FastCast--Wednesday, Oct. 18 to Tuesday, Oct. 24:
With a strong atmospheric river directed into British Columbia, warm southerly flow will bring mostly sunny conditions to Western Washington on Wednesday and Thursday, with highs increasing significantly to the upper 60s to low 70s. However, from Friday onward, temperatures will decline significantly, ending up below average by next week. On Friday, expect mostly cloudy skies with highs dropping to the low to mid 60s. Cloudy conditions with a chance of showers will prevail from Saturday to Monday, with highs in the upper 50s to low 60s. From Wednesday to Sunday, expect lows in the upper 40s to low 50s. On Monday, expect lows to drop to the mid 40s. By Tuesday, the chance of showers will increase, and highs will drop to the upper 40s to low 50s, with lows in the upper 30s to low 40s. These colder temperatures will continue into next week, so stay tuned for updates.
---------------------------------------------------------------
Continue reading the full blog below!
Washington will experience a few more days of above average temperatures, before a significant cooldown will bring colder temperatures to the Pacific Northwest starting next week. Let's take a look at the forecast!
Let's start with the forecast for high temperatures from the European model, starting with Wednesday's highs.
Expect lowland and Willamette Valley highs in the upper 60s to low 70s, with similar highs in Eastern Washington. Coastal highs will reach the low to mid 60s. Notice cooler highs from Bellingham northward, as a strong atmospheric river impacts British Columbia. Clouds associated with this atmospheric river will bring cooler temperatures to Whatcom, San Juan, and Clallam Counties.
Next, let's look at Thursday's highs, also from the European model.
On Thursday, expect lowland and Willamette Valley highs in the upper 60s to low 70s, with Eastern Washington reaching the upper 60s to mid 70s, the coast reaching the low to mid 60s, and areas under the atmospheric river (North Coast & NW Interior) reaching the low 60s.
Friday's highs will cool west of the Cascades, but remain warm to the east. The European model forecast is below.
On Friday, expect lowland highs in the upper 50s to low 60s, coastal highs in the low to mid 60s, Willamette Valley highs in the mid 60s to low 70s, and Eastern Washington's highs in the upper 60s to mid 70s. Areas along the Strait of Juan de Fuca and in the NW Interior will remain in the mid 50s to low 60s.
On Saturday, temperatures will continue to decrease in the lowlands, while remaining warm in Eastern Washington, as seen below.
On Saturday, lowland highs will decrease to the upper 50s to low 60s, with the Willamette Valley reaching the low to mid 60s, and the coast reaching the upper 50s. Eastern Washington will remain warm, with highs reaching the upper 60s to mid 70s.
Now, let's take a look at the reason for both the warm temperatures on Wednesday and Thursday and the cooler temperatures in the state's northwest corner. A potent atmospheric river is aimed directly at Southern British Columbia, barely clipping NW Washington. The European model forecast shows total rain from this atmospheric river.
Notice 0.1-0.2" of rain from Snohomish County southward in Western Washington. Most of this rain has already fallen. Areas from Everett to Bellingham could get 0.2-0.4" of rain. The atmospheric river has a very sharp cutoff on its south side. From Forks northward on the coast and north of a line from Orcas Island to Lynden will get 0.5-2.5" of rain. Parts of the Vancouver Island coast (like Tofino) will get a staggering 8-12" of rain in under 3 days, with Metro Vancouver, eastern Vancouver Island, and the Sunshine Coast getting 2.5-5".
The contrast is most notable between Bellingham and Vancouver, 45 miles as the crow flies. Bellingham will get 0.3", while Vancouver will get up to 3.5"!
We'll round out the blog by looking at the extended forecasts for Seattle and Spokane, seen on the European EPS model.
First, Seattle, seen below.
Notice warmth and above average temperatures until around Monday, then a significant change to below average conditions, with highs in the low to mid 50s and lows in the upper 30s to mid 40s.
A similar situation is seen in the forecast for Spokane, seen below.
In Spokane, highs will be warmer than Seattle (through Saturday), then cooler than Seattle (Monday onward), with lows remaining colder than Seattle. By next week, Spokane's highs will be in the mid 40s to low 50s, with lows in the low to mid 30s. The first frost is likely for Eastern Washington next week. (Add 3-5° to these temperatures for the Columbia Basin).
Stay tuned for more information as colder fall weather arrives in the Pacific Northwest.
No comments:
Post a Comment