textproduct: Pendleton

KEY MESSAGES

1. Breezy through the wind prone areas Saturday and light showers in the Cascades

2. Dry and cooler temperatures over the weekend

3. Pattern shift at the beginning of the week will bring seasonal temperatures through midweek

DISCUSSION

Current nighttime satellite is showing mostly cloudy skies over the region. This will keep overnight temperatures a little warmer than the last few nights. NBM shows overnight temperatures to be in the upper 30s to low 40s through central OR and the eastern mountains while the remainder of the lower elevations will see low to mid 50s with some isolated 50s along the foothills of the Blues due to continued downsloping winds.

Saturday models show the next synoptic pattern to make its way south from the Gulf of Alaska. 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 HREF raw ensembles, 70-80% 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. Along with the winds through the Gaps, light precipitation is expected along the crests of the Cascades. Models show 0.03 inches of rain in a 24 hour period with 80-90% probabilities.

By Saturday afternoon the models show the shortwave moving off to the northeast and a more zonal flow set up dominating. Models show dry conditions to persist under this flow through Sunday afternoon when the next synoptic system begins to infiltrate the region. As the system moves closer to the area, southwest flow will take over and dry conditions will persist.

By Tuesday models show the upper level low to be shifting south off the coast of California and undercutting the region. Southwest flow will continue to dominate through Tuesday. Clusters are struggling to resolve the positioning and amplitude of the low. However, models do show that the low continues to move southwards and onshore, the potential for some wrap around moisture on the eastern side of the low making its way into the eastern mountains. QPF clusters are showing the highest chances to be Thursday with low confidence (20- 30%) for 0.01 inches of rain. With the uncertainty in the clusters, confidence in the potential for rain is low (<20%).

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

VFR conditions will persist through the forecast period. The frontal passage will bring slightly breezy conditions the wind prone sites of DLS/PDT. Winds elsewhere will be below 12 kts. CIGs will be 25 kft to SKC.

Preliminary Point Temps/PoPs

PDT 69 35 61 37 / 0 0 0 0 ALW 69 40 63 42 / 0 0 0 0 PSC 72 35 64 35 / 0 0 0 0 YKM 70 35 62 37 / 0 0 0 0 HRI 70 37 63 35 / 0 0 0 0 ELN 61 32 59 34 / 0 0 0 0 RDM 66 29 62 29 / 0 0 0 0 LGD 70 36 67 38 / 0 0 0 0 GCD 73 35 71 37 / 0 0 0 0 DLS 69 40 67 43 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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