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."
Following a southward push of cool, dry air at midweek, clouds, showers and higher humidity will return to the Northeast.
Even though the tremendous rains have come and gone, flooding will continue on the major rivers in the South Central states for the next couple of weeks.
Severe weather, including isolated tornadoes, will once again target the nation's midsection into Wednesday night.
Summer heat to set the stage for thunderstorms from England to France and Germany on Friday and Saturday.
Major Hurricane Blanca will threaten Baja California with flooding rain and damaging winds this weekend.
While the center of Andres will remain a thousand miles away, its moisture will still get drawn into the Western United States and enhance thunderstorm activity later this week.
Dulles Airport, Washington, D.C. (1991)
4.25 inches of rain -- normal for all of June is 4.23 inches.
Great Comanche Tornado commenced near Cedar Rapids, IA, and ended over Lake Michigan; 175 killed, destroyed Comanche village on Mississippi River.
Thunderstorms in northwestern Kansas produced up to 18 inches of hail near Salden during the early evening. Crops were completely destroyed and total damage from the storm was nearly 500,000 dollars. Temperature dropped from near 80 degrees before the storm to 38 degrees at the height of the storm.