OAR Forecast Discussion 32
11:00PM PDT FRI APR 27 2012
06 UTC, 28 APR 2012
…High seas, strong winds to persist overnight…
GALE WARNING FOR ALL OF PACIFIC CANADIAN MARITIME WATERS
Short term forecast:
A weak 1009mb low is situated near 51N 132W and is moving toward the east, and a warm front associated with the low is moving over Vancouver Island currently. Strong southeast winds sustained at 20 to 30 kts are located behind the warm front, and a buoy located offshore Tofino near 48.8N 126.0W has reported increasing winds during the past few hours–now reaching 20kts. Wave heights have ranged from 6 to 9 ft. A scatterometer pass at 18 UTC revealed a large swath of 20 to 30 kt winds located ahead of the cold front associated with the low, so these conditions will persist throughout the night. Strong southeast winds should persist through midday Saturday; the cold front will then pass and winds will die down a bit and shift to northwesterly by late Saturday. Expect rough seas throughout the forecast period.
Extended forecast:
Another weak secondary low pressure center is expected to spin up over the open ocean and approach maritime Canada by late Sunday, bringing a return to southeasterly winds for at least some time. Given the uncertainty in the exact forecast of the low, I can’t yet tell how long southeasterly winds will persist; however, model guidance currently suggests that the strongest winds associated with this low will remain well offshore. In any event, we can probably expect brisk westerly winds–and perhaps with some fortune, a northwest tailwind–over the area by late Monday as the parent surface low stalls out in the Gulf of Alaska.
Zone forecast for Tofino to Ucluelet, including offshore waters out 100 nautical miles
Winds Seas
+03HR: SE @ 20-30kts 6 to 9 ft.
+06HR: SE @ 20-30kts, G35kts 6 to 9 ft.
+09HR: SE @ 20-30kts 8 to 12 ft.
+12HR: SE @ 15-20kts, G25kts 8 to 12 ft.
+15HR: SW to S @ 10-15kts 5 to 8 ft.
+18HR: WNW to NW @ 10kts 5 to 8 ft.
+21HR: NW @ 5-15kts 5 to 8 ft.
+24HR: NW @ 5-15kts 5 to 8 ft.
Extended (large errors possible)
+30HR: NW @ 10-15kts 5 to 8 ft.
+36HR: W @ 10-15kts 4 to 6 ft.
+42HR: W @ 10-15kts 4 to 6 ft.
+48HR: S to SE @ 10-15kts 5 to 8 ft.
Powell