AgWeatherNet Weekly Weather Outlook Monday Update for February 8 to February 14, 2021

COLD temperatures and lowland snow for the end of the work week

Mark Ingalls, AgWeatherNet Intern
Craig Oswald, Field Meteorologist

Synopsis:

The weather this week will be headlined by cold temperatures and lowland snow. This is thanks to an arctic air mass that is currently invading the upper Midwest. Some of this air looks to gradually make its way across the Rockies and into Washington from the northeast with temperatures continually dropping throughout the week and bottoming out Friday. This combined with a rather complex synoptic setup and two weather systems/disturbances expected to move into the region around Thursday looks to lead to strong lowland snow chances for the state, including western Washington, as well as breezy to windy conditions.

Discussion:

The period starts with a few light mountain snow showers lingering across the state. These showers look to continue to trend dry through the evening and night. However a low chance for a stray light mountain snow shower or two will be maintained through the state for the first half of the work week. Dry conditions are expected elsewhere. As alluded to, colder air will gradually filter into Washington through the week in conjunction with a potent arctic air mass invading the upper Midwest. With a general north/northeast to south/southwest temperature gradient expected, the lowest temperatures are to be observed in the northeast corner of the state and the warmest in the southwest corner of the state. Temperatures currently look to bottom out on Friday with a gradual warming trend to begin through the weekend. With that being said, small towns throughout the valleys north of Spokane are expected to see overnight lows dip just below zero by the latter half of the work week. While lows throughout most parts of southwest Washington look to maintain mid 20s.

By Wednesday winds are to increase and eventually become breezy to windy by Thursday through the state. Conditions are to remain breezy to windy Friday and strong gusts can be expected throughout parts of the Basin and Palouse as usual. However, due to the strong northeasterly direction of the surface wind expected by Thursday, potent wind gusts through the Cascade gaps are likely. Additionally, this looks to be a classic Fraser gap wind set up with plenty of cold dense air located immediately to the east. Meaning strong winds can be expected here through the week with gusts in excess of 50 mph possible by the latter half of the week as strong winds work their way down the Fraser River Valley. Please be aware of enhanced wind chill values if any outdoor work is to take place through the week and weekend as these strong winds pair with cold temperatures.

There is still a lot of uncertainty with the precipitation forecast for the second half of the work week due to the complex nature of the synoptic set up. This is also reflected in the disagreement among weather models with almost every model producing a slightly different outcome. The set up expected maintains a sharp temperature gradient roughly south/southwest to north/northeast across the state, Thursday and Friday particularly. A low chance for a few light mountain snow showers (below pass levels and confined mostly to the Olympics and Cascades) and a low land rain shower or two across western Washington may be possible Wednesday as an upper disturbance moves adjacent to the state. Any showers would move in from the northwest. This is mostly contingent upon adequate moisture making it into the dry air mass expected to be over the state at that time. With a sharp gradient between the colder and drier air mass to the north, and mostly situated over the state, and the warmer moister maritime air to the south and west off the coast, it is likely conditions stay dry, but a low chance must at least be acknowledged as indicated above.

By Thursday more potent forcing and a better source of moisture are anticipated as an upper disturbance moves southeast into Washington and a modest surface cyclone moves into Oregon from the west in conjunction with an upper low moving off coast of California. With warmer and moister air moving into the region form the southwest thanks to the surface cyclone and over running much colder air with additional forcing and lift being provided by the southeast moving upper disturbance, it is almost certain that low land snow can be expected. The greatest snow totals with this set up will be across the southern half of the state. And it is entirely possible that locations in the northeast corner of the state or along the Canadian border east of the Cascades don’t receive any snowfall as it will be difficult for moisture to penetrate that far north and across such a steep gradient with dry arctic air in palce. Therefore most of the action will likely be located along the Oregon/Washington boarder with heavy west to east bands of snowfall possibly setting up locally. Lowland areas of western Washington are also expected to receive snowfall, primarily during the overnight hours. A transition to a mostly rain/snow mix can be expected during the day. The most southwestern parts of the state and especially near the coast will have more chance to trend toward rain/snow mix.

This activity is expected to linger through Friday while trending dry through Friday night. However, another and slightly stronger surface cyclone looks to begin enhancing showers in the same region Saturday. This is expected to be a slightly warmer event as a better established warm front looks to be the main influencer of precipitation. Showers will gradually move into the state from the west/southwest with a good chance for lowland snow and rain/snow showers to continue through most locations. The southern half of lowland western Washington will likely trend more toward rain with this event however. Conditions look to trend mostly dry by Sunday.


Important Points About Next Week's Weather

South Central Washington
Remainder of the Week
  • Wind: N/NE and light. Turning SW Wed and becoming breezy. N/NE and breezy Thu and Fri with some gusts 30+ mph possible.
  • Precipitation: Dry conditions expected into Wed. Snow showers Thu and Fri, possibly heavy at times.
  • High Temps: Mid 40s Tue, upper 30s Wed, mid 20s Thu, near 20 Fri.
  • Low Temps: Mid 20s Mon night, mid 20s Tue night, low 20s Wed night, low teens Thu night.
  • Sky Cover: Mostly sunny/clear to partly cloudy. Becoming mostly cloudy by Thu and Fri.
Weekend
  • Wind: N/NE and breezy with some gusts 30+ mph possible Sat. Trending light and variable Sun.
  • Precipitation: Continued snow showers Sat. Trending dry Sun.
  • High Temps: Low 20s Sat, upper 20s Sun.
  • Low Temps: Low teens Fri night, mid teens Sat night, near 20 Sun night.
  • Sky Cover: Partly cloudy to mostly cloudy.

North Central Washington
Remainder of the Week
  • Wind: N yet variable and light. N/NE and breezy by Thu and Fri with some gusts 30+ mph possible, particularly throughout the Basin.
  • Precipitation: Dry conditions expected into Wed. Snow showers possible Thu and Fri with a greater chance for activity to the south and through the mtns.
  • High Temps: Upper 20s Tue, mid 20s Wed, near 20 Thu, near 20 Fri. Cooler in high terrain.
  • Low Temps: Mid teens Mon night, mid teens Tue night, upper single digits Wed night, mid single digits Thu night. Cooler in high terrain.
  • Sky Cover: Partly cloudy to mostly cloudy.
Weekend
  • Wind: N/NE and breezy with some gusts 30+ mph possible Sat, particularly throughout the Basin. Trending light Sun.
  • Precipitation: Continued chance for snow showers with greater activity to the south and through the mtns. Trending dry Sun.
  • High Temps: Low 20s Sat, upper 20s Sun. Cooler in high terrain.
  • Low Temps: Upper single digits Fri night, low teens Sat night, upper teens Sun night. Cooler in high terrain.
  • Sky Cover: Partly cloudy to mostly cloudy.

Eastern Washington
Remainder of the Week
  • Wind: N/NE and light. Turning SW Wed and becoming breezy. N/NE and breezy to windy Thu and Fri with some gusts 40+ mph possible.
  • Precipitation: Dry conditions expected into Wed. Snow showers Thu and Fri, possibly heavy at times with greater activity to the south.
  • High Temps: Near 30 Tue, upper 20s Wed, upper teens Thu, upper teens Fri. Cooler through the Blue Mtns.
  • Low Temps: Upper teens Mon night, mid teens Tue night, low teens Wed night, mid single digits Thu night. Cooler through the Blue Mtns.
  • Sky Cover: Partly cloudy through mid week. Becoming partly to mostly cloudy by Thu and Fri.
Weekend
  • Wind: N/NE and breezy to windy with some gusts 40+ mph possible Sat. Trending light and variable Sun.
  • Precipitation: Continued snow showers Sat. Trending dry Sun.
  • High Temps: Low 20s Sat, mid 20s Sun. Cooler through the Blue Mtns.
  • Low Temps: Near 10 Fri night, mid teens Sat night, near 20 Sun night. Cooler through the Blue Mtns.
  • Sky Cover: Partly cloudy to mostly cloudy.

Western Washington
Remainder of the Week
  • Wind: Generally light and Variable, breezier near the sound and coast. Turning NE by Thu/Fri and becoming breezy with windy conditions near the sound and Fraser Gap with gusts 50+ mph possible. Gusty gap winds through the Cascades expected as well.
  • Precipitation: Dry conditions expected into Wed with a few light snow showers possible over the Cascades/Olympics. Snow and rain/snow showers Thu and Fri, possibly heavy at times with greater activity to the south.
  • High Temps: Low 40s Tue, near 40 Wed, low 30s Thu, mid 30s Fri. Cooler through the Cascade and Olympic Mtns.
  • Low Temps: Low 30s Mon night, low 30s Tue night, mid 20s Wed night, mid 20s Thu night. Cooler through the Cascade and Olympic Mtns.
  • Sky Cover: Mostly cloudy.
Weekend
  • Wind: E/NE and breezy to windy with gusty gap winds continuing Sat. Trending light and variable Sun.
  • Precipitation: Continued snow and rain/snow showers Sat, trending more toward rain toward the south. Trending dry Sun.
  • High Temps: Mid 30s Sat, upper 30s Sun. Cooler through the Cascade and Olympic Mtns.
  • Low Temps: Mid 20s Fri night, mid 20s Sat night, upper 20s Sun night. Cooler through the Cascade and Olympic Mtns.
  • Sky Cover: Partly cloudy to mostly cloudy.

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