In 1969 Neil Armstrong walked on the moon, the Woodstock festival changed music and perhaps the culture forever, Sesame Street debuted on television and Richard Nixon became president. The first quarter of that year was also the only one in Pennsylvania since 1895 drier than the start of 2009, according to Penn State weather and precipitation experts.
The winter of 2008-2009 was a dry one, according to Bryan Swistock, extension water resources specialist in the College of Agricultural Sciences, who attributed the lack of precipitation in most parts of the state to a La Niña weather pattern. The dry trend has continued into the spring.
"Currently we are looking at a widespread, drought-related pattern of rainfall that is missing almost all of the state," Swistock said. "Just like this past winter, we are seeing a lot of storms traveling up to our west and causing heavy precipitation in Ohio, Michigan and even further into the Midwest. The same storms that are causing floods in the Midwest are bypassing eastern Pennsylvania, which is 50 to 70 percent below its average rainfall."
Droughts in Pennsylvania are rarely statewide. The southern tier of the state, eastern Pennsylvania and the Poconos region have been extremely dry, and those areas already are starting to see low groundwater levels indicative of a hydrologic drought. "In contrast, northern and western Pennsylvania are in a less precarious situation, and precipitation rates are fairly normal in those regions," Swistock said.
Mercer County, bordering Ohio, is the only entire county currently averaging above normal precipitation for 2009, said Paul Knight, Penn State climatologist and meteorology instructor. Other western counties, such as Crawford, Venango, Butler, Lawrence and Erie, all have measured near normal for rain and snow so far this year.
Meanwhile the rest of the state has been waiting for rain. "The region spanning from the Laurel Highlands in Somerset County to the southern Poconos in Carbon County and southward to the Maryland and New Jersey borders has averaged 50 to 70 percent below average precipitation this year," said Knight. "The other 62 counties in Pennsylvania have been between 10 and 50 percent below their average precipitation rates since the first of the year."
Regular rainfall over the last several weeks has helped to ward off a serious drought, agree Penn State experts, but the precipitation has done little to make up for the deficits. The month of April is going to be critical in combating drought conditions, Swistock noted. "So far April has been fairly close to normal, with a pattern of routine precipitation," he said. "The problem is an existing 4 to 6-inch deficit, so an average amount of rainfall will not make up for the year's dry start."
If weather records are any indication of what's to come, the state might be in for more dry weather in the next few months, Knight pointed out. "It should be noted that six out of the 11 driest first quarters in Pennsylvania have had below-normal rainfall during the heart of the growing season," he said.