‘Drought-filled summer’ developing in Oregon, across the Pacific Northwest

PORTLAND, Ore. ( KOIN ) — The historic July heat wave that resulted in investigations of possibly 16 heat-related deaths across the state and broke temperature records in Portland for five consecutive days , is sapping Oregon of moisture and returning the region to a state of drought.

Oregon State climatologist Larry O’Neill told KOIN 6 News that heat is the main reason that climate experts placed most of Oregon in the “abnormally dry” drought category last week. Areas of Central and Southern Oregon, meanwhile, were moved into a “moderate” state of drought, per the U.S. Drought Monitor.

“We are unfortunately quickly heading into a drought-filled summer in Oregon and the Pacific Northwest in general,” O’Neill said.

Low relative humidity is also contributing to Oregon’s worsening drought conditions. The low humidity levels, combined with the ongoing summer heat, have essentially wiped out the beneficial rain that Oregon received during the winter and spring, O’Neill said.

“Most of Oregon experienced minimum relative humidities below 15% during each day of the heat wave,” he said. “This drove exceptionally high evaporation rates from soils and vegetation. Even though we had about an average amount of precipitation during the winter and spring, that benefit has now mostly evaporated into thin air, leaving behind a landscape that is about as dry as it has been during the last four summers, as measured by soil and fuel moisture.”

For now, Oregon’s above-average snowpack is keeping the state in a lower stage of drought. However, the melting snow can only provide temporary drought relief.

“Higher elevations above about 4,500 feet had average to above-average snowpack this winter that melted out mostly on time,” O’Neill said. “This is great because it will keep these landscapes moister and cooler for at least a few more weeks.”

The summer heat isn’t expected to let up anytime soon. KOIN 6 Meteorologist Kelley Bayern forecasts more above-average temperatures in this week’s forecast.

“The hot and summery pattern sticks around all week with temps hovering above average in the upper 80s to low 90s,” Bayern said. “Tuesday looks the hottest with temps pushing back into the upper 90s, briefly.”

The heat wave at the start of July resulted in

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