Forecasts have now come into more agreement on the potential for a major windstorm across the Pacific Northwest on Tuesday. This event has a chance to produce major impacts across the region.
This event will happen in stages as a strong low approaches the coast. First, strong winds will hit the coast, especially the Oregon Coast, from Monday evening to midday Tuesday. Strong winds will hit the Washington Coast and Willamette Valley a bit later, from early Tuesday morning through midday. Peak winds in the Puget Sound area are expected from early afternoon to late evening, followed by an evening westerly surge down the Strait of Juan de Fuca.
Peak Winds (estimated):
Oregon Coast: Monday night to midday Tuesday
Willamette Valley: Early Tuesday morning to midday Tuesday
Washington Coast: Early Tuesday morning to Tuesday night
Puget Sound Lowlands: Midday Tuesday to Tuesday evening
Strait of Juan de Fuca: Tuesday afternoon to Tuesday night
Below is the first forecast we'll look at. This is the NAM forecast, which accurately predicted the winds on Monday morning.
The NAM model paints a dangerous picture, showing peak gusts of 60-65 mph for the lowlands around 3 PM Tuesday. At other times, this forecast shows peak gusts of 60-80 mph on the Oregon Coast, 60-70 mph on the Washington Coast, 50-60 mph in the Willamette Valley, and 55-70 mph along the Eastern Strait. Eastern Washington will get gusts of 40-55 mph.
Next, we'll look at the HRRR forecast for peak winds in the lowlands.
The HRRR shows 55-65 mph gusts for the lowlands around 2 PM Tuesday. The Oregon Coast could reach 65-85 mph, 60-70 mph on the Washington Coast, 40-55 mph in the Willamette Valley, and 60-70 mph on the Eastern Strait. Eastern Washington will get gusts up to 50-65 mph.
So...why are winds this strong possible? The UW forecast below shows the low pressure system offshore at 7 AM Tuesday.
Notice the elongated low pressure moving onshore, with a massive pressure gradient down the Oregon Coast.
Fast-forward to 4 PM Tuesday.
There is a very strong pressure gradient across the Puget Sound area. This is what fuels the potential for 50-65 mph winds across the region.
Two additional impacts from this storm will be very high waves, with 25-35 foot breakers and significant coastal flooding on the Washington & Oregon Coasts. Additionally, southerly winds and very low pressure will bring coastal flooding and tidal overflow in Puget Sound.
Finally, another round of heavy rain is expected for the entire region. Below is the HRRR high-resolution forecast for rain through Tuesday night.
The HRRR shows 1-1.5 inches of rain in the lowlands and a significant soaking of 3-5 inches on the coast and in the mountains. Eastern Washington even gets 0.3-1.25 inches.
Next, the NAM high-resolution forecast, also for rain through Tuesday night.
The NAM shows 0.75-1.25 inches for the lowlands, 3-5 inches for the coast, 3-7 inches for the mountains, and 0.25-1.25 inches in Eastern Washington.
Stay tuned. This is potentially a major wind event, so I will post an update Tuesday morning.
No comments:
Post a Comment