textproduct: Pendleton

KEY MESSAGES

- Above-normal temperatures this weekend into early next week.

DISCUSSION

An upper-level ridge is building over the Pacific Northwest early this morning. Temperatures will be near normal today, but confidence is very high (95 percent) that they will warm to above normal through the weekend and into early next week as the ridge remains overhead. Widespread 70s are advertised by the NBM for Sunday and Monday, and there is a medium-high (40-70 percent) chance the Yakima Valley and lower Columbia Basin will reach 80 degrees Monday.

Dry conditions are expected (95 percent confidence) under the ridge through the weekend, but guidance is showing low (10-20 percent) chances of showers and very low (5-10 percent) chances of thunderstorms Monday as a weak shortwave wriggles into the Pacific Northwest and interacts with what long-range CAMs are showing as a weakly unstable environment (MUCAPE <500 J/kg) over the mountains (primarily the Blues).

There is significant uncertainty in pattern details Tuesday onward. To give a broad overview, ensemble guidance generally depicts a closed low in the Pacific approaching the OR/CA coast while a second closed low and secondary shortwave trough dive down from Canada across either the Northern Tier (roughly 50 percent of members) or farther south into the Pacific Northwest (roughly 50 percent of members). Temperatures would be near or below normal should the latter scenario materialize. Right now, winds on Tuesday are the best chance of a headline-worthy event. The NBM suggests a low-medium (20-50 percent) chance of reaching or exceeding advisory-level wind gusts (45 mph or greater) through the Cascade gaps and across wind-prone portions of the Columbia Basin and surrounding lowlands.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

VFR conditions with winds of 12 kts or less are forecast for all sites over the next 24 hours.

Preliminary Point Temps/PoPs

PDT 60 35 68 40 / 0 0 0 0 ALW 59 40 67 44 / 0 0 0 0 PSC 63 36 70 40 / 0 0 0 0 YKM 62 35 68 41 / 0 0 0 0 HRI 63 36 70 40 / 0 0 0 0 ELN 57 32 64 39 / 0 0 0 0 RDM 62 28 71 35 / 0 0 0 0 LGD 57 32 66 38 / 0 0 0 0 GCD 58 32 67 36 / 0 0 0 0 DLS 64 40 71 44 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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