Daylight Saving Time and Weather Forecasts
Of course, Sunday morning is the beginning of Daylight Saving Time. I love the extra daylight at the end of the day, but for “weather nerds”, Daylight Saving Time means the models come out an hour later. For those of us on Eastern Time, the evening models become available inconveniently late for the next day’s forecasts!
I’ve written extensively about this in past years—
Little Known Facts about Daylight Saving Time and TV Weather Forecasts
In yesterday’s forecast, I mentioned the possibility of cloudiness for Sunday afternoon. Several of the models have low cloudiness moving in on an easterly flow Sunday afternoon.
The model blend statistical treatment shows about 40% mean (average) cloudiness, but the standard deviation (a measure of the spread in the models or it can be interpreted as uncertainty) is as high 45-50%, especially west of Philadelphia Sunday afternoon by 3 PM.
The high resolution NAM-NEST shows low level cloudiness moving in, with a mix of high and middle level clouds further to our west—
So, there’s uncertainty in the degree of cloudiness for Sunday afternoon, but I’m thinking it might be significant by 3 PM.
High temp Sunday 63.7º with a high confidence of 0.8º standard deviation. (The standard deviation can be thought of as 67% of the time, the temperature will fall with ± 0.8º of the mean temp 63.7º)