textproduct: Pendleton

KEY MESSAGES

- Critical fire weather conditions continue through the Columbia Basin of Oregon through 10 PM tonight due to breezy winds and low relative humidities.

- Widespread moderate/major HeatRisk developing through early next week.

- Elevated fire weather conditions persist through the next several days with low relative humidities and diurnal breezy winds developing.

DISCUSSION

A mid/upper level short wave is present in British Columbia, allowing breezy winds to develop over the next few days. Dry air across the region will persist and, with tandem to the earlier mentioned breezy winds, bring elevated fire weather conditions through at least the next few days with critical fire weather conditions developing through 10 PM tonight in the Columbia Basin in Oregon.

Guidance and cluster analysis is in great agreement (70-90% chance) that the shortwave will exit the region in the Monday time frame and the ridge that is currently situated over the Great Plains will dominant the weather pattern and allow a warming trend to begin and persist through mid-next week. This looks to probably be the biggest heat wave so far this year with NBM advertising 50-80% chances of high temperatures exceeding 100 degrees Tuesday in the populated areas in the Columbia Basin & Yakima Valley. Chances slightly decrease Wednesday, but considerably drop down to 30-50% on Thursday. Looking at HeatRisk chances, widespread moderate chances develop with 80-100% chances Tuesday through Thursday, with major chances of HeatRisk at 40-70%. Will need to monitor over the next few days, but it's becoming likely that heat highlights may be warranted if trends continue as they are.

The pattern is likely (50-70% chance) that it will become cooler and wetter going into the second part of next week with a mid/upper level low pushing through the PacNW and a tropical storm in the Pacific just off Mexico influencing the moisture transportation into the region. Chances of showers (20-40% chance) develop across the Blue Mountains mid-week with the greatest chance occurring Thursday.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

VFR conditions currently across all sites, which will stay the course through the period. However, KPDT/KALW/KRDM/KBDN may drop briefly to MVFR due to reduced visibilities caused by smoke from nearby wildfires. KDLS/KPDT/KRDM/KBDN will also experience breezy winds this afternoon as gusts of 18-25kts are expected. 75

Preliminary Point Temps/PoPs

PDT 91 56 91 61 / 0 0 0 0 ALW 93 62 93 64 / 0 0 0 0 PSC 95 59 94 61 / 0 0 0 0 YKM 92 58 94 63 / 0 0 0 0 HRI 93 60 94 63 / 0 0 0 0 ELN 84 56 91 59 / 0 0 0 0 RDM 91 51 93 59 / 0 0 0 0 LGD 94 56 94 59 / 0 0 0 0 GCD 96 55 96 60 / 0 0 0 0 DLS 89 61 95 65 / 0 0 0 0

Preliminary Point Temps/PoPs

PDT 91 55 91 60 / 0 0 0 0 ALW 93 61 93 64 / 0 0 0 0 PSC 95 57 93 61 / 0 0 0 0 YKM 92 57 94 63 / 0 0 0 0 HRI 93 59 94 62 / 0 0 0 0 ELN 84 54 91 59 / 0 0 0 0 RDM 91 49 93 60 / 0 0 0 0 LGD 94 54 94 59 / 0 0 0 0 GCD 96 54 96 60 / 0 0 0 0 DLS 89 59 96 65 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...Red Flag Warning until 10 PM PDT this evening for ORZ691. Air Quality Alert until noon PDT Monday for ORZ050-502-503-505- 506-508.