DISCUSSION
(tonight through Wednesday)...not much in way of change, as strong high pressure remains anchored along the west coast of the USA. This will maintain hot afternoons/early evenings, with warm nights for this weekend into early next week. Already today, temperatures were in the upper 80s to lower 90s by 1 pm. Not a good omen, as look on track to reach 100 deg in the Willamette Valley and Columbia River Gorge. Even along the normally cooler coast, temperatures on Friday afternoon climbed into the middle 80s, with temperatures closer to 90 into the nearby coastal river valleys of the Coast Range.

As for Saturday through Monday, will see pattern continue, with hot afternoons/early evenings, with temperatures reaching 100 to 105 deg for most interior lowlands, but in the middle 80s to middle 90s in the Cascades and the Coast Range/Willapa Hills. But, with thermal trough over the region, will not see all that much in way of winds.
So, will feel rather hot. At least humidity will be down, with afternoon minimums of 15-25%. But, this comes with a price. With hot temperatures and low humidity, one can easily become dehydrated. So, everyone should keep hydrated to avoid more serious injuries from heat, as well as avoiding more strenuous activities between 11 am and 6 pm. Got animals? Consider if they have adequate shade and water, and perhaps consider taking them out earlier in the day or in the evening as it starts to get a bit cooler.

Speaking of cooling, it will take some time for temperatures to fall in the evenings. Many lowlands areas may not see temperatures drop back under 90 until 8 pm (especially in more urban areas). Overnight lows will fall back to the upper 50s to middle 60s for many areas, but, does appear will generally stay the warmest in the urban areas where overnight lows will stay in the upper 60s to lower 70s. As such, may take a while for any refreshing coolness to take hold, and that may be not until 2 or 3 am.

Will see an uptick of onshore flow Saturday night, enough to drop the coast back to more pleasant temperatures for Sunday. This onshore flow may be enough to knock down morning lows a bit. But, air mass remains dry and warm, so this so-called coolness will be fleeting.
With the thermal trough sitting over the Willamette Valley on Sunday, will see another hot day on Sunday, but with lighter winds. Bit cooler along the coast, with highs in the 70s to middle 80s along the coast for Sunday into early next week.

Again, will have hot afternoon/early evening temperatures across the region (away from immediate coastal areas) into early next week. As such, the duration of the heat will be memorable. For the Willamette Valley, the record most days in a row of 100+ deg is 5 days, set in mid-July 1941 at Portland airport. Many areas in the Willamette Valley/Clark County have seen 4 days in row a few times, such as back in August 2023, or 2015 or in 1981. This year, it looks like 4 days of 100+ deg heat is a good bet, but will see if the record 5 days is reached. A lot will depends on temperatures on Tuesday. Current thoughts are that will have last hot day on Tuesday (across the interior). As such, will extend the current Excessive Heat Warning and Heat Advisory through Tuesday evening.

Warmest day looks to be the 8th of July (Monday). Highest potential of the the highest heat looks focused on areas around the Portland/Vancouver metro and then to the east (through the Columbia Gorge) and to the south (throughout the Willamette Valley).

What are the odds of reaching 100+/105+ deg at select cities, based on data as of Friday morning:

6 Jul 7 JUL 8 JUL 9 JUL 100 105 100 105 100 105 100 105 ======================================================== Kelso 35% 1% 45% 5% 50% 20% 80% 20% Portland* 90% 20% 90% 30% 85% 45% 90% 50% Salem 90% 40% 90% 40% 80% 50% 85% 45% Eugene 85% 35% 80% 30% 80% 35% 75% 30% Hood River 65% 7% 75% 20% 95% 40% 95% 60%

The % of reaching 110 or higher is <5% for all areas, except is 5-15% on Monday and Tuesday in the Willamette Valley.
*Portland is for Portland/Vancouver metro area

Will see onshore flow increase Tuesday night into Wednesday, as the thermal trough shifts east of the Cascades. This will bring back westerly winds to the west side of the Cascades, with a modest cooldown for the interior for Wednesday. Overall, temperatures on Wednesday look to be in the upper 80s to middle 90s, but even cooler temperatures for Thursday, as look to stay in the 80s. /Rockey

FIRE WEATHER
hot weather will combine with dry and gusty afternoon northerly winds again this afternoon/evening as thermal low pressure strengthens over SW Oregon, tightening surface pressure gradients, especially across the southern Willamette Valley. While fuels today are not quite ready for our fire weather zones to be eligible for a Red Flag Warning, the hot and dry weather will rapidly dry out vegetation over the coming days. Unfortunately overnight relative humidity recoveries appear poor over the higher terrain for several nights moving forward, further working to chip away at fuel moisture.
Forecast guidance still suggests winds will be lighter Saturday, but it will still be very hot, dry, and unstable near the surface with thermal low pressure overhead.

AVIATION
Minimal impacts expected with widespread VFR conditions across the airspace. Calm winds each night will give way to gusty northerly winds each afternoon (19Z-21Z) through late evening (05Z-07Z) Gusts up to 25 kt along the coast and gusts up to 20 kt for inland locations.

PDX AND APPROACHES...VFR with clear skies. Gusty northerly winds each afternoon (20Z) through late evening (06Z) with gusts up to 20 kt. /42

MARINE
High pressure over the eastern Pacific paired with a thermally induced low pressure over California/Southern Oregon and the Great Basin. This pattern will persist through the weekend and likely into the start of next week. Therefore, expect Small Craft conditions across all waters with gusts up to 30 kt. Winds continue to follow a diurnal cycle, reaching Small Craft Advisory criteria each afternoon and evening, then decreasing overnight.
Seas will be predominately wind-driven resulting in 4-7 ft at 9-11 seconds.

PQR WATCHES/WARNINGS/ADVISORIES

OR...Excessive Heat Warning until 10 PM PDT Tuesday for ORZ104>125.
Heat Advisory until 10 PM PDT Tuesday for ORZ126>128.

WA...Excessive Heat Warning until 10 PM PDT Tuesday for WAZ202>210.
Heat Advisory until 10 PM PDT Tuesday for WAZ211.

PZ...Small Craft Advisory until 2 AM PDT Saturday for PZZ251>253-271.
Small Craft Advisory until 8 AM PDT Saturday for PZZ272-273.