AgWeatherNet Weekly Weather Outlook for June 24 to June 30, 2017

Heat Wave Begins This Weekend; Relief Arrives Next Week

Nic Loyd, Meteorologist, 509-786-9357

Even though the summer solstice and the peak annual solar radiation potential are now behind us, the summer-time heat is just beginning. A major heat wave is presently developing, and will be fully upon us in the coming days. Overall, the maximum temperatures should slowly shift from west to east through Monday. Here is an estimate for the timing and magnitude of the highest anticipated temperatures:

Coast: Saturday; 90s and 80s, Slight cooling on Sunday
Interior Western WA: Sunday; Upper 80s to 90s, except around 100 for Vancouver, and 80s for some areas near the Strait of Juan de Fuca like Sequim
Central WA: Sunday or Monday; Upper 90s to mid 100s south; mid 90s to low 100s north
Eastern WA: Monday; 90s

It is worth noting that western Washington will not escape this hot spell, and there are likely to be some areas that are warmer than their eastern counterparts this weekend. Aside from a few possible exceptions like Sequim and the San Juan Islands, nearly all of the state is expected to be very hot at some point in the next few days, although the duration may be short for regions such as the coast. Therefore, heat and water stress may be issues for crops and people. By Monday, the coast should be much cooler, while the interior west is forecast to experience a degree of relief, and then even more cooling on Tuesday.

Monday's forecast is a tough call, especially east of the Cascades, as a weather pattern transition begins. Timing will be everything, but given the warm morning, eastern areas should heat up quickly before any cooling arrives. The other wildcard is some instability depicted in certain model runs. Without a disturbance or an obvious trigger, even isolated thunderstorms seem unlikely. However, given the parched land and vegetation, any lightning on Monday would be a concern. In any case, even the east should be noticeably cooler by Tuesday, as marine air floods into the region. Despite lower temperatures, dry winds could once again increase the fire danger. Alas, there may be another round of heat returning later in the period, such that locations east of the Cascades will not remain seasonal for long.

Thus, a heat wave followed by substantial western relief (and modest eastern relief) early next week is a certainty. It does appear that generally well above normal temperatures, even for late June, could continue for the foreseeable future. Still, the conditions are expected to be variable and not persistently oppressive. One silver lining is that none of 2017's numerous hot spells so far have lingered for more than a few days without at least some brief moderation.

Temperatures
  • Hot through early next week.
  • Becoming cooler from west to east for early to mid next week.
  • Warmer later next week.

Precipitation
  • Mostly dry. A slight chance of eastern showers or thunderstorms on Monday or Monday night.

Wind
  • Breezy to windy around late Monday and into Tuesday.

8 to 14 Day Outlook - July 1, 2017 to July 7, 2017
  • Overall, near to above average temperatures and near to below 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 80s to around 90 and lows in the 50s to around 60.
Weekend
  • Mostly dry.
  • Highs in the 90s on Saturday, and mid 90s to low 100s on Sunday.
  • Lows in the 50s on Saturday morning, and mid 50s to low 60s on Sunday morning.
Next Week
  • Mostly dry.
  • Highs in the mid 90s to mid 100s on Monday, and then cooler, and warmer later in the week.
  • Lows in the 60s to low 70s on Monday morning, and then cooler, and possibly warmer later in the week.

North Central Washington
  • Normal conditions for this time of the year would be highs in the low to mid 80s and lows in the 50s.
Weekend
  • Mostly dry.
  • Highs in the low to mid 90s on Saturday, and mid to upper 90s on Sunday.
  • Lows in the 50s to low 60s on Saturday morning, and mid 50s to mid 60s on Sunday morning.
Next Week
  • Mostly dry.
  • Highs in the mid 90s to low 100s on Monday, and then cooler, and warmer later in the week.
  • Lows in the 60s to low 70s on Monday morning, and then cooler, and possibly warmer later in the week.

Eastern Washington
  • Normal conditions for this time of the year would be highs in the upper 70s to mid 80s and lows in the upper 40s to mid 50s.
Weekend
  • Mostly dry.
  • Highs in the 80s to low 90s on Saturday, and low to mid 90s on Sunday.
  • Lows in the upper 40s to mid 50s on Saturday morning, and 50s on Sunday morning.
Next Week
  • Mostly dry. A slight chance of showers or thunderstorms on Monday or Monday night.
  • Highs in the 90s on Monday, and then cooler, and warmer later in the week.
  • Lows in the upper 50s to 60s on Monday morning, and then cooler, and possibly warmer later in the week.

Western Washington
  • Normal conditions for this time of the year would be highs in the low to mid 70s, except cooler at the coast, and lows in the upper 40s to mid 50s.
Weekend
  • Mostly dry.
  • Highs in the mid 80s to around 100 on Saturday, except possibly cooler around Sequim and the Strait of Juan de Fuca.
  • Highs in the upper 80s to around 100 on Sunday, except cooler at the coast.
  • Lows in the 50s to around 60 on Saturday morning, and mid 50s to mid 60s on Sunday morning.
Next Week
  • Mostly dry.
  • Highs in the upper 70s to mid 80s on Monday, except cooler at the coast, and then cooler region-wide starting on Tuesday. Warmer later in the week.
  • Lows in the upper 50s to mid 60s on Monday morning, and then cooler, and possibly warmer later in the week.


Washington State University