June and I are weather hounds. We check the weather 5, 7, even 10 days before a race or a long run. Sometimes I check the weather 5, 10 times per day. And that's not just today's weather. I mean I'm checking the 10-day forecast sometimes on the hour, every hour while I'm at work.
As obsessed as we both are with the weather, we're always arguing about it online. A typical IM session goes something like this:
Vic: Well, it looks like great weather for the race on Sunday.
June [types a SMILING emoticon]: Yeah, sunny and 40 degrees.
Vic: It's going to be sunny alright but the temps say mid-60's
June [perturbed]: I'm looking at the forecast right now and it says 40 degrees.
Vic [gleefully and cheerfully]: Well, I'm looking at the forecast right now too and it says mid 60's. Where do you see 40 degrees?
June [types an ANGRY emoticon]: Click2Houston.com!!!
Vic [types a BIG GRIN emoticon]: Oh, I'm on weather.com and it says mid-60's for the low on Sunday.
June [types a ROLLING EYES emoticon]: Well, I don't use weather.com. Anyway, it's going to be 40 degrees. [June closes the conversation window and logs off]
[Vic cheerfully and gleefully goes back to work because he's such a nice guy]
You see who the good guy and the bad girl are in these conversations. Anyway, I had to get to the bottom of this to save our friendship. How can we be looking at the forecast for the same day and be so off? How can I see 60 for the low on Sunday and June sees 40? I mean, I know one thing FOR SURE. June is ALWAYS right!!! So, what's so screwed up about weather.com? What exactly is the difference between Click2 and weather.com? So, I conducted my own little investigation.
First, I called meteorologist Anthony Yanez at Channel 2. Nice guy, by the way. He told me that the low and the high for any give day are forecast for a 24-hour period from midnight to midnight. That means given a forecast low on Wednesday of 50 and a high of 80, the low will most likely fall before dawn on Wednesday morning and the high of 80 will occur later that afternoon. So, it's from midnight to midnight which is good. That's how June was interpreting it. She was right. Then what gives with weather.com? Why is it different?
To find out, I e-mailed the help desk at weather.com and here is the prompt reply that I received:
Each day of the 10-day forecast is divided into two forecast periods: 7am - 7pm and 7pm - 7am. The high temperature shown for any given day is the highest expected temperature for that day between 7am and 7pm. The low temperature is the lowest expected temperature later that night, between 7pm and 7am.
For example, if the high/low values shown for a Monday is 80/62, the forecast high temperature during the 7am-7pm period on Monday is 80, and the forecast low temperature for Monday night/Tuesday morning from 7pm-7am is 62.
The Weather Channel Interactive
So, it appears that I was right too. So, if you are reading weather.com, to find the low for Sunday morning, you have to look at the forecast low for Saturday, which covers the 12-hour 7pm to 7 am period, Saturday night, early Sunday morning.
The lesson here...not all forecasts are created equal!
[Vic types a HUGS emoticon for June]