Growers will be faced with threats of frost three nights out of the next four, with the potential for record-setting cold also in the forecast.
The National Weather Service opted against issuing a Frost Advisory for the northern Cumberland Plateau on Wednesday, even though temperatures are expected to drop into the mid 30s overnight with clearing skies — creating an environment capable of frost formation, although persistent light winds could help to nullify that threat.
While the NWS’s forecast does call for patchy frost to develop towards daybreak Thursday morning even on the Cumberland Plateau, the greater risk of frost is viewed as being in northeast Tennessee, where an advisory has been issued for some locations.
On the plateau, which is higher in elevation and more susceptible to winds, a northwest wind between 5 and 10 mph could help limit frost potential. Meteorologists from both NWS offices in Nashville and Morristown opted against a frost advisory.
The areas along the northern plateau most likely to see patchy frost Wednesday night are low-lying areas.
Unfortunately, growers who are spared frost tonight likely won’t be as lucky Friday night, when a replenishing shot of cold air has been delivered to the region. In fact, it could be cold enough to produce a limited chance of snow before clouds begin to break up early Friday night.
As winds diminish and clear skies prevail, frost formation appears likely for Friday night and early Saturday. In a Forecast Discussion published Wednesday afternoon, meteorologists at the NWS’s Morristown office said that “areas of frost seem a high likelihood” Friday night.
In addition, it’s possible that Friday night’s cold air could be record-setting. The current record for the date is 29 degrees, set in 1976. The NWS’s forecast is for 28 degrees.
Temperatures are expected to drop to freezing again Saturday night into early Sunday. Widespread frost is expected again by Sunday morning.
If a hard freeze occurs Friday night — which means temperatures drop to 28 or below — it will be the latest hard freeze on record in Scott County since 1976. That year, a hard freeze occurred as late as May 20. In the 44 years since, a hard freeze has occurred only once in the month of May: on May 5, 1984. The average date for the last hard freeze of the season in Scott County is April 12.