could become a threat in the stronger storms. Since low pressure has created some spin in the atmosphere and surface heating is intensifying, there is a small chance for tornadoes.

Is it a good call? Well, the SPC  knows the dynamics of what variables constitute a Watch. Admittedly, I think it's overdone. But, I am all for safety and it only takes one brief spin-up to verify their reasoning.

Pay close attention to the skies and have access to local media or your programmed weather radio.

MS

Analogs Favor Severe Weather

UPDATE 7:00pm edt
Finally received confirmation of a 93 mph gust and tree damage around the Mesonet site near Bowling Green. I say it was a brief spinup or an awesome microburst. I would hope NWS investigates the damage because there was rotation before the storm hit the area and there was large hail just north of the site.
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UPDATE 4:55pm edt
Strong and severe thunderstorms approaching Louisville. Expect winds of 35-45 mph on average.

No confirmation on 92mph wind gust near Bowling Green. Did get reports of 1" hail. Unless there was a brief spinup, that gust could be an error.
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UPDATE 4:25pm edt
92 mph wind gust from Mesonet site from Warren County near Bowling Green. Waiting for confirmation.
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As part of my tool pack for the SQUALCON Index, I use the top 15 analogs, find the 5 closest ones that fit our region and average them out by rank.

Lately, our region has been averaging about 9.0 or a little higher. If we had the top 5 analogs in our region, you would add 1, 2, 3, 4, 5 and the sum would be 15. Divide that by 5 and get an average of 3, which is the most bullish scenario for severe weather coverage. So, 9.0 is somewhat low.

However, my latest calculations have Kentucky in the crosshairs for severe weather in 5 of the top 7 analogs for an average of 4.8.

This is a very bullish sign for widespread severe weather. As long as the atmosphere does not get worked over too much from earlier convection, we are primed for a severe weather episode that includes the whole arsenal of damaging storms, yes, including tornadoes.

MS

SQUALCON Watch

UPDATE 4:00PM
Dewpoint reading at my house is running between 72 and 73 degrees...parts of western KY coming in at 77 degrees. Ick! Heat index in Bowling Green at 102 according to Mesonet site.
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UPDATE 2:30PM
Cloud cover limiting convective potential near Louisville...Short-range models are in pretty good agreement that only scattered coverage of storms will be with us this afternoon. Tonight, around or after 11pm edt, storms will begin impacting the region from the west-northwest. Heavy rain potential exists along with lightning chances and high winds. Cannot tell if severe potential will be favorable, but since storms will be most prevalent after dark, only an MCS type storm may be able to generate enough umph to bring about isolated severe reports. Otherwise, heavy thunderstorms look to be the case.
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UPDATE 11:00AM
SPC downgrades severe risk to slight for today...now includes slight risk for Louisville on Friday. I am still keeping my SQUALCON Index heightened today/night, only shaving off a miniscule amount at 3.6 for the region with Louisville at the center of the region. I will include numbers for Friday later tonight.
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It's still several hours away, but residents should prepare for a potential damaging wind threat. SPC places parts of the region of north central Kentucky in an enhanced risk for severe weather.

In addition, while analogs do not support a widespread severe weather outbreak, I have calculated an average number of 9.0 / 13 based on the 5 top analogs that involve our region.

That is still rather low, but closer to a low-end moderate risk. I would rather see a value of 8.0 before putting us in a moderate risk category ( 3 being the most bullish and 13 the least bullish).

Of course, the usual suspect that could hinder severe development is cloud debris that may preclude aggressive storm initiation at the best time in the afternoon. Nevertheless, for the Thursday time frame, I am using the SQUALCON Index. Any value above 3.0 indicates an increasing likelihood for severe weather.

I have calculated a 3.7 for the region, which is one of the highest values I have assigned to the Louisville region this season, which encompasses Hancock County in the west to Fayette County in the east and LaRue County to the south.

I may have to use the SQUALCON Index again for Friday.

MS

High Winds Cranking Across Upper Midwest

UPDATE 10:40 am edt
Parts of Iowa reporting damage to buildings including a roof blown off of a school. 60-90 mph winds in Independence, IA. A wind report of 93.9 mph in the area. I have seen observations of 68 and 74 mph in non-thunderstorm winds in southern MN.
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Despite the heavy rains, intense lightning for some, and damaging winds for others in our region, check out some of the weather conditions in parts of southern Minnesota, northern Iowa, and eastern South Dakota.

High wind warnings are in effect for a couple more hours. These are non-thunderstorm winds wrapping in behind a small scale low pressure area producing sustained 40-55 mph winds with gusts near 70 mph.

A recent observation at Worthington, MN, close to the southern state line shared with Iowa in the southwest part of Minnesota, had a sustained wind of 56 mph and gusts of 74 mph. Partly cloudy skies were noted.

True, there are mean storms ahead of the system, but the most likely scenario for damaging winds exist as low pressure scoots by.

This is only a brief event lasting a few hours but how remarkable a small scale storm system like this can have such a dramatic impact on one's weather. Definitely not something I would like to wake up to.

MS

Ohh Nooo!...Mr. Bill

Not too many times do we see a tropical system or the remnants of one come to town. But when we do, it can be interesting. The most famous tropical system that came through here, in my opinion, was Ike. Not much rain, but a combination of its remnants and other atmospheric voodoo created a sustained wind event that reached hurricane strength at times. I still recall seeing huge limbs just fall out of trees while the sun was shining brightly. Very strange indeed.

Bill's remnants look to be a traditional soaker for us. While NWS offices may be calling for averages of 1-3", look for higher amounts in those bands that just seem to keep coming. You'll know the expression "when it rains, it pours", because these systems can put down an inch in 15-20 minutes easily.

Be safe out there. Turn around and don't drown.

MS

Some of Us Need Rain

Yes, despite all of the rain we had in April, we are presently undergoing a shortage of water. Not quite a drought, but some of us are in an 'abnormally dry' condition at present.

However, indicators are showing up that several episodes of downpours are on the table over the next week.

We start with today. Dewpoint reading at my house as of 2pm was 70 degrees. That's uncomfortable. However, am seeing a lot more clouds. Lots of cumulus clouds are popping up on visible satellite images during the heat of the day. And these are yielding small showers across Kentucky with lightning down around Campbellsville.

More concentrated storms are located across southern Indiana in the vicinity of a front.

With decent instability and lack of capping that we've seen for the past couple of days, some us will get some needed relief albeit temporarily, but the lawn will thank you. And my garden will like it too.

I still have a whole lot of rain stored up though. The garden is looking good right now despite the heat.

MS

Severe Weather Chances and SQUALCON

This is already becoming a tough forecast. A weakening band of rain and embedded thunderstorms is approaching our region of Southern Indiana and Central Kentucky this morning. Still, moderate to occasionally heavier rains are occurring over western part of Indiana.

Question becomes, will future redevelopment of vigorous storms initiate later today in the wake of early to mid-morning cloud debris?

I think the farther south you live, higher the chances for severe weather.

At this point, SQUALCON Index is at 3.3 / 5.0. This may not seem like an impressive number but is an average from Southern Indiana to central Kentucky.

Once the squall line develops, it will become quite rambunctious for a time as a few bowing segments will occur. Wind damage will be the primary mode of severe weather.

Obviously, depending on how quickly the atmosphere reloads, current thinking is from right along the Ohio River to points south stand a better than 3.0 / 5.0 for severe weather. Any value above 3.0 on my index increases the likelihood for severe storms.

Although current analogs are not bullish for widespread severe weather, with a 9.9/13 average or quite low ( 3 highest and 13 lowest), the potential exists for the most widespread wind/hail event this season in our region.

Let's see how this morning's cloud cover does and I will provide an update for severe chances shortly afterward.

MS