AgWeatherNet Weekly Weather Outlook for September 21 to 27, 2013

Blustery and Wet on Sunday in Western Areas; Cool and Showery Early Next Week

Nic Loyd, Meteorologist, 509-786-9357
Gerrit Hoogenboom, Director, 509-786-9371

Unsettled conditions on Saturday will give way to wet and stormy weather on Sunday, before the weather calms down later next week.

As a weak storm moves through Washington early on Saturday, light rain will change to showers across western Washington, as cooler air and a chance of showers arrives for eastern areas. After a partly cloudy but drier break on Saturday night, another stronger storm will slam into the coast on Sunday, before spreading into eastern areas later in the day. The potent cold front will pack quite a punch, and should be the first truly autumn-like system of the season. Rain could become locally heavy by afternoon in western areas and in the mountains, as winds gust to 40+ mph at the coast. A brief period of rain is likely even in central Washington in the afternoon, and rain should spread into Pullman and Spokane by later in the evening. Showery conditions are likely in western and eastern areas on Monday and Tuesday, as a deep trough enters Washington in the wake of the frontal passage. The main impacts of the active weather will be cool day-time temperatures statewide, periodically breezy to windy conditions, and heavy rain of up to 2 inches in western and mountainous areas through early next week. The snow level could be as low as 6500 feet in the mountains, such that snow should fall in the Cascade high country next week.

Central Washington will be mainly dry next week thanks to the southwesterly air flow during the period. However, light rain is possible during the frontal passage on Sunday night, and isolated showers are a potential next week. As the trough departs the area around the middle to latter part of next week, showers and clouds will slowly decrease. By the end of the week, drier and warmer days are likely. However, very cool overnight temperatures are possible during the transition period from cool and wet to warmer and drier conditions later next week. Depending upon how quickly the clear skies and calmer conditions arrive, cold areas are likely to drop into the 30s sometime during the Wednesday to Friday morning time period.

Temperatures
  • Cool, especially during the day, from Sunday through mid to late next week.
  • Cooler lows arriving by the middle of next week.

Rainfall
  • Light rain showers likely on Saturday in the west, with a chance of showers or possibly weak thunderstorms in the east.
  • Rain developing on Sunday in the west, and becoming heavy by afternoon.
  • Rain or showers early in the week, decreasing on Wednesday, and ending later in the week.
  • Mostly dry in central Washington, with a slight chance of rain or showers at times.

Wind
  • Breezy on Saturday, and windy on Sunday, especially at the coast.
  • Breezy to windy through the middle of next week.
  • Calmer later next week.

8 to 14 Day Outlook - September 28 to October 4
  • Overall, above average temperatures and near to above average rainfall 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 upper 70s and lows in the mid 40s to around 50.
Weekend
  • A slight chance of showers on Saturday, and then light rain possible on Sunday.
  • Highs in the upper 60s to 70s on Saturday, and 60s to low 70s on Sunday.
  • Lows in the low to mid 50s on Saturday morning, and mid 40s to low 50s on Sunday morning.
Next Week
  • Mostly dry and breezy, with a slight chance of showers around the middle of the week.
  • Highs in the 60s to low 70s, and then warmer by the end of the week.
  • Lows in the mid 40s to low 50s on Monday morning, and then cooler by mid week.

North Central Washington
  • Normal conditions for this time of the year would be highs in the mid to upper 70s and lows in the upper 40s to around 50.
Weekend
  • A slight chance of showers or thunderstorms on Saturday, and then light rain on Sunday.
  • Highs in the upper 60s to mid 70s on Saturday, and 60s to around 70 on Sunday.
  • Lows in the 50s on Saturday morning, and mid 40s to low 50s on Sunday morning.
Next Week
  • A slight chance of showers through the middle of the week.
  • Highs in the upper 50s to 60s, and then warmer by the end of the week.
  • Lows in the mid 40s to low 50s on Monday morning, and then cooler by mid week.

Eastern Washington
  • Normal conditions for this time of the year would be highs in the low to mid 70s and lows in the low to mid 40s.
Weekend
  • A chance of showers or thunderstorms on Saturday, with rain developing later on Sunday.
  • Highs in the mid 60s to low 70s on Saturday, and low to mid 60s on Sunday.
  • Lows in the mid 40s to mid 50s on Saturday morning, and 40s to around 50 on Sunday morning.
Next Week
  • Rain showers and breezy early, and then drier later in the week.
  • Highs in the upper 50s to mid 60s, and then warmer by the end of the week.
  • Lows in the mid to upper 40s on Monday morning, and then cooler by mid week.

Western Washington
  • Normal conditions for this time of the year would be highs in the upper 60s to low 70s and lows in the upper 40s to around 50.
Weekend
  • Rain changing to showers on Saturday morning.
  • Rain developing on Sunday, and becoming locally heavy by afternoon and windy.
  • Highs in the 60s on Saturday, and upper 50s to mid 60s on Sunday.
  • Lows in the 50s on Saturday morning, and low to mid 50s on Sunday morning.
Next Week
  • Rain or showers early, and then drier later in the week.
  • Highs in the upper 50s to mid 60s early, and then warmer later in the week.
  • Lows in the low to mid 50s on Monday morning, and then cooler by mid week.

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