Many people believe a large acorn crop is a predictor of a harsh winter. The truth is, the acorns on the ground today are the prediction of weather conditions two or three years ago.
Bucknell University Professor of Biology Emeritus Warren G. Abrahamson, Ph.D and Executive Director of the Archbold Biological Station (located in Venus, Fla.) James N. Layne, Ph.D worked together on a study of acorn production during the years of 1969-1996 (with the exception of 1991).
The pair observed and recorded the acorn crops of two white oak and three red oak species.
"Jim Layne was really the one who got the project started," said Abrahamson. "He also was the one to make sure the data got collected each year."
The findings of the team may surprise you. In a published report dated September 2003, the research showed that the volume of acorn production each year is partly controlled by external factors like precipitation affecting the acorns during different stages of development during prior years.
Acorn production from bud to completed acorn takes nearly two years for species of the white oak and three years for species of the red/black oak, according to Abrahamson.
In 1989, the oaks in the study were subject to a freeze during the growth cycle. Only one species of oak, the Chapman Oak, was damaged. The damaged trees produced their third highest crop of acorns over the entire 27 year of the study in 1990.
The team reported that they did not experience a complete crop failure of any oak species during the study.
If you've noticed a lot of acorns around your house, Abrahamson who resides in Central Pennsylvania, said the Chestnut Oaks are producing them.
"I have never seen such a large crop in the 30 years I've lived here," he said. "Walking around my property is like walking on marbles."
The rainfall and temperatures in Central Pennsylvania during the springs of 2010-2012 have been favorable for acorn production. The table below list the precipitation and temperature totals for the months of March-May for each of the three years.
|Year||Avg. Precip.||Actual Precip.||Percent of Normal||Temp. Percent Above Norm.|
If favorable weather conditions for acorns mean a bumper crop two or three years later, the crops of 2013-2015 may bring some of the largest crops yet.
"Weather was a very important factor in the study," said Abrahamson. "The production of acorns definitely is not forecasting but hindcasting the weather."
A tropical wave is likely to become the Atlantic Basin's next tropical storm as it approaches or crosses the Caribbean Sea later this week.
Following some rain and gusty winds on Tuesday, a strong storm will target the United Kingdom on Thursday.
Bouts of wet weather will soak the northeastern United States during the last full week of September.
Typhoon Megi will threaten lives and property across Taiwan and eastern China into the middle of the week.
Flooding downpours will continue to cause problems in southern Texas into Monday night.
A stretch of dry weather across Germany will continue for much of the week ahead across Germany resulting in continued pleasant conditions for Oktoberfest.
Washington, D.C. (1975)
Last of nine straight days with some rain. Total rainfall of 9.86 inches; total for September 1975 was was 12.36 inches.
Cape Hatteras, NC (1989)
Rained every day from the 12th to the 25th for a total of 15.51 inches. Normal for all of September is 5.78 inches.
Portland, ME (1991)
Record combined August-September rainfall of 19.65 inches up to Sept. 25. Old record was 14.65 inches in August-September 1954.