Friday, April 6, 2012

Appalachian Frost Concerns Give Growers the Chills



Apr 6, 2012; 2:11 PM ET
Apple orchards, berry farms and vineyards across the Northeast and central Appalachians are scrambling to protect their crops for the foreseeable future as freezing temperatures threaten each night through the weekend.
After an unprecedented stretch of warm weather throughout much of March, trees, plants and vines continue to bud and bloom well ahead of schedule.
Many residents jumped for joy as early summer warmth flooded the Northeast, but farmers were well aware of the danger that such unusual temperatures posed. Exposed buds and flowers are extremely susceptible to damage from freezing temperatures.
Now, their fears are being realized.

This is the area that AccuWeather.com meteorologists are concerned about freezing temperatures early Friday morning.
There are well over a thousand apple orchards all across the Northeast and Appalachians. Most of these orchards lie in sheltered valleys and flat, low-lying plains. These areas are particularly vulnerable to heavy frosts and freezes, which occur on clear, calm nights usually associated with a large dome of high pressure. Typically, freezes like this occur for a night or two, before the weather pattern turns warmer.

This map shows locations of apple orchards in the Northeast region.
For at least the next week, the concern will be with a much chillier overall weather pattern, where brisk northerly winds will allow cool, Canadian air to settle in over the region for many nights in a row. As the jet stream dives to the south, brisk afternoons lead to hard overnight freezes, threatening many fruit trees and orchards.
The freeze threat will linger much longer in this situation, since it will take a large shift in the overall weather pattern to drive the jet stream back to the north and allow warmer air into the area.
So what can growers do to save their crops?
Some orchards across the Northeast burn small fires in what are called 'smudge pots.' These highly controlled fires burn slowly in contained areas all across the orchard, providing some heat to the nearby agriculture.
Other techniques involve using wind turbines, fans and helicopters to keep air moving over the plants. This is particularly effective on calm nights, since the air closest to the surface can drop below freezing while just a few feet above the ground remains above the 32-degree mark. While the blades themselves do not generate any warm air, they keep colder, below-freezing temperatures from pooling near the ground.
A more familiar practice involves the use of irrigation. This is more frequently seen on southeast orange farms during the winter months. The concept is the same - using sprinklers to shower the tender plants with warmer water. Not only can this physically warm the plants, but the added moisture in the air around the orchard makes it much more difficult to cool off at night. This is an expensive method however, and much of the Northeast does not have this type of infrastructure in place.
Naturally, money is the driving force behind how many growers are handling this cold snap. In some cases, the cost of preventative measures to protect the fruit flowers is greater than what the grower would bring in from the crop itself. It will be a careful balancing act for many across the Northeast this week, as orchard owners assess just how much money should be invested into preserving what is left of the fruit crop.
Unfortunately for growers, this cold weather pattern looks to continue into next week across the Northeast and the central Appalachians.
AccuWeather consensus keeps overnight temperatures below freezing across much of New York, Pennsylvania and nearby areas.
It will be a tough fight, but growers are confident they can preserve what remains of their crop.
In fact, some orchards and vineyards have reported that the recent cooler weather has slowed the budding and blossoming process a bit, fortunately.
Statistically speaking, by the time seasonable warmth returns later this month, average lows will fortunately be above freezing throughout much of the region.

No comments:

Post a Comment