textproduct: Pendleton

KEY MESSAGES

- Gusty west winds and low relative humidity will combine to create critical fire weather conditions This Afternoon, mainly across the Columbia Basin of Oregon.

- Another chance of showers and thunderstorms and gusty winds toward the of the week, associated with an upper low.

DISCUSSION

An upper level split flow pattern in place Today will shift over the next 24 hours to more upper southwest flow over the western half of the region and ridging across the Interior Northwest. Breezy winds across the Eastern Columbia River Gorge Today will develop early as winds at DLS are already gusting to around 15kts overnight. By Afternoon sustained winds will reach around 20 mph with gusts to around 30 to 35 mph across the Gorge, Oregon Columbia Basin, central Oregon and the Kittitas Valley. Heat and Low relative humidity will be the maim impacts from the daily strong surface heating across the lower elevations. HeatRisk will be mainly in the minor category (yellow), but the warmest day, Thursday, will bring pockets of more elevated Heat Risk in the moderate category, across the Columbia Basin, central Oregon and and the eastern Blue Mountains. Mid level shortwave energy ahead of an advancing coastal low on Friday into Saturday will drive breezy to windy conditions again, with potential to enhance fire weather and strong wind gusts though the Cascade Gaps even during the overnight hours. Winds at this time look below advisory criteria as NBM members suggest only about 10- 20% chances for sustained winds exceeding 39 mph in the eastern Columbia River Gorge Saturday.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Terminals all reporting VFR conditions this morning with clear ceilings and no signs of smoke reducing visibility. Some of the Oregon terminals may see daytime reductions of vsby once again to 5 sm. Look for breezy westerly conditions at DLS, PDT and ALW and YKM Today.

FIRE WEATHER

A cross barrier pressure gradient will lead to westerly winds through the Cascade gaps Today. Red flag warnings remain in place for the Lower Columbia Basin of Oregon from late this morning through 10 PM This Evening for wind and low relative humidity. Expect winds of 15 to 20 mph with frequent gusts in the the 25 to 35 mph range, coupled with relative humidity in the 15 to 20 percent range. West northwest winds with gusts persisting through around 9 pm are expected to diminish to around 10 mph by late evening through he overnight.

Preliminary Point Temps/PoPs

PDT 91 54 90 58 / 0 0 0 0 ALW 92 62 91 64 / 0 0 0 0 PSC 95 57 93 57 / 0 0 0 0 YKM 95 60 92 61 / 0 0 0 0 HRI 93 60 92 59 / 0 0 0 0 ELN 87 58 88 58 / 0 0 0 0 RDM 91 48 92 50 / 0 0 0 0 LGD 92 54 93 57 / 0 0 0 0 GCD 93 55 95 57 / 0 0 0 0 DLS 90 60 91 61 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...Air Quality Alert until 1 PM PDT Wednesday for ORZ041-505-506- 509>511. Red Flag Warning from noon today to 10 PM PDT this evening for ORZ691-701-703.