textproduct: Pendleton

KEY MESSAGES

- Very warm temperatures to develop with Moderate level Heat Risk developing.

- Dry air with breezy winds will bring elevated fire weather concerns over the next several days.

DISCUSSION

Current radar and satellite depict dry and clear conditions across the region as a mid-level ridge still influences the pattern. A shortwave will enter the region Friday Night/Saturday with an area of low pressure over British Columbia that will develop locally breezy winds. Dry air is expected to prevail with minimum relative humidities dropping in the 10-18% percent range (especially in the lower elevated areas) through the next several days. Dry air in-tandem with the expected breezy winds (60-80% chance) will bring elevated fire weather concerns in the Columbia Basin, Kittitas/Yakima Region, and areas across Central Oregon. Temperatures will reach a peak (now through the weekend) on Friday with highs generally in the low to mid 90s. NBM has great confidence (>90% chance) that temperatures will at least exceed 90 degrees across the lower elevations. This will bring a moderate Heat Risk (values of '2') across the Columbia Basin, Kittitas/Yakima Region, with isolated areas of Major Heat Risk (values of '3') across parts of Central Oregon. We'll see a brief relief from the heat (>85% chance) through the weekend thanks to on-coming shortwave and the broad area of trough across British Columbia.

Guidance is in good agreement that a ridge just offshore will move in-land in the Monday timeframe, raising temperatures in a secondary peak in the mid to upper 90s and possibly in the triple digits by Tuesday (as advertised by the NBM). Current guidance suggests Tuesday will be the hotter day (40-60% chance) with NBM v5.0 giving 60-80% chance of the Washington Columbia Basin exceeding 90 degrees, which drops to 30-60% in the Oregon Columbia Basin, Kittitas/Yakima Region, and Central Oregon. Those percent chances jump to 70-90+% in all of the previously mentioned areas for Tuesday. Tuesday also introduces chances of high temperatures exceeding 100 degrees in the Columbia Basin at 10-20% chances. This will depend on the strength of the ridge where a stronger ridge will raise chances of experiencing 100 degrees early next week whereas chances drop with a weaker ridge. Regardless, temperatures are expected to get very warm and any heat related preparedness should be taken.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

VFR conditions prevail with light and variable winds through the period. SKC to SCT cloud coverage with high ceilings decks expected, with no CIG or VIS issues expected overall.

Preliminary Point Temps/PoPs

PDT 86 55 92 59 / 0 0 0 0 ALW 87 59 93 63 / 0 0 0 0 PSC 90 58 95 62 / 0 0 0 0 YKM 89 60 95 59 / 0 0 0 0 HRI 89 58 94 62 / 0 0 0 0 ELN 86 56 91 57 / 0 0 0 0 RDM 86 49 91 50 / 0 0 0 0 LGD 85 52 91 55 / 0 0 0 0 GCD 89 50 94 54 / 0 0 0 10 DLS 91 64 95 62 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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