Category Archives: stuff

Another little snow tonight

Sat.,Feb. 6,2021  5:30 P.M.

Another weak upper air disturbance system crosses the Ohio Valley tonight.  Once again, the Gulf is cut off from the flow, so producing much moisture will take a valiant effort from the upper air contribution.  It doesn’t appear likely to happen.

As a surface cold front pushes through overnight, it’ll probably produce some flurries and snow showers for a few hours, especially around Midnight.  Models are in agreement that one-half inch accumulation (on grassy areas) should be the upper limit.  So, not much to hope for.

Colder tomorrow with a high near 30.

The “big Blast” of cold air is still on track for next weekend.  Sat/Sun should be very cold followed by a quick warming.  Current GFS says this should be a one-time deal with no significant follow-ups expected.


Popular myth says that sharks can detect one drop of blood in an Olympic-sized swimming pool. NOT TRUE   While sharks, and fish in general, have good smelling abilities, they don’t came anywhere close to that claim.

Another popular shark myth is that once they get a taste of human blood, they will continue to search for more humans.  These are called “rogue sharks.”  Research, however, has shown that there are NO rogue sharks.  They much prefer a seafood diet.

Don’t believe everything you hear on “Shark Week.”

Snow has arrived!

4 P.M. Wed., Jan. 27, 2021

Best snow of season, so far

Fast-moving upper air disturbance is moving over lower Ohio Valley now.  Highest energy with the system is now streaking over TN.  North of the jet streak the air is cold enough for some light snow.  Over central Kentucky temperatures are still above freezing, so that’ll cut our accumulation a bit.  Colder areas north and west of Louisville should see the heaviest accumulations from this storm.  However, the rapid eastward movement of the upper support will limit the duration of snowfall so no major accumulations are likely.

Snow will gain intensity quickly and then fade quickly on the other end.  Heaviest snow should fall between roughly 5 P.M. and 8 P.M. in Louisville.  During that time, accumulations should run about one-half inch an hour – mostly on grassy areas.  Roadways will stay wet for most of the evening rush hour, so major problems are not expected.  However, temperatures are expected to drop to 32 between 6 and 7 P.M.  So, some of the later commuters will probably experience some slick spots – especially bridges and overpasses.

Overall, the Louisville area should expect 1″ – 2″ on grassy areas.  Roadways will most likely see less than an inch of snow.  Major roads around the area should be fine by morning, but, as usual, untreated roads will be icy.

Outside of Louisville, conditions will be different.  West and north of Louisville, colder air I expect will bring higher accumulations.  Most of southern Indiana should expect 2″ – 3″ of snowfall.  Wouldn’t be too surprised to see some reports over 3″.

Also, east of Louisville, most of the snow will fall after dark, which also favors higher accumulations.  From Oldham, Shelby and Spencer Counties and east,  2″ – 3″ of snow is likely.


The official definition of “heavy snow” varies across the country.  In snowier areas the threshold is six inches to use  the term heavy snow.  Our area’s threshold is four inches, so it’s not likely we’ll see that this time.  But winter’s not over!

Deja Vu

Monday, January 11, 2021  6 P.M.

It’s happened again!

Yesterday’s post was about a little “pet peeve” about the National Weather Service’s failure to update forecasts when they go bad.  For details, read yesterday’s comments.  Well, it really surprised me to see the same situation again today.  Only this time, the forecast also hit upon another one of may pet peeves.

Today’s forecast called for mostly cloudy skies this morning with skies becoming partly cloudy during the afternoon.  A late morning look at the situation showed that clearing, if any, would be very slow this afternoon.  So a forecast update then should have been a downgrade to at least “mostly cloudy” or , even better, “cloudy.” But, since midday updates aren’t required anymore, nothing happened.

My second pet peeve of the day is this…many times the morning forecast contains messaging for “this morning” and “this afternoon” rather than “today.”  That’s good.  After all, weather does change.  To me, it seems like a sensible idea that around Noon the forecast should be reissued removing the “this morning” wording.  Makes sense to me.  But, I can’t tell you how many times I’ve gone to the NWS forecast during the afternoon and the first phrase of the forecast contains the words “this morning.”  It’s just common sense.


One of my favorite quotes…Common sense isn’t.


Wednesday, June 10, 2020

Latest NWS forecast reads like this:

Detailed forecast for

Jefferson County

Late This Afternoon
Breezy. Partly cloudy. Slight chance of showers and thunderstorms early in the evening. Some thunderstorms may be severe with damaging winds and large hail early in the afternoon. Southwest winds 15 to 25 mph. Chance of precipitation 20 percent.
It is confusing, at the least.
Missed opportunit
Although we did see some showers yesterday, rain totals were small.  Today’s missed opportunity was our last chance for awhile, and that’s bad news.
 A strong upper air ridge will be building over the mid U.S. and will provide a long stretch of dry weather.  Temperatures are expected  to remain near-to-below normal, so it won’t be heat wave conditions,  but the ground will be drained of moisture quickly.  Early in the growing season is a bad time to have a dry spell because dry areas tend to feed on lack of moisture and grow.  Normally, summers tend to get drier as we get into July and August.  That usually bodes poorly for the growing season.  If these trends continue, we could be in for a hot, dry late summer.
1).  Coronavirus  cases in the U.S. are growing again as we reopen.  However, deaths from the virus are continuing to fall – about 1000 per day lately.  Seems like the older generation (people like me) is sticking by the masks and quarantining while the younger ones are less severely ill from the virus.
2). Cudos to our Prevaricator In Chief.    Must give credit where its due.  When he ran for President, Mr. Trump  (PIC) ran on two big issues.  1).  Build a wall.  2).  Make America Great Again.  Well, he has succeeded at both.  First, he imagined a great wall to keep the “good guys” (us) in while keeping the bad guys (Latin Americans) out.  He got his wall, but it didn’t quite work out as he imagined.  Instead, the much smaller wall around the White House is designed to keep the good guys (concerned Americans) out while keeping the bad guy in – hiding in his bunker.  Yes, PIC the world is laughing – not at us, but at you.
Then there’s MAGA.  Frankly, I never quite understood this slogan.  At least for the past 200 years when compared to the rest of the world, America has always been great.  We’ve had our problems, but we’ve been slowly improving over time.  But, when faced with a crisis, our PIC has really come through.  Yes, we’re NUMBER 1 – in a big way!  By huge margins,  we lead the world in coronavirus cases and fatalities!  Yes, we are NUMBER 1.

Computer models, part 3

Tuesday, May 5, 2020  6 P.M.

Current weather:  A strong upper air disturbance over upper midwest now will rotate southeast toward Kentucky tonight.  This system will provide some reasonably potent lifting motions over the lower Ohio Valley late tonight.  Not much moisture is available, but additional periods of light rain/drizzle are likely late tonight into tomorrow’s morning rush hour.

We’ll get to see some sunshine as tomorrow wears on, but temperatures will remain unseasonably cool.  The below normal temperatures will likely continue through the next week or two.

Computer models, part 3

The past two posts have told the story how weather forecasting and computers have been wedded since the beginning of electronic computing.  Today there are computer models/projections for just about everything.  Even one that predicted Secretariat to win the Super Derby last Saturday.

We all know that weather forecasts certainly are still not perfect, even though meteorologists have been at it the longest.  Other forecast models have the same problem, but do get better with age.  That leads us to the Coronavirus Models,  Unlike sports, weather, economics, etc., the available data on pandemics is pretty sparse.  Luckily not many pandemics occur.  Nevertheless, models have been built and put into action.  As expected we are hearing a variety of conflicting reports.  Pandemic modelling is a relative new field…its going to take some time for the model errors to shrink.  But with more data rapidly becoming available, improvement will occur.

Early talk of millions of deaths possible in the U.S. were simply “potential”.  They assumed no precautionary steps taken.  When precautions/restrictions went into effect across the country, the oft-quoted University of Washington model predicted 100,000 to 240,000 fatalities.  Our PIC (prevaricator in chief) just laughed that off.  Meanwhile, as the volume of data escalated, a few weeks later, UW lowered its prediction to 60,000.  Subsequent revisions went to 68,000 and then to 76,000.  All the recent revisions have been ridiculously low.  I’ve been watching the case/death numbers closely.  They just didn’t mesh with the predictions.  For example, Monday UW estimate was still in upper 70,000’s.  Just following the daily data, it was obvious we’d exceed that this week.  But, then, yesterday…

Kudos to the New York Times

For some (obvious) reason, it appears that PIC and his gang have been withholding information from an internal government forecast model.  That model predicts total U.S. deaths at 135,000.  To me, that number seems about right.  But with the recent rush to reopen the country, even that number could be low.  Thanks to the Times for breaking this story.  PIC, however, will likely just discard it as “fake news.”    (The only thing worse for PIC was if Jeff Bezos’ Washington Post had broken the story.)

Computer models, part 2

Monday, May 4, 2020  6 P.M.

First, our local weather

A weak low pressure system will work its way across the southern plains tonight and across Kentucky tomorrow.  It’ll bring us some rain tonight (after Midnight) into tomorrow.  Any rain after mid-morning tomorrow will be very light.  Total rainfall is expected to be in the quarter inch to half inch range.  Cooler air filters in tomorrow and we’ll see below normal temperatures likely through the weekend, at least.

Computer models and forecasting, part 2

After the Army built the first eniac  (computer) from 1943-6, the Navy decided to build a second one in cooperation with the private sector.  A group of mathematicians and meteorologists was chosen to complete the project.  Why meteorologists?  Two reasons: first, the earliest computers had no what we now call “software.”  The machine had to be built to solve one single problem.  It would have no other use since the “software” had to be built into the machine,  Second,  the project leader was  John von Neumann, a mathematician.  Von Neumann, however, was familiar with Richardson’s work from the 1920’s.  (previous post)

He figured the team had an already-solved problem.  All they had to do was build the machine to perform the calculations.  Thus, he reasoned, meteorology had the problem and a pre-existing method to solve the problem.  That would save a lot of time.

In reality, Richardson had made some mistakes and faulty assumptions.  The meteorology team spent a lot of redoing the physics and methodology before the machine could be built.

Finally, in 1950, in a large lab at Princeton University, eniac produced the world’s first non-military computer “output” – a 24 hour numerical weather forecast.  It took the machine 24 hours to produce it.

Within two years, the computer time dropped to two hours.  The world of “computer weather forecasting models” accelerated from there.  Improvement has been immense.

Other models:

Computer modelling has expanded over the years.  Virtually anything you can think of is under the scrutiny of various models.  Weather has had 70 years working on the problem and we still make mistakes.  Same goes for other models you may hear mentioned.  Which brings up today’s most talked about model – the coronavirus model.  The conversation continues tomorrow.

non-Derby Weekend odds and ends

Sunday, May 3, 2020  5 P.M.


Weekend forecasts for Louisville were reasonably good although temperatures were several degrees higher than predicted yesterday. If this had been a “business as usual” Derby Day, I wonder how many bad sunburns the infield crowd would have suffered.  Today’s temperature forecast was far worse than yesterday’s.  The expected showers finally arrived, but rain so far has hardly been worth the effort.  We’ll still maintain a chance for a few more light showers until about 8-9 P.M.

Looks like a nice day tomorrow with mid 70’s highs, then a good shot at a more significant rainfall tomorrow night into Tuesday.

Below normal temperatures will prevail from midweek through the weekend.

Forecast Models

Homo Sapiens (that’s us) evolved, we believe between 200,000 and 300,000 years ago, but did not  develop language skills until about 50,000 years so.  So, we’ve been trying to predict the future for at least 50 thousand years.  The first scientific numerical attempts, that I’m aware of,  were by Lewis Richardson in the early 1920’s.  He used equations developed by Wilhelm Bjerknes ( the Farther of modern meteorology) to create a numerical “model” of the atmosphere.  He then extrapolated the input data forward in time.  He produced a 6-hour forecast for two cities in Europe.  Sounds pretty simple, but there are an enormous number of calculations required to move forecast data horizontally and vertically through the atmosphere, even for just six hours.  Working off and on, Richardson took six MONTHS to complete his 6-hour forecast!

The numerical prediction did not produce realistic results.  But, the concept was proven correct. But the huge number of calculations needed proved it was not feasible at the time.

Jump ahead two decades.  During World War II the military wanted some way to speed calculations needed during battles.  Started in 1943 the project ended in 1946 by calculating (very rapidly) trajectories for canon balls by a machine called eniac  (electrical numerical integrator and computer).

Story continues tomorrow



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.


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”.


Grasping at more straws

Thursday,Feb. 6, 2020

Light snow possible late tonight

Snow chances have been few and far between this winter.  We started with tad about an inch of grass-only snow in November and haven’t been able to match it since.  However, we’ll see two chances over the next two days.  Best chance for breaking past one inch will come Saturday morning.

A strong upper level trough is passing over today, but so far is having trouble with surface development.  That problem should end tonight as a major surface storm will be developing/accelerating northeastward along and just east of the Appalachians tonight.  Latest forecasts have the storm path a bit farther east than earlier models.  That’s bad news for the Louisville area.

We were expected to be in the western edge of snowfall from this system.  Now, it looks like we’ll be “really” on the edge.  Far southeastern KY could get up to 6″ overnight.  As you head northwest from there, snowfall will lessen.  Bowling Green, Lexington and NE KY should be in the 2″-4″ range.  E-town, Bardstown, Shelbyville, and Henry County will likely be in the 1″-2″ zone.  West of that, snow will fall off quickly. SE Jefferson County could get up to .5″ while downtown will probably get a dusting.  North of the Ohio River…little to nothing.

In the Louisville area, snow is likely to begin about 3-4 A.M. and probably be over around 7-8 A.M.  Any accumulations will be on grassy areas.  Roads should be wet, but icy conditions are likely on some bridges and overpasses.

As the upper trough moves eastward tomorrow, a (probably) weak Alberta Clipper will run southeastward along the backside of the trough.  Models are projecting another area of light snow with the clipper and put us in its projected path.  I’ll check back on that tomorrow.


Together, Kobe Bryant and LeBron James played in every NBA Championship Finals from 2008 until 2018.  But, they never played each other.

Snow tonight

Not much, but it’s a good start

Monday, November 11, 2019

Forecasters and forecast models all seem to be on the same page with the cold front moving through this evening.  Late afternoon rain should change over to light snow between 7 – 8 P.M. around the metro area.  Snow should be light and be over by midnight.  Then a wintry blast of cold air takes over for a few days.

It’ll probably take about 1-2 hours after the snow begins before temperatures drop below freezing. Nevertheless, we’ll probably see a little snow on grassy areas – up to 1″ in colder suburban areas.  No more than a few icy spots on roads, especially bridges and overpasses.  No problems are expected for the morning rush hour(s).


No wonder squirrels seem busy these days.  It takes at least 100 acorns for an average squirrel to make it through a winter.