textproduct: Pendleton

KEY MESSAGES

1. Dry and warm conditions will persist through the week

2. Breezy to windy through the gaps Sunday

3. Pattern shift Sunday will bring chances mountain showers becoming more widespread Monday onwards

DISCUSSION

Current satellite shows mostly clear skies over the region with a few cumulus clouds beginning to bubble up through portions of central OR. High pressure over the region will keep the region under dry and continued warming conditions through the week with temperatures today lingering in the mid 70s and low 80s (90% probabilities).

Models show the upper level ridge to remain over the region through at least Sunday morning ahead of a pattern shift. Temperatures will continue to warm through the period with temperatures peaking Saturday. Raw NBM ensembles show temperatures to be in the upper 70s to low 80s starting tomorrow with 70-90% probabilities. By Saturday temperatures will be in the low to mid 80s with 70-90% probabilities. In office difference calculations from climate shows temperatures to be 5 to 10 degrees above seasonal normal today and tomorrow before reaching 10-15 degrees above normal by Saturday.

With the upper level low pressure system expected to arrive Sunday evening, in house model guidance is showing a tightening of the pressure gradients along the Cascades. This will lead to increased winds through the Cascade gaps and along the foothills of the southern Blues. NBM raw ensembles show the sustained winds of near 25 mph through these areas with 60-80% probabilities through the Gorge and Kittas Valley and 20-40% probabilities across the foothills of the southern Blues.

Sunday is when the models show the next system will make its way into the PacNW. Deterministic models are in relatively form agreement with a shift in the pattern. However, ensembles clusters show there to be a deviance in the amplitude of the upper level low pressure system. 80% of the ensembles clusters are in agreement with a bit of a deeper trough coming across the region Sunday. With that said, models are showing increased chances of mountain precipitation Sunday as well as increased winds. Models show Sunday night could see some light precipitation over the Cascades before becoming more widespread Monday and Tuesday. Models show upwards of 0.15-0.20 inches of rain across the Blues with 50-60% probabilities and near 0.3-0.4 inches along the Cascades with 40-50% probabilities. With the system, temperatures are expected to drop to the low to mid 70s. 90

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

VFR conditions and winds less than 10 kts are expected through Friday.

FIRE WEATHER

Dry and warm conditions will persist through the weekend with a pattern shift expected Sunday evening. Daytime RHs highest over the next three days ahead of the upper level low. RHs Friday will be in the low to mid teens through central OR and the Ochco-John Day highlands. Pockets of low RHs along the southern Blues and in the Basin. Saturday RHs will become more widespread across the region with low RHs across the vast majority of the lower elevations. Sunday is the highest day of concern, especially in the Kittitas Valley where RHs will be in the low to mid 20% and winds will be between 15-25 mph. This puts this area of the region in moderate fire weather concerns.

Preliminary Point Temps/PoPs

PDT 46 80 50 83 / 0 0 0 0 ALW 50 80 54 83 / 0 0 0 0 PSC 48 85 53 88 / 0 0 0 0 YKM 51 84 55 87 / 0 0 0 0 HRI 48 83 54 85 / 0 0 0 0 ELN 47 78 51 79 / 0 0 0 0 RDM 41 81 45 83 / 0 0 0 0 LGD 42 77 46 82 / 0 0 0 0 GCD 39 80 44 85 / 0 0 0 0 DLS 54 85 56 82 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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