Plenty of rain yet to go, however, we do see an extended pleasant dry cycle returning in October.  Refill that Mug.  Here goes - -

Moderate-to-heavy rainfall today, as the main front of this series passes overhead (this morning’s satellite image below). Intense showers, along with a thunderstorm or two thrown in a the colder air behind the front moves onshore.  We see the potential for a relatively small, but strong, Low pressure cell making landfall near Astoria on Wed around 3 or 4 in the morning.  This tight system could produce a strong wind field, esp along the central-to-north OR coast and the Willamette Valley.  Please heed any Nat’l Wx statements that may be released.  Yet another, much less powerful, ‘wave’ Low will likely move onshore Thu morning, keeping breezy conditions going, along with added rain/showers.  Drying out a bit on Friday, with some of the coolest daytime temperatures of the season, to date.  There will be a few showers early in the day Friday.

Next Weekend.  Last day of Sept 2023 (Saturday) will present as cool & dry.  Showers east of the Cascades, primarily over OR.  Sunday Oct 1 looks mild, dry west of the Cascades, but quite wet east of the mountains for OR, WA & ID - as moisture circulates around a Low over northern NV.  

Rain/showers over the eastern basins of OR, WA & ID will continue into Mon Oct 2nd.  A weak system may also bring a ‘quick-shot' of rain to west side locations on Mon.  By Tue though, model solutions chart a MILD and sunny period for several days in early Oct.  Gradual increase in afternoon temperatures, peaking in the Oct 9-12 period.  There is a chance for a spurt of rain and/or showers over Vancouver Is. & the Puget Sound Thu night Oct 5, but other than that, the PNW could be DRY from Wed Oct 4 through Thu Oct 12.

A wet period is almost upon us.  Also, there have been large swings in the long-range outlook for early October - from quite wet, to dry and warm.  Which will it be?  

Fall officially starts tonight at 10 mins to midnight, so the Autumn Rain period is perfectly timed.  The heaviest rainfall looks to arrive late Sunday through Tue.  Saturday does look cooler, with the steady rain possibly holding off until late day or early evening (earlier for the Puget Sound, north).  It will become rather windy, esp along the coast later on Sunday into Monday.  RAIN will be moderate-to-heavy across the entire western portions of the PNW - with a couple of inches probable in many west side locations.  A good ole’ fashion fall drenching.  

Another storm, although not as wet, is possible on Wed.  A few model runs suggest this one could be a decent wind producer for western OR, but it’s too early to verify.  Overall, conditions should begin to dry down a bit on Thu & Fri next week.  Scattered showers, cool fall temperatures, with an onshore breeze.  The weekend of Sept 30-Oct 1 is trending DRY and warmer.  Here’s where there have been wide swings in the long-range outlook.

For several days, early Oct was trending quite wet & rather stormy; then, models swing back to earlier solutions of dry & summer-like warm.  The latest batch of charts indicate the later.  For now, we’ll lean that direction, with a nice dry stretch of early Oct weather.  Temps in the 70s to upper 80s, depending on how far north one goes during the Oct 2-8th period.  Hazelnut growers could use a dry stretch for harvesting; so too, wine & concord grape harvests.  We’ll try to narrow the actual forecast down, as that time frame nears.  

For now, prep yards, patios, gardens, outdoor furniture for rain & wind — Fall ! 🍁

<< Note: we will present details about the upcoming Annular Solar Eclipse (morning of Oct 14) next week. >>

A few adjustments in the long-range outlook, so let’s review the latest.

Cooler temperatures have arrived, so too, will a rapidly moving cold front later tomorrow.  The Low dropping down the BC coast late Tue is weak, but a bit more organized than the one that brought today’s cloudiness & milder temps.  Therefore, we can expect a few showers - mainly north of Salem overnight Tue into early Wed; similar for the Puget Sound area.  Enough precip to wet the pavement, yet not enough to provide relief for dry soils.  After the front passes, it will be turn FALL COOL this Wed & Thu.  Warmer on Fri (upper 70s, maybe 80-82 in the southern Willamette Valley, south). 

Overnight Fri on into the coming weekend of Sept 23,24, a notable shift in the overall weather pattern will begin.  Model solutions suggest that the Gulf of Alaska will be ‘filled’ with a broad Low pressure trough, with subsequent ‘waves’ of fronts spinning closer & closer to the PNW in the Sept 23-26 timeframe.  Early on, it looked like the rain fields from the string of systems would steadily move onshore during that weekend.  Now, the broad Gulf trough may remain far enough west to delay arrival of steady rain fields for a few more days.  That said, the first band will move into Vancouver Island & far NW WA as early as Friday night - so expect some rain there.  The weekend is likely to remain dry & mild elsewhere (70s).  The Fall Equinox happens the 22nd at nearly midnight; the 23rd at 2:50 a.m. for the eastern time zone.

A deep, powerful Low pressure center is modeled to form late Sunday well off the coast of BC.  There will be a moderate-to-heavy rain field move over Vancouver Island & southern BC on Mon the 25th; the rest of the PNW will, again, miss out most of the precip, as the front will weaken considerably before it moves over west side locations on Tue.  Still, we can expect showers around western OR & SW WA Tue & Wed, Sept 26,27.  Mainly a cloud event, not a drenching rainstorm.  This could change, but for now, that ’s what the models indicate.  

1st big fall storm.  While precise timing is uncertain, a couple stronger systems are currently charting for Thu and Fri Sept 28, 29.  WET and WINDY.  California may get in on the action, as the Fri Low spins heavy rain into the Golden State.  Best to plan on a rainy weekend, Sept 30 - Oct 1.

Early October is coming into view.  The main aspect is for the Gulf of Alaska to remain under a broad trough of Low pressure - which typically leads to fall storms over the PNW.  We’ll see.

Half way through the Ninth month.  The weather outlook remains rather stable.  Sip & read.

A warm-to-hot weekend ahead.  Temps in the upper 80s to lower 90s; cooler over the Sound.  Later Sunday a weak system may have enough strength to bring clouds and a few showers, mainly north of Chehalis - but that has been charted weaker by the day.  Either way, the entire PNW should cool down a bit next week, with pleasant afternoon temperatures for September.  Enjoy.

As you know, we have been monitoring a probable “change” in pattern beginning NEXT Friday for well over a week now.  Should models verify, a cold front will spin south along the BC coastline, ushering in fall temperatures along with on & off showers for the weekend of Sept 23,24 and a few days thereafter.  Appropriate wx for the Autumnal Equinox on the 23rd.  Most current solutions keep the main Low offshore, as it skirts south along the OR coast, which would spin bands of moisture over the west side of the Cascades through mid-week (Sept 27).  We could get a few thunderstorms out of this pattern, as well, esp late in the cycle, as that Low crosses into northern CA.  That’s the trend, anyway.

For Thu & Fri, Sept 28,29, a dry pattern may return, with mild temperatures & plenty of sunshine to end Sept and get October underway that weekend.  We do not see temps reaching into the 80s, at this time (except possibly Medford area).  Our current warm-up could be the last of 2023.

🌀LEE remains a notable threat to the NE tip of the US - along the Canadian border.  It will weaken below hurricane strength, but has a large wind field to ‘drive’ seawater into the coastal communities.  Rain, too.  The next system (would be named NIGEL) will likely remain offshore, turning away from the US & Canada a week from today - as a 'Fish Storm'.

This week will start out mild, with a 'Vancouver Clipper' ushering in clouds & showers over the far NW corner of the PNW later tonight and Tue.  For those that enjoy rather warm afternoons, that will be the state of the weather later this week, esp over western OR & SW WA.  Temperatures will begin to warm up on Thu, then tease out in the upper 80s to low 90s Fri, Sat and possibly Sunday, Sept 15-17.   An onshore flow will cool down the region later on Sunday, to set up the following week’s wx pattern.

Monday Sept 18 - Fri, Sept 22 is trending very similar to this week, with a weak front passing over Vancouver Island with clouds/showers on Sunday the 17th, then a short period of warmer temps near the end of the week, as the onshore flow weakens.  Some model runs suggest a closed Low developing off the northern CA coast on Fri, which often leads to thunderstorms along the Cascades that can drift over the Willamette Valley.  We’ll see.  

The main “change”, if the models are correct, is for a rainy 24-36 hrs to arrive during the weekend of Sept 23,24.  Not every model run presents this solution, but it has charted several times over the past week, hence our report.  Should this change verify, we can expect the first WET weekend of the fall, with notable rainfall from BC down to northern CA.  The other model scenarios chart continued dry conditions and mild temperatures.  Which way will it go?

🌀 Hurricane LEE is likely to strengthen again and may take an unfavorable turn toward Cape Cod area - then turn north, skirting the NE Atlantic coast.  Yikes.  This storm will cause serious beach erosion, etc along the eastern seaboard. Another Atlantic hurricane is likely to follow LEE’s path, but it could make landfall a bit farther south (!) - this hurricane will be named NIGER.  Stay tuned.