AgWeatherNet Weekly Weather Outlook Monday Update for February 1 to February 7, 2021

Slight cooling and briefly dry conditions by midweek

Mark Ingalls, AgWeatherNet Intern
Craig Oswald, Field Meteorologist

Synopsis:

Washington continues to reside under a relatively moist southwesterly flow regime as a long wave trough remains in place along the west coast. The trough is expected to move eastward through Tuesday with the axis roughly centered over the state by Wednesday morning. This move will transition the region to drier weather and slightly cooler temperatures midweek with a ridge of high pressure building into the Gulf of Alaska. As the trough continues east, Washington’s position looks to become situated downstream of the ridge axis and will allow for a shortwave disturbance to pass through the region from the northwest. This is anticipated to provide a round of showers throughout some parts of the state Thursday night. Conditions look to trend dry statewide through Friday with warmer air creeping into the region from the southwest. Another upper disturbance is anticipated to skirt the state again Sunday.

Discussion:

Monday's outlook looks to remain mostly on track with Fridays. The longwave through that has been positioned along the west coast and keeping Washington State under relatively moist southwest flow looks to move to the east through Tuesday. Precipitation and windy conditions look to remain in effect Tuesday as the trough progresses, also lowering snow levels throughout the day Tuesday and Tuesday night with levels eventually reaching below pass levels. The main weather effects after the initial frontal passage look to be continued breezy to windy conditions, slightly cooler temperatures, and a decrease in rain and mountain snow showers by Wednesday. The trough axis looks to be situated over the state by Wednesday morning promoting the coolest and driest weather conditions of the week as the entire state looks to trend mostly dry by that time.

As the trough continues to move east, a strong ridge is expected to build into the Gulf of Alaska, helping to create a highly amplified wave pattern across the U.S and Canada. In fact, the trough that is progressing east looks to be an integral part in a weather pattern across the upper Midwest that looks to produce HIGH temperatures below zero for the weekend. Luckily for Washingtonians, our temperatures look to remain seasonable through the period as the state is influenced primarily by a dirty ridge and northwesterly flow with a high pressure center located well offshore for the remainder of the period.

As alluded to in last Friday's outlook, a shortwave disturbance aloft is still expected to move through the region bringing more light precipitation by Thursday night. Snow levels look to be lower than what we have been experiencing yesterday and today (Sunday and Monday) and snow can be expected at pass levels with the majority of which expected through the northern half of the Cascades where several inches are likely at the northern passes. Lowland snow and rain/snow also look likely in areas north of the Columbia Basin and on the Palouse, particularly along the Idaho border. It is possible that the Columbia Basin remains dry with this disturbance and only a low chance for precipitation is acknowledged.

Conditions are to trend dry statewide again Friday with only rain and high elevation snow showers lingering through the Cascades as snow levels rise in accordance with warmer air sneaking into the region from the southwest. Dry conditions are expected across the state on Saturday with slightly warmer temperatures. Guidance indicates a potent short wave moving across the north Pacific from the west will essentially knock the top off the upper ridge and flatten it. This shortwave is currently indicated to move into British Columbia Sunday, bringing a chance for precipitation across northern portions of western Washington and the northern Mountains primarily. This situation will be reexamined in Friday's outlook.


Important Points About Next Week's Weather

South Central Washington
Remainder of the Week
  • Wind: S/SE and light to breezy. Becoming S/SW and windy Tue with gusts 30+ mph. Trending light to calm and variable Wed. SW and increasing again Thu with gusts 40+ mph, remaining breezy/windy Fri.
  • Precipitation: A few light rain showers through Tue. Mostly dry expected Tue and Wed. Low chance for a rain shower Thu night into Fri. Dry Remainder of Fri.
  • High Temps: Near 50 Tue, mid 40s Wed, upper 40s Thu, low 50s Fri.
  • Low Temps: Upper 30s Mon night, low 30s Tue night, near 30 Wed night, mid 30s Thu night.
  • Sky Cover: Partly cloudy.
Weekend
  • Wind: S/SW and trending light to breezy Sat and Sun.
  • Precipitation: Dry conditions expected.
  • High Temps: Upper 40s Sat, upper 40s Sun.
  • Low Temps: Low 30s Fri night, low 30s Sat night, low 30s Sun night.
  • Sky Cover: Mostly sunny/clear to partly cloudy.

North Central Washington
Remainder of the Week
  • Wind: S/SE and light to breezy. Becoming S and breezy/windy Tue particularly through N/S oriented valleys and with gusts 40+ mph throughout the Basin. Trending light to calm and variable Wed. S/SW and increasing again Thu with gusts 40+ mph throughout the Basin, remaining breezy/windy Fri.
  • Precipitation: Periods of lowland rain and mountain snow showers continuing through Tue. Trending dry Tue night and mostly dry expected by Wed. Lowland rain/snow and mountain snow showers Thu night into Fri, drier across the Basin. Dry Remainder of Fri.
  • High Temps: Mid 40s Tue, low 40s Wed, near 40 Thu, mid 40s Fri. Cooler in high terrain.
  • Low Temps: Mid 30s Mon night, near 30 Tue night, mid 20s Wed night, upper 20s Thu night. Cooler in high terrain.
  • Sky Cover: Partly cloudy to mostly cloudy.
Weekend
  • Wind: S/SW and trending light to breezy Sat and Sun.
  • Precipitation: Dry conditions expected Sat. Chance for mountain snow showers Sun.
  • High Temps: Low 40s Sat, low 40s Sun. Cooler in high terrain.
  • Low Temps: Upper 20s Fri night, upper 20s Sat night, upper 20s Sun night. Cooler in high terrain.
  • Sky Cover: Mostly sunny/clear to partly cloudy.

Eastern Washington
Remainder of the Week
  • Wind: S/SE and breezy to windy. Becoming S/SW and remaining windy Tue with gusts 40+ mph. Trending light and variable Wed. SW and increasing again Thu with gusts 40+ mph, remaining breezy/windy Fri.
  • Precipitation: Light rain showers and mountain snow Tue. Trending dry Tue night and mostly dry Wed. Rain/snow and mountain snow showers Thu night into Fri with mostly snow expected along the Idaho border. Trending dry Fri.
  • High Temps: Mid 40s Tue, upper 30s Wed, upper 30s Thu, low 40s Fri. Cooler through the Blue Mtns.
  • Low Temps: Near 40 Mon night, low 30s Tue night, low 30s Wed night, low 30s Thu night. Cooler through the Blue Mtns.
  • Sky Cover: Partly cloudy to mostly cloudy.
Weekend
  • Wind: SW and trending light to breezy Sat and Sun.
  • Precipitation: Dry conditions expected.
  • High Temps: Low 40s Sat, low 40s Sun. Cooler through the Blue Mtns.
  • Low Temps: Near 30 Fri night, near 30 Sat night, near 30 Sun night. Cooler through the Blue Mtns.
  • Sky Cover: Mostly sunny/clear to partly cloudy.

Western Washington
Remainder of the Week
  • Wind: S/SE and light to breezy. Becoming S/SW and windy Tue with gusts 30+ mph, especially near the coast. Trending light and N/NW yet variable Wed, breezy through the sound. SW and increasing again Thu with gusts 40+ mph near the coast, remaining breezy/windy Fri.
  • Precipitation: Lowland rain and mountain snow showers through Tue night. Trending dry Wed. Showers returning Thu. Trending dry Fri.
  • High Temps: Mid 40s Tue, mid 40s Wed, upper 40s Thu, upper 40s Fri. Cooler through the Cascade and Olympic Mtns.
  • Low Temps: Upper 30s Mon night, mid 30s Tue night, mid 30s Wed night, upper 30s Thu night. Cooler through the Cascade and Olympic Mtns.
  • Sky Cover: Partly cloudy to cloudy.
Weekend
  • Wind: Mostly light and variable.
  • Precipitation: Dry conditions expected Sat. Chance for lowland rain and mountain snow across the northern half of the region.
  • High Temps: Upper 40s Sat, upper 40s Sun. Cooler through the Cascade and Olympic Mtns.
  • Low Temps: Mid 30s Fri night, mid 30s Sat night, mid 30s Sun night. Cooler through the Cascade and Olympic Mtns.
  • Sky Cover: Partly cloudy to mostly cloudy.

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