SALEM, Ohio – According to the National Weather Service, a period of dry weather that started more than a year ago prompted the August 2001 issuance of the drought watch across most of central Pennsylvania. Continuing dry conditions prompted the watches to be upgraded to the current status recently, which differ by county across the state.
Last November. For the month of November 2001, all 67 Pennsylvania counties had below normal precipitation.
Cumulative rainfall for the period Jan. 1 through Dec. 5, 2001, ranged from 24.9 inches in Bedford County to 39.1 inches in Greene County. Normal yearly precipitation for the state is 35-46.5 inches, according to the National Weather Service.
Nationally, January marked the fourth consecutive month with below- to much-below-normal precipitation for the Northeast region, with the October-January period ranking as the second driest such period in the 108-year record.
The dryness was associated with unseasonably warm temperatures, with 2001-2002 having the second warmest November-January on record with the National Climatic Data Center. Last year marked the third consecutive year of below-normal precipitation, following nine years of precipitation surpluses nationwide.
At its widest point last year, drought affected about 20 percent of the contiguous United States. The areas most severely affected included parts of the southern Great Plains, much of the western part of the country and, by December, much of the Eastern Seaboard, including Pennsylvania.
Severe to extreme drought covered approximately 18 percent of the contiguous United States at the end of January.
February data. Precipitation data released by the National Climatic Data Center for Feb. 17-23 indicates severe drought conditions for all of Pennsylvania, with the eastern half of the state receiving less than a quarter inch of precipitation during the week. The western half of the state fared slightly better, recording between one-quarter and one-half inch of precipitation.
Across western Pennsylvania, February precipitation has been below normal with deficits averaging from 15 percent to 25 percent across the watch area. In the northwest part of the state, 180-day precipitation levels ranged from near normal to 10 percent below normal.
For the past 60 days, precipitation deficits have ranged from 15 percent to 25 percent; a 15 percent long-term deficit is considered the threshold for drought conditions.
In the past six months, precipitation levels across the counties with declared drought emergencies range from 7 to 9 inches below normal, and in watch and warning counties, from near normal to 6 inches below normal.
Across western Pennsylvania, rivers in the Allegheny River Basin are currently 60 percent to 80 percent of their normal streamflow.
Outlooks issued for March call for normal precipitation and above normal temperatures.
