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  • Updated

Friday, July 30th, 12:30 P.M. 

After a warm start to the day, temps will soar close to 100° in the Portland metro area this afternoon/early evening. We are keeping an eye on some clouds and showers over the Cascades this afternoon. I can't rule out the chance for a brief shower or thunderstorm in the metro area or central valley this afternoon and evening.

High pressure will slowly back off over the weekend, but we will still have a southerly wind overhead. Thin smoke and high elevation clouds will be possible at times, and isolated storms could fire up during the afternoons & evenings along the Cascades and east of the mountains. Highs should trend back into mid 90s to upper 80s Saturday and Sunday.

High pressure will continue to inch away from the Pacific Northwest next week, resulting in cooler temperatures. Afternoon highs will slowly trend back down into the 80s, with overnight lows in the upper 50s and low 60s. 

  • Posted

9pm Wednesday…

I feel like we’ve done this before.  Oh yes, it was last year.  A very mild and boring winter, then suddenly it cools off starting Super Bowl Sunday.  Yep, it happened last year.  Although this year we don’t see a lowland snow event in the days following Sunday.

First, the warm weather.  January has been very warm compared to the 30 year average.  The only cool period was mid-month when we flirted with low elevation snow and a cold Gorge wind was blowing.

Almanac Monthly Temps So Far

As of this evening, with two days left to go, we’re running 5th warmest January on record.  But with two warm days ahead, including a 60 degree day Friday (assuming rain shifts north), we could end up at #2

Record Warm Month Top Five

And of course it’s been wet!  It’s so nice to see solid rain for day after day; that’s after a very dry October through December.  January has been the wettest month in almost three years; the wettest since 10″+ fell in February 2017

Rain Record PDX

But don’t complain!  If you live in the foothills of, or in, the Coast/Cascade Ranges it has been a huge soaker.  Some spots are approaching four feet of rain!  Again, this isn’t record-setting, but it seems “crazy wet” because we’ve gone through two relatively dry winters

Rain Coast Cascade Range

What’s ahead?

Three more very mild days.  An upper-level ridge strengthens over us through Friday.

ecm_friday

That pushes just about all the rain north of the Columbia River by Friday midday or so.  There should be 12-18 hours dry later Friday through early Saturday.  And the temps should be amazing!  Highs Friday should reach 60 or above from the metro area south through western Oregon.  Even the lower elevations of Eastern Oregon will reach the 60s (Hermiston, Pendleton) and maybe central Oregon.

Then a sharp cold front moves across the region Saturday evening, dropping snow levels from around 9,000′ midday Saturday to 1,000′ by Sunday morning.   Check out the drop

ECMWF Snow Level From 850mb Temps LONG TERM

We’ve had “mixed showers” in our forecast for Sunday off/on the past four days for this reason.  It’s the “chilly onshore flow showers” snow setup that rarely produces sticking snow at the lowest elevations.  Expect some snow on the Coast Range summits Sunday morning, and well down into the Cascade foothills.  Skiing will be MUCH better Sunday too, fresh snow!

Could it snow in the lowlands Saturday night or Sunday? 

Yes, in the air, or at least mixed with rain, but sticking snow on the ground is very unlikely.  850mb temps are marginal, around -6 to -8 and we have onshore flow in progress.  Showers taper off Sunday night and we should be dry Monday.  Yes, totally dry for ONE DAY!

Rain returns at some point next Tuesday, and of course there’s always the possibility it starts as snow.  But what models are showing is a classic setup for a quick warmup.  Breezy southerly wind arrives at the same time as precipitation.  Maybe a brief mix in spots, then a snow level jump up to at least 3,000′.  The ECMWF model agrees with basically no lowland snow through next Wednesday.

ECMWF Snow Accumulation

By Wednesday of next week (February 5th), models show the pool of cold air has moved off to the east

ecm_wed_5th

But then three major models are hinting another pocket of cold air may drop down the West Coast about 10 days from now.  Check out the ECMWF, GEM, & GFS models for next Saturday the 8th…looks chilly!  I’ll be watching this closely

The ECMWF ensemble chart today showed a HUGE variety of solutions beyond the middle of next week.  Some ensemble members were VERY cold, others just remain mild.  It’s 8-10 days away so plenty of time to wait and see how modeling comes together.

For now, enjoy the warm three days ahead!  I’ll be back at work for the shows Sunday evening after the Super Bowl.

Chief Meteorologist Mark Nelsen

  • Posted

6pm Wednesday…

So far this winter we’ve seen very mild conditions, no lowland snow in Portland, and hardly any storminess.  Sure, we're getting some sticking down around 1,000' east of Portland this evening (Sandy, Estacada), but no snow down into the lowlands.

Now it seems increasingly likely that SOMETHING is in the works along the I-5 corridor for next week.   Some sort of snow/ice/cold “event” may be on the way. Maybe even out to portions of the coastline.

It’s still too far out (5-7 days) to know how things will play out in detail, but now that we’re getting closer it’s fair to make these statements:

  1. Some (or a large) part of western Oregon and/or western Washington lowlands will likely get a significant snowfall (2-4″+) within the next 8 days.
  2. There is also a decent chance for hard freezing conditions (below 25 degrees) sometime beyond Tuesday.  That’s from at least the metro area north up into Washington, and of course east of the Cascades plus Gorge.  That said, it already happened earlier this winter at Thanksgiving.  So your pipes/faucet covers should be in good shape.
  3. Start planning ahead… “what if there is some sort of significant snow/ice event the middle of next week?”.  Somewhere in the Tuesday-Thursday time-frame. How would you deal with it if that’s the case?  If we get lucky nothing happens, but at least you can be prepared.

At this point, we are not able to make statements like this:

 I expect a, (6″? 8″? 10″?)  snowfall over the Portland metro area next Wednesday, or Thursday” or “I expect a snowstorm in late January or February

Portland will be a frozen hellish white mess Tuesday through Friday next week

Snow Portland Preview

WHAT ARE WE SEEING RIGHT NOW?

All models are in good agreement forecasting the general weather pattern for the next 7 days.  They all agree that a series of systems drop into the Pacific Northwest on cool northwesterly flow through Sunday.   That’s valley rain and mountain snow.  Expect a MAJOR snow storm on Mt. Hood Friday night and Saturday, then again Saturday night and Sunday.  First big weekend on Mt. Hood with all resorts fully open (Skibowl opens tomorrow) + 1-2 feet snow + tons of traffic = big mess possible Hwy 26 & 35 Saturday/Sunday.  Friday afternoon through Sunday evening should feature 2-4 feet of snow up there…

7 Day Forecast Cascades Mt Hood Government Camp

Then Sunday through Tuesday an especially cold upper-level trough (big dip in jet stream) drops south through western Canada.  Here’s Sunday:

gfs_sundayam

Then next Tuesday… 6 days from now.  Models generally agree to this point

gfs_tuesdayam

Notice that very cold low is sitting up there in southern British Columbia.  When we get our big arctic blasts, a low like that drops directly overhead on its way south and east.  No model is forecasting that to happen early-mid next week. That’s what happened Thanksgiving weekend, but of course the airmass was not nearly so cold early in the season.  In this setup, which models agree on up to this point, we generally see cold “onshore flow” showers.  Wind at sea level is coming in from the southwest or west, off the 50 degree ocean.  In this case the air is taking a very short trajectory from western Canada out over the cold water and coming onshore as snow showers.  This is the classic setup for lots of snow on hilltops and a slush mix in the lowest elevations.  If you live at 1,000′ this can give you big snow.  But this isn’t how we get our big “Portland shuts down” sort of snow events.  That’s why we have mixed snow/rain showers in Monday’s forecast and then mainly flurries for Tuesday.

2 of 3 main long-range models (GEM & ECMWF) say we still have weak onshore flow (although very cold onshore flow!) Tuesday.  Bitterly cold arctic air is poised just north of us at that point.  Of course the crazy GFS is still blasting in cold air Tuesday, but at least it has been backing off on that time-wise. A couple days ago it has the “arctic front” (leading edge of cold north & east wind) coming through late Sunday.  Now it’s doing that Tuesday.  It’s been unreliable for the really cold stuff so far in this event.  So at this point the most likely scenario is that we’re going to be flirting with low elevation snow Monday/Tuesday, but the showery/slushy stuff; no frozen/hellish commute issues.  You get the idea with the ECMWF snowfall forecast through Tuesday:

ECMWF Snow Accumulation

Beyond Tuesday?  Of course we’re talking 7 days out in time, but models are hinting we could see a classic snow/ice storm setup somewhere west of the Cascades.  ALL models agree that an approaching system from the west will pull cold/dry arctic air south & west from Washington and through the Gorge.  Then moisture rides over that cold air…a classic!  But will it be a relatively brief snow/ice event after Tuesday or a historic drawn-out snow storm?  It’s too far out in time and both are possible.  Luckily we have many days to figure it out.  The reason I have confidence that we’re going to see at least SOMETHING is the ensembles from the different models.  43 of 51 ECMWF ensemble members show at least 2″ snow around Wilsonville (I chose a location along I-5 corridor) by next Friday.  You don’t often see such good agreement among the ensembles, clearly a spike around next Wednesday/Thursday.

ecmwf-ensemble-KUAO-indiv_snow_24-8484800

Stay tuned!

Chief Meteorologist Mark Nelsen

  • Posted

8pm Sunday…

Here we are, finally at the end of Christmas Vacation for the kids.  It’s been a fun two weeks for many of us; full of family events, parties, and WAY too much eating and…drinks.  Time to get back to work and school.  First, a quick recap of where we stand meteorologically:

  • We are at the midpoint of our  “cold season/winter/storm season” (whatever you want to call it) west of the Cascades.  That’s November through February.  By March 1st we’re done with winter west of the Cascades unless we get a sloppy/wet brief snowfall.  Last year’s early March record cold & snow would be an extreme example of how winter can hang on very late here every few decades.
  • It’s been so boring for meteorologists with a lack of stormy weather, lowland snow/ice, etc… But great for you!  Weather has barely affected our lives so far, except for the brief snowy travel issues at Thanksgiving and lack of snow in Cascades.  Officially we have not seen measurable snow in Portland.

Now we seem to be turning a corner, at least for the next 10 days.  We’re now in a cooler & wetter weather pattern; back to normal!

Highlights

  1. Expect at least SOME rain each of the next 7 days as a series of relatively weak weather systems move off the Pacific and into the Northwest.
  2. None of these systems look particularly strong, windy, or cold.  But each will add to our January rain total in the lowlands and snowpack in the Cascades
  3. Snow levels vary between 1,500′ & 5,000′ through Saturday
  4. Models are hinting that snow could stick even lower at some point between next Sunday and the days following (12th-15th).  Some produce NO snow, others give us a big outbreak of cold arctic air and several inches.
  5. That period will likely feature the lowest snow levels since our brush with lowland snow Thanksgiving weekend.  I’ve put on my snow tires (finally) just in case…

Expect 2 to 5 feet of snow in the Cascades now through next Sunday. Here’s the ECMWF model (Euro).  Can’t wait to see that 25% of normal snowfall on Mt. Hood jump up big-time the next 10 days!

ECMWF Snow Accumulation

What I don’t see within the next week (through Sunday the 12th)

  • Sticking snow at lowest elevations west of the Cascades OR along I-84 in the Gorge
  • Freezing Rain
  • Flooding
  • A Windstorm
  • A Hard Freeze (below 28 degrees west of Cascades)

We’re in a wet westerly flow right now with a nice Pacific jet stream aimed at the West Coast.  Here’s the ECMWF ensemble forecast 500 millibar height map right now:

euro now

But by next Monday, ALL models agree we’re in a pattern with an upper-level high out around 150-160W longitude (south of Alaska) and a cold trough centered over the western USA.  This is the ECMWF for next Monday

euro ensemble monday 14th

The Canadian and GFS are similar.  Click on each for a larger view.

So that’s relatively simple…cooler (or colder) and still a bit wet 8 days from now.  But in our climate, with hundreds of miles of 50 degree water just to our west, everything has to work just right to get us real cold or snow all the way down to sea level.  So all models may agree on the general pattern by next Monday, but how we get to that point and exactly how all the weather features line up is critical.  Slight changes mean the difference between a hellish snowy commute at some point in Portland, or just 40 degree rainy weather.

Example A:  For several days the (new and improved) GFS model has been constantly trying to dig weather systems farther west out of Canada as they move southeast into the cool trough across the western USA.  That’s for this coming Saturday, Sunday, or Monday.  It has been most aggressive bringing cold arctic air south into the Pacific Northwest.  Today’s 18z model was very extreme, going all out for widespread snow in our area with a cold east wind Sunday night.  See the arctic boundary (snow to sea level) way down into Oregon on that model (yellow highlighting)

gfs18zSunday evening

The GEM at the same time has a surface low sliding into NW Washington, keeping cold air bottled up north.  On Sunday evening the GEM would say it’s 40 degrees with a gusty south wind blowing in Portland…totally different even though upper-level is similar.  It’s all about low/high pressure locations for us.

gem12zSunday evening

The ECMWF?  It says “mainly dry” with the arctic boundary up north and a weaker low heading farther south.  This says snow showers to 1,500′ and nothing interesting happening in Portland Sunday evening.

ecm12zSunday evening

To summarize:

  1. I think SOMETHING interesting is on the way NEXT week, but it’s too early to know what.  Too early to know if it involves lowland snow/ice/cold or just a brush with flurries again like Thanksgiving.
  2. Keep a close eye on forecasts, this blog, and on-air at FOX12 OREGON.
  3. As a nod to the GFS, I put one little lonely snowflake mixed in with the rain on our 7 Day Forecast (next Sunday)
  4. And, for the love of any sort of deity…stop staring at weather apps!  They are good for general weather forecasting during benign weather, but useless in situations like this.  Totally automated.  Plus, what does a snowflake for next Monday mean; a snowy day? a few flurries?

Weather App Snow Forecasts

Chief Meteorologist Mark Nelsen

  • Posted

These first 10 days of December have been mild; quite a turnaround from that cold Thanksgiving week.

web_PDXTemp_13days

Of course we’ve been on the dry side since early October too.  Both Oregon/Washington saw a dry fall.  Take a look at the precipitation percent of normal for the past 60 days

anomimage

I do see three wet days ahead.  A Pacific system moves inland tomorrow afternoon followed by lots of post-frontal showers in the colder airmass Thursday and Friday.  There are hints we could see vigorous showers Thursday with maybe hail or thunder.  Then I see another somewhat “splitty” jet stream setup this weekend and part of next week.  That’s a return to weak systems.  You can see the upper-level system heading into California on Tuesday

gfs_tuesday

All models advertise strong southwesterly flow of some sort later NEXT week (about 10 days out).  The GFS 500 millibar heights and anomaly for Friday the 20th…

gfs_fri20th

What I don’t see, at least during the next 10 days, is any setup for lowland snow or a freeze.  I’m sure not going to bother putting on my snow tires for now.  Maybe next week.

Snow levels will vary between 2,000-6,000′ in the next 10 days.  Probably lowest this weekend.  Notice not a single one of 51 ECMWF ensemble members produces snow in Portland through Christmas Eve either!  Leading up to the Thanksgiving cold spell there were multiple ensemble members hinting that we might see some snow fun.  But you see nothing here.

ecmwf-ensemble-KPDX-indiv_snow_24-5979200

I’ve also been noticing the consistency in those ensembles for 850mb temps (temp in Celsius around 4,000′) through the next two weeks.  Not a single member down below -6; that’s when I start getting interested in lowland snow setups.

tseries_850t_000-360_Portland

The last time we saw snow in December was Christmas Eve 2017.  You may remember a couple hours of light snow, followed by a bunch of freezing rain.  It was a “Silver Christmas Morning” in 2017.

December Snow PDX 2017

To summarize

  1. There’s no sign of lowland snow or a hard freeze in the next 10 days, possibly longer
  2. That means we’ll make it at least 2/3rds of the way through December without snow
  3. We can’t see much beyond that point, although there are no hints of anything a little farther out.  It’s too early to know if we’ll be close to snow or ice for Christmas Week

Chief Meteorologist Mark Nelsen

  • Posted

6pm Wednesday…

Am I getting old, or does it seem like a warm sunshine and temps in the 70s was just a few weeks ago?  Time is flying…

Forget about that warm stuff; it appears that winter is going to move in quickly over the next two weeks in the Pacific Northwest.

First, those weather apps.  This is what Brian MacMillan’s iPhone app showed today

iphone snow JPG

I use the FOX12 Oregon app which does not show lowland snow.  Keep in mind these apps are automated with no human intervention; although that isn’t as shocking as it was just five years ago.  I bet within 10 years most weather forecasting will be automated.  We’re not there yet but computer modeling is getting better.

Weather App Snow Forecasts

So what is going on next week?  I think SOMETHING is up with respect to cold and/or lowland frozen precipitation in the next 10+ days.  But it’s far too early to pin down any sort of details.  Our seven day forecast is snow-free right now, but it’s that time of year to start paying close attention to the forecast.

First, we have beautiful weather for three more days.  East wind keeps us mainly cloud/fog free through Saturday.  A warm upper-level ridge of high pressure keeps storms away and temperatures mild.

ECM_FRI22

By Sunday the flow overhead turns westerly and cools a bit.  Nothing too exciting, but we’ll likely get some light rain out of the first system.

ecm_sun24

But look at the change by next Wednesday!

ecm_wed27

A cold upper-level trough drops in over the western USA.  It’s still there the Saturday after Thanksgiving; the following is from the 18z GFS model.  A warm upper-level ridge into southern Alaska and a cold trough over the Pacific Northwest.  This is a very chilly weather pattern for us; historically a good setup for lowland snow west of the Cascades.

gfs_sat30

Look at the drop in temps the next 10+ days from the ECMWF model.  Forget highs near 60 like today.  Get used to 40s, which is typical mid-winter stuff for us.

ecmwf-operational-KPDX-daily_tmin_tmax_ecmwf-4251200

We have to see a specific placement of surface low pressure, wind direction, and precipitation; but snow CAN make it to sea-level with this setup.  Models have been all over the place the past few days on details.  On Sunday night the ECMWF model produced a snowstorm with 5-15″ snow in the metro area next Wednesday.  Last night the ECMWF brought a deep low into Central Oregon, dumping 2-6″ snow in the south Willamette Valley.  Today’s ECMWF (for example) doesn’t bring any snow west of the Cascades (other than flurries) because it’s much drier.  The latest 18z GFS brings snow into some of the lowlands on Black Friday and Saturday.    You get the idea…

Because of these wild run-to-run gyrations we use “ensemble forecasting”.  The ECMWF model is also run 51 times at a lower resolution.  A graphic showing each of those 51 members (horizontal lines) below shows about 6 of those 51 members produces notable snow (over 1″) in the metro area (Aurora) through Thanksgiving Weekend

ecmwf-ensemble-KUAO-indiv_snow_24-4251200

The GFS has 21 ensemble members, each going out two weeks.  Not much snow there, only 2 of those produce notable snow in the metro area through Thanksgiving Weekend

gfs-ensemble-all-KPDX-indiv_snow_24-4251200

To wrap it up…pay close attention to the forecast as we head toward Thanksgiving and beyond.  It’ll be turning colder.

One thing that’s also obvious, we sure aren’t heading into any sort of real wet/stormy pattern.   Just colder, and a little wetter.

I’m taking an extra day off this “weekend”, so probably no posts until Sunday.

Chief Meteorologist Mark Nelsen

  • Posted

6pm Tuesday…

Quite a change out there today.  Yesterday we were 62 and mainly sunny, today we stayed around 50 degrees and remained under a thick gray blanket of cloud cover.

As expected, this first half of November is turning out to be mild and uneventful.  November is typically the start of the rainy season in the Pacific Northwest.  But in the lowlands we’ve seen much below normal rainfall.  So far, less than 1/2″ rain in P-Town and there won’t be much more by Friday the 15th.

Mark November Rain

Lowland Highlights

  • There’s no sign of a typical stormy November weather pattern for at least the next 10 days
  • Weak weather systems will bring rain at times Friday, next Monday, and again late next week
  • There’s no sign of cold/freezing weather like we saw back in late October
  • Weather shouldn’t impact your life too much for the next 7-10 days

Why so quiet and mild?  An area of higher-than-normal upper-level heights (also known as “ridging”) wants to remain near/over the West Coast.  This diverts storms to the north or weakens them as they move inland.  This was also a persistent feature for much of last winter (until February).

Satellite SurfaceNow take a look at the 500 millibar height map from the ECMWF model.  This is actually an average from 51 “ensemble” members.  The solid lines are contours, showing the height of that pressure surface.  Wind at this level (~18,000′) follows the lines.  So in the case of the map below you’re seeing westerly flow into far NW USA and western Canada.  The colors represent the anomaly.  Red = higher than average heights, blues/pinks = below average.  That’s quite a bit of ridging over the western USA!  This map is for Sunday.  So here we are at November 17th and the pattern continues.

ECM_SUN17

It appears the ridge will “back up” a little bit for NEXT week.  Check out Tuesday as a chilly upper-level trough has dropped into the PACNW.

ECM_TUE19

But for the rest of next week things remain the same, both on the ECMWF and GFS models.  Here’s Friday the 22nd, showing a bit of a “Rex Block”.  That’s an upper-level high north of an upper-level low.  It can sometimes be a stable pattern.  Definitely a drier than normal pattern for us.

Up to this point I’m feeling pretty confident about the general trend…drier and milder than average for the next 10 days.  But right after, models diverge.  5 days later we’ve reached the two-week point of the operational forecast models.  The GEM and ECMWF both continuing ridging for this day before Thanksgiving (ECMWF below)

ECM_WED_27

But the GFS goes cool and wet, quite a pattern change…we’ll see.

GFS_WED27

So again, no big changes for at least the next 10 days.

What does this mean for the ski/snow season?

After a cold end to September and the coldest October in decades, some of us were getting excited.  Hard to believe there was two feet of snow on the ground at Timberline a couple weeks ago.  It’s all gone after many days in the 40s and even some 50s.  The view this morning before it rained…

Timelapse Timberline Lodge

So we’re starting from zero again.  No early start to the ski season this year.  Little or no snow on the ground through Sunday the 17th

Mark Ski Areas Not Open

We should see a little snow around Tuesday the 19th with the previously mentioned upper-level trough.  Then it’s mainly dry or mild/warm through the following weekend.  We use this graphic on our 6pm show during the cool season on FOX12.  Sometimes on other shows as well.

7 Day Forecast GOVT CAMP

Mark Ski Areas Not Open2

Cascade Ski/Snow Summary

  • No sign of a cold/snowy weather pattern
  • No skiing this weekend
  • Ski area openings unlikely the weekend of 23rd/24th, that’s the weekend before Thanksgiving
  • We can’t see beyond that point; models diverge on whether to maintain the mild/dryish pattern or go wetter/cooler
  • No reason to panic, this is normal!  But if it looks like this a month from now it’s a different story.

Enjoy the dry weather Wednesday & Thursday!

Chief Meteorologist Mark Nelsen

  • Posted

7pm Sunday…

Today was spectacular wasn’t it?  Other than some spots of morning fog, wall-to-wall sunshine for the entire region.  I just caught the sun setting from our Shilo Inns Seaside camera out at the coast

Cam Seaside

Portland made it above 70 degrees today, the first time we’ve reached “normal” in 11 days!  It was quite a cool end to September and early October too.  I suppose that’s perfectly reasonable after months (years) of above average temps.  The warm temps were courtesy of a warmer atmosphere overhead plus a good amount of morning easterly wind.  Vista House gusted to 42 this morning; a small preview of the upcoming 5 months.

Tomorrow will be dry west of the Cascades from Longview to Eugene, at least up until around 5pm.  At some point after that (depending on location) the chance for showers picks up and your home may even get an hour or two of steady rain between 5-11pm Monday evening.  The rain will be along a strong cold front.  Freezing levels start at 11,000′ tomorrow at 5pm and within 12 hours plummet to 4,000′!  It’s another sharp upper-level trough dropping out of Alaska, headed for Washington and Idaho.  This one appears to be slightly colder than the one a week ago, for our area.  Not as cold for the northern Rockies.  But we’re also 8-10 days deeper into the autumn season; the same airmass overhead should be a bit cooler in the lowlands.   So even with partial clearing Tuesday afternoon plus a mainly sunny Wednesday, it’ll be tough to get out of the 50s.

I don’t see much rain out of this cold front tomorrow evening through Tuesday afternoon.  In fact much of the lowlands will see less than a tenth of an inch.  The flow will be strongly “orographic”, meaning the strong west/northwest wind overhead will squeeze a lot of precipitation out of the clouds in the Cascades and Coast Range.  About 10 times as much!

RPM Precipitation Accumulation

Much of this precip moves over the Cascades before snow levels drop much.  There should be enough precipitation left after a changeover to snow that Timberline sees 3-7″ snow and 1-2″ at Government Camp.  That’s from 5am Tuesday through evening.  Here’s the WRF-GFS snow forecasting ending Wednesday AM:

or_snowacc.72.0000

Weak upper-level ridging returns Wednesday through at least Friday, possibly through next Sunday.  Models disagree on whether a quick-moving disturbance late Saturday and Sunday gives us showers.  We’ll see if they get their act together the next few days.  This means that for about a week beyond this Tuesday we won’t get much rain.  Total rain for the next 10 days from both GFS & ECMWF show 1/2″ or less in the lowlands west of the Cascades.

Other than the shot of cold air Tuesday with a bit of mountain snow, nothing all that interesting occurs between now and mid-month.  I don’t see a “stormy Eastern Pacific” pattern setting up through at least the middle of NEXT week.  It’s typically too early for that, but every few years we do get October storms.   There doesn’t appear to be a good pattern for the “October thunderstorms” either.

Summary

  • We’re going to be dry far more often than wet the next 10 days, you will have many opportunities to participate in outdoor activities/recreation.
  • There’s no sign of significant snow in the Cascades the next 10 days (that’s normal for October)
  • Expect lots of sunshine Wednesday-Friday, maybe parts of next weekend too.

By the way, peak color on our leaves tends to occur within the next two weeks, often around the 20th of October.  Of course each tree species is different, but that seems to be the case just about every year.

Chief Meteorologist Mark Nelsen