Summertime Blues
Remember this one???
“Sometimes I wonder what I’m a gonna do
but there ain’t no cure for the Summertime Blues.”
Summer poses a special challenge for meteorologists that work here in the Deep South. Quite frankly, we do a lousy job of handling the small scale features that bring subtle weather changes on a day to day basis.
WHAT WE KNOW: The weather will be hot and humid just about every day June through August. And, it will rain during the afternoon on a daily basis.
WHAT WE DON’T KNOW: There is no way of knowing at 7:00 a.m. where the showers and storms will form on a summer afternoon at 3:00 p.m. in most cases. There is no real skill in forecasting placement and coverage of airmass thunderstorms that form on just about every summer afternoon in Alabama, and that can frustrate the pants off the best forecasters.
POP HATER: POP in this case means “probability of precipitation”. The NWS uses POPs, and quite frankly we started using them last year in the seven day forecast that shows up on ABC 33/40 News. We did that in response to public demand; we are not here to produce products that make us happy, but products that match our viewers needs. But, let me clearly me say I do not like POP in a public forecast.
For example, on most summer days, you will hear this kind of forecast: “Partly sunny, hot, and humid with scattered, mostly afternoon and evening showers and thunderstorms. Probability of precipitation is 30 percent”.
Now, let’s review that. I have learned that most people, and many weather forecasters don’t know the true definition of POP. I honestly don’t know the right answer myself. So, how in the world can people use that information if they don’t understand it.
BOTTOM LINE: On most summer days, there is actually about an 80 to 90 percent chance that showers and storms will form during the peak of the daytime heating process. BUT, the chance of any one neighborhood getting wet at any given time is only 30 percent, and that is why you see it in the forecast.
THE PROBLEM: To any one person at any one point, it is either raining, or it is not raining. So, in their eyes, to be correct the POP in a forecast really needs to be zero, or 100. If the forecast is perfect, and we have scattered showers and storms around, the person under one of those scattered storms thinks we are fools because we say there is only a “30 percent chance of rain” when it is pouring as they drive down the road. This is when they say “I am using my windshield wipers to get that 30 percent off my windshield”. They have no idea it isn’t raining in most other places. POPs only get forecasters in trouble.
SO… Just understand the weather just doesn’t change much on a daily basis June through August. It will be hot and humid, and it will rain somewhere just about every afternoon. Just understand we don’t know when and where, and nobody can tell you until they begin to show up on radar during the early afternoon hours.
CAN’T REMEMBER IT BEING THIS HOT? Almost every year, I hear from people that tell me “I can never remember the weather being this strange”. And, understand I have been doing this for 32 years. The truth is that our weather is “strange” every year. Averages are just that; averages.
For those of you that say you can’t remember it being this hot in June during your lifetime, I say you have a short memory. The decades of the 30s and 50s were brutally hot in Alabama; our hottest June temperature on record is 106 degrees, set on June 29, 1931 (based on data for Birmingham). Our hottest temperature on record is 107, set on July 29, 1930.
Don’t forget, we are coming off a few very mild summers, so we were due for one. Alabama is a low latitude state that is stuck in mT air (maritime tropical), with lots of sunshine and winds aloft that are light and variable as the mid-latitude westerlies hang around well to the north of here. It is supposed to be hot around here. Always has, and always will.
ONE THING can break up the monotonous summer weather, and that is a tropical storm or hurricane. The big ones usually come in August and September, and it does indeed seem that all parameters are in place this season for a bunch of them. Even a tropical depression can be quite a heat buster with flooding potential. So, look to the south for big changes, and not to the north. Alabama is a cold front graveyard this time of the year; while you can get an intrusion of dry, continental air in summer, is just doesn’t happen very often.
THINGS TO WATCH: I recommend you pay attention to the various parameters on our seven day forecast during the long, hot, summer. Sure, the words won’t change much. You know… “hot and humid with scattered afternoon and evening showers and storms”. But watch for the parameters like “percentage of available sunshine”, “hours of rain”, and “rainfall potential”. That will give you a clue concerning our thinking about afternoon storm coverage and placement.
So… as I wait for October and my favorite season (I have been a fall fan boy for many years), let’s just do the best we can to enjoy summer. Sure, it is too hot and humid, but think back to your childhood and those long summer days. It can be a fun time of the year, even for a meteorologist in Alabama.
June 15th, 2010 at 1:39 am
There are people at UAH, including Dr. John Mecikalski’s group, and some people in our group (Kevin Knupp’s) that are looking at convective initiation (CI) on summer days, and trying to find ways to make the placement of thunderstorms in forecasts better. Things like thermal boundaries due to yesterday’s storms, differences in soil moisture, land cover type (trees, crops, urban, water), mountains, and urban heat islands all affect where storms form.
However, there is a lot to learn, and as James points out, right now it’s very difficult. So, be patient with all of us weather people. Maybe in 10 years, we can say there is a 50% chance of storms in Cullman but only a 20% chance in Tuscaloosa. In most cases, we can’t do that now.
June 15th, 2010 at 3:48 am
That is a good point as the things that happen today weather wise would affect the next day as well. The thing that makes the PoP bad right now in my opinion is that to the everyday person it has a different meaning Than it does to the professionals and the weather geeks like myself. It took several times for me to be able to explain it out to my Father-in-Law and my Father how it works out. I am sure however as the technology improves and knowledge is gained weather predictions will improve vastly over the next ten years.
My hopes are very high that in the world of meteorology that the things we learn on a day to day basis will lead not just to better forecasts. They will lead us to more advanced watches and warnings. Yes, weather is a very fascinating thing to study, and can be beautiful to watch out in an open area, but being able to reduce the threat to lives of the public will be the best thing to come of the things we learn today.
June 15th, 2010 at 5:22 am
When I was young, weathermen (the weather girl hadn’t happened yet) would stand in front of a chalk board. He’d draw an outline of the U. S., then draw the weather features as he explained them. When the first graphic weather maps appeared, we didn’t know what to do with the information because there was no one drawing the progression of the fronts or the little pictures of the sun.
After a while, we learned how to compare what the television weatherman said to what actually had happened, and found a new point of reference.
There are so many unbelievable stressors that people have to face every day that I feel confident saying that they no longer prioritize what they come across. Whereas when I was younger and people got wet when it rained and they didn’t have their umbrellas, nowadays their day is destroyed beyond repair, they’ll fight with everyone, road rage overcomes them, and they’re doomed.
Your op/ed couldn’t have come at a better time, James. Carry a little umbrella with you when you go out in the afternoons, like we used to. Go outside, gauge the humidity in the air, feel the breeze and listen to it in the trees, notice the wind direction, look carefully at the clouds and their formations. How fast are the clouds moving? What is the dark-to-light ratio? Watch James Spann, make your best decision, then move on.
And if anybody who needs it doesn’t take advantage of the incredible, and I mean incredible advances in meteorology that have leaped forward in the past 50 years, shame on you! If you’re in the very small group that absolutely functions or doesn’t function dependent on the weather and you’re not on the cutting edge of the science, you should be. James Spann can help you there too.
I enjoy every day that I can follow meteorology as a hobby. I’m flattered when people ask me “what’s the latest on the weather?” I know who to thank when I can tell them.
But for heaven’s sake, get a small umbrella and carry it with you this time of year! And a bottle of water would be good too.
June 15th, 2010 at 8:26 am
I live in rural Texas but in the DFW TV market. I typically watch WFAA channel 8 here, which is the ABC affiliate. Our weekend weather guy (who I think is the best we have… he will actually say what he thinks will happen and always gives some technical explanations as opposed to sticking with averages) says “tomorrow there will be about a 20% coverage of showers/storms.” I think this is very clear and it never leaves me wondering what he actually means. James, I spent all my early years in AL and owe my weather fascination to geeks like you… thanks for all you do!
June 15th, 2010 at 8:48 am
Hard to believe any Alabaman would say this (or that)
weather is ‘strange’ to Alabama. Needless to say, I remember
many hotter years, drier years, etc. and I’m not that old! (48).
This is my ancestral land. I love it, for all of its weather,
topographical features, and culture. If I really hated one of
those, I would move.
Always understood the percentages, doesn’t add much to the forecast.
When I look at the 7 Day, I mainly look at night temps and windspeed.
Just glad I have it available to look at. Helps with a lot of planning.
June 15th, 2010 at 10:52 am
Great point about the POPS. To me a 30% chance means about a 1 in 3 chance of me getting wet, and personally, I’ll feel like I’m one of the lucky ones if I do get a shower or even a heavy thunderstorm, just to break up the monotonous heat.
What really gets me is a 20% or even 10% chance of rain being mentioned in a forecast. I’ve even seen people put a 5% chance of rain in a forecast. Are those low probabilities really worth mentioning and assigning a value to, when anyone who’s lived here any length of time knows it’s hard to rule out a passing shower any summer day?
But then if you don’t assign a percentage or somehow indicate the probabilities of any one person getting a shower/thunderstorm, people feel like they’re missing out on something. With things like your blog and the videos, you can explain this to people better. It’s very difficult to put that into a seven-day forecast succinctly, but I admire your efforts – percentage of avail. sunshine, rainfall potential, etc.
Oh and I love that old Eddie Cochran song. It always makes me laugh when people think Alan Jackson was the original artist.
Can’t say I’m really hoping for a hurricane, esp. with all the oil down at the coast, but . . . a weak tropical system bringing a lot of rain and wind might be nice.
June 15th, 2010 at 10:56 am
Excellent blog, thank you! The summer pattern hasn’t changed in my lifetime, that’s for sure: hot, and it might rain. We can hope for a cool breeze from nearby rain, or a late-day shower that won’t kick the humidity sky-high. Sounds right on the nose to me.
June 15th, 2010 at 11:59 pm
[...] Spann – Summertime Blues – an [...]
June 16th, 2010 at 3:29 pm
[...] skill in forecasting the placement and coverage of thunderstorms on summer afternoons in Alabama; you can read it here. Very appropriate considering the big difference between yesterday’s stormy day and [...]