textproduct: Pendleton

KEY MESSAGES

- Windy conditions and low relative humidities will lead to extremely critical fire weather conditions today.

- Wind advisories are in effect for portions of the area.

- Continued dry, with a warming trend through next week.

DISCUSSION

Southwesterly flow was over the region early today in advance of low pressure moving into British Columbia. The trough associated with this low will move across the region later today and bring a dry cold front along with it.

As these features move through, the pressure gradient will tighten, resulting in breezy to windy conditions developing across much of the area. The breezy to windy conditions have prompted the issuance of both wind advisories and red flag warnings due to the low humidities as well. The very dry antecedent conditions and gusty winds could lead to extreme fire weather conditions across the area today. As a result red flag warnings have been issued with PDS (particularly dangerous situation) red flag warnings for a portion of the time.

NBM probabilities of wind gusts >= 39 mph are >80 percent across most of the Kittitas Valley, Columbia Basin, Gorge, Simcoe Highlands and 50-80 percent across the Foothills of the Blue Mountains. NBM probabilities of wind gusts >=47 mph are >80 percent for the Kittitas Valley and locally >70 percent but for the wider area are much lower. The ECMWF EFI has some areas of 0.8 to 0.9 and even an area of 0.9 to 0.95 for wind gusts today across the Columbia Basin, however it is a small area and not widespread.

After today, there is a second dry trough that drops down on Sunday that will keep things breezy, though not nearly as windy as today. NBM probabilities of wind gusts >= 25 mph are fairly widespread, but wind gust probabilities >= 39 mph are relatively small.

After Sunday, we get into a more west to northwest flow of dry weather with warming temperatures through at least midweek.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Predominantly VFR conditions are expected through the TAF period, though smoke from area wildfires will continue to be present and will have the potential to reduce CIGs/VSBYs, especially in the mornings. Additionally, a subset of CAMs within the HREF and REFS depict MVFR CIGs in low stratus (1.5-2.5kft AGL) overnight into Sunday morning at BDN/RDM. Confidence in persistent CIGs was low (<30%), but did include FEW025 to highlight the potential for low stratus.

Winds will continue to increase in magnitude late this morning through the afternoon, with breezy to locally windy westerlies (generally 15-25 kts with gusts of 20-35 kts) persisting at all sites through evening before slackening overnight into Monday.

FIRE WEATHER

The combination of gusty winds and low relative humidity values will make for critical to extremely critical fire weather concerns across much of the region today. Red Flag Warnings have been issued from 11 AM until 11 PM with WA690, 691, 692, 693 and OR691, 692, 693 694, 695, 696 and 700 under a particularly dangerous situation (PDS) Red Flag Warning from 2 PM until 8 PM. Winds should gust to 30 to 40 mph across these areas today with some locally higher gusts.

Preliminary Point Temps/PoPs

PDT 83 46 76 45 / 0 0 0 0 ALW 87 52 78 51 / 0 0 0 0 PSC 92 51 81 50 / 0 0 0 0 YKM 85 52 80 51 / 0 0 0 0 HRI 86 52 80 49 / 0 0 0 0 ELN 76 49 73 49 / 0 0 0 0 RDM 81 40 78 38 / 0 0 0 0 LGD 87 47 77 44 / 0 0 0 0 GCD 92 48 81 44 / 0 0 0 0 DLS 79 56 79 55 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Red Flag Warning until 11 PM PDT this evening for WAZ690>693. Wind Advisory until 11 PM PDT this evening for WAZ024-026>029- 521. Air Quality Alert until 2 PM PDT Monday for WAZ028>030. OR...Red Flag Warning until 11 PM PDT this evening for ORZ691>704. Wind Advisory until 11 PM PDT this evening for ORZ041-044-507- 508-510. Air Quality Alert until 2 PM PDT Monday for ORZ044-049-050-502- 503-505>511.