Posts Tagged weather
Temperature combines badly with humidity to maximize misery
The Twin Cities tied its record high temperature yesterday at 97 degrees Fahrenheit. However, the winds blew strong with air at a dew point in the low 60s, which made the heat relatively tolerable. After spending most of August at our second home in southwest Florida (leaving there just as Hurricane Idalia hit), my wife and I got acclimated to a far more uncomfortable daily combination of heat and humidity.
Before departing for Minnesota, I set up a SensorPush to monitor temperature, humidity and dew point—the temperature at which air becomes saturated with water vapor. I want to be on guard for the air conditioning going out. If that happens in Florida homes, mold can grow. After experiencing this once (due to renters not running the A/C) and dealing with an expensive remediation, I am keen to prevent another episode.
Closely related to dew point is the wet-bulb temperature, which, as chemical engineer, I learned how to measure with a sling psychrometer. The wet-bulb-temperature can then be converted to relative humidity.
To prevent heat-related deaths in training camps, the US military developed a more sophisticated measure called the wet bulb globe temperature (WBGT). It provides a good measure for the advisability of being active in full sun. The Texas University Interscholastic League requires that outdoor practices be shut down if WGBT exceeds 92.
“As with all indices that integrate elements of the thermal environment, interpretation of the observed levels of WBGT requires careful evaluation of people’s activity, clothing, and many other factors, all of which can introduce large errors into any predictions of adverse effects.”
– Grahame M Budd, Wet-bulb globe temperature (WBGT)–its history and its limitations
Other measures use to gauge comfort are Heat Index and Feels Like Temperature (FLT). I like the FLT because it accounts for the benefits of evaporative cooling. For example, as I write this, the actual temperature is 95 degrees and the FLT is only slightly higher at 96.
I’m getting too hot and bothered with all these measurements to continue much longer, but here’s yet another approach used by AccuWeather—the RealFeel Temperature.
What really matters is how you feel and what can be done to avoid discomfort. For example, earlier this summer I went to our Minnesota’s Washington County Fair on a very hot day and stopped in at a beer garden for a cold brew. However, I soon realized that its hot tin roof radiated heat down to the picnic tables—overcoming any advantage to being in the shade.
Sometimes you can find no relief other than hunkering down in an air-conditioned area. How did we ever get by without it?
Hurricane season off to a hot start with great uncertainty ahead
Posted by mark in Nature, Uncategorized, Weather on June 30, 2023
After narrowly dodging Ian’s devastating blow last fall—predicted the day before landfall to hit just a few blocks from my southwest Florida winter home, I am keeping a close watch on this year’s storms.
Just prior to 2024 season on June 1, the National Oceanic and Atmospheric Administration (NOAA) predicted it would be near normal. The NOAA forecasters figure on the winds from the Pacific’s El Nino counteracting the storm inducing temperatures in the Atlantic.
A clash of the titans lies ahead as developing El Niño and notable warmth in the Tropical Atlantic go toe-to-toe.
Ryan Truchelut—the Weather Tiger’s Atlantic Hurricane Season Outlook for May 2023
The Weather Tiger (quoted above) calculated Florida landfall odds this year at slightly above 50/50 for at least 1 hurricane. That was before Tropical Storm Cindy formed behind Tropical Storm Bret in June, creating the first case of two storms in the tropical Atlantic in June since record keeping began in 1851–an alarmingly aggressive start to the season.
Based on these forecasts and the history of USA hurricanes, it seems certain to me that, before 2023 is over, our home will come into harm’s way. Therefore, I keep a close watch on NOAA’s graphical forecasts that display cones showing the probable track of the center of every tropical cyclone. These cones create a great deal of consternation and confusion due to difficulties comprehending probabilities, overly high expectations in the accuracy and precision of forecasting models, and other issues.
While admiring the continuing advancements in meteorology, including this year’s extension to 7 days for hurricane forecasts, I believe (but only half seriously) that if a weather forecast one-day ahead puts me at the bullseye of an oncoming storm, then it will be a miss. This worked for Hurricane Ian. But to hedge my bets, I greatly reinforced our home over the winter to resist wind, rain and flooding—bringing it all up to current hurricane codes and beyond.
Best be safe!
Hurricane forecasters getting in the zone with their cone
Posted by mark in Nature, Uncategorized on September 13, 2018
Owning a home in Florida, I keep a close eye on the National Hurricane Center (NHC) forecasts throughout the June-through-November season. I see that Florence is now predicted to make landfall around mid-day tomorrow just south of Wilmington, North Carolina—the gateway to the aptly named Cape Fear. Even though that’s less than 24 hours away, it’s still subject to a broad zone of uncertainty–on the order of 100’s of miles. However, it’s very impressive that the NHC forecast made 48 hours ago remains right on. According to a Wall Street Journal report yesterday their 5-day conical projections have improved by more than 100 nautical miles (115 land miles) in radius over the past decade. That’s even more impressive.
However, WSJ advises we’d best remain very leery of the NHC’s spaghetti plots (an alternative to the cone), because they include very simple forecasts along with those that are state-of-the-art. This can be very disconcerting as I discovered when Irma came along a year ago to graze my place along the west coast of Florida. You can see in this Business Insider report on Irma that, only 3 days beforehand, this hurricane’s predicted landfalls ranged from Louisiana to Massachusetts. The article says that NHC suggests that people not focus on the specific tracks. That seems obvious to me based on the ridiculously high variance. I’d like to see these tracks vary by thickness according to the sophistication of the models—the thinner the weaker.
In any case, let’s hope that Florence fizzles out, after all.
Algae World News: Red snow melts glaciers
Just in time for our first snow in Minnesota when we eagerly bring out our cross-country skis and sleds—both self-propelled and motorized, comes this news of a melt-inducing microbe. I’ve seen and tasted the resulting “watermelon snow” up in the Rockies. It seemed harmless enough—a natural frozen novelty. But a simple comparative experiment by Alaskan researchers showed a 17% increase in melting where the snow became darkened by the algae stain. On the positive side it will be watermelon snow-cones all around.
Arctic vortex delivers an impressive “Cold Force” for mid-December
As you can see, I awoke this morning to an outside temperature of minus 20.2 degrees F, which comes to precisely minus 29.00000 on the Celsius scale according to this metric converter. When I opened the window, the air provided an impressive slap to my face—no need for coffee to provide an eye-opener. However, I had to quickly shut out the cold before it gave me a brain freeze.
The iconic fellow pictured on my La Crosse Technology Wireless Weather Station, whom I generally find very indicative on temperature, did not get dressed warmly enough today. He needs a mask to avoid a frostbitten nose and frozen ears. When the Arctic express whistles down into our mid-Continent winter wasteland, I fall back on the Anderson Cold Scale, which came up just shy of Freezing Force 6 in the predawn hour. That tells me to don 6 layers before venturing out for my morning walk. I start with Long Johns. If this is your first winter up north and you need a warm undergarment, check out this traditional one from the Gentleman’s Emporium — fire engine red with rear fireman’s flap.
Models responsible for whacky weather
Posted by mark in Basic stats & math, pop, science on August 14, 2016
Watching Brazilian supermodel Gisele Bundchen sashay across the Olympic stadium in Rio reminded me that, while these fashion plates are really dishy to view, they can be very dippy when it comes to forecasting. Every time one of our local weather gurus says that their models are disagreeing, I wonder why they would ask someone like Gisele. What does she and her like know about meteorology?
There really is a connection of fashion and statistical models—the random walk. However, this movement would be more like that of a drunken man than a fashionably-calculated stroll down the catwalk. For example, see this video by an MIT professor showing 7 willy-nilly paths from a single point.
Anyways, I am wandering all over the place with this blog. Mainly I wanted to draw your attention to the Monte Carlo method for forecasting. I used this for my MBA thesis in 1980, burning up many minutes of very expensive main-frame computer time in the late ‘70s. What got me going on this whole Monte Carlo meander is this article from yesterday’s Wall Street Journal. Check out how the European models did better than the Americans on predicting the path of Hurricane Sandy. Evidently the Euros are on to something as detailed in this Scientific American report at the end of last year’s hurricane season.
I have a random thought for improving the American models—ask Cindy Crawford. She graduated as valedictorian of her high school in Illinois and earned a scholarship for chemical engineering at Northwestern University. Cindy has all the talents to create a convergence of fashion and statistical models. That would be really sweet.
New Summer Glory Index provides proof positive of great weather
Minnesotans love to point out what a pain in the posterior (PIP) it is to endure the climate from November through March. Minnesota’s Department of Natural Resources (DNR) State Climatology Office (SCO) quantifies the suffering with this Winter Misery Index (WMI). As you can see by their chart, last year’s WMI ranked highly for PIP.
I actually like the cold (good for ice skating!) and snow (great for cross-country skiing). Therefore I agree with the DNR suggesting the WMI be renamed WFI, that is, Winter Fun Index. However, even I must admit to favoring spring, summer and fall over the winter.
It’s been especially nice here for the past few months—only a few really hot days. This is confirmed by the MN DNR climatology wonks who concocted this Summer Glory Index (SGI). They figure the sweet spot (“full credit”) is high and low temperatures of 73-79 F and 57-64, respectively, with less than 60 F dew point and at most 0.01 inches of rain. By these measures we Twin Citians are enjoying a mostly glorious summer.
Looking back some years on the chart a few summers fall into the “wretched” category, primarily due to extreme heat. I recall many a summer night lying awake in my upper bunk on the second floor of our home in St. Paul with the window pulled down and begging for the least bit of breeze. That really was wretched. Thank goodness for air conditioning now being so ubiquitous in buildings and vehicles!
Check out my granddaughter Laine enjoying our great outdoors. Glory be! : )
Oh, snow–but it was ice out
Walking the dog to the park on a decent day yesterday (today being terribly cold and rainy) I came across this remnant of the mountain of snow piled up in the cul de sac. Yuk! On the other hand, many of the area’s lakes enjoyed ice-out this week. Nearby White Bear Lake was declared open on Wednesday morning (it’s a bit of a judgement call, evidently). According to records that go back 86 years this year’s ice-out fell nine days later than the median date but well ahead of the record of May 4, 1950.
I am looking forward to the dirty-snow-out coming soon. Then I feel it really will be Spring.
P.S. I noticed the postal-deliverer wearing the USPS summer-shorts uniform, so that’s a good sign. : )
White squirrel on fresh snow
On my triple-long commute into town this morning I enjoyed my scenic route along County Road B2 in Roseville. One may as well make a savory slurpee out of the snowstorm as sit in traffic stewing. This route paralleled the gob-stomped Highway 36 so moving along the stopped traffic made this bypass all the more satisfying. I happily paid heed to the calming advice of the mellifluous public radio announcer that “you will get to where you going in due time.”
While admiring the flakes falling on the white-bedecked urban forest I was startled by a clump of snow scurrying down a tree trunk and then disappearing when it hit the deck. It was an albino* squirrel who managed to survive standing out all summer amongst all the greenery. Cool!
You really can see a lot just by looking—to paraphrase Yogi Berra.
*Not being close enough to look it in the eye, I cannot be sure it wasn’t a plain old white squirrel (black eyed) but from the map posted at this website , my guess is it’s an albino. If so, that’s very rare—only 1 out of 100,000 squirrels exhibit this trait, according to my research.
Holing up on a frozen Minnesota lake
The March issue of Minnesota Business magazine, a valuable source of information and insight for growing companies,* provided a fascinating statistic, hard to believe really: 25,000—the number of ice fishing holes drilled last month for an ice-fishing contest on Gull Lake. Minnesota-based StikeMaster Corporation provided the augers. See their video for a demonstration.
Meanwhile (reported on page 44), elsewhere on Gull Lake (far from the 25,000 holes, I hope), Grand View Lodge offered the ideal meeting place for getting away from the office. See this report from our local CBS television affiliate—you will be amazed.
Sadly it seems that spring is nearly sprung so we must now endure 6 months of warm weather before the fun can begin again.
*Full disclosure: My daughter Emily is Graphic Designer for the production of this publication by Tiger Oak Media of Minneapolis.