National Summer Season Precipitation - June-August 2002

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The graph to the left is a time series depicting precipitation averaged across the contiguous U.S. Based upon preliminary precipitation data, June-August 2002 was slightly drier than average, ranking 30th driest in the last 108 years. This belies considerable regional variability as can be seen from the maps below.

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Record summer dryness occurred in Nevada in 2002. Four other states in the Southwest (CA, AZ, UT and CO) and one in the east (OH) also received much below average precipitation with Utah having its second driest summer on record. Minnesota received record high precipitation for the June-August period, and 2 other states (ND, FL) also received much above average rainfall over the three summer months.

August Precipitation

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The graph to the left is a time series depicting precipitation averaged across the contiguous U.S. Based upon preliminary precipitation data, August 2002 was near average, ranking 46th driest. August 2002 marks the second consecutive August which has been near average, nationally. There has been no significant trend in mean national August precipitation over the last century.

There was considerable regional variability in precipitation across the country. States in the Southwest U.S., and in the Northeast received less rainfall than average in August, while states in the northern Great Plains and the Great Lakes received above average rainfall this month. Three states, Minnesota and the Dakotas, were much wetter than average for August with a rank of 3rd wettest August on record for South Dakota. Maine was record driest for the month of August and California and Nevada had their 2nd driest August on record. Drought continued to worsen in much of the West and Southwest and despite a generally wetter than average March-June for the Northeast, dryness began to creep back into this region. While rainfall in New Mexico was near average for July, the mountains in northern New Mexico have received only 50-70% of their normal rainfall for the year according the National Weather Service in Albuquerque. Less than average monsoon season precipitation in August has continued to exacerbate the long-term drought.

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In North Carolina on the evening of Sunday 25th, up to 8 inches of rain fell in the area north and east of Raleigh (shown in the satellite image to the left). This led to flash flood warnings for several counties and some road closures. Heavy rain continued across eastern North Carolina through the 26th and 27th. The rain was a result of an upper level low combined with humid air across the Southeast. Monmouth County, New Jersey declared a state of emergency after storms ripped through the area on Friday 2nd of August. High winds and lightning damaged homes and property and left emergency crews clearing debris from roads and trying to restore power to around 140,000 homes. Ocean County was also affected by the storms, but damage was less severe.

Precipitation Departures

The map to the right, based on more than 500 airport stations, shows August 2002 total precipitation as a percent of the 1971-2000 station normals. Above normal precipitation generally occurred in the northern Plains and Mississippi Valley region, with more than 190% of normal precipitation falling in parts of the upper Midwest. However, dryness extended across most of the northeast and Ohio Valley where as little as 25% of normal rainfall was recorded. Along the west coast, less than 10% of normal precipitation fell at most stations in California, Nevada, Oregon and Washington. Texas was also mostly dry except for the southeastern corner.

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National Precipitation - September 2001-August 2002

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The graph to the left is a time series depicting precipitation averaged across the contiguous U.S. Based upon preliminary precipitation data, September-August 2002 was drier than average, ranking 29th driest in the last 108 years. The last 3 September-August periods have averaged below the long term mean precipitation.

Record dryness occurred in 6 states (NV, UT, CO, AZ, VA and NC) averaged over the last 12 months. The pattern of state-averaged September-August precipitation can be seen in the map to the right. Eight other states ranked in the top ten driest such periods. Five states (MN, WI, IL, IN and MI) received much above average rainfall for the 12-month period, with a record wet September-August occurring in Michigan. This is a result of a relatively persistent pattern of dryness in the west and east and excessive rainfall in the central area of the contiguous U.S.

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Questions?

For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division:

Climate Services Division NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4876 phone: 828-271-4800 email: questions@ncdc.noaa.gov

For further information on the historical climate perspective presented in this report, contact:

Catherine Godfrey NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4328 email: Catherine.S.Godfrey@noaa.gov

Jay Lawrimore NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4328 email: Jay.Lawrimore@noaa.gov

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