Drought — Northern Coos, New Hampshire

2021-07-01 to 2021-07-31 · Northern Coos, New Hampshire

Event narrative

Drought conditions improved across southern and central New Hampshire during July due to well above normal rainfall. The July 1 issuance of the U.S. Drought Monitor had 90% of New Hampshire at a drought level of D0 or greater. A moderate drought level (D1) or higher was in place for 58% New Hampshire. Severe drought (D2) conditions were designated for 4% of Coos County in New Hampshire. By the end of July, only 30% of the state was designated in drought and those areas were exclusive to northern counties. A large portion of central and southern New Hampshire reported a foot or more of rainfall during the month as frequent heavy rain events impacted the area. Coos County received less rainfall with Errol Airport reporting 4.36 and Berlin 5.34.

Hydro operators balanced needs of lake levels, hydroelectric power generation needs, and the discharges to maintain stream flow needs downstream.

Wider weather episode

The U.S. Drought Monitor classified northern New Hampshire in drought. The drought developed as a result of below normal precipitation this spring followed by a warm and dry start to the summer season. The active weather pattern in July resulted in some areas receiving significant rainfall while others missed out. The coastal and foothills of mountains received the least amount of rainfall with these areas remaining in the severe drought introduced in late June. The coastal counties received and three times their normal rainfall, effectively ending drought conditions for southern counties. The Lakes and Mountains regions saw less rainfall averaging 75-125% of normal, effectively keeping a status quo on the severe drought conditions. Continued drought across watershed headwaters kept most area rivers and reservoirs below normal levels. Precipitation in July was 200 to 500% of normal across central and southern portions of New Hampshire, and 150 to 300% in southern Maine. Northern Maine and New Hampshire saw rainfall amounts 75 to 150% of normal.

Source: NOAA Storm Events Database, event_id 975640. Narrative written by the NWS forecast office that issued the report.