textproduct: Pendleton

KEY MESSAGES

1. Continued dry and warm conditions *Heat Advisory in Effect*

2. Isolated to scattered thunderstorms Wednesday and Thursday *Red Flag Warning in affect for Abundant Lightning*

3. Hot, dry and windy conditions return Friday & Saturday

DISCUSSION

Current satellite shows some cumulus beginning to pop up over central OR. So far no thunderstorms have made their way into the region as of yet. Abundant lightning is still expected through the afternoon and the Red Flag warning is in effect through 11 PM tonight. Outflow winds of 25-45 mph with small hail and heavy precipitation possible with these storms.

Even with the lingering smoke, temperatures around the region have been in the upper 90s with little overnight recovery temperatures. Temperatures today are expected to reach into the upper 90s with overnight lows in the upper 60s to 70s. Due to the high daytime temperatures and moderate overnight low, a Heat advisory has been issued for the Gorge, Columbia River Basin of OR and WA, the foothills of the Blues of OR & WA as well as the Kittitas and Yakima Valley through 9 PM Thursday. Confidence in the temperatures is high (80-90%)

We are already beginning to see cumulus work its way into the region in central OR. Models are still on track showing mid level moisture will continue to surge into the region bringing with it instability and the increase in thunderstorms. Isolated to squattered thunderstorms are expected to persist through the early evening hours. On the ground IMET in the region released a balloon as was able to get us some local data. The sounding shows CAPE values in the 800-900 J/km range with DCAPE values in the 1200 J/kg range. Lapse rates of 9 C/km and PWATs around 1 inch. Forecast soundings for the same area show very similar numbers as well as LIs of -3. This shows that the models are in good agreement with what is currently happening on the ground. Expect these storms to produce small hail, gusty outflow winds of 25-45 mph and the potential for heavy rain. Thursday models show the thunderstorms to be a bit more broad in spread. The Cascades could see some stray storms through the afternoon. The highest signal for thunderstorms is along the foothills of the Blues and through Wallowa County. A Red Flag Warning has been issued for abundant lightning through those areas for Thursday beginning after 1200.

Models show an upper level low off the coast of the PacNW. The low will shift across the Cascades by Friday and will bring elevated winds across the region. NBM raw ensembles shows there to be 80-90% probabilities of sustained winds of 20-25 mph through the Gorge,foothills of the southern Blues, north central and central OR, Yakima and Kittitas Valleys. Saturday raw ensembles show the same probabilities for the same locations but winds are 25-35 mph sustained. This coupled with the very dry conditions on the ground fire weather conditions will be elevated.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Thunderstorms are impacting BDN and RDM that are expected to last through 01Z. Afterwards, lingering showers persist in the area with 10-25 percent chances persisting a few hours after. Otherwise, haze and smoke continue to impact TAF sites in the Columbia Basin down to Central Oregon bringing MVFR to IFR conditions over the next 24-hours. Smoke will somewhat improve through late Thursday, but will continue to linger to bring visibilities down.

FIRE WEATHER

Isolated to scattered thunderstorms expected across central OR and eastern mountains through the day today with a Red Flag Warning in effect through 11 PM for abundant lightning. Another round of abundant lightning is expected along the Blues and through the Wallowa Mountains Thursday and another Red Flag Warning has been issued for those areas.

Friday will see increased winds across the region with critical RHs. This will lead to fire weather concerns for hot, dry and winds both Friday and Saturday.

Preliminary Point Temps/PoPs

PDT 67 96 62 97 / 0 10 0 0 ALW 72 99 69 99 / 0 10 0 0 PSC 70 101 66 100 / 0 0 0 0 YKM 73 100 64 99 / 10 10 0 0 HRI 71 99 66 99 / 0 0 0 0 ELN 69 95 61 94 / 10 10 0 0 RDM 58 93 55 95 / 50 0 0 0 LGD 66 100 62 100 / 0 40 10 0 GCD 62 99 59 100 / 10 20 0 0 DLS 70 92 65 97 / 10 10 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Heat Advisory until 9 PM PDT Thursday for WAZ024-027>029. Air Quality Alert until 9 AM PDT Friday for WAZ028>030. OR...Heat Advisory until 9 PM PDT Thursday for ORZ041-044-507. Red Flag Warning from 11 AM to 8 PM PDT Thursday for ORZ694- 695-697>699. Red Flag Warning until 11 PM PDT this evening for ORZ698-700- 705.