textproduct: Pendleton

KEY MESSAGES

- Widespread rain is likely overnight into Sunday.Areas in the flood watch should have many way to get alerts.

- Wind gusts above 30MPH are likely much of Sunday morning.

DISCUSSION

A low pressure system currently located off the coast of Oregon and Washington is moving south eastward, it should move ashore during the afternoon. After moving inland the low should begin steering towards the northeast. Rain should begin to develop as it moves inland. Overnight the rain will become more widespread.

Ensemble and deterministic gudience still remains in disagreement on QPF totals. Holistically the CWA should see an above normal amount of rain this time of year with EFI values between .8 and .9 and SOT of 2 and 1 on the Oregon/Washington border, putting emphasis on a potential for a high QPF rain event. Overall the QPF has decreased over the last several runs and reseeded more north toward our neighboring CWAs. NBM 10th percentile has the Kittitas valley receiving 1" of rain and the Colombia Basin and the Blue Mountains mostly receiving .20". The southern leeward side of the Cascades will likely be rain shadowed out of higher QPF totals. The 90th percentile QPF again Has the Kittitas Valley in higher QPF values and the Columbia Basin exceeding 1.20". Probabilities of >= .50" occurring excluding those along southern leeward side of the Cascades which will again be rain shadowed. >= 1" is where the Probs really decline throughout most of the area, aside from the Kittitas and Yakima Valley which remain >=80% chance.

Thunderstorms remain at <= 20% chance mostly occurring in the higher elevations of the Blue Mountains overnight. A potential exists for flooding over the Paradise and Hagen fires subsequent flood watches have been issued for those areas.

Wind gusts probs through much of Columbia Gorge, Basin, Kittitas Valley and Foothills of the Blue Mountains have a >90% chance of 35mph or greater. Most of the CWA should see at least 20-30 with those areas mentioned seeing higher gusts.

Temperatures over the weekend remain well below seasonal averages. Sundays high temperatures will remain in the 60-65F with cooler temperatures in the higher elevations. After sunday and through out the week temperatures will rebound to climate norms.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

VFR conditions at most sites, which is expected to stay the course through the period. The only terminal currently experiencing MVFR is PSC due to reduced visibility of 5SM due to moderate rainfall and breezy winds. This is expected to subside shortly as winds begin to decrease slightly. YKM is also expected to drop to MVFR condition overnight due to reduced ceilings of 2kft related to the passing system and wrap around moisture bringing another batch of light showers to all Sunday morning and afternoon. RDM/BDN will be the only sites not included in this second shower as the moisture will stay further north. Breezy winds will return Sunday morning and afternoon accompanied with the second wave of showers, with gusts of 20-25kts expected. 75

Preliminary Point Temps/PoPs

PDT 48 62 44 69 / 100 60 50 0 ALW 52 62 49 70 / 100 70 70 0 PSC 52 63 45 73 / 100 60 40 0 YKM 51 61 44 68 / 100 90 10 0 HRI 50 64 44 72 / 90 60 40 0 ELN 47 57 41 66 / 100 100 20 0 RDM 39 61 33 70 / 100 10 10 0 LGD 46 61 42 70 / 90 60 70 0 GCD 46 61 40 70 / 100 40 20 0 DLS 51 65 50 74 / 100 50 10 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Flash Flood Watch through Sunday evening for WAZ030. OR...Flash Flood Watch through Sunday evening for ORZ502.