textproduct: Pendleton

KEY MESSAGES

- Dry and locally breezy for the next few days.

- Elevated fire weather concerns through the end of the week.

- Increasing heat around the middle of next week.

DISCUSSION

Dry westerly flow will be over the region through Thursday. By Friday, the flow becomes more southwesterly, in response to low pressure off the coast of British Columbia and high pressure near the Four Corners. This ridge of high pressure will expand north and eventually west as we move into next week.

Diurnally breezy conditions are expected, mainly over the Cascade Gaps, Simcoe Highlands, Kittitas Valley and Columbia Basin and Gorge. Winds gusts will mainly be in the 20 to 30 mph range. NBM probabilities of wind gusts >= 25 mph are greater than 80 percent through Saturday. However, wind gusts >= 39 mph are generally less than 50 percent, with the exception of the Kittitas Valley.

As we get into next week, a large area of high pressure over the Great Basin will move northward then eventually westward. Guidance has been very consistent in bringing increasingly hot weather starting around the middle of the week. What guidance has been less consistent about is exactly how hot it gets and how long it will last. Some of that is simply due to the time scale of the forecast. Some of that is due to the position of the ridge and how it sets up.

Temperatures close to 100 degrees, if not above 100 degrees look to start around Tuesday or Wednesday of next week in the lower elevations and potentially go up from there. A 40 to 50 percent chance of moderate HeatRisk returning with Major Heat Risk at least in the Columbia Basin and Yakima Valleys is possible as well. If some of the more bullish guidance ends up being correct, there could end up being multiple days of 100 plus temperatures in the lower elevation areas. Stay tuned on this one.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

VFR conditions persist through all sites. No major CIG or VIS issues expected. Only concern will be breezy winds at DLS, RDM, BDN, and YKM. Breezy winds will persist in DLS, with winds decreasing in PDT by 05Z. RDM and BDN will see winds develop to around 15-25 knot gusts from 0820Z to 0905Z.

FIRE WEATHER

Diurnally breezy winds over the next few days in the 20 to 30 mph range (with locally higher areas) combined with RH values will keep elevated fire weather concerns. A red flag warning is in effect for the Kittitas Valley through this evening as winds have been quite gusty there.

For Thursday, winds will be marginal, around 30 mph again, with RH values mainly in the teens. The area of focus on shifts to the Columbia Basin and Gorge and will need to see if any headlines become necessary.

Breezy winds continue Friday and Saturday, but RH values look to be slightly higher....in the 20s in many locations.

Preliminary Point Temps/PoPs

PDT 88 55 88 55 / 0 0 0 0 ALW 90 60 89 60 / 0 0 0 0 PSC 93 57 91 58 / 0 0 0 0 YKM 92 57 91 58 / 0 0 0 0 HRI 91 58 90 59 / 0 0 0 0 ELN 82 54 84 55 / 0 0 0 0 RDM 86 47 87 48 / 0 0 0 0 LGD 88 53 88 53 / 0 0 0 0 GCD 90 50 90 52 / 0 0 0 0 DLS 85 58 88 60 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Red Flag Warning until 8 PM PDT this evening for WAZ690. OR...None.