June climatology in the Tennessee Valley, and a look back at May rainfall stats.

Before we look ahead at June climatology for the area, we will take a look back at rainfall stats for the previous month to try to get an idea of where we are in the rainfall department. Those of you that have followed us for a while know that the main NWS climate reporting station in our viewing area is located at the Northwest Alabama Regional Airport in Muscle Shoals. It naturally doesn’t perfectly capture everything everywhere, but it does a good job of representing the overall stats and climatology for not just northwest Alabama but also our small portion of southern middle Tennessee and far northeast Mississippi as well.

For the month of May, rainfall came in very close to normal. The airport there in Muscle Shoals typically averages 4.55″ of precipitation for the month of May, and they came in at 4.17 inches.

There is still a year-to-date surplus of +6.28 inches, with 30.27 inches of precipitation being measured so far since the beginning of the year. This is certainly good news after the significant drought we had from late last summer through this past winter!

Generally speaking, most everyone across the viewing area was either very near normal for rainfall in the past month, or they were ahead by a little bit. Iuka was the driest observation site, coming in at roughly 4.4″ of rain for the month and putting them at only 79% of what is considered normal. Everyone else across the area ranged from near 5″ to over 7.5-8″ in a few cases. The rounds of thunderstorms over middle Tennessee and areas of north Alabama, especially east of U.S. 43, have really helped keep the May rainfall stats in good shape without causing too much in the way of significant flooding.

We have to be careful as we head into the summer months though. I know we like to have dry and sunny weather so we can do yard work, lay out by the pool, have cookouts, etc., but we need to make sure we don’t trend too dry for too long. We’re not outlooked in any drought categories, but there are still some parts of southern middle Tennessee that have long-term rain deficits of nearly two FEET. It wouldn’t take too long of a period of hot and dry weather during the mid to late summer to put us right back into drought conditions later this fall when we head into our typically drier months of the year around September and October. As bad as it is for our outdoor plans, we need to get a little ahead in the rainfall department between now and August to early September so we have room to go dry in September and October without risking drought conditions returning to the area.

Now, we look ahead to the month of June and what the weather is capable of being like across the Tennessee Valley from the standpoint of climatological stats. June 1st is the start of meteorological summer, with astronomical summer beginning on June 20th this year. For a monthly average high, we come in right around 89 degrees here in our part of the Tennessee Valley, with us starting around 86 at the beginning of the month before averaging out in the lower 90s as we head out of June into the start of July. We can certainly run much hotter though. That NWS climate reporting site in Muscle Shoals has a record monthly high of 108 degrees, set back in 1914! While that milder weather means milder overnights too, with an average monthly low of around 68 degrees, we have been known to get down into the 50s here, especially during the early part of the month. The Muscle Shoals reporting site’s record low for the month of June is all the way down to 42 degrees, set in 1894! June averages out to still be a somewhat wet month across the Tennessee Valley, coming in with an average monthly rainfall of 5.05 inches. That comes from a combination of daily hit-or-miss afternoon and evening thunderstorms, thunderstorm complexes that often affect us from the late spring through the first half of summer, and occasionally, some early-season tropical activity from the Gulf of Mexico.

While severe weather is still something to be mindful of in the Tennessee Valley, tornadoes start becoming less of a problem. You can see our blog article going into detail about this very topic right here. While tornadoes still can happen in the month of June, their frequency becomes SUBSTANTIALLY less from that of the spring months. And with the exception of two F3 tornadoes from a single VERY RARE late season June supercell outbreak on June 26, 1994, none of the other tornadoes in our area in the month of June have been rated greater than F2 or EF2 intensity. Going back to tornado records in the mid 1800s, the states of Tennessee, Alabama, and Mississippi have never once had a violent tornado (F4-F5/EF4-EF5 intensity) on record in the month of June. The wind shear needed for high-end tornadoes usually shifts north of our area as we head into June.

June 1st is also the official start of the Atlantic Hurricane Season that runs all the way through the end of November. While June tropical storms aren’t unheard of by any means, they don’t happen super frequently. A full-blown hurricane is pretty rare for the month of June, but it certainly can and sometimes will happen. The most likely areas for tropical development in the month of June are incidentally in the Gulf of Mexico and far northwest Caribbean, as well as off the Southeast coast. In these cases, this is often in relation to stalled and decaying frontal boundaries moving offshore with thunderstorm complexes that persist and help spur low pressure development that then festers into a tropical system. Occasionally, a system will develop from the “Central American Gyre” of low pressure in the western Caribbean of Bay of Campeche. It is very rare for a long-tracking tropical wave from the African coast to get going into a full-blown system this early in the season.

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