AgWeatherNet Weekly Weather Outlook for July 7 to July 13, 2012

Oppressive Heat This Weekend and Next Week

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

Oppressive heat will arrive this weekend, and remain through much of next week. The hottest weather looks to occur from Sunday through early next week, with highs in eastern Washington ranging from the mid 90s to mid 100s at the peak of the heat wave. This may be the hottest weather that parts of Washington have experienced in several years. Some record breaking heat is possible, and temperatures during the afternoon will potentially reach dangerous levels if precautions such as proper hydration and limiting sun exposure are not taken. The trend of low temperatures east of the Cascades will be for increasing values through at least Monday morning, before decreasing later next week. Somewhat comfortable readings in the 50s and 60s on Saturday morning will give way to balmy nights and lows in the 60s and 70s by Monday morning, due to increasing humidity and clouds. Lower dew point temperatures should return later next week. Overall, it will be partly sunny in most areas, with generally light winds.

It will also become hot west of the Cascades this weekend, with well above normal temperatures in the 80s to low 90s at inland and southern areas. Areas such as the immediate coast, the Strait of Juan de Fuca including Sequim and Port Angeles, and the San Juan Islands should maintain some wind off the water to keep temperatures mainly in the 60s and 70s. Lows at night will be tolerable in western Washington, and generally in the 50s to low 60s. Temperatures should peak around Sunday. The absolute temperatures will generally be lower, and the duration of the heat wave will likely be shorter than what is expected to occur east of the Cascades. Cooling may begin around Monday, and slowly spread inland by later in the week. There will be a large temperature gradient present across western Washington at times, as a shallow and cool marine layer will periodically insulate the immediate coastline from the extreme heat over much of the region. By mid to late next week, nearly seasonal conditions could exist at the coast, while the heat continues east of the Cascades.

There is a chance of dry, high-based thunderstorms at times, especially over the mountains, as southerly flow attempts to transport upper level monsoonal moisture and instability into our region from the southwestern United States. The best chance of thunderstorms in central Washington appears to be from Sunday evening to Monday evening. If this occurs, it would serve to perhaps lower day-time temperatures slightly, although the associated increase in humidity and clouds would increase night-time temperatures, and therefore would provide little relief from the heat. Storms could also cause increasingly dangerous fire conditions since any lightning or sporadic wind gusts that occur will not likely be accompanied by rain.

Temperatures
  • Well above normal in most of the state throughout the outlook period.
  • Very hot through the period east of the Cascades.
  • Hot in western Washington by Sunday, with moderately warm conditions at the coast.
  • Slight cooling possible by Monday at the coast, and into interior western Washington by mid week.
  • Less hot, but still above normal temperatures are expected by late next week east of the Cascades.

Rainfall
  • Very light to none through the period.
  • A slight chance of high-based thunderstorms, especially over the mountains.
  • Any storms that occur may contain little or no rain.

Wind
  • Generally light.
  • Possibly windy at times at the immediate coast.

Important Points about Next Week's Weather

South Central Washington
  • Normal conditions for this time of the year would be highs in the upper 80s and lows in the 50s.
Weekend
  • Mostly sunny. Becoming much warmer, with a slight chance of thunderstorms later on Sunday.
  • Highs in the mid 90s to around 100 on Saturday, and upper 90s to mid 100s on Sunday.
  • Lows in the mid 50s to mid 60s on Saturday morning, and 60s on Sunday morning.
Next Week
  • Mostly sunny and very hot. A slight chance of thunderstorms early in the week.
  • Highs in the upper 90s to mid 100s early, and becoming less hot later in the week.
  • Lows in the mid 60s to low 70s on Monday morning, and becoming slightly cooler later in the week.

North Central Washington
  • Normal conditions for this time of the year would be highs in the mid to upper 80s and lows in the mid 50s.
Weekend
  • Mostly sunny. Becoming much warmer, with a slight chance of thunderstorms later on Sunday.
  • Highs in the 90s on Saturday, and upper 90s to low 100s on Sunday.
  • Lows in the 50s to around 60 on Saturday morning, and upper 50s to 60s on Sunday morning.
Next Week
  • Mostly sunny and very hot. A slight chance of thunderstorms early in the week.
  • Highs in the upper 90s to low 100s early, and becoming less hot later in the week.
  • Lows in the mid 60s to low 70s on Monday, and becoming slightly cooler later in the week.

Eastern Washington
  • Normal conditions for this time of the year would be highs in the low 80s and lows around 50.
Weekend
  • Partly sunny. Becoming much warmer, with a slight chance of thunderstorms.
  • Highs in the low 90s on Saturday, and mid to upper 90s on Sunday.
  • Lows in the low to mid 50s on Saturday morning, and mid 50s to around 60 on Sunday morning.
Next Week
  • Mostly sunny. A slight chance of thunderstorms.
  • Highs in the mid 90s to around 100 early, and becoming less hot later in the week.
  • Lows in the mid 50s to low 60s.

Western Washington
  • Normal conditions for this time of the year would be highs in the 70s (except mid to upper 60s at the coast) and lows in the low to mid 50s.
Weekend
  • Mostly sunny. Becoming much warmer.
  • Highs in the upper 70s to 80s, except mid 60s to mid 70s at the coast on Saturday.
  • Highs in the 80s to low 90s, except upper 60s to mid 70s at the coast on Sunday.
  • Lows in the upper 40s to mid 50s on Saturday morning, and 50s to around 60 on Sunday morning.
Next Week
  • Partly sunny and mostly dry.
  • Highs in the upper 70s to 80s on Monday, except mid 60s to low 70s at the coast.
  • Highs ranging from the mid 70s to mid 80s inland to the 60s at the coast by mid week.
  • Lows in the 50s to low 60s, and slightly cooler later in the week.
Washington State University