Snow on March 6? The clouded outlook for long-range forecasts
Those long-range forecasts have a long way to go.
Congratulations to loyal reader William F. Albert III, who is getting married on April 29 in beautiful Mercer Island, Wash.
At the outset, we'll eschew advice, but we are offering a wedding gift: We'll keep track of the weather forecast for him. (Who says we're cheap?)
More precisely, we'll keep track of Accuweather's 90-day forecast, which now captures his wedding date.
Right now, the forecast calls for a chance of a shower out that way, with a high of 65 on April 29. But based on our own monitoring and that of some Penn State folks, Mr. Albert has no need to order complimentary ponchos just yet.
We posted back in April about AccuWeather's ambitious attempt at three-month, day-by-day forecasting, which was greeted with a storm of skepticism in the meteorological community.
We remind our readers that these forecasts aren't to be confused with the government seasonal outlooks that are confined to probabilities of below- or above-normal temperatures and precipitation for the entire period.
These are day-by-day, high-low, precipitation forecasts.
Locally, the latest version would be a source of depression for snow-enthusiasts. It sees a grand total of about an inch of snow in February, with the biggest snowfall scheduled for March 6 to 7: 1.3 inches.
We say "would be" because experience tells us that the only reliable way to nail snow amounts is to wait until it stops.
So why can't anyone get anything close to a decent handle on the behavior of the atmosphere more than about 10 days into the future ?
Computer models that have been so successful in short ranges aren't as useful as they project deeper in time.
Critical to their reliability is capturing the "initial state" of the atmosphere, and then projecting how it will evolve.
Unfortunately, the atmosphere is an immensely complex place that is imperfectly measured at any given time. And once in motion, it is what the scientists describe as a chaotic nonlinear system.
In the meantime, we are prepared to give the 90-day a chance, and we'll keep you apprised.