textproduct: Pendleton

KEY MESSAGES

1. Diurnally driven winds Tuesday

2. Chances of dry thunderstorms Wednesday and Thursday

3. Dry conditions will persist through the week

DISCUSSION

Current satellite shows little cloud cover over the region with only a few cumulus clouds forming in the south and some along the Cascades. Mostly clear conditions will persist through the rest of the night with smoke lingering overhead.

Southwest flow aloft will continue through the periods with a shortwave making its way across the region. This will bring elevated winds to the region through the day today. The primary areas for elevated winds will be through the Cascade Gaps, Basin, Gorge and the Kittitas/Yakima Valleys. Winds are expected to reach to 25-35 mph with NBM showing probabilities between 70-90%. Winds will settle after Tuesday as the region becomes wedged between the Four Corners high and the upper level low over the PacNW. Westerly winds will then take over. Winds will turn to diurnally driven through the remainder of the week. Even with the elevated winds, the shortwave will bring cooler temperatures therefore raising the RHs just enough that fire weather concerns will be elevated but not critical.

Another shortwave will makes its way into the region Wednesday bringing a bit of instability with it mainly across the southern portion of the region. Lightning density shows the southern portion of the region being where the storms are likely to occur with probabilities in the 10-20% range. These will likely be high based storms. Looking at forecast soundings, the NAM has MUCAPEs in the 500-700 range with lapse rates of 8-8.3 C/km, LI of -2, bulk shear of 25 kts and PWATs at only 0.50 inches. These storms will also be dry in nature.

With the southwest flow turning to west flow, conditions will remain dry over the region through the week outside of the occasional thunderstorms. Temperatures will be primarily near normal except for through the eastern mountains where temperatures will be slightly above. Temperatures will be in the 80s to low 90s through the week with confidence in the temperatures between 70-80%.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

VFR conditions to prevail through the period. Winds will gust 20 to 30 kts this afternoon, before decreasing this evening. There is still a chance of some MVFR conditions due to wildfire smoke mainly overnight and into the morning hours at any site.

FIRE WEATHER

Elevated fire weather concerns through the period due to winds. RHs will increase slightly as and upper level shortwave moves across the region. The next day for the potential for fire weather concerns will be Wednesday with the possibility of high based dry thunderstorms.

Preliminary Point Temps/PoPs

PDT 87 54 86 56 / 0 0 0 0 ALW 90 59 88 60 / 0 0 0 0 PSC 92 56 90 57 / 0 0 0 0 YKM 89 55 89 56 / 0 0 0 0 HRI 90 56 89 58 / 0 0 0 0 ELN 81 51 85 54 / 0 0 0 0 RDM 87 47 88 47 / 0 0 0 0 LGD 90 53 90 54 / 0 0 0 0 GCD 92 52 93 53 / 0 0 0 0 DLS 83 58 87 58 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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