Hard freeze hits Midwest and Northeast fruit trees

Large portions of Michigan, Ohio, and Pennsylvania shivered through a hard freeze (temperatures below 28°F ) this morning, and cold temperatures will cause widespread damage to flowering plants fooled into blooming by last week's unprecedented "Summer in March" heat wave. Growers of apples, pears, peaches, nectarines, plums, and cherries worked during the night and early morning to minimize the damage by running large fans and propane heaters in their orchards in an attempts to keep temperatures a few degrees warmer. While freezing temperatures for an extended period will not kill the trees, they will destroy the flowers and fragile buds that are needed to produce fruit later in the year. I expect that this morning's freeze was severe and widespread enough to cause tens of millions of dollars in damage to the fruit industry, but it will be several weeks before the extent of the damage is known. It would take several nights of temperatures in the 20s to cause a more significant billion-dollar disaster, such as occurred in 2007. A warm spell in March that year was followed by cold temperatures in early April that were 10 - 20 degrees below average, bringing killing frosts and freezes to the Midwest and South that caused $2.2 billion in agricultural damage, wiping out apple, peach, winter wheat and alfalfa crops.

During the remainder of this week, temperatures are expected to be much warmer than they were this morning, so the freeze damage will be limited compared to 2007. However, we still have two more months to go this spring when temperatures commonly fall below freezing. Plants will steadily grow more susceptible to cold temperatures in the coming weeks as the growing season progresses, and the odds of more destructive frosts and freezes for the Midwest and Northeast fruit industry are high.


Figure 1. Low temperatures this morning dipped below 30 degrees over Eastern Michigan, Northeast Ohio, Northern West Virginia, and much of Pennsylvania, in regions where spring bloom was well-advanced due to last week's record "Summer in March" heat wave. Widespread agricultural damage likely occurred in these areas.

History of billion-dollar U.S. freezes
Freezes can cause big damage to agriculture. According to NOAA's National Climatic Data Center, there have been six billion-dollar U.S. freezes since 1980, accounting for 5% of all billion-dollar weather-related disasters. Five of these freezes affected California or Florida; one hit the Midwest. Ranked by damages (in 2011 dollars), here are the six billion-dollar U.S. freeze events since 1980:

1) California Freeze of December 1990. Severe freeze in the Central and Southern San Joaquin Valley caused the loss of citrus, avocado trees, and other crops in many areas. Several days of subfreezing temperatures occurred, with some valley locations in the teens. $5.9 billion in direct and indirect economic losses, including damage to public buildings, utilities, crops, and residences.

2) Florida Freeze of December 1983. Severe freeze central/northern Florida; about $4.5 billion damage to citrus industry.

3) California Freeze of December 1998. A severe freeze damaged fruit and vegetable crops in the Central and Southern San Joaquin Valley. Extended intervals of sub 27° F temperatures occurred over an 8-day period; $3.5 billion estimated damages/costs.

4) Florida Freeze of January 1985. Severe freeze in central/northern Florida; about $2.5 billion damage to citrus industry.

5) East/Midwest freeze of April 2007. Widespread severe freeze over much of the East and Midwest (AL, AR, GA, IL, IN, IA, KS, KY, MS, MO, NE, NC, OH, OK, SC, TN, VA, WV), causing significant losses in fruit crops, field crops (especially wheat), and the ornamental industry. Temperatures in the teens/20's accompanied by rather high winds nullified typical crop-protection systems. Over $2.2 billion in damage/costs.

6) California Freeze of January 2007. For nearly two weeks in January, overnight temperatures over a good portion of California dipped into the 20's, destroying numerous agricultural crops, with citrus, berry, and vegetable crops most affected. $1.5 billion estimated in damage/costs; 1 fatality reported.

Scotland records its all-time warmest March temperature
The ridge of high pressure that brought "Summer in March" to the U.S. last week moved over Western Europe over the weekend, bringing sunny skies and record-breaking high temperatures to the U.K. Scotland broke its record for hottest March temperature on record on Sunday, when the mercury hit 22.8°C at Fyvie Castle, Aberdeenshire. The record lasted only one day, as a new high of 22.9°C was recorded in Aboyne, Aberdeenshire, on Monday. That record also lasted just one day, as Aboyne, Aberdeenshire has hit 23.4°C today. The previous March record in Scotland was 22.2°C at Gordon Castle (Morayshire) in March 1957, and at Strachan (Kincardineshire) in March 1965.

Canada's 1926 all-time March temperature record questioned
I reported last week that the 29.2°C (85°F) measured at Western Head, Nova Scotia on March 22, 2012 was the third warmest temperature ever recorded in Canada in March. Environment Canada lists the hottest March temperature as a 31.1°C at Beaver Creek on Vancouver Island, BC on March 29th, 1926. However, weather records researcher Maximiliano Herrera has looked into this record, and concluded that it is likely bogus. A station just a few miles away at Port Alberni measured a much cooler high temperature of 23.3°C that day, and the temperature range between the high and low temperature at Beaver Creek was almost 30°C, which is far too great for a station so close to the ocean. Such large differences between min and max temperature on sunny days usually commonly imply poor siting of the temperature instrument. He maintains that the highest March temperature in Canada should be the 29.4°C in 1921 at Wallaceburg, with the second highest being the 29.2°C (85°F) measured at Western Head, Nova Scotia on March 22, 2012.

Jeff Masters