In one word: Hot.
Right now, it looks like a lot of factors are coming together to give us another hot summer. I mentioned this back in April that I thought this summer was going to start out very warm and then ease back a bit as we move through July and August.
A lot like last year.
The Analogs
El Nino
This year’s forecast is a bit trickier, though. As this year it looks like there is only one analogous ENSO year to pull data from: 1953.
Earlier this year the data was showing that some loose ENSO analogs could include the years 1969, 1977, and 2005.
But as the Winter turned to Spring, ENSO data has shown that the only real analog to pull from is 1953.
So what was it like in 1953?
In one word: Hot.
Back in 1953, the Summer started pretty warm with the average high in June of 94 degrees.
The area eclipse the century mark once and was within two degrees of hitting it four other times. There were only seven days with more than 0.10″ of rain. And the month ended with about 4.5″ of rain – that is about average.
Gulf of Alaska
But ENSO isn’t the only thing to watch for seasonal outlooks.
The sea surface temperature anomaly in the Gulf of Alaska is also a good indicator for seasonal temperature variability for the southeast.
The Gulf of Alaska looks to have sea surface temperatures well above average for this time of year. As the Gulf of Alaska runs warmer it tends to shift the storm track a bit. That allows for stronger areas of high pressure to form in the southeast. A stronger area of high pressure usually creates warmer conditions.
Gulf of Mexico
Another place to look is into the Gulf of Mexico. Since South Mississippi is right near the Gulf, generally when it is running above average, temperatures inland run above average, too. That said, there is an asterisks, because a warmer Gulf of Mexico can change the sea-breeze dynamics – slightly. And, full disclosure, I don’t know enough about sea-breeze dynamics to make a forecast based on that system.
Preseason Rainfall Totals
Other less-important but still-relevant data for a summer weather outlook for the southeast is rainfall totals across the southern Plains and Midwest.
Rainfall totals across the eastern two-thirds of the country have been well-above average in a lot of places. This translates to higher than average soil moisture. And when soil mositure is higher, it means that near-ground temperatures tend to run warmer. That is because water has a higher specific heat than regular dry dirt or dry air.
Recall from Chemistry class that Specific Heat is a measure of how much energy it takes to change the temperature of something by one degree. The higher the specific Heat, the more energy needed to change the temperature.
So, once the water is in the ground, and warm, it takes more energy to cool it down. So it just stays warm. And you might ask, “well, why does it stay warm?”
It stays warm because the Sun is out during the day radiating heat energy at it all day long. Warming it up. And since the sun is ‘up’ longer than it is ‘down’ the net result is more warming than cooling for the southeast.
The Forecast
The Climate Prediction Center shows that above average temperatures and near-normal precipitation is favored for the Summer in South Mississippi.
There aren’t many arguments to be made against this forecast. However, the only place where it may not line up directly with analogs and the data collected for this post is for seasonal rainfall. Data suggests near or below-normal rainfall for South Mississippi – generally – for this summer.
The only hiccup there would be if the area dealt with a tropical system. In that case, the area would, likely, be dealing with above-average precipitation. But it would come in one shot rather than extra rain every week.
The Madden-Julian Oscillation
…. This will be covered in another post. But, an early estimate shows that the July 1 – August 15 time frame may see an increased threat for tropical activity in the Gulf of Mexico.
