In a case of a delayed Indian Summer, the week of October 17 has produced record or near-record warm temperatures in the Mid-South. On Monday central Arkansas saw temperatures of near 90 degrees.
What might be in store for the rest of the year and for 2017? Dennis Cavanaugh, National Weather Service Warning Coordination Meteorologist in Little Rock, spoke with Delta Farm Press on Tuesday. Among his comments:
On the current heat wave…
“The most recent heat wave, or near-record bout with heat we’re currently experiencing, is due to a high ridge of pressure over the South. It’s been in place for quite a while – since Hurricane Matthew threatened the East Coast.
“An upper level ridge is self-reinforced. One of the things that causes a ridge to build up is simply being hot. When there’s heat the ridge gets stronger.
“What’s needed to break the ridge down is a strong push of cold air from the north. That, in turn, allows weather systems to come through.
“We’ve been a very persistent pattern – often referred to as a ‘blocking pattern.’ For example, the Northwest has been receiving lots of rain whereas the Southeast has been very dry. Again, since we’ve been stuck in the hot and dry pattern it is reinforcing itself.”
What about the short-term forecast?
“There’s actually a rather strong cold front that will move through the Mid-South (Wednesday) night. That’ll likely bring scattered thunderstorms and cause temperatures to cool down a good 15 to 20 degrees. All the way through the weekend we’ll be looking at normal seasonal temperatures, or perhaps slightly below.”
“This isn’t a deterministic forecast but does provide an idea about the general climate. There isn’t a super strong signal for Arkansas either way but the signal that is available points to a slightly warmer and dryer winter than normal. That holds for the entire Delta, as well. That warmer pattern continues almost all of 2017.
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“That doesn’t mean we won’t have a very cold period included. But, on average, the climate signal suggests we’ll above normal for temperatures for the next 15 months, or so.”
On the 2016 growing season…
“During the spring, we had 23 inches of rain – way above normal. That’s 8 to 9 inches more than normal for the central part of the state. The White River and Black River basins got even more rain, of course, which led to lots of flooding. That inundated many crops.
“In Little Rock, from June through August we ended up quite a bit above normal in terms of precipitation. There was over 16 inches of rain through the summer months. That’s a good 7 inches above normal. Most of that came from thunderstorms – not nice steady rains but heavy downpours.
“In August alone, we had 7.56 inches. That’s a bit over 2 inches more than normal. The record in Little Rock for the month is 14.6 inches so we were well below the record. The record was in 1966.”