Area Forecast Discussion

KEY MESSAGES

- Weather system will push through the area Tuesday, bringing chances of showers and thunderstorms in the mountain areas.

- Chances of isolated thunderstorms greatest on Thursday through the afternoon to evening hours.

- Fall like weather continues through the week with high temperatures in the low to high 70s.

DISCUSSION

Satellite and radar advertise dry conditions with mostly clear skies across the region. Fall like conditions with highs in the low 70s to high 70s. Winds are generally light with typical diurnal winds through the area. Our next weather maker will arrive sometime Tuesday with a trough/shortwave making its way down from BC, clipping the PacNW in the process. Flow aloft in the process will shift to the southwest, allowing for moisture transportation to bring PoP's up to 15-40% over Central Oregon and the mountain region. Most weather will be stratiform with light to moderate rain showers through the late morning to late afternoon hours.

Guidance is in good agreement that the low will be cut-off over Oregon and northern California (80-90% confidence). Chances of isolated thunderstorms for Central Oregon and mountain regions increase Thursday (up to 25% chance) with the low overhead. Wetting rains will remain local, with areas receiving the heaviest showers/storms receiving wetting rains. Otherwise, guidance becomes less confidence as we head into Friday after the shortwave becomes a cutoff low. About 49% of clusters advertise a drier pattern associated with weaker trough/shortwave, while the remaining 51% advertise the opposite. Confidence is better in the latter part of Saturday and Sunday as most members show at least zonal flow or slight ridging overhead that has drier weather in place by the weekend. Although guidance is no where in a conscience how it wants to handle the shortwave beyond Sunday, although conditions appear benign until at least the beginning of next week.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

VFR conditions are expected through the TAF period. CIGS will lower during the day as low pressure moves toward the region by the end of the period. There is a very low (<20 percent) chance of SHRA by the end of the period as well, mainly at YKM, DLS, BDN and RDM. However, since the chances are so low, have not included in any of the individual terminals at this time. Winds will mainly be 10 kts or less, though there is a chance 30-40 percent) of winds gusting to around 15 kts in the afternoon at BDN and RDM for a couple of hours.

Preliminary Point Temps/PoPs

PDT 42 68 44 72 / 0 0 10 0 ALW 47 70 48 75 / 0 0 10 0 PSC 45 71 46 78 / 0 10 10 0 YKM 47 66 47 74 / 0 10 10 0 HRI 44 71 46 76 / 0 0 10 0 ELN 42 60 42 70 / 0 20 10 0 RDM 37 69 39 68 / 0 0 40 10 LGD 41 71 45 74 / 0 0 10 0 GCD 41 74 45 74 / 0 0 20 10 DLS 50 73 54 80 / 0 0 10 0

PDT WATCHES / WARNINGS / ADVISORIES

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