AgWeatherNet Weekly Weather Outlook for January 14 to January 20, 2017

Much Warmer and Stormy Next Week; Rapid Snowmelt and Localized Flooding Possible

Nic Loyd, Meteorologist, 509-786-9357

With a sudden and major warm up on the way, and snow covering all of central and eastern Washington, the stage is set for a messy weather week ahead. Rapid snowmelt and potentially heavy rainfall look to conspire with frozen ground and ice-clogged drainage systems to increase the possibility of urban and small stream flooding. There is still uncertainty in the magnitude and duration of the upcoming temperature increase and potential total rainfall amounts, but confidence in the overall pattern is high. An energetic and consolidating jet stream will propel warmth and moisture from the Pacific Ocean into Washington beginning later on Monday and continuing through the mid-week time frame. Western sites should break 50 degrees, while eastern areas will likely peak in the 40s and possibly 50s in warm spots.

Given that snow melt is governed by a surface energy balance, air temperature is just one critical factor. The increasingly moist and windy conditions are likely to melt snow much quicker than would calm and dry weather. Also, warm rain falling on snow is particularly nefarious given that it has a double impact of contributing water to the land surface via the rain drops themselves and the melting snowpack.

In the meantime, cool and benign weather is expected this weekend, as slow temperature moderation occurs. Still, strengthening inversions could cause stagnant and foggy conditions in the lowlands. Depending upon the timing of the precipitation and the amount of lingering, low level cold air trapped east of the Cascades, there may be an initial period of freezing rain or mixed precipitation around Monday night or Tuesday morning that could cause some icy conditions. By mid-week, the cold air should be gone from most of the state, as mild and stormy conditions overtake the region. Somewhat calmer weather may arrive late in the period, as the upper air mass slowly cools. However, with its maritime (and not continental) origins, any cooling is anticipated to be minimal. Overall, a major regime change from cold weather to the warmest temperatures since November is forecast for next week. During the transition, ice is possible east of the Cascades, and then active and mild weather may instigate flooding by mid-week.

Temperatures
  • Cold on Saturday, and then milder.
  • Becoming much warmer and well above normal next week.

Precipitation
  • Rain likely, possibly heavy at times, in the west for early to mid next week.
  • Rain at times east of the Cascades beginning on Monday night, possibly starting as wintry precipitation.

Wind
  • Windy at times next week.

8 to 14 Day Outlook - January 21, 2016 to January 27, 2017
  • Overall, near average temperatures and near average precipitation are expected during the 8 to 14 day time frame.

Important Points about Next Week's Weather

South Central Washington
  • Normal conditions for this time of the year would be highs in the mid 30s to mid 40s and lows in the 20s to low 30s.
Weekend
  • Mostly dry. Fog and low clouds possible.
  • Highs in the 20s on Saturday, and 20s to mid 30s on Sunday.
  • Lows in the single digits to teens.
Next Week
  • Rain likely at times after early Monday, possibly beginning as freezing rain.
  • Highs in the mid 20s to 30s on Monday, and much warmer by mid week.
  • Lows in the teens on Monday morning, and much warmer by mid week.

North Central Washington
  • Normal conditions for this time of the year would be highs in the 30s and lows in the low to mid 20s.
Weekend
  • Mostly dry. Fog and low clouds possible.
  • Highs in the upper teens to 20s on Saturday, and 20s to low 30s on Sunday.
  • Lows in the single digits to teens.
Next Week
  • Rain likely at times after early Monday, perhaps beginning as snow or wintry precipitation.
  • Highs in the mid 20s to mid 30s on Monday, and much warmer by mid week.
  • Lows in the teens on Monday morning, and much warmer by mid week.

Eastern Washington
  • Normal conditions for this time of the year would be highs in the mid 30s to around 40 and lows in the 20s to around 30.
Weekend
  • Mostly dry. Fog and low clouds possible.
  • Highs in the 20s on Saturday, and 20s to mid 30s on Sunday.
  • Lows in the single digits to teens.
Next Week
  • Rain likely at times after Monday, possibly beginning as freezing rain or mixed precipitation.
  • Highs in the mid 20s to 30s on Monday, and much warmer by mid week.
  • Lows in the teens on Monday morning, and much warmer by mid week.

Western Washington
  • Normal conditions for this time of the year would be highs in the mid 40s to around 50 and lows in the mid to upper 30s.
Weekend
  • Mostly dry. Fog and low clouds possible.
  • Highs in the mid 30s to mid 40s on Saturday, and upper 30s to 40s on Sunday.
  • Lows in the upper teens to 20s on Saturday morning, and 20s to mid 30s on Sunday morning.
Next Week
  • Mostly dry early on Monday, and then rain at times. Possibly drier later in the week.
  • Highs in the 40s on Monday, and then warmer, and possibly cooler later in the week.
  • Lows in the upper 20s to 30s on Monday morning, and then warmer, and possibly cooler later in the week.
Washington State University