Winter Weather Alert - January 22, 2025
They say history doesn’t repeat, rather it rhymes. And right now, it’s feeling much like January 2014-2015 over here:
- Jan. 7, 2014: The term “polar vortex” enters the public lexicon with extreme damaging cold temperatures. A similar historic event would repeat Feb. 20, 2015.
- Jan. 15, 2015: OSU defeats Oregon in the first 2014 CFP national title, 42-20.
Ten years later in 2025, OSU wins the first expanded CFP national title and this evening’s forecast tonight calls for lows throughout the state anywhere between 1F and -11F (Figure 1), with cold temperatures (< 0F) expected to persist from 8pm through 10am.
Figure 1. Forecast nighttime low temperatures Jan 22, 2025. Figure from https://weather.gov.
Some key differences from 2014-2015:
- Vine cold acclimation is much better than in 2014-2015. A late first fall freeze aided in improving winter hardiness through extending wood maturation, carbon and nutrient reassimilation.
- Sustained below-freezing temperatures through January (Figure 2) have aided in achieving maximum cold hardiness while minimizing deacclimation and freeze/thaw cycles, which often leads to more extensive bud/tissue injury.
Figure 2. Average temperature departure from long-term mean from 22 Dec 2014 through 20 Jan 2025. Figure from https://climate.osu.edu.
- Persistent snowpack provides an insulating layer that helps protect the base on the vine trunk.
- Our most recent estimates of LT50 (e.g., minimum temperatures that result in 50% bud injury) from cultivars at Unit 2 suggest many Vinifera cultivars have attained cold hardiness to approximately -10F and hybrids < -15F. These values are similar to reported LT50 estimates from Cornell University.
We will be following up in the coming week with temperature minimum descriptions, incidence of bud injury, and recommendations for adjusted pruning.
In the meantime, stay warm!