Why Can't We Predict Rain With Greater Precision?

"It's tough to make predictions, especially about the future" Yogi Berra famously quipped. I feel his pain. We all demand perfection - in an imperfect world.

But meteorologists have such cool gadgets: Doppler radar, satellite images from space with half kilometer resolution - some of the most powerful supercomputers on the planet running simulations.

And yet we still can't say with a high degree of specificity what time it will rain, especially during summer hit-or-miss thunderstorm season. We can tell when conditions are ripe for storms, but what time, which neighborhoods? Good luck with that.

This year, when in doubt, predict rain. Odds are you'll be right. Early storms are followed by warm sunshine later today. Daytime highs top 80F through the end of the week, with the next surge of T-storms Friday into
Saturday. Sunday looks like the cooler, drier day of the weekend. 70s early next week give way to a cooler front with 60s in a week.

Meanwhile the dregs of Tropical Storm Imelda are soaking Houston with potentially life-threatening rains. 

Super-storm Sandy imagery from 2012: Mel Shapiro, NCAR.


Rainfall Forecast by Friday Morning. The model above is NOAA's 3 KM WRF, predicting over 1" of rain for much of southern Minnesota over the next 60 hours. Map: pivotalweather.com.



Mild Bias Into Early October. There is a considerable amount of variation from extended GFS run to the next, which means overall confidence is even lower than usual looking out 2 weeks. The latest run of NOAA's Global Forecast System suggests relative warmth for most of the USA, including Minnesota, into at least the first few days of October.

Fall Color Update. 25-75% of the trees along the North Shore of Lake Superior are turning color, according to the Minnesota DNR.

Record Rainfall Causes Erosion Problems in Southern Minnesota River Towns. Star Tribune has the story: "With yet another storm looming, the mayor of this waterlogged southeastern Minnesota river town sat down last week with a roomful of state and federal officials looking for some financial help. A flood channel and a dike built years ago to protect this city of 207 residents from high water had been seriously damaged by erosion caused by a series of storms that had pounded southern Minnesota since spring, and Zumbro Falls needed nearly $200,000 for repairs. The Zumbro River carved a 300- to 400-foot slice off a dike that runs the length of town, and jostled loose a series of boulders in a coulee built after a 2010 flood swamped the city and destroyed 10 houses, including Mayor Bruce ­Heitmann’s place..."

Photo credit: Dan Browning – Star Tribune. "Zumbro Falls Mayor Bruce Heitmann pointed out the erosion on a dike that protects his city of 207 residents from the Zumbro River. The city is seeking help to reinforce the dike after this year's heavy rains."


Praedictix Briefing: Issued Tuesday afternoon, September 17th, 2019:

  • The tropical disturbance off the Texas coast has become better organized over the past few hours, and with a special 12:45 PM CDT update from the National Hurricane Center was named Tropical Storm Imelda. At 1 PM, the system made landfall near Freeport, TX.
  • The main threat with this system will continue to be heavy rain over the next few days across southeastern Texas. Rainfall amounts of 5-10”+ will continue to be possible through Thursday across this region, including Houston. This will lead to potentially significant and life-threatening flash flooding.

Tropical Storm Imelda Has Formed. The tropical disturbance we mentioned this morning off the Texas Coast has become better organized over the past few hours, and in special updates over the Noon hour from the National Hurricane Center was named Tropical Storm Imelda. There was a report in Freeport, TX, of 40 mph sustained winds with a wind gust of 47 mph with this system. As of 12:45 PM, Imelda had sustained winds of 40 mph and was moving north at 7 mph. The center was located over Freeport, TX, or 40 miles southwest of Galveston, TX.


Imelda Track. Imelda will continue to track to the north, moving inland over the next few hours west of Houston. The system will eventually be downgraded to a tropical depression by Wednesday morning.



Tropical Alerts. While some strong wind gusts are expected with this storm, the main threat will continue to be heavy rain, as mentioned in the previous briefing earlier today. Due to expected tropical storm conditions, coastal Tropical Storm Warnings have been put in place from Sargent, TX, to Port Bolivar, TX. These Tropical Storm Warnings are in place for land areas in the following locations: Galveston Island and Bolivar Peninsula, Coastal Galveston, Coastal Harris, Coastal Brazoria, and the Brazoria Islands.



Heavy Rain Potential. Heavy rain continues to be the major impact with this system across the region, especially in and around the Houston metro. Over 2” of rain has been reported in Beaumont since midnight. Downpours of 1-3”+ per hour at times will continue to be possible through the middle of the week, with rainfall tallies of at least 5-10” possible. Some areas could see isolated 15” amounts. This will continue to bring at least a moderate flood risk to the region through Thursday, and by Wednesday and Thursday could produce significant and life-threatening flash flooding across the region.


Flash Flood Watch. Flash Flood Watches remain in place through Wednesday afternoon across the Houston metro due to the expected heavy rain, but I would expect these to be extended into Thursday.

D.J. Kayser, Meteorologist, Praedictix


The Northern Hemisphere Just Had its Warmest Summer on Record. Capital Weather Gang has the post: "The Northern Hemisphere just had its hottest summer on record since 1880, according to National Oceanic and Atmospheric Administration data released Monday. NOAA found the average global surface temperature taken by thousands of thermometers, buoys and other sensors on land and sea tied with that of 2016 for the top spot, with a temperature anomaly of 2.03 degrees (1.13 Celsius) above the 20th-century average. In addition, August was the world’s second-hottest such month, according to both NOAA and NASA, with unusually hot conditions seen from pole to pole and across every ocean. What’s remarkable about 2019′s record warmth is that it comes in the absence of a strong El Niño event in the tropical Pacific Ocean. Such events tend to boost global temperatures by warming the seas and sending more heat into the atmosphere..."

Photo credit: "Children playing in a water fountain in Antwerp, Belgium, in July." (Virginia Mayo/AP).




It's a Myth That Tornadoes Can't Hit Cities. In light of the 3 EF-2 tornadoes that hit the south side of Sioux Falls, South Dakota, a story at Argus Leader is timely: "It's a question anyone living in Sioux Falls knows the answer to — but cities having nothing to fear from twisters remains a pervasive myth. Adam French, an associate professor at the South Dakota School of Mines & Technology, teaches in the school's Atmospheric and Environmental Program and said it's something he's heard many times before. "I think the biggest thing it boils down to is that a tornado is a small-scale feature," French said. It mostly comes down to a numbers game. The country gets an average of 1,253 tornadoes per year, but when only 3% of the country's land area is made up of urban areas, the odds of one being hit drop significantly. "The likelihood of a tornado hitting a given place is extremely small," French said..."

Image credit: "In video released by the City of Sioux Falls, damage done to multiple businesses and homes can be seen." Courtesy of City of Sioux Falls.


Extreme Weather Events (and the Costs) Are Piling Up. Here's a clip from a summary at NBC News: "...But the growth of extreme weather extends beyond hurricanes. An analysis of weather disasters that did more than $1 billion in damage from the National Centers for Environmental Information finds that such high-cost events are up markedly since the 1980s. (The dollar figures for the events were adjusted for inflation.) There have been 250 such events since 1980 and almost half them, 111, have occurred in the current decade. And the 2019 figure does not include any events after May, so Dorian is not on the list yet. There were only 28 billion-dollar weather events in the 1980s..."


112-Year-Old White Sox Fan Celebrates Birthday By Going to His First Game. CNN.com has a heartwarming story; here's an excerpt: "CP Crawford's been a Chicago White Sox fan for almost as long as he's been alive, but he'd never been to see them play -- until he turned 112. The supercentenarian was born in 1907, just seven years after the Sox moved to Chicago. He religiously watched them on TV from his nursing home in Lansing, Illinois…"


Would You Stay at a Hotel at the North Pole? Another intriguing story from CNN; here's an excerpt: "Ever dreamed of spending the night in an igloo at the North Pole? For one month only, travelers will have the opportunity to do just that -- provided they've got a spare $100,000.A temporary hotel site is opening at the northernmost place in the world in April 2020, offering a once-in-a-lifetime experience for adventurous explorers. South-facing window pretty much guaranteed! North Pole Igloos hotel will be made up of 10 heated domes in which guests can sleep under the stars in the frozen center of the Arctic Ocean…."

Photo credit: Luxury Action.


88 F. maximum temperature yesterday in the Twin Cities.

71 F. average high on September 17.

81 F. high on September 17, 2018.

September 18, 1997: An F3 tornado destroys several buildings and damages numerous others. Hundreds of trees are knocked down. A number of cattle are also killed in a collapsed barn. One man is injured when the tornado engulfs his car and throws it into a nearby woods. A second man is critically injured when his garage collapses, then dies several weeks later. The total path length of the tornado from 1 NE of Lastrup to Onamia is 17 miles. Total property damage is estimated at $1.7 million. In total, 6 tornadoes touch down in Morrison, Mille Lacs, and Kanabec.

September 18, 1991: Duluth gets 2.5 inches of snow five days before the beginning of Fall.

September 18, 1971: A brush fire at Lake Alexander in Morrison County spawns a 10-foot wide, 50-foot high 'fire whirl.' It moved out over the lake, overturned a 1,800 pound pontoon boat, and then dissipated as it moved back to shore.

September 18, 1903: 3.75 inches of rain falls in the Minneapolis area.



WEDNESDAY: AM T-storms, then clearing. Winds: SW 15-25. High: 82

THURSDAY: Partly sunny, less humid. Winds: E 5-10. Wake-up: 63. High: near 80

FRIDAY: Humid again. Scattered T-storms, some heavy. Winds: SE 8-13. Wake-up: 66. High: 81

SATURDAY: Lingering showers, few T-storms. Widns: SW 10-15. Wake-up: 68. High: 78

SUNDAY: Mix of clouds and sun, a drier day. Winds: W 10-15. Wake-up: 58. High: 75

MONDAY: Partly sunny and pleasant. Winds: S 8-13. Wake-up: 57. High: 79

TUESDAY: Blend of clouds & sun, probably dry. Winds: S 8-13. Wake-up: 61. High: near 80


Climate Stories....

Climate Change is Having Widespread Health Impacts. Scientific American has a summary of recent research: "The climate crisis is making people sicker—worsening illnesses ranging from seasonal allergies to heart and lung disease. Children, pregnant people and the elderly are the most at risk from extreme weather and rising heat. But the impact of the climate crisis—for patients, doctors and researchers—is already being felt across every specialty of medicine, with worse feared to come. “There’s research suggesting that our prescription medications may be causing harm because of changing heat patterns,” said Aaron Bernstein, a pediatric hospitalist who is the co-director of the Center for Climate, Health and the Global Environment at Harvard University..."

Illustration credit: Sonny Ross The Guardian.


75% of Americans Now Believe Humans Fuel Climate Change. Here's an excerpt from Big Think: "A strong majority of Americans believe humans are fueling climate change, with roughly half of respondents saying action is urgently needed, according to two recent polls. The results come from a CBS News Poll, which was released as part of Covering Climate Now, and another unrelated poll conducted by The Washington Post and the Kaiser Family Foundation (KFF). The CBS poll found that, among Americans:

  • About 70 percent believe human activity contributes "a lot" or "some" to climate change.
  • About 56 percent believe humans should act on climate change "right now..."

Hello from 2050. We Avoided the Worst of Climate Change - But Everything is Different. Bill McKibbon looks ahead for a special edition of TIME.com: "...By 2020, renewable energy was the cheapest way to generate electricity around the planet—in fact, the cheapest way there ever had been. The engineers had done their job, taking sun and wind from quirky backyard DIY projects to cutting-edge technology. Batteries had plummeted down the same cost curve as renewable energy, so the fact that the sun went down at night no longer mattered quite so much—you could store its rays to use later. And the third realization? People began to understand that the biggest reason we weren’t making full, fast use of these new technologies was the political power of the fossil-fuel industry. Investigative journalists had exposed its three-decade campaign of denial and disinformation, and attorneys general and plaintiffs’ lawyers were beginning to pick them apart. And just in time..."



Greta Thunberg is the Climate Heroine We Need. Greta Thunberg was dying from depression and starvation when she had a nightmare about climate change that saved her life. It might just save all of us. The Daily Beast reports: "When Swedish climate change activist Greta Thunberg was 11 years old, her body had started to shut down due to severe self-starvation tied to debilitating depression. She spoke to almost no one but her immediate family. She was afraid of crowds. She was lost in her own world, and the world very nearly lost her. But thanks to the formal diagnosis of Asperger’s syndrome coupled with high-functioning autism and obsessive compulsive disorder, the now-16-year-old Swede has become quite literally the poster child for the generation that will have to deal with the destruction of our planet. Once she started receiving multifaceted treatment, Thunberg was able to channel her anxiety into something we should all be concerned about: the health of the planet and the science behind apocalyptic warnings of its demise..."


The Kids Are Rising: Climate Nexus has headlines and URL's: "Swedish teen activist Greta Thunberg led around 1,500 youth climate protesters in a demonstration outside the White House Friday, the latest Fridays for Future climate strike that began more than a year ago with Thunberg protesting alone outside the Swedish Parliament. Last week's protest comes as a preview of the country- and worldwide planned walkout on September 20, three days before the UN Climate Summit begins in New York City. New York Mayor Bill de Blasio said last week that the Department of Education will excuse children who decide to skip school next Friday for the climate strike. Since arriving in New York last month following a two-week transatlantic boat journey, Thunberg has appeared on multiple news outlets, including an interview with The Daily Show's Trevor Noah. "It feels like many people are debating about the climate crisis, which they are doing everywhere," Thunberg told the Washington Post in an interview ahead of Friday's protest. "But here, it’s like they even doubt facts." (DC strike: Washington Post $, Time, ReutersAPThe Hill, USA Today, NPR. NYC: New York Daily News, New York Post).


Climate Change May Be Affecting Tornadoes. The Oklahoman connects the dots: "...Studies show twisters are spawning less often in western Texas and Oklahoma, part of the historically tornado-prone area known as Tornado Alley. That could indicate a shift of average tornado genesis to the east, affecting more populous regions near the Mississippi River. What scientists aren't sure about, but have a hypothesis, is that climate change is causing drier conditions to push eastward across the central United States; convective storms that spawn tornadoes need warm, moist air for energy. In many cases, researchers see effects long before they find a cause. Such is the case with evidence that shows hurricanes are intensifying more rapidly, another outcome linked to climate change..."

Photo credit: "Debris left behind at the American Budget Value Inn in the aftermath of a tornado in El Reno on May 26. Studies show twisters are spawning less often in western Texas and Oklahoma, part of the historically tornado-prone area known as Tornado Alley." [Chris Landsberger/The Oklahoman]


The World Needs Carbon-Neutral Flying. Here's How to Bring It One Step Closer. The World Economic Forum has an interesting post; here's an excerpt: "...Hybrid propulsion, whereby electric motors would provide initial thrust on take-off and landing for example, could on the other hand reduce emissions in medium- and long-haul flying, but this also will take years to make a substantial impact. This leaves sustainable aviation fuels, or SAF, as the most realistic option today for greener flying. SAF could come in various types of sustainable bio-fuels (derived from waste and not in competition with any food crops) that are in use already today. Synthetic fuels are another potential source, capturing CO2 during their production phase. SAF – which can reduce the carbon footprint of aviation fuel by up to 80% over their full life cycle – started testing on commercial-sized aircraft systems in 2008..."

Photo credit: REUTERS/David Gray.


Is Climate Change "Evil"? A post at The Guardian caught my eye; here's a clip: "...Robinson is chair of the Elders, an independent group of global leaders founded by Nelson Mandela that works for human rights. She will say in her speech: “I believe that climate change denial is not just ignorant, it is malign, it is evil, and it amounts to an attempt to deny human rights to some of the most vulnerable people on the planet.” “The evidence about the effects of climate change is incontrovertible, and the moral case for urgent action indisputable,” she will say. “Climate change undermines the enjoyment of the full range of human rights – from the right to life, to food, to shelter and to health. It is an injustice that the people who have contributed least to the causes of the problem suffer the worst impacts of climate change...”

Photo credit: "Mary Robinson: ‘I believe that climate change denial is not just ignorant, it is malign, it is evil." Photograph: Johnny Savage/The Guardian.


Polls Show Americans Are Thinking About Climate--But We're Still Lagging Behind: Climate Nexus has headlines and links: "Climate change is increasingly becoming an urgent issue for a majority of Americans, two new polls show, but a separate poll shows that the US still leads the world in denial. A CBS News poll, conducted as part of the network's Covering Climate Now coverage, shows that more than half of Americans think action needs to be taken "right now" to address climate change, while more than 25 percent think climate change is a "crisis," and 36 percent consider it a "serious problem." A separate poll conducted by the Washington Post and the Kaiser Family Foundation finds that 4 in 10 Americans consider climate change a crisis, while 8 in 10 respondents say human activity is making the planet warmer. But it's not all good news: a survey conducted by YouGov shows that 15 percent of Americans have some sort of skepticism about climate change--the highest percentage of deniers in the population of any country in the world." (CBS: CBS, The Guardian, The Hill. Post: Washington Post $. YouGov: FT $)

File image: Leslie Berg.

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Ration of Thursday Sun, Then More T-storms. Update on Imelda, Humberto and Jerry