textproduct: Pendleton

KEY MESSAGES

- Dense Fog This Morning.

- Gusty Winds over the eastern mountains Today.

- Rain late Today through the overnight, redeveloping Monday.

DISCUSSION

Mesoanalysis was already indicating patchy dense fog developing over the Kittitas valley/Lower Eastern Cascades slopes of Washington just northwest of Ellensburg to Cle Elum as seen on highway cams and mesonet observations. The deterministic HRRR aggressively develops low visibility through the Kittitas valley by 0400 and removes the fog by 1100. With recent rains leaving the near surface layer cool and moist, and mid levels clouds clearing west to east, monitoring for development of fog and stratus will be an ongoing challenge through about mid to late morning. 24 hour precipitation totals indicated up to a few hundredths across the Columbia Basin of Washington west to the Kittitas valleys and the lower slopes. The Upper slopes of the WA Cascades received between a quarter inch and three quarters of an inch rainfall. Additional rainfalls are expected Tonight as a cold front is driven across these same mountains and valley zones, between about 11 pm and 2 am Tonight, as RRFS forecasts wetting rains in the the 0.10 to 0.50 range on the 6 hourly basis probability matched means. Lighter amounts under 0.10 are expected over the Blue Mountains and Blue Mountain Foothills early Sunday Morning. Breezy to windy conditions are still anticipated associated with this system. Model pressure gradients are the driver for NBM means bringing about 30 to 40 knots gusts by the early evening and remaining breezy through about 3 or 4 am Sunday morning. Beyond the weekend, the trend is for warmer 60s for afternoon highs Tuesday and onward following a relatively cool and wet Monday afternoon. Widespread pops in the 10 to 20 percent range for the Columbia Basin of WA and OR is sandwiched by higher pops across both mountain ranges heading into Monday evening.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Dry though the day with VFR conditions are anticipated. A cold front will move across the Cascades spreading rains east of the the Cascade Crest Tonight with VFR ceilings around 4,000-8,000 ft AGL near YKM to DLS between 03 and 10 UTC. Higher cigs in the foothills of the the Blues (PDT/ALW) with light rains will be possible later in the morning (11 to 15z) and less than 20% chances.

Preliminary Point Temps/PoPs

PDT 65 43 57 38 / 0 0 40 0 ALW 66 48 56 41 / 0 0 40 0 PSC 59 40 61 35 / 0 10 10 0 YKM 59 39 59 34 / 0 20 10 0 HRI 61 39 60 36 / 0 0 20 0 ELN 54 33 50 26 / 0 50 10 0 RDM 68 38 52 30 / 0 10 20 0 LGD 59 42 52 36 / 0 0 20 10 GCD 67 40 55 36 / 0 0 0 0 DLS 62 44 58 40 / 0 70 20 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Dense Fog Advisory until 11 AM PST this morning for WAZ026-523. OR...Wind Advisory from 9 AM this morning to 8 PM PST this evening for ORZ049.