High Wind — Western Alaska Peninsula, Alaska

1999-03-21 to 1999-03-22 · Western Alaska Peninsula, Alaska

Wider weather episode

An intensifying storm in the northwest Pacific moved quickly northeast across Shemya between 7am and 8 am Sunday. At this remote, western Aleutian ex-air force station, now relegated to 'caretaker' status...winds responded just as in any hurricane...diminishing rapidly to less than 20 mph for an hour or two...then reversing direction and increasing again. The center moved into the southern Bering Sea to a position less than 60 miles south of Saint George Island (Pribilofs) Monday at 9am as a 959mb center. The low then began to curve slightly south of due east..moving to about 30 miles southwest of Cold Bay as a 977mb center just before 3pm Tuesday. The front associated with the storm moved into the central Aleutians at 3am Sunday, elongating east and more slowly north...to a position extending from just north of Saint Matthew Island, across the southern tip of Kodiak Island, into the northeast Pacific Sunday afternoon. By Monday evening, the original low had weakened to a 987mb center near Cold Bay and was no longer producing significant weather.Strong southeast winds initially preceded the front late Saturday and Sunday...decreasing in strength as the front moved further and further out from the parent low. Extremely strong storm force winds were also observed within 360 miles southwest semicircle of the low...initially gusting in excess of 100 mph. These winds around the 'back side' of the storm were much slower to diminish. AWOS adjusted prefrontal (pre-low) southeast winds reached 92 mph at Shemya between 10pm and 11pm Saturday. The center moved over the station with barometric pressure readings of 27.63 (estimated at 935.7 millibars). On the back side of the low, winds increased steadily, reaching hurricane force between 1pm and 2pm Sunday. Adjusted AWOS wind gusts at Shemya reached 122 mph from the northwest between 1pm and 2:30 pm Sunday. Minor damage was reported...including bent and/or toppled light posts, one section of roof blown off and 1 garage door blown off its hinges. An anemometer 250 feet off the ground on top of the Shemya radar was blown off, just after recording 110 mph gusts. At Adak, conditions were very similar, with ASOS adjusted southeast, prefrontal gusts reaching at least 73 mph between 3am and 5am Sunday. On the back side of the low, the ASOS adjusted gusts reached 116 mph from the southwest early Sunday afternoon. It wasn't until 4pm Monday before the winds finally decreased to below 40 mph. At Adak damage to metal roofs, to overhead doors and supply piers at the docks was reported. Power was out for 45 minutes and several electrical arcing episodes were reported. At Dutch Harbor, in the eastern Aleutians, prefrontal gusts only reached 51 mph. However, on the back side of the storm, strong westerly wind gusts as high as 73 mph were reported Tuesday from 1pm to just after 8pm by a contract observer at the airport (using an F420 wind system). Wind gusts over 100 mph were reported by a tug out in Unalaska Bay Monday afternoon. Across the Pribilofs, prefrontal wind gusts reached an adjusted 64 mph at the Saint Paul Island ASOS Sunday just before 3pm, with winds diminishing rapidly below 40 mph with the frontal passage some 3 hours later at 6pm. At Saint George, adjusted ASOS wind gusts topped out at 75 mph just after 3pm, with frontal passage occurring at 7pm. At Saint George, however, it wasn't until 3am Monday before winds finally dropped below 40 mph.Along the Alaska Peninsula, prefrontal, adjusted ASOS gusts reached 69 mph, as reported at Cold Bay, between 5pm and 6pm Sunday.Strong southeast winds were observed along the western tip of Bristol Bay late Sunday night and Monday. Adjusted speeds of 75 mph were recorded at Cape Newenham, where winds are accelerated by terrain, between midnight and 6am Monday ahead of the front. Winds finally diminished below 40 mph across the zone by 6am Monday morning.At Mekoryuk, at the southwest end of the Kuskokwim Delta zone, wind gusts reached 67 mph between 11pm Sunday and 3am Monday, finally diminishing below 40 mph at noon Monday.

Source: NOAA Storm Events Database, event_id 5681129. Narrative written by the NWS forecast office that issued the report.