textproduct: Pendleton

KEY MESSAGES

- Dry and cooler temperatures over the weekend

- Pattern shift at the beginning of the week will bring seasonal temperatures and chances of precipitation through midweek

DISCUSSION

Current nighttime satellite is showing partly cloudy skies over the region with a few areas of patchy fog forming in central and north central OR. Overnight temperatures are expected to remain above freezing across much of the region with the exception of the cold prone mountain ridges as well as areas around Seneca where temperatures will be slightly below 30 degrees.

Hi-Res models show a weak southwest flow has settled over the region as the upper level ridge moves east and the upper level low moves down the coast. This flow regime will keep the region under dry conditions with near normal to slightly above normal temperatures. In house calculations show temperatures to be 1-5 degrees above seasonal normal. NBM shows temperatures to be in the low to mid 60s for much of the region with a few areas along the eastern mountains seeing low 70s through Wednesday.

By Monday models show the upper level low to be shifting south off the coast of Oregon and bringing a sharper southwest flow over the region. Models are in firm agreement that a closed low will form and traverse towards the coast of California and stretch as far north as Oregon. Clusters differ slightly in the track and the amplitude of the low, but are in agreement with it shifting south and undercutting the region By Tuesday and Wednesday. The variance in the amplitude will determine the amount of rainfall expected as models show the potential for wrap around moisture making its way into the region from the east. NBM raw ensembles show a 20-40% chance of precipitation for the aforementioned areas Wednesday. By Thursday, NBM raw ensembles show a 30-60% chance of precipitation becoming widespread across the region.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

VFR conditions and predominantly light, diurnally and terrain- driven winds of 10 kts or less are expected (90% confidence or higher) through the period.

Preliminary Point Temps/PoPs

PDT 64 36 63 36 / 0 0 0 0 ALW 65 41 63 40 / 0 0 0 0 PSC 66 36 65 37 / 0 0 0 0 YKM 64 39 64 39 / 0 0 0 0 HRI 65 36 64 37 / 0 0 0 0 ELN 61 35 61 34 / 0 0 0 0 RDM 63 29 59 29 / 0 0 10 10 LGD 68 39 70 36 / 0 0 0 0 GCD 72 39 71 38 / 0 0 0 0 DLS 68 43 66 42 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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