textproduct: Pendleton

KEY MESSAGES

- Light showers continue through this afternoon with isolated storms possibly developing today.

- Breezy winds developing in the Simcoe Highlands and Kittitas Valley today, with winds peaking Friday.

- Cooling trend through Saturday, warming early next week.

DISCUSSION

Radar currently shows light showers across the area that will continue through the rest of the afternoon hours. Parts of the Southern Blue Mountains are seeing clearer conditions than earlier this morning, allowing for daytime heating to build into the area. This allows CAPE values to develop in the 250-500 J/kg range with 30-35 knots of 0-6km shear, bringing slight (10-20 percent) chances of an isolated thunderstorm this afternoon. Not expecting any of these storms to be severe, but heavy rain and pea size hail may impact areas where the strongest storms are present.

An oncoming shortwave with an embedded cold front will push through the area Thursday/Friday, allowing pressure gradients to tighten and bring breezy to windy conditions across the Simcoe Highlands, Kittitas Valley, and the Columbia Basin. Higher winds are expected across the Simcoe Highlands and Kittitas Valley (70-90% chance) though wind values appear to be sub-advisory level with more common values of wind gusts staying at 25 to 35 mph (50-70% chance). NBM does advertise 50-70% chances of exceeding wind advisory Friday, but confidence is not great enough to warrant a wind advisory yet. The oncoming trough will bring moderate rain and snow showers across the Cascades Friday and Saturday, but will leave most of the area east of it dry due to rain shadowing. Dew points and relative humidity will remain dry and, with combination of the expected breezy conditions Friday, bring elevated fire weather concerns through parts of the Columbia Basin (see 'FIRE WEATHER' below). Temperatures will cool down to the mid 60s to low 70s in lower elevation areas as a result of the systems passage. By Sunday, highs will hover in the mid to high 70s and be stable through at least through mid-next week (40-60% chance).

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

VFR conditions to prevail through the period. Light radar returns are currently moving through the Columbia Basin, but little if no precip is currently making it to the ground according to area cameras and station observations. Nonetheless, a prob30 for light showers were included at sites PDT/ALW through early this evening. Breezy winds 12-20kts with gusts up to around 30kts will continue at sites PDT/RDM/BDN through this evening, becoming light through the remainder of the period. Site DLS will see these breezy winds through the period. Sites YKM/ALW/PSC will remain mostly light, with sites YKM/ALW seeing a gust up to 20kts this evening. Lawhorn/82

FIRE WEATHER

Elevated fire weather concerns expected this Friday across parts of FWZ WA691 (Columbia Basin of Washington). Concerns arise with the combination of breezy to windy and low relative humidity conditions developing. Minimum relative humidities will dry out in the 20-25% range Thursday and Friday. Breezy wind gusts will develop Friday in combination with the low relative humidity values, resulting in the potential for elevated fire weather potential.

Preliminary Point Temps/PoPs

PDT 47 75 47 73 / 10 0 0 0 ALW 53 76 52 75 / 10 0 0 0 PSC 52 80 49 78 / 10 0 0 0 YKM 48 80 47 75 / 0 0 0 0 HRI 50 78 50 75 / 0 0 0 0 ELN 45 72 44 66 / 0 0 0 0 RDM 37 76 40 74 / 0 0 0 0 LGD 44 74 43 76 / 20 0 0 0 GCD 42 77 42 81 / 10 0 0 0 DLS 53 77 52 71 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Wind Advisory until midnight PDT tonight for WAZ026-521. OR...None.