On/Off, On/Off, that's what you may have been doing recently with the air conditioning. Perhaps over the weekend you switched the AC back on, I know I did yesterday and it's humming as I write this. However, tomorrow and Wednesday, I will have it off and the windows open.
This has been a familiar move for many of us this Spring. We just can't seem to get into a consistent weather pattern, so why should the next couple of days be any different????
We are watching a broad upper-level area of low pressure that is sitting over New England, the Mid-Atlantic and the Ohio Valley. This upper-low or cold pocket of air aloft is about to make its move south towards North Carolina and Virginia. What does this mean for us? You guessed it, cooler weather along with clouds and perhaps showers and storms.
As this cold pocket of air moves across our state tomorrow, the difference in temperature at the surface and the colder air aloft will create a lot of instability. When we start the day, the temperature spread will be small so the instability will be low. At this time there should be plenty of sunshine. But as soon as the sun heats the surface of the earth, a great temperature difference will develop creating the instability. This in turn will develop a considerable amount of cloud cover in the afternoon. This instability will also create spotty showers and storms. Since the air is cold aloft, the freezing level will likely be lower to the ground which will allow for the production of small hail within the storms. So don't be surprised if pea to marble sized hail pops out of any of the storms tomorrow afternoon. Once the sun sets and the daytime heating ceases, we should see the showers and storms slowly die off. What will also aid in creating instability are small waves of low pressure embedded within this upper-level low. We have a wave of low pressure that will move across the state tomorrow afternoon. It's likely Wednesday that we won't have one of these embedded lows affect us.
The addition of the clouds tomorrow and the showers will keep temperatures down. Our highs will likely be in the low-mid 70s and come in the early afternoon before any rain starts. Once we start to see showers, the temperatures may drop as the rain pulls the cooler air down from above. We may see temperatures fall into the 60s once you see a shower move into your community.
Wednesday will likely see the same scenario as the heart of the cool pocket of air will be upon us. We will likely start with sunshine Wednesday morning then see clouds develop in the afternoon with perhaps some spotty light rain but not the kind of rain we could see tomorrow. It will likely be cooler Wednesday with highs only in the 60s. This brings the whole point of this blog entry.
Our forecast high for Wednesday is 66 degrees. The record low high temperature for the day at RDU is 65 degrees set back on 1990. It is possible we could tie that record low maximum or even break it.....What a weird Spring we have had. It makes you wonder what our Summer will be like.