Just after dark on March 19 of this year, lightning flashed south of our home in central Otsego County. This electrical storm was caused by the northward aggression of the southern branch of the planet’s northern jet stream. This allowed a southern moisture-laden air mass to slam into a drier cold air mass. This collision caused huge amounts of condensation, and thus rainfall, great electrical activity and a rapid drop in air temperature. Exactly a half year later, the jet stream is supposed to do the exact opposite, allowing southbound frigid air masses into our region. What made this meteorological drama particularly unique this year was that this phenomenon repeated itself elsewhere in our region on March 25. That said, it seemed reasonable to this writer to consider these two events as part of the same weather happening. It was logical to use an average date of March 22 as the launch point for forecasting the end of the frost-sensitive crop growing season, 182.5 days into the future.
The climatological factor that supports my forecast is known as the jet stream polar drift rule. That edict states that the first serious electrical storm of spring in latitudes near the 45th parallel (halfway between the equator and the North Pole) will be followed a half-year later by autumn’s first killer frost. Thus, counting 182.5 days forward from March 22, we could expect our first killer frost to impact much of our Northeast region on or about Sept. 21. This was how this forecast scenario was supposed to play out – unless El Niño or La Niña “misbehaved.”
According to climatologists, an El Niño (Spanish for Little Boy) takes place when Pacific Sea surface temperature (PSST) rises by more than 1.5º C above normal for that particular time of year. These scientists also say that a La Niña (Little Girl) occurs when PSST drops by more than 1.5º C below normal for that time of year. Back in March, at the time of that first spring-time electrical storm, what was occurring, PSST-wise, was what these scientists called mild La Niña. The Little Girl was bouncing between 0.6º and 0.9º C below normal. Feeling that she would behave closer to normal than not, I went out on a limb and made my Sept. 21 first fall frost forecast.
Here’s how the flash-to-frost script materialized: On the evening of Sept. 23, the TV weather report threatened frost in Utica’s outlying, low-lying areas. Thus warned, I covered the tomatoes, peppers and zucchini in our raised bed gardens with tarps. Dawn the following morning, our truck and car windshields were adorned with one-tenth-inch of ice crystals (which vanished rapidly when hit by morning sunshine). This is my 33rd growing season of keeping score opposite Jack Frost. My batting average tallies at 24 hits (landing at or within two days of actual first frost), six misses and three recusals – a .727 batting average. Recusals take place when late winter El Niño/La Niña activity makes me nervous about making six-month forecasts.
But what took place, agriculturally, during that six months, was very unique, with a list of achievements, to which the Little Girl – even though she was “mild” – can lay claim. La Niña pushed the jet stream farther north during the northern hemisphere growing season, impacting weather in the U.S. and Canada. Her patterns delivered excessively hot, dry conditions to most of South America, in regions heavily planted to corn and soybeans. The resulting threatened harvest shortfall in our southern neighbors enticed U.S. growers to attempt bumper crops, in anticipation of higher commodity prices. Corn and soybean growers pulled out all stops, despite drought in many parts of the U.S. and much higher fertilizer prices.
The latest outlook, published Sept. 13 by the National Weather Service (NWS), has increased the chances of La Niña sticking around through this November to 91% – almost a near certainty. The pattern may also linger into winter, with an 80% chance of La Niña from November to January, plus 54% chance from January to March. Examining a current NWS forecast map, we see that this 91% ties into a warmer than normal forecast for much of America through the end of November. For our Northeast neck of the woods, we see that the Little Girl should create warmer than normal temperatures just past Thanksgiving. The region involved here is a big triangular parcel, stretching from Norfolk, VA, to Buffalo, NY, all the way through northern Maine.
In addition to monitoring the well-being of my tarped vegetables, I windshield-surveyed a lot of standing corn within a 50-mile radius of my Hartwick residence a couple days after that first frost. I saw a lot of corn that was slightly gray, but none that appeared dead. Most corn experts consider corn to be dead from frost when the veins in the neck connecting the ear to the stalk are so ruptured that nutrient-laden sap can no longer be transferred to the ear. Often corn can be frosted from the top down, not quite reaching ears. Odds are, as I write, the vast majority of corn in our region is very much alive. It’s best to sample ears for maturity, understanding that the way kernels develop may be impacted by the strange package of growing degree days and precipitation that most growers experienced this season.
A very simple test used to pronounce corn alive involves hand-harvesting ears of corn. A couple days after suspected killing frost, squeeze the ear neck with pliers, depositing liberated sap on a white plate. Sap from a live ear will be a very light greenish-yellow. Sap from a dead ear will be a very light tan. Open-pollinated varieties generally escape more frosts than is the case with modern hybrids. OPs are higher in natural sugars than almost all hybrids. Plant sugars in OP sap solution function quite well as a natural antifreeze.