The Perils of Predicting Summer Storms

"Partly to mostly with a chance." Paul, can you possibly be a little more vague? Sunset today is 8:40 pm. Everything else is very much up in the air.

Summer weather forecasts can be especially maddening. Unlike storms during fall, winter and spring, when precipitation is steadier and more widespread, summer rain is "convective": pop-up thundershowers a few miles in diameter. Frontal boundaries create a temperature tug of war that increases instability, and the risk of bumping into a shower. Sometimes cold storms aloft can be just enough to tip the atmosphere over into a stormy display, especially late afternoon hours. Statistically, the best odds of dry weather are morning hours.

Remarkably, showers and storms may hold off for most of Minnesota until Sunday night or Monday. That's right, 6-7 dry days in a row for many communities, coming after the 5th wettest start to any year since 1871 in the metro area.

Soak up mid to upper 80s because a much cooler, more comfortable front spills out of Canada next week.

File image credit: Citizens Climate Lobby.

Rare Tornado Flattens Hundreds of Acres of Trees at Voyageurs National Park. I had no idea the damage was so extensive. Here are a couple excerpts at National Parks Traveler: "Tornadoes are commonplace in the Midwest, routinely showing up in Oklahoma, Kansas, Nebraska and eastern Wyoming and Colorado. When one touched down in Voyageurs National Park earlier this month, though, it raised the question of whether a change in extreme weather events is coming to the northern Minnesota park...The twister, the first reported to have touched down in the park's 44-year history, arrived with a strong cell of thunderstorms about 8 p.m. on July 17. Park staff reported Wednesday that the tornado touched down in the park's Kabetogama Peninsula and caused significant forest damage along an approximately 2.5-to-3.5-mile-long, 200-to-600-yard-wide path between Locator Lake and Marion Bay on Rainy Lake. The National Weather Service office in Duluth, Minnesota, estimated the wind storm as a moderate EF-1 strength tornado with maximum winds of 100 mph..."

Photo credit: "A tornado left a 2.5-to-3.5-mile path of downed trees in Voyageurs National Park in July." NPS.

ECMWF Accumulated Rainfall Into Sunday Evening. If European guidance is right (and I hope it is) showers and T-storms will be limited to the northern third of Minnesota this weekend, with the best chance of pop-up storms north of a line from Detroit Lakes to Brainerd to Duluth. We shall see, but many towns in central and southern Minnesota will go 6-7 days in a row without rain. Unheard of. Map: WeatherBell.

GFS Temperature Guidance. NOAA's models are a little more aggressive with the heat this weekend.

ECMWF Temperature Guidance. I think the "Euro" has the right idea with mid to upper 80s in the metro into Sunday, then cooling off into the 70s the latter half of next week as a touch of September arrives.

Lingering Heat (and Potential Hurricanes?) There is close to zero confidence in a 2-week hurricane outlook, so take the (apparent) storm off the Carolina coast the evening of August 15 with a super-sized grain of salt. Heat continues to bake much of America, with slight relief over the northern tier of the USA, including New England into mid-August.

12th Wettest July on Record at MSP. 6.48" of rain at MSP in July would make it the 12th wettest July on record, according to National Weather Service data.

Praedictix Briefing: Issued Thursday, August 1st, 2019:

  • We’re tracking a couple named tropical systems in the Pacific this morning, as well as a couple of areas in the Atlantic, one of which has a high chance of formation in the next five days.
  • In the Pacific, Hurricane Erick continues to weaken and will pass south of Hawaii over the next couple days. This system will bring parts of the Hawaiian Islands – especially the Big Island – heavy rain today through Saturday. The second system, Tropical Storm Flossie, continues to move west-northwestward and could approach (but at the moment just pass north) of Hawaii early next week.
  • In the Atlantic, showers and storms with a disturbance will move offshore the Southeast coast through the weekend before merging with a frontal system. While this will produce heavy rain for Cuba, the Bahamas, and parts of the Southeast, it only has a 10% chance of formation over the next five days. A second area, located about 1,000 miles west-southwest of the Cabo Verde Islands, has a high (70%) chance of formation as it continues to move to the west-northwest over the next five days. It could form into a tropical depression this weekend, and be near the Lesser Antilles early next week.
  • Rounds of heavy rain are likely across parts of the central United States – including Kansas City – over the next couple days, particularly tonight and Friday Night. Overall totals of 4-6”+ could lead to flash flooding, especially since these areas have also been hit with heavy rain over the past couple of days.

Tracking Erick. We continue to track Hurricane Erick, which is weakening southeast of the Hawaiian Islands. As of 11 PM HST, Erick had sustained winds of 90 mph and was moving to the west-northwest at 13 mph. The center of the storm was located about 400 miles southeast of Hilo, HI, or about 610 miles southeast of Honolulu, HI. Erick will continue to weaken as it moves to the west-northwest over the next couple days, becoming a tropical storm later today. The center of Erick will remain south of Hawaii, passing about 150 miles south of the Big Island tonight.

Main Impact: Heavy Rain. The main impact Erick will have on the Hawaiian Islands is heavy rain through Saturday. The potential exists for 4-6” of rain on the Big Island, especially along the south and southeastern facing slopes. This could lead to flash flooding, and due to that, a Flash Flood Watch has been issued for the Big Island from Thursday afternoon through Saturday morning. Also (not shown) is a high surf threat, with a High Surf Warning in place along the north, south, and east-facing sides of the Big Island through 6 PM Thursday as the surf could rise to 15-20 feet.

Tracking Flossie. Further east we have Tropical Storm Flossie, which had become a hurricane Tuesday but weakened back into a tropical storm yesterday due to strong upper-level winds. As of 11 PM HST, Flossie had sustained winds of 65 mph and was moving to the west-northwest at 16 mph. The center of Flossie was about 1,675 miles east of Hilo, HI. Not much change is expected in the strength of Flossie over the next couple days as it continues to move to the west-northwest, although a decrease in forward speed is expected. This motion would put Flossie near Hawaii by early next week, but right now models are trending the system northward, bringing the center of circulation north of the state. This is still several days out, however, and that overall track could continue to shift. Either way, like Erick, impacts will extend far from the center of the storm and could include another round of heavy rain as well as high surf.

Two Areas Of Interest In The Atlantic. In the Atlantic, two areas are being monitored for potential development over the next five days.

The first, located near the northwestern Bahamas, will continue to produce showers and thunderstorms across portions of the Bahamas, Cuba, and Florida over the next couple of days. While conditions do become slightly better for development this weekend, it is unlikely that it will become a tropical system at this time as it’ll merge with a frontal system Sunday. This system has a 0% chance of formation in the next two days and a 10% chance in the next five days.

The second area of interest is located about 1,000 miles west-southwest of the Cabo Verde Islands this morning. While it is currently disorganized, conditions are expected to become favorable this weekend in the central Atlantic for further development and a tropical depression could form east of the Lesser Antilles. Models have a wide range of outcomes with this system – as some form it into a hurricane and others have the system falling apart once it reaches the Antilles – so this will be one to keep an eye on over the next several days as it continues to move west to west-northwestward. This system has a 20% chance of formation in the next two days and a 70% chance in the next five days.

Flash Flood Risk In The Central U.S. Several rounds of heavy rain are expected across portions of the central United States over the next couple days. While rain is falling across the area this morning (with several Flash Flood Warnings across eastern Kansas), another line of storms is expected to form tonight and move across the same general areas. Another round is then expected Friday Night into Saturday morning. With both additional rounds of storms, rainfall rates of 2” per hour will be possible, with two-day totals of 5”+ possible. Due to the already wet conditions across the region (with flash flood guidance showing that less than 2” of rain in a three-hour period could cause flash flooding) on top of the additional heavy rain expected, a Moderate Risk of Flash Flooding is in place across portions of eastern Kansas, western Missouri, and northeastern Oklahoma for both the today/tonight and Friday/Friday Night timeframes.

Potential For 5”+ Of Rain. As mentioned above, models are indicating the potential for very heavy rain across portions of Kansas, Missouri, Arkansas, and Oklahoma through Saturday. Some areas could see over 6” of rain, which would lead to additional flash flooding across the region. Due to this, Flash Flood Watches are in place through Saturday morning.

D.J. Kayser, Meteorologist, Praedictix

NASA Casts a Double Eye on Hurricane Flossie. A story at caught my eye: "NASA's Aqua and Terra satellites provided infrared views of Flossie before and after it became a hurricane while moving through the Eastern Pacific Ocean. Both satellites analyzed Flossie's cloud top temperatures and structure as the storm strengthened..."

Image credit: "On July 30 at 7:17 a.m. EDT (1117 UTC) the AIRS instrument aboard NASA’s Aqua satellite analyzed Flossie’s cloud top temperatures in infrared light. AIRS found coldest cloud top temperatures (purple) of strongest thunderstorms in two areas were as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius)." Credit: NASA JPL/Heidar Thrastarson

How Better Weather Forecasts Are Changing The Way Cities Are Run. A story at caught my eye; here's a snippet: "...The increase in lead time before potentially dangerous events has given weather agencies much more time to communicate risks to residents. Hurricane Harvey, which hit Houston in 2017, ended up dropping a record-breaking 51.88 inches of rain on parts of the city. A dire warning issued by the National Weather Service that conveyed the severity of the predicted rainfall long after the hurricane made landfall was credited with saving lives. But more time is only part of the equation, as illustrated by Hurricane Katrina striking the Gulf Coast in 2005. “We had a pretty good two, or two-and-a-half, day forecast,” says Blum about Katrina. “Technically speaking, that was excellent for the time: It was better than average for the previous decade of hurricane forecasts...”

Ozone Season Lengthens Across Country. Climate Central has details: "Last week, we showed that hot summer temperatures are linked to air stagnation—which is increasing in most of the country. Stagnation traps harmful air pollutants like PM2.5 and ground-level ozone. This week, our new report takes a deeper look at ground-level ozone, the pollutant that exceeds national standards in counties that house 124 million Americans. Unlike natural stratospheric ozone, which protects us from the sun’s ultraviolet radiation, ground-level ozone is a pollutant. It forms when heat and sunlight allow the reaction of two other pollutants: nitrogen oxides and volatile organic compounds. These chemicals come from industrial plants, electric utilities, vehicle exhaust, wildfire smoke, and oil and gas extraction. High heat can accelerate this process. The resulting ground-level ozone can build up to unhealthy levels—especially without wind or rain to mix up the air..."

New Bill Aims to Break Cycle of Repeated Flooding and Rebuilding. Definition of insanity? Doing the same thing over and over, expecting different results. That old proverb came to mind reading a post at "...This is a chance for us to tell local communities that when you have property that has had several losses, there's a chance for you to take a second look and figure out whether that's a place where you need to build something in the future," Scott said. Scott says 1% of properties that have flooded repeatedly have received 33% of the payout from FEMA's National Flood Insurance Program (NFIP). He says that may not sound like a lot-- but it is. From October 2015 to September 2016, the NFIP paid out about $140 million in total claims in South Carolina. Scott says the large portion of that insurance payout that goes to properties that rebuild repeatedly have placed an enormous financial burden on the program, which many flood victims rely on..."

Graphic source: Fourth National Climate Assessment, 2018 and NOAA.

Home Are Being Built the Fastest in Many Flood-Prone Areas, Study Finds. A story at The New York Times left me shaking my head; here's the intro: "In many coastal states, flood-prone areas have seen the highest rates of home construction since 2010, a study found, suggesting that the risks of climate change have yet to fundamentally change people’s behavior. The study, by Climate Central, a New Jersey research group, looked at the 10-year flood risk zone — the area with a 10 percent chance of flooding in any given year — and estimated the zone’s size in 2050. Then the group counted up homes built there since 2010, using data from Zillow, a real estate company. For eight states, including Connecticut, Rhode Island, Mississippi and South Carolina, the percentage increase in homes built in the flood zone exceeded the rate of increase in the rest of the state. There are many reasons construction persists despite the danger..."

Photo credit: "" Jane Beiles for The New York Times.

Behind the Forecast: 5G vs. Accurate Forecast? Hopefully that's a choice we won't have to make, but a story and video at WAVE3 News caught my eye: "Would you trade an accurate weather forecast for the ability to scroll through social media and surf the internet on your phone faster than ever before? Soon, we may be making that choice. In March 2019, the Federal Communications Commission (FCC) auctioned off the 24-gigahertz frequency band to wireless phone carriers in preparation for the next generation of cell phone service or 5G. The sale netted the United States $2 billion. 5G technology would make our phones more reliable and 100 times faster than on current networks. However, for this to work, there needs to be a move to radio frequencies not currently used for cell phone service. Many meteorologists and other scientists fought this decision because of the potential to unintentionally set weather forecasts back decades..."

Parents Are Giving Up Custody of Their Kids to Get Need-Based College Financial Aid. Working the loopholes, or outright fraud. A story from ProPublica may leave you steamed; here's the intro: "Dozens of suburban Chicago families, perhaps many more, have been exploiting a legal loophole to win their children need-based college financial aid and scholarships they would not otherwise receive, court records and interviews show. Coming months after the national “Varsity Blues” college admissions scandal, this tactic also appears to involve families attempting to gain an advantage in an increasingly competitive and expensive college admissions system. Parents are giving up legal guardianship of their children during their junior or senior year in high school to someone else — a friend, aunt, cousin or grandparent. The guardianship status then allows the students to declare themselves financially independent of their families so they can qualify for federal, state and university aid, a ProPublica Illinois investigation found..."

Photo credit: "The University of Illinois Urbana-Champaign campus pictured on Monday." (Kristen Norman for ProPublica Illinois).

Careful with Those Overhead Bins. Wait, they can get a human up there but I can't fit my carry on bag? Whaaaat? CNN Travel has the story: "...Passenger Veronica Lloyd was surprised to find a flight attendant in the overhead compartment on her Southwest Airlines flight from Nashville to Atlanta on Monday. "She was up there for about five minutes. More than half the flight was boarded before she got down," Lloyd said. "It was pretty hilarious." "She was greeting passengers as they walked by," Lloyd added. Southwest said its employees "are known for demonstrating their sense of humor and unique personalities." In this case, the flight attendant "attempted to have a brief moment of fun with customers during boarding," the airline said in a statement. "Of course, this is not our normal procedure, and Southwest crews always maintain safety as their top priority..."

FRIDAY: Partly sunny and warm. Winds: SW 5-10. High: 86

SATURDAY: Hazy-blue sky, light winds. Winds: S 3-8. Wake-up: 66. High: 87

SUNDAY: Warm sunshine, few storms up north. Winds: SW 8-13. Wake-up: 68. High: 87

MONDAY: Passing shower or T-shower. Winds: NW 10-20. Wake-up: 69. High: 82

TUESDAY: Mix of clouds and sun, a bit cooler. Winds: NW 10-20. Wake-up: 65. High: 81

WEDNESDAY: Blue sky, hints of September. Winds: NW 10-15. Wake-up: 60. High: 78

THURSDAY: Wait, where did summer go? Windy with some sun. Winds: NW 10-20. Wake-up: 57. High: 74

Climate Stories....

"It's Going to Be Worse": Event Aims to Prepare Local Officials for Floods, Extreme Weather. Wisconsin is experiencing more frequent/extreme floods as well; here's a clip from a post at Wisconsin Public Radio: "...Jeff Last, a meteorologist with the National Weather Service of Green Bay, said Wisconsin communities across the state already feel the effects of climate change. "What we’ve seen with the warmer climates are more extremes," Last told the group. "There are more heavy precipitation events. More April snowstorms. … There’s no one particular event that we can say is the result of a warming climate, but in sum, there is evidence that it is part of that.” Green Bay was struck by flooding in March as a result of rainfall and melting snow across the region. And 2019 has been an extraordinarily wet year, Last said. But rainfall isn’t the only thing that can cause flooding. Just this month, heavy winds from the northeast swept over the bay, causing flooding in the area even though there was no heavy rain nearby..."

Photo credit: Wisconsin Emergency Management

A Second Night of Climate Debate (!): Headlines and links courtesy of Climate Nexus: "Democratic presidential candidates spent 13 minutes on climate change in the second presidential debate Wednesday evening in Detroit--one more minute than the 12 spent on Tuesday evening, according to a Washington Post tally. Washington governor Jay Inslee, whose campaign has centered around the issue, kicked off the discussion by centering climate change as "all the issues that we Democrats care about. It is health. It is national security. It is our economy." Sen. Cory Booker (NJ) joined Inslee in targeting former Vice President Joe Biden's plan to continue fossil fuel use and Booker calling out Biden's brag that he will rejoin the Paris Agreement. "Nobody should get applause for rejoining the Paris climate accords," Booker said. "That is kindergarten." As Robinson Meyer writes in The Atlantic, tech mogul Andrew Yang's argument that a universal basic income is the best way to mitigate climate impacts "is not a good response to losing your house to higher sea levels." (Washington Post $, Mother Jones, Vox, KOMO, The AtlanticNBCThe Week. Commentary: The Atlantic, Robinson Meyer analysis, CNN, Jay Inslee op-ed)

Is There a Windfall in Climate Change for Private Equity? The short answer appears to be yes. Here's an excerpt of a post at Forbes: "According to CDP, an international nonprofit, approximately 200 of the world’s largest companies collectively peg their climate change exposure at nearly $1 trillion. Manufacturers around the globe cite changing weather patterns and rising seas and rivers as increasingly disruptive to their supply chain. Within the U.S. utility industry, executives name climate change as one reason behind increasingly fierce wildfires, which have destroyed transmission and distribution infrastructure. While all of this may portend darkening financial skies, some see a different forecast developing. One where there are not only ideas but also action and financial opportunities. Some experts even see tailwinds for investors..."

Brain-Eating Amoeba, Flesh-Eating Bacteria. Climate Change Will Raise Florida's Risks. The pool is suddenly looking like a (slightly) better option, after reading a story at The Miami Herald: "...But as global temperatures rise, scientists say, so do your chances of catching a nasty — or even deadly — bug. The scary one making headlines this summer is Vibrio vulnificus, also dubbed in media reports as “flesh-eating bacteria.” Historically, it has been found in warm salt and brackish water, like the Gulf of Mexico. So far this summer, one death has been linked to the disease and another man spent nearly two weeks in the hospital — both in Gulf coast locations. But Vibrio isn’t the only danger found in warming waters. Freshwater lakes and canals can have Naegleria fowleri, also known as the “brain eating amoeba.” And pools, particularly public ones, may contain the gut-upsetting parasite called Cryptosporidium..."

Serious Melt in Greenland: Climate Nexus reports: "Greenland is suffering through a massive heat wave that could have devastating impacts on the region's crucial ice sheet. The heat wave that blanketed Europe last week has moved up to Greenland, causing what scientists say is one of the most severe melting events ever observed. This summer could see potentially greater impacts on the ice sheet than 2012, when the ice sheet lost 450 million metric tons--more than 14,000 tons per second. Surface melting and low snow levels on the ice sheet may combine to ensure "this is the year Greenland is contributing most to sea level rise," Columbia University's Marco Tedesco told the Washington Post." (Washington Post $, Rolling Stone, Gizmodo, CNN, Vice, Grist)

Read more here:

Read more here:

Climate Makes An Appearance At Debate: Climate Nexus has headlines and links: "Climate change made up 11 percent of the questions asked at CNN's first presidential debate Tuesday evening--up from six percent at the NBC debates in June--as moderators first introduced the issue nearly an hour and a half into the debate. Media Matters reports that eight of the 10 candidates onstage were invited by moderators to weigh in on topics including the Green New Deal and eliminating gas-powered cars, while the other two candidates were asked about the Flint water crisis. In keeping with the progressives versus moderates theme seen in other topics at the debate, Media Matters notes that moderators directed their questions initially at some of the centrist candidates onstage, and the questions were structured around the feasibility of progressive proposals like the Green New Deal. As Kate Aronoff writes in The Guardian, little-known candidates John Delaney and John Hickenlooper got more speaking time on Tuesday night than climate change has gotten in all three debates thus far." (Media Matters, Washington Post $, LA Times $, Mother JonesHuffPost, Politico. Commentary: The Guardian, Kate Aronoff op-ed, The Atlantic, Robinson Meyer analysis. Fact checks: AP, Washington Post $).

Audiences Are (Finally) Paying More Attention to Climate Stories. Here's a snippet from a story at Columbia Journalism Review: "...In response to a request from CJR, Hang analyzed climate-related articles in roughly 1,300 media websites worldwide (mostly in North America and Europe) between January 2017 and June 2019. Looking at the first quarter of each year, she found that the number of “engaged minutes” site visitors spent with climate stories in the first quarter of 2019—in other words, the minutes people spent reading—had almost doubled from the time spent in previous years. “The amount of time and attention readers are paying to climate change is strong and growing stronger,” Hang says. The jump in interest has been noticed at the Los Angeles Times, where, over the past year, the average climate story has outperformed average stories in other news sections, in terms of total audience, subscriber audience, and conversions from reader to subscriber..."

Meanwhile, in Boston:

Don't "Demonize" Energy Firms: BP Climate Boss Says Climate Activists Should Avoid Polarizing Society. Decades of industry-funded spin, misinformation and denial also tends to have a polarizing effect. has the story: "...BP Chief Executive Bob Dudley urged climate activists not to “demonize” companies, following several weeks of protests designed to highlight how fossil fuels contribute to climate change. The energy giant has been targeted by climate activist groups on numerous occasions in recent months, with demonstrators increasingly angry about the lack of progress toward a lower carbon future. “I don’t think it helps anything to demonize companies or groups. It gets society polarized and it is really hard to move through big complex problems when you set that up,” BP CEO Bob Dudley told CNBC’s “Squawk Box Europe” on Tuesday..."

Higher Temperatures = More Stagnant Air. Climate Central explains: "...Heat and stagnation are closely linked. Climate Central analyzed this link using the NOAA/NCEI Air Stagnation Index—which incorporates upper atmospheric winds, surface winds, and precipitation to calculate the daily level of stagnation—and summer high temperatures. Since 1973, 98% of the cities analyzed show a positive correlation between summer high temperatures and the number of summer stagnant days. Only five cities along the California coast lack this correlation;  their local heat comes from downsloping, offshore winds such as the Santa Ana winds, which mix up the air and limit stagnation. However, that doesn’t preclude those cities from having more stagnant days or unhealthy air..."

Older Post

Welcome to August - Heating Up To Near 90F by Weekend

Newer Post

In Praise of August (and September Too)