283 FXUS66 KPDT 081706 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1006 AM PDT Sun Jun 8 2025 Updated Aviation Discussion .AVIATION...18z TAFs...VFR conditions will prevail over the next 24 hours. Expect mostly clear skies and light northerly winds less than 12 kts. Winds will become terrain- driven overnight. Evans/74 && PREV DISCUSSION... /issued 1241 PM PDT Sat Jun 7 2025/ SHORT TERM...Today through Monday...Main story over the period continues to be the heat, as a strong high pressure ridge moves in over the region by Sunday afternoon. Satellite imagery shows just how defined this ridge is with extensive clearing just off the coast of the PacNW. Hottest day of the period looks to still be Monday, with much of our Basin and adjacent zones reaching triple digits by the late afternoon. Highs will be in the mid to upper 90s elsewhere across the lowlands. Only real change across guidance is to keep ridging persistent until at least the first half of Tuesday - a little longer than originally anticipated - before SW flow starts to prevail. As far as headlines/messaging is concerned, have opted to go with Heat Advisories across the areas initially under an Extreme Heat Watch, resulting in a 3-day Heat Advisory for the Basin and nearby zones. HeatRisk does suggest that a few zones technically qualify for a warning, but given the relatively short duration (the worst of it only occurs on Monday) and the geographic discontinuity of the zones, have opted to go straight Heat Advisory for the sake of simplifying messaging. A good argument could be made either way, however, especially given how relatively early in the season it is for some of these areas to receive triple-digit temperatures. Evans/74 LONG TERM...Tuesday through Saturday...With the longer persistence of the high pressure ridge, chances for dry thunderstorms have pushed back more into the Tuesday/Wednesday time period, but remain concentrated over the mountains of central and eastern Oregon. Rather than a pair of shortwaves, guidance seems to favor a more prolonged SW flow pattern initiated by a deep low over the north Pacific. This has also caused models to back off a bit on instability, but the synoptic pattern does remain favorable for at least a slight (15-20%) chance for isolated dry thunderstorms across the aforementioned areas, even if the setup isn`t as ideal as it appeared a couple of days ago. Ensemble guidance strongly favors a troughing pattern prevailing over the region Thursday onward. This will work to reverse the heat we`re expecting this weekend, giving us more seasonable readings (and even slightly below average) for temperatures by next weekend with highs in the 70s and 80s. With the synoptic pattern turning more progressive by the midweek next week, however, expect winds to pick up through the Cascade Gaps, spilling over into portions of the Basin. NBM already suggesting good chances (60-70%) of wind gusts exceeding 35 mph for the Kittitas Valley and Columbia River Gorge Wednesday and Thursday afternoon, with 20-30 mph gusts elsewhere across the Basin and central Oregon. Evans/74 && .PRELIMINARY POINT TEMPS/POPS... PDT 96 62 101 64 / 0 0 0 0 ALW 94 67 99 69 / 0 0 0 0 PSC 99 62 104 64 / 0 0 0 0 YKM 98 67 102 65 / 0 0 0 0 HRI 99 62 104 65 / 0 0 0 0 ELN 97 64 99 64 / 0 0 0 0 RDM 95 54 97 55 / 0 0 0 0 LGD 89 58 94 61 / 0 0 0 0 GCD 92 57 96 59 / 0 0 0 10 DLS 100 69 100 65 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Heat Advisory until 9 PM PDT Tuesday for ORZ041-044-507. WA...Heat Advisory until 9 PM PDT Tuesday for WAZ024-026>029. && $$ SHORT TERM...74 LONG TERM....74 AVIATION...74