textproduct: Pendleton

KEY MESSAGES

- Limited to Moderate HeatRisk on Tuesday Afternoon

- Mountain rain shower and isolated thunderstorm chances return midweek

DISCUSSION

Last overnights windy conditions will ramp down quickly this morning as an upper shortwave exits the region and high pressure develops as the primary sensible weather driver, resulting in light winds less than 10-12 knots across the entire forecast for Today. As compared to Sunday, the NBM is forecasting warmer temps across the Washington Cascades and central Oregon for This afternoon, and similar temperatures as compared to Sunday afternoon elsewhere.

The ridging pattern will become messy by day 2 and 3 (Tuesday and Wednesday) as the models have to come to a solution on an eastern Pacific low resolving along the PAC NW. Varying solutions in the ensemble clustering groups vary between a more hot and isolated dry thunderstorms pattern with elevated heat risk, and other members that develop closer to normal temperatures with more of a pattern recognition favoring a few more scattered thunderstorms across central Oregon and the eastern mountains on Wednesday. That said with uncertainty with how the upper low will play out, at least Tuesday looks like the warmest day of the week, if the slightly wetter/more convective pattern develops Wednesday. NBM means on Tuesday bring highs to the upper 80s across the lower elevations and even low 90s across central Oregon and the Ochoco John Day basin. Uncertainty shows up strongly in the NBM's high temps , for instance at Stampeded Pass where the forecast highs range from 45 to 62 degrees on the 25th to 75th percentile, and likewise 73 to 89 degrees at Pasco. Tuesday the heat risk will be elevated to level 2 or 3 in central Oregon in the afternoon, affecting those who are sensitive to heat, especially those without cooling and hydration as well as some health systems industries. Lightning will be a possibility on Wednesday into Thursday, for which at this time, the NBM probability for thunder on a 6 hour basis Wednesday afternoon is about 18-25% across the central Oregon to and eastern mountains of Oregon.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Much lighter winds are in store Today as the system that caused windy conditions Sunday is exiting the region favoring a more stable subsident weather regime. VFR conditions at all terminals as passing clouds will be limited to cirrus.

Preliminary Point Temps/PoPs

PDT 75 47 85 54 / 0 0 0 0 ALW 76 51 88 59 / 0 0 0 0 PSC 80 50 91 58 / 0 0 0 0 YKM 79 49 87 56 / 0 0 0 10 HRI 78 48 88 57 / 0 0 0 10 ELN 74 45 83 53 / 0 0 0 10 RDM 81 44 91 46 / 0 0 0 10 LGD 77 45 91 53 / 0 0 0 0 GCD 83 46 95 51 / 0 0 0 0 DLS 81 52 89 57 / 0 0 0 10

PDT WATCHES/WARNINGS/ADVISORIES

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