After a very warm start to fall, seasonal temperatures have finally arrived in East Tennessee, and an even stronger push of chilly air is en route to the region for the weekend.
We're still running a whopping 6.4 degrees above normal for the month, despite the recent cool-down, but that's changing.
Today's high in Oneida is projected to only get to 48 degrees, and the National Weather Service has issued a frost advisory for the entire region tonight, with temperatures forecast to drop to 36 degrees under decreasing cloud cover.
A warming trend will begin in earnest tomorrow, but it won't last long, with another frontal boundary set to push through the region on Friday. That sets the stage for a wet weekend — the NWS is currently forecasting a 50 percent chance of rain Friday night and a 90 percent chance of rain Saturday — as post-frontal precipitation moves through the region.
Along with the rain, the coldest temperatures of the season appear to be on the way. The NWS is forecasting a high of 53 on Saturday. Despite cloud cover, temps should drop into the low to mid 30s Sunday night, followed by a high only in the mid 40s on Sunday.
The NWS is even forecasting the precipitation to mix when or change to snow late Saturday night. It's the first time this season that the "S" word has crept into the forecast.
Model output statistics from this morning's run of the GFS forecast model show temps only getting into the mid 40s on Saturday, and staying there on Sunday. Raw data from the same model run, while probably a few degrees too cold, shows temperatures very reluctant to warm up on Saturday. Taken verbatim, the model has temps hanging out at about 38 degrees at sunrise, and rising to only 39 degrees by 1 p.m. before finally warming into the 40s as rain tapers off later in the afternoon.
The combination of about 1.5 inches of rain and cold temperatures in Saturday's forecast forced the Scott County Chamber of Commerce to push its much-anticipated Fall on the Mall festival in Huntsville back one week. The festival has been rescheduled for Saturday, Nov. 4.
While Saturday appears cold, Saturday night will be even colder. The raw data has the northern Cumberland Plateau region dropping to freezing Sunday morning, 32 degrees. That would obviously be the first time that's happened this season.
We are thus far without a widespread frost this season, although some folks recorded patchy frost one week ago today, when temperatures dropped to a season-low 34 degrees.
Last week's temps saw temperatures drop into the 30s from Oct. 17 all the way through Oct. 21, even though the afternoon high on Oct. 21 was all the way up to a balmy 78 degrees. Incredibly, 11 of 24 days this month have seen temperatures rise into the 80s in Oneida, with the high being 84 degrees on Oct. 10.
It was a very warm start to October after a very warm finish to September. While September's overall average was actually cooler than normal, by about two degrees, the second half of the month was very warm. From Sept. 16 through Sept. 29, every day featured highs in the 80s in Oneida, with a one-week stretch of Sept. 22 to Sept. 28 featuring temperatures of 85 or above each day.
Those days are apparently behind us now, although this is a La Nina pattern we're entering into, and warm snaps are hallmarks of La Nina patterns. For the next three to four weeks, NOAA's Climate Prediction Center is showing the bulk of the warmth limited to the East Coast and New England, and to the Desert Southwest and Southern Plains. But for the months of November, December and January as a whole, the CPC is predicting a 40 percent chance of above-average temperatures overall for the entire Southeast, including Tennessee.
Eye to the Sky is a weather blog by Independent Herald editor Ben Garrett. Garrett is a weather enthusiast who has long blogged about interesting weather on his personal website. He is not a professional forecaster or a meteorologist and information on this blog should not be considered a substitute for forecasts, advisories or other products from the National Weather Service.