textproduct: Pendleton

KEY MESSAGES

- Cooler Today

- Increasingly Breezy to Windy overnight peaking Sunday Afternoon

DISCUSSION

A combination of nighttime microphysics RGB GOES satellite and METAR data showed pockets of mostly clear conditions across the Lower Columbia Basin, but scattered to broken over most of the Blue Mtn Foothills, Cascades and eastern Mountains overnight, as the boundary layer was under a westerly and relative drier push of air. As wetter ground, colder air aloft and clouds to day influence the thermal profiles, temperatures are anticipated to be even cooler struggling into he lower 70s even across the typically warmer Lower Columbia Basin by the late afternoon. The pattern of upper troughing will continue to influence the cross Cascades pressure gradient as models converge on Sunday as a much more windy day through the gaps and Lower Columbia basin/Kittitas valley, underscored by breezy to windy conditions overnight Saturday increasing though Sunday Afternoon.

Slowly rebounding temperatures with continued westerly surface flow through much of next week before some ensembles/cluster differences of potential impact by Friday through Sunday. Cluster 4 the more potentially wet and cooler solution with a cutoff upper low along the PAC NW coast for the July 4th Holiday weekend, is also seemingly more of an outlier to the other clusters as members account for only about 11% of the total. Even adding in cluster 3 while not a closed low is also a cooler troughing lower height solution, the cooler wetter patterns account for about 30%.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Westerly winds will become increasingly breezy across the region this forecast period. Most sites are seeing winds above 12 kts with gusts nearing 20-30kts except BDN, which will see winds after 19Z. DLS/YKM are both also expecting some wind shear WS019/28035KT for DLS and WS020/31040KT for YKM. Lastly, BDN/RDM have a 30% chance or less of isolated vicinity thunderstorms after 21Z persisting through 00Z.

FIRE WEATHER

Isolated dry thunderstorms with lightning risk is possible this afternoon in the Cascade Crest and John Day Highlands (10-20 % confidence). Other than that, limited fire weather is expected risk over the weekend as cooler weather takes hold, limiting the lower bounds for afternoon relative humidity. Westerly winds will be getting stronger through the overnight and into Sunday afternoon as relative humidity Sunday afternoon remains around 40% or higher across central Oregon and into the Columbia Basin. Isolated dry thunderstorm with lightning risk is possible this afternoon in the Cascade Crest and John Day Highlands (10-20 % confidence).

Preliminary Point Temps/PoPs

PDT 69 46 73 47 / 0 10 10 10 ALW 71 52 74 52 / 10 10 10 10 PSC 76 50 81 50 / 0 0 0 0 YKM 74 49 81 51 / 0 10 10 0 HRI 73 48 77 48 / 0 0 0 0 ELN 67 46 71 48 / 0 10 10 0 RDM 62 36 67 35 / 20 20 0 0 LGD 63 44 66 45 / 20 30 20 10 GCD 62 39 66 40 / 70 50 20 10 DLS 70 52 73 52 / 20 10 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...None.