* WHAT. Flooding caused by snowmelt continues to be possible. * WHERE. Rivers and creeks draining the Brooks Range including areas around Atigun Pass, Galbraith Lake, and The Dalton Highway from Mp 232 To Mp 356, the Central Arctic Plains, Central Beaufort Sea Coast, Eastern Beaufort Sea Coast, and Western Arctic Plains. * WHEN. Through Tuesday afternoon. * IMPACTS. Rapid snowmelt and ice jams could lead to flooding of rivers and streams across the North Slope. Access to roads, airstrips, and low-lying infrastructure may be affected. High flows could lead to bank erosion that could threaten nearby roads. * ADDITIONAL DETAILS. - Flooding is likely across portions of the North Slope due to an unusually deep and persistent late-season snowpack combined with a sharp and prolonged warming trend through next week. A rapid onset of snowmelt has begun as temperatures have warmed into the 50's and 60's over the past couple of days across the North Slope and are expected to remain well above average through the middle of next week. River levels have begun to rise and will likely crest early next week. Ice has begun to breakup on the upper part of the Sag River on Thursday with DOT reporting water over a portion of the Dalton Highway near MP 323. There has been an emergency closure of the Dalton Highway between MP 305 and 356 due to a major washout at MP 315 caused by a failed culvert. Reports also show that the Colville River is breaking up. A 2-mile long ice jam was reported Friday evening along the Colville at Ocean Point with no flooding or impacts. Very high flow is leading to minor flooding near Umiat. Intact ice remains on many of the larger rivers, and the sudden influx of snowmelt runoff could lead to ice jam formation. These jams can cause sudden and severe rises in water levels, posing a significant threat to roads or other infrastructure near the affected waterways. - Http://www.weather.gov/aprfc
