Archive for category 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!