Monthly Archives: March 2020

A little rain tonight

Sunday, March 22, 2020  6 P.M.

A weak upper air system will pass over the area tonight.  However, it’s not likely to bring much rain.  Low level moisture is very low, so it’s going to take a long time for the rain/snow above us to saturate the air to bring us some rain.  A few sprinkles or patches of light rain are possible this evening.  However, our best chance for some light rain will be for rush hour tomorrow morning.  Overall, total rainfall from this system will most likely be a trace to a couple hundredths of an inch.

If you’ve been watching radar this afternoon, you’ve been seeing in action what I described above.  If you have watched Louisville radar, you’ve seen rain all around us, but none close to us.  However, if you’ve seen so-called “composite” radar, it looks like we’ve had rain for the past few hours.  In fact, it has been raining aloft, but not reaching the ground.  It’s evaporating before it hits the ground.  You may see gray vertical streaks coming from the clouds.  That’s called virga – falling precipitation evaporating before it reaches the surface

Note:  Composite radar, which most media outlets show, integrates data from all NWS radars in the area.  Locally, what we are seeing is a merging of radar data from our radar (at Ft. Knox) with data from Nashville, Cincinnati, Indy and Evansville.  While our radar sees no rain, the others all show rain aloft over Louisville.  Compositing also creates problems for accurately locating thunderstorms.

Stuff

Being of a certain age, I’ve been closely following the spread of the coronavirus.  I’m also a scientist and have been closely watching the numbers.  As a result, I’m convinced we’ve reached the point of no return. Within the next day or two,  I expect the U.S. healthcare system to become completely overrun.  Our Prevaricator In Chief (PIC) constantly tells us we have all the medical supplies we need.  But where are they?  (Perhaps he sent them to our friends in North Korea?)  It’s obvious PIC has no sense of science.  Many of his serious science statements have been just harmlessly funny.  But, this time, his failure to even consider his science/medical advisers has allowed a great plague to take hold of our citizens.  He was advised of the possible consequences of coronavirus as early as January.  Instead, we got “It’s just the flu” , “Don’t worry about it” and it’s a “Democrat Hoax!”

It looks to me as though the next two weeks (at least) are going to be very bad.  PIC and Congress will throw trillions of dollars at the problem, but it’s not going to do much good.  That’s a lot of money to spend on a “Democrat Hoax”.

 

Storm update- 11 P.M.

Thursday, March 19, 2020  11 P.M.

After Midnight, periods of thunderstorms/heavy rain/possible flash flooding over the southern third of IN, but stay north of Ohio River until about 5 A.M.

Louisville area has showers/thunderstorms 5 – 8 AM.

NO severe thunderstorms are expected, and flash flooding threat fading over the area, especially south of the Ohio River.

Flash Flood, Tornado Watches tonight

Thursday,March 19, 2020

Flash flooding likely: severe storms iffy

A fairly strong upper air disturbance will come across the lower Ohio Valley tonight.  Lucky for us, it’s focused mostly on Indiana.  With this upper system, we’ll see two clusters of thunderstorms overnight.  With the rains of the past two days, periods of heavy rain, especially over southern IN, will pretty much guarantee widespread pockets of flash flooding over northern KY and southern IN.  If you live in a flash flood-prone area, you know the drill.

The first cluster of thunderstorms will be over the area this evening.  The southern side is weak and will provide plenty of rain to west and central KY and initiate some of the expected flash flooding.  But no severe thunderstorms.

The first cluster of storms will be more noteworthy over the southern half of Indiana.  Severe storms are moving over southern Illinois and will race eastnortheastward.  Heavy downpours are likely and a few severe storms will be possible between, roughly, 8 P.M. and Midnight.  Primary threat will be strong winds and possibly some hail.

The second cluster of storms will move through the area between about 2 A.M. and 8 A.M.  This one is much stronger and is likely to produce an outbreak of severe storms from Arkansas, southeast Missouri and southern IL this evening.  By the time this cluster arrives in the Louisville region, it is likely to be weakening.  Plus, atmospheric instability will be diminishing. Also, the strongest dynamics will remain north of our area.

The result will be a very noisy night north of the Ohio River.  Flash flooding will probably become  a serious problem.  Storms will be strong, but probably not severe.  Along and south of the Ohio River, the primary line of thunderstorms most likely won’t arrive in Louisville until 5 A.M. or later.  They will not be very strong, but deposit enough rain to make a very messy rush hour before the exit the area by 8 A.M.

 

Recent trends looking good for us

Strongest storms will stay south and west of Louisville

Thursday, March 12, 2020  4:45 P.M.

Latest radar trends and short term forecast models are strongly indicating that we’ll get plenty of rain this evening, but severe weather will not reach the Louisville area.  Severe storms are forming along the approaching cold front over western KY and dropping rapidly southeast.  That area of severe storms is heading toward central Tennessee.

Meanwhile, area of showers and non-severe thunderstorms has been expanding over  SW IN and is moving our way.  Cold front may produce some gusty winds as it passes through the Louisville area between 6:30 and 8:30 this evening.  Our biggest problem will be with heavy rain and possible areas of flash flooding.

 

 

Two rounds of thunderstorms this evening

Thursday, March 12, 2020  4 P.M.

Cluster of rain/thunderstorms in the area now is not showing any signs of severe weather,  Instability is very low, but the dynamics are quite strong.  Nevertheless, severe weather is not expected with this area.  However, stronger storms appear likely later this evening.

Current showers/t-storms are forming along a warm front slowly pushing north.  Once we get into the warmer/moister air south of the front, we’ll have the potential for slightly higher instability for a few hours.

During that time, a cold front will be moving over southern IN/western KY.  That system should pass through our area between 6 and 8 P.M.  The front is already creating severe weather to our west.  Instability should still be weak, but the wind fields will be strong enough to create a strong wind threat – possibly severe (58 mph or more) in a few areas.  Atmospheric structure favorable for tornadoes should remain south and west of Louisville.

After 8 P.M., threat for severe weather will move south and east of Louisville area.