textproduct: Pendleton

KEY MESSAGES

- Critical fire weather conditions through this evening as breezy to locally windy conditions overlap with dry conditions

- Diurnally breezy winds with dry conditions persisting through the week

- Another weak cold front passage Tuesday will bring increased winds across the area, with elevated to locally critical fire weather conditions

DISCUSSION

Satellite imagery this afternoon shows mostly clear skies with elongated plumes of smoke coming from fires in central and eastern OR. Cumulus have also been noted developing within some the plumes emanating from the Shingle, Crosswhite, and Bench fires. Otherwise water vapor imagery shows a shortwave coming ashore in WA. At the surface, westerly winds are increasing across the forecast area as the shortwave and an accompanying cold front approach the forecast area.

Today, winds will increase (15-25mph with gusts 30-45mph) across the forecast area as the shortwave and cold front push inland. The cold front boundary will continue to push east today, with winds shifting from southwest to west this afternoon, then shifting again to the northwest late this evening. Winds through the Cascade gaps will stay their usual direction (west to northwest). These increasing winds will also overlap with low relative humidities in the lower elevations, resulting in critical fire weather conditions through this evening. Winds will remain breezy post the cold front passage tomorrow, but will be lighter (10-20 mph with gusts up to 35mph). Dry conditions will remain across the region, but will increase slightly as afternoon temperatures lower slightly. While fire weather conditions will remain elevated, localized areas of central OR and the lower elevations in the eastern mountains may see critical fire weather conditions develop for a few hours in the afternoon (confidence 55-70%).

Through Friday, there is great agreement that the forecast area will remain between upper level troughing in the northeast Pacific and an upper level ridge over central and southwest CONUS. This will place a dry, southwest flow aloft over the PacNW that will keep temperatures near seasonable. That said, a weak shortwave and cold front boundary will lift across northwest WA, producing another round of breezy conditions and slight cool down. The most recent run of the NBM shows low probabilities (<20%) of wind/RH overlap Tuesday afternoon. That said, confidence is mod- high that elevated fire weather conditions will be present across the lower elevations.

Thursday through Friday, there is good agreement that while the forecast area remains under southwest flow aloft, upper level ridging over the central CONUS will gradually retrograde west, which will allow temperatures to warm from the upper 80s to low 90s into the mid to upper 90s across the forecast area (confidence 60-75%). Lawhorn/82

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

VFR conditions currently across all sites, which will stay the course through the period. Breezy winds of 15-25kts with gusts of 20-30kts continues for KDLS, but will taper off through the early morning hours. Gusts of 15-25kts return for KDLS/KPDT/KRDM/KBDN toward the end of the period. 75

FIRE WEATHER

A weak cold front passage will bring breezy to locally windy westerly winds across the region, while afternoon RHs are expected to be near to below critical levels. This has resulted in Red Flag Warnings being issued across most of our lower elevation locations through 8PM this evening. Breezy to locally breezy winds will continue tomorrow while RHs will be slightly higher due to cooler temperatures. That said, locally critical fire weather conditions may be present tomorrow afternoon. Elevated fire weather conditions will remain through the week as diurnally breezy winds redevelop, with RHs near to just above critical thresholds. Lawhorn/82

Preliminary Point Temps/PoPs

PDT 57 88 55 88 / 0 0 0 0 ALW 63 90 61 90 / 0 0 0 0 PSC 61 92 60 92 / 0 0 0 0 YKM 58 90 58 91 / 0 0 0 0 HRI 61 91 60 91 / 0 0 0 0 ELN 55 84 54 85 / 0 0 0 0 RDM 52 88 50 88 / 0 0 0 0 LGD 58 92 56 91 / 0 0 0 0 GCD 57 93 54 92 / 0 0 0 0 DLS 60 86 60 88 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Air Quality Alert until 11 AM PDT Monday for WAZ028>030. OR...Air Quality Alert until noon PDT Monday for ORZ049-050-502-503- 505-506-508-509-511.