Wednesday, June 10, 2020
Latest NWS forecast reads like this:
Detailed forecast for
Wednesday, June 10, 2020
Latest NWS forecast reads like this:
Detailed forecast for
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.)
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.
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.
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.
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
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”.
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.
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.
Ohio Valley part of storm fades
Oct. 21, 2019 4 P.M.
Since late last week I’ve been hearing all these horror stories about today’s weather – heavy rain, flash flooding, possible severe storms, strong winds, etc.
Well, Monday has arrived and only (mostly) one part of the forecast will be correct. We have had strong winds – gusts in the mid 30’s. Although we were led to believe they’d be about 10 mph stronger.
Periods of rain are likely through about 9 P.M. though total rainfall should be about a quarter-inch or less. A little lightning will be possible around 8 P.M. Winds will still remain gusty- gusts possible of 30-35 mph late afternoon but diminishing this evening.
This situation brought back a story about a former WAVE weathercaster from waaaay back. He had predicted the next day to be sunny, windy and warm. Instead, we had a cloudy, cool, rainy and windy day.
His next broadcast began this way…”See, I told you it was going to be windy today!”
Just checked the afternoon forecast from the NWS. Cloudy with a high in the upper 70’s.
Here we are sitting under cloudy skies, light NE winds at about 60 degrees. How are we going to get almost 20 degrees of warming over the next 4-5 hours? We’re not. Even if the clouds cleared immediately, we’d be hard pressed to get that warm. In reality, clouds should begin to thin by 3-4 P.M. Even with thinning clouds, we’ll be lucky to reach the low 70’s. Around 70 seems more likely.
What’s up? Isn’t anyone paying attention?
A little perspective…
Slashing and burning of the Amazon has been going on for decades. All of a sudden this year, it became the “climate destruction gang’s” next big thing on the climate agenda. But why now? The average amount of deforestation over the past five years has been only about 50% of what was occurring 20 years ago.
Don’t get me wrong on this, Amazon deforestation is (and has been) a big climate problem. But, programs have been ongoing for years to reduce the burning. Success has been modest, but this certainly is not a new problem.
Sat. Aug. 31, 2019 3:30 P.M.
Much better news for Florida!
Over my 50+ years of trying to into harmony with nature, I repeated countless times, “Don’t trust any forecast beyond two days.” We still miss forecasts in days 1 and 2, but that forecast is usually pretty accurate. But when you get beyond 2 days, things change.
Hurricane Dorian forecasts this week have been a prime example. Early this week Dorian was projected to hit somewhere along the Florida east coast. Where? We have many different models looking at the storm (you’ve probably seen the “Spaghetti Diagrams” on tv), but the U.S. showcase is the GFS and the top model in the world is referred as the EURO. Let’s just track those two.
Early in the week, the GFS landfall was predicted to be along the FL/GA border. The euro focused on southern FL. Over the next day or two, the GFS gradually worked its landfall southward to close to the euro position. Yesterday, the GFS still predicted a hit north of Miami then at least a two day journey northward over Florida. That matches the horrific damage projection I mentioned Thursday.
But, yesterday’s morning euro changed! It no longer predicted Dorian to hit Florida. Instead, it would get within a 100 miles or so, then turn slowly northward along the coast and probably not hit land until about North Carolina. That’s VERY important! As far a potential damage goes, there’s a huge difference between a hit and a near miss. Meanwhile, the GFS maintained it’s devastating forecast.
This morning, the GFS caught up to the euro with the “close miss” scenario, but was still putting landfall along the area along the North/South Carolina border. Today’s euro, however, has shifted the storm track farther east, possibly even missing the Outer Banks.
So, what’s going to happen?
Good question. We’re still more than two days away from U.S. coastal interaction and “trends” sometimes do reverse. So, no one from Florida to North Carolina is completely out of danger yet. But, current trends are indicating a much better situation, especially for Florida. As it stands now, Florida’s biggest threat will come from beach erosion. But remember, things change!
GFS vs. euro
Remember earlier this summer when the National Weather Service made a big fuss over it’s introduction of its “new and better” GFS version? The model was designed to oust the euro as world’s best. Dorian has been the first big test for the new GFS. So far, so bad. But, things change. Let’s see how it plays out.
The director of the Internal Revenue Service during the mid 1940’s later went to jail for failing to pay his income taxes.