textproduct: Pendleton

KEY MESSAGES

- Drying and warming trend will continue through early Tuesday as upper level high pressure moves over the region

- A series of upper level low pressure systems will bring periods of rain, breezy westerly winds, and isolated thunderstorm chances Tuesday into Friday

DISCUSSION

Short term upper ridging will influence the weather across the region Today leading to a day of warmer temperatures and low relative humidity area-wide. Widespread 80s are expected highs This Afternoon with cooler 70s in the foothills and mountain zones. Surface high pressure will lead to light northeast winds across WA (slightly breezy over the Oregon Columbia Basin) and light south winds over the the John Day Basin and areas south.

HREF showed up to about 250 j/jg mean MUCAPEs across limited reach of the eastern Blue Mountains/Wallowas Tuesday afternoon with limited, less than 15% chances for lightning between about 18z and 23z especially over Wallowa co.

Chances for wetting rains are in the the 60 to 85% confidence range for the 24 hours ending 00z Thursday across the eastern mountains and the the Cascades eastern slopes. Low end CWRs increase to Likely (60% even across the Columbia Basin and higher) and moreso across the entire forecast area by the end of the day Thursday. A look at expected 2 day combined rain (Wed/Thur) looks like near a wetting rain over the WA Columbia Basin, to near a quarter inch of rain over the foothills of the Blues, central Oregon...to as much as one half to three quarters of an inch over the Blue Mounties and one inch or more along the Cascade Crest.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Clear sky over the entire region will lead to VFR conditions with light winds under 10 knots. Gusts to around 20 to 25 kts will develop at DLS after midnight as a system approaches the region with scattered to broken high clouds overnight.

FIRE WEATHER

Minimum RH values will range from the low 20s across the Kittitas, Yakima Valleys and the Cascade east slopes, and around 20 percent and less every where else. More breezy winds are expected Tuesday though the Oregon Columbia Basin and the Columbia River Gorge/Kittitas and Yakima valleys. No significant areas of combined probabilities for red flag (critical low rh and wind) shows up in the forecast This Week. Chances for wetting rains increase Wednesday through Thursday.

Preliminary Point Temps/PoPs

PDT 86 51 83 50 / 0 0 0 50 ALW 89 57 84 55 / 0 0 0 50 PSC 89 53 87 51 / 0 0 0 40 YKM 85 59 87 56 / 0 0 0 30 HRI 88 54 86 50 / 0 0 0 40 ELN 80 54 82 49 / 0 0 0 40 RDM 87 45 78 39 / 0 0 30 40 LGD 88 53 86 48 / 0 0 10 50 GCD 91 54 86 50 / 0 0 10 50 DLS 88 60 79 55 / 0 0 0 20

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...Air Quality Alert until noon PDT today for ORZ041-505-506- 509>511.