textproduct: Pendleton

KEY MESSAGES

1. Dry conditions will persist through the week

2. Slight Chances of dry thunderstorms Wednesday and Thursday

3. Diurnally breezy winds and low RHs

DISCUSSION

Current satellite shows clear skies over the region this morning. Smoke and haze will linger across the region as southwest flow aloft continues to move the smoke to the northeast. Much of the smoke is aloft but cannot rule out light surface smoke first thing in the morning across the Basin and the foothills of the Northern Blues.

Models show the region to be influenced by an upper level low off the coast that is bringing in southwest flow aloft. Looking at the satellite imagery of low to high level moisture, much of the moisture is aloft with dry air at the surface. Models show the flow to continue through the week with a few rounds of shortwaves making their way across the area. These dry conditions will persist through the week.

Models show the first round of shortwaves to make their way across the region today bringing with it low chances of thunderstorms across the eastern and southern mountains of the county warning area. Looking and the ECMWF lightning density, it shows much of the southern portion of the region could see some isolated thunderstorms. Forecast sounding from the NAM shows there to be enough MUCAPE in the region to initiate a storm or two with values above 500 J/kg, lapse rates of 8.6 C/km and higher, LI of -2 and bulk shear of 33 kts. These conditions could lead to isolated thunderstorms. PWATs are also below 1 inch so these storms will likely be dry in nature. While the confidence in thunderstorms is low (10-15%), confidence in the instability across the region is high. Instability over the fire on the ground could cause for some active fire behavior in the afternoon.

The remainder of the week the pattern will stay with southwest flow and dry conditions. RHs will recover somewhat as the temperatures remain cool, but some areas will still remain near critical. Diurnally driven breezy winds will also persist through the week until the pattern shifts slightly on Saturday.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

VFR conditions will persist through the forecasted period. Winds will be breezy between 10-20 kts and gusts to near 25 kts at DLS with gusts to near 20kts at BDN/RDM. Otherwise, light winds through the period. Moderate confidence (50-60%) smoke will not impact VIS at any sites this period just a light haze.

Preliminary Point Temps/PoPs

PDT 86 56 88 55 / 0 0 0 0 ALW 88 62 90 61 / 0 0 0 0 PSC 90 60 92 59 / 0 0 0 0 YKM 89 58 91 59 / 0 0 0 0 HRI 89 60 91 59 / 0 0 0 0 ELN 85 55 86 56 / 0 0 0 0 RDM 88 48 88 49 / 0 0 0 0 LGD 91 57 92 56 / 0 0 0 0 GCD 94 55 94 56 / 0 0 0 0 DLS 87 60 86 59 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...Air Quality Alert until noon PDT today for ORZ041-044-049-050- 502-503-505>511.