textproduct: Pendleton

KEY MESSAGES

1. Dry and warm conditions through the end of the week

2. Breezy conditions through the Grande Ronde Valley Friday with light mountain precipitation.

3. Breezy through the wind prone areas Saturday

DISCUSSION

Current nighttime satellite is showing clear skies over the region. This will allow for cooler overnight temperatures. Temperatures will be in the upper 20s to low 30s across portions of central OR and the eastern mountains in locations like La Pine and Seneca. The Basin, Gorge, foothills and Yakima/Kittitas Valleys will see temperatures in the upper 30s to low 40s.

Deterministic models are in firm agreement with the upper level ridge remaining over the area through Friday afternoon. Temperatures will peak on Friday with in office calculations showing temperatures to be nearly 15-20 degrees above seasonal normal. Looking at the ensemble guidance, 80-90% of the HREF raw ensembles show temperatures to be in the low to mid 70s through the Basin, foothills, Gorge and Yakima/Kittitas Valleys while central OR and the John Day Basin will see upper 70s with some possible 80s mixed in.

Models show that Friday will begin to see the synoptic transition of the upper level ridge moving east and an upper level trough building into the region from the northwest. As the ridge exits the area, a surface high will form in Treasure Valley while a weak surface low will form over the Columbia Basin. This is the perfect synoptic set up for easterly breezy winds through the Grande Ronde Valley. Winds through the area are expected to begin to pick after midnight reaching its peak after 11 AM and persisting through 5 PM. HREF raw ensembles show sustained winds of 20-25 mph with gusts of 30-35 mph with some isolated 40 mph gusts with 80-90% agreement.

Saturday models show the upper level trough beginning to dig into the PacNW. As the leading edge of the trough wedges itself against the Cascades, the pressure gradients begin to tighten leading to breezy conditions through the typical winds prone gap areas. Looking at the NBM raw ensembles, 60-80% are in agreement that the Kittitas Valley will see winds between 20-25 mph sustained winds with gusts of 30-35 mph. The Gorge will see 15-20 mph sustained winds and gusts of 25-30 mph.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

VFR conditions will persist through the forecast period. Winds will be generally light through the period with only DLS seeing winds near 9 kts after 21Z. Clear skies will also persist through the period.

Preliminary Point Temps/PoPs

PDT 69 38 74 43 / 0 0 0 0 ALW 69 44 75 50 / 0 0 0 0 PSC 72 36 70 38 / 0 0 0 0 YKM 70 42 69 43 / 0 0 0 0 HRI 70 38 71 40 / 0 0 0 0 ELN 67 37 67 39 / 0 0 0 0 RDM 75 33 79 35 / 0 0 0 0 LGD 70 40 70 46 / 0 0 0 0 GCD 75 36 76 38 / 0 0 0 0 DLS 74 44 75 46 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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