The Weather Cafe ® by Rufus

Written by Rufus La Lone since 1994.

Back to the Future

Posted by Rufus La Lone on

Monday December 19
Patrons that have brought their Mug to the counter here for several years know that often model projections swing back-n-forth, meaning that what was projected earlier oft ends up being the actual weather event at the present.  Such is the case with the outlook for the end of this week.   Snow, sleet, freezing rain is again likely on Thu & Fri Dec 22, 23.  Here ya go —
The modified Arctic Front has arrived across the far NW WA / BC area (temperature in Bellingham this morning dropped to 16, with snow yesterday and last night across much of the Puget Sound.  The White is back.  Patrons in NW WA can expect additional snow over the next couple of days (inches!), as a Low moves onshore to the south.  It will remain cold.  
For Patrons in OR, the front has been delayed (a common aspect of these patterns) until early this week.  By Wednesday, eastern basins in OR, as well as valley temps will be quite cold (negative F in eastern WA, close to that for the usual cold locations in OR).  As such, the east wind out of the Columbia Gorge will ROAR - as strong as 80-100 mph at Crown Point - Thu through Fri Dec 22,23.  The cold air settles in on Wed.  Dry & cold for western OR.  The ‘depth’ of Arctic Air east of the Cascades should be enough to push subfreezing temps across the Willamette Valley / north OR coast by Thu the 22nd.  
 
This forecast, if verified, is the Back to the Future one, as earlier expectations called for a very MESSY WINTER EVENT to end this week, right at the time so many folks are traveling for the holiday weekend.  Why?  With the cold air settling in at the surface, west of the Cascades, any moisture riding up over that cold air will set off frozen precip issues.  The forecast for Thu into Fri is complicated, so please heed Nat’l Wx Service watches & warnings that are likely to be posted soon.
We will forecast the possibility for all three forms of frozen precipitation - snow, sleet, freezing rain - depending on your location as a warm front moves onshore by sometime Thu.  The farther south one is in the PNW, the less likely to have any or all three types of frozen precip (unless in the mountains).  Therefore, for:
  1. Eugene area north to Albany, the surface air flow could turn from the south early enough to usher in rain, or light freezing rain first, then all rain.  Depending on how cold it gets, rain/snow mix is an outside chance, but models push a ‘finger of warm’ air into the mid-level atmosphere, which melts snow flakes and causes freezing rain, if surface temps are below 33.  You know the drill.  Plan on freezing rain Thu night.
  2. Areas north of Salem, the chance two of the three, or at least freezing rain, from the event coming is more likely.  Gorge winds could keep SNOW as the type of frozen precip arriving first, before progressing to sleet or freezing rain, THEN rain if the moisture source continues.  The quicker the front approaches, the less issue with snow.  East Portland into the Gorge will be quite wintery.  Travel after dark on Thu and into Fri will be dangerous.
  3. SW WA up into the southern Puget Sound region, it will be possible to get all three forms of frozen water before any rain.  Right now, it may remain at or below freezing as the storm passes.  In other words, it may not rain until Sat.  Travel will be impacted.
  4. Seattle north to BC,  Patrons could experience another significant shot of snow before sleet and then freezing rain on top of those layers of frozen water.  Travel will be dangerous; expect delays in air travel.
    Christmas Eve / Day.  The winter event should be over (except for east of the Cascades & the mountains).  RAIN will rapidly move in on Saturday for everyone.  RAIN will be in play on Christmas Day, as well.  Forget the dry holiday we expected a week ago.  It will be quite WET.  But wait, there’s more.
    Week after Christmas heading into the New Year is modeled to bring on another high wx impact event.  HEAVY RAINFALL.  Models for the past week have been charting a series of WET Pacific storms moving onshore right after another through the entire week.  The ‘jet stream’ by Wed Dec 28 will be extremely strong and aimed right at western OR.  Multiple inches of rain are possible for BC, western WA, western OR and northern CA as the last days of 2022 click by.  
    Let’s get through the Christmas period first, then we’ll deal with the water issues.  Just be ready if you live in flood prone locations as a big slam-bam goodbye twenty-twenty-two looks probable.  Yikes.
    “At Christmas consider not so much the gift of a friend but the friendship of the giver."
    -Rufus
    Copyright © 1994-2022 - All Rights Reserved - The Weather Café ®
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    A Lesser Extent

    Posted by Rufus La Lone on

    Friday December 16
    As Elvis once sang, “I’m all shook up!”, so too are those of us trying to formulate weather reports out of the ever-changing computer model outputs.  Let’s try again, shall we?
    The position of the anticipated modified-Arctic air mass is being adjusted by the models; meaning, we are less likely to have a huge winter event over the next week.  Still, there will be some surface snow & the potential for sleet and/or freezing rain in places.  As alluded to, the key is the ‘depth’ and position of the Arctic air as it moves south into the US.  The first round is following projections closely, so expect precipitation to fall as snow down to the surface, and esp 500-1,000 ft starting in far NW WA overnight tomorrow, Saturday; light snow is possible (1/2" - 1.5”) around Bellingham north; same for many locations in the Puget Sound by mid-day Sunday.  How far south the snow threat goes will depend on the movement of the cold front.  We do not have super-cold air east of the Cascades, and thus a cold outflow to the west will be minimal in the first round.  The moisture may not extend as far south as Salem.
    On Monday, modified-Arctic air will continue to seep into eastern basins; wind will be strong out of the Fraser Gap - and a weaker wind in the Columbia Gorge - adding to the cold air pooling west side in WA; to a lesser extent in NW OR.  Another Low will track south along the BC coast before moving onshore in north Vancouver Island.  This is much farther north that we expected in earlier reports; which equates to rain at the surface because of southerly breezes, although snow is possible over NW WA as the moisture begins to arrive.  For most of western WA and nearly all of OR can expect plain rain.  The Gorge could have frozen precip issues early on.
    The coldest pool of that 2nd shot Arctic air will track east of the Rockies, missing the PNW, which is why the next PNW system on Thu & Fri will be RAIN and not the heavy snow and icy conditions we were concerned about a few days ago.  The forecast is “all shook up”, indeed.  Anyway, best news is that holiday travel should proceed under normal PNW conditions, easing frustrations during an already hectic week.  
    Christmas Weekend:  another favorable ’turn’ in the forecast — it now looks dry, with a bit of a chilly NE wind.  Ho Ho Ho.
    Post Christmas - well, if we are to believe the current chart pattern, warmer temps, VERY WET weather following Christmas on into the next holiday.  Moderate-to-heavy rain is possible, with cooler temsp and lots of mountain snow for skiers probable by week’s end.  It should be rather blustery, as well.
    Bottom line: we may have missed a major winter mess during a critical travel period.  Keep alert, as all of this is variable. 
    “You cannot do a kindness too soon because you never know how soon it will be too late.” - Ralph Waldo Emerson
    -Rufus
    Copyright © 1994-2022 - All Rights Reserved - The Weather Café ®
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    SPECIAL UPDATE

    Posted by Rufus La Lone on

    
    Wednesday December 14
    — SPECIAL UPDATE —
    Winter pattern on the way that could impact Christmas holiday travel.  Be prepared.  Subject to change, of course.
    The 1st clip of cold air will infiltrate NW WA & BC this weekend.  A weak surface disturbance arriving late Sunday will increase the chance for low elevation snow (500-1,000 ft) or even to the sea level for areas north of Mt Vernon.  This increases on Monday & Tuesday as a stronger push of moisture moves in and heads south.  SNOW SHOWERS at the surface is probable on Tue., extending across all of the Puget Sound region.  Rain or rain/snow mixed possible for NW OR & SW WA Tue, depending on track of the Low; however, models suggest colder air will follow the weak front, so precip could turn to all snow late Tue from north of Salem.  The Columbia Gorge and eastern basins will be wintery.  
    Turning notably COLDER by the middle of next week, as modified Arctic Air arrives.  The Fraser Gap outflow will be substantial, as we discussed in our last forecast.  
    A 2nd, much colder air mass continues to drop south out of the interior of Canada by Thu morning, setting up strong east-to-northeast winds and chance for FROZEN precipitation moving over the top by sometime Thu Dec 22.  Moisture will arrive at the same time that the coldest air settles in east of the Cascades - and heads into OR, as well.  
    SNOW ahead of sleet and then freezing rain - starting from western OR (roughly Salem) moving north - is looking possible on Thu Dec 22.  Snow could be HEAVY over western WA and in the Columbia Gorge, east Portland before turning to SLEET and eventually freezing rain overnight. Yikes.   Puget Sound could be hammered with frozen precip, as the high moisture laden front moves north.  The event could last through mid-day on Friday before the front crosses the Cascades.
    Travel may be interrupted both on land and by air.  Consider options, just in case.
    We will update this outlook in detail on Friday Dec 16.  This event may NOT happen, but we consider the chance for some sort of winter wx that impacts pre-Christmas travel (Salem north into southern BC) to be probable enough to warrant planning alternative travel or the timing of travel.  
     
    No alarm bells just yet.  Please.
    -Rufus
    Copyright © 1994-2022 - All Rights Reserved - The Weather Café ®
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    Arctic Event Possible

    Posted by Rufus La Lone on

    Monday December 12
    Well, the extended outlook has taken quite a turn toward Winter.  We will present the possibilities knowing that all could change.  Before filling your Mug, please accept an opening commentary.
    ’Table ☕️ Talk' — While the coffee is getting ready, a few comments.  Long-time Patrons here (as we’ve started the 29th year of writing these forecasts), know that the crystal-ball weather models used to build our forecasts have lots of variability.  A few years ago, one model - the GFS (U.S. NOAA) - underwent revisions and updated ‘code’ to improve the charting of potential atmospheric changes.  It is the personal opinion of our staff (me, myself & I), that the variance in model outlooks has widened.  Concurrently, the earth’s climate continues to change (as it has always done, human-influenced or not) which may or may not be accounted for in the model projections.  We request Patron tolerance for what can be quite a difference in the weather forecast vs what actually happens.  As difficult as it is to be ‘spot on’ in forecasting weather for your planning purposes, we will not back off presenting ‘what if' scenarios to help Patrons.  Our motto has always been “be prepared, just in case.”  
    Ah, now the coffee is ready.  Mug is full.  Onward.
    This week’s weather will start out on the calm side, with spotty fog possible along with air stagnation.  By Thu Dec 15, high pressure will rapidly build to the E-NE, setting up STRONG outflow WINDS from the Fraser & Columbia Gaps.  This will help ‘clear the air’, if you will, but also make traveling east along the Gorge a real grip-the-steering-wheel experience.  We will notice a drop in temperature overnight in wind sheltered areas.  With the weekend will come the potential for SNOW or a mix of snow/rain.  Yes, it is becoming more-and-more probable, if the models verify.  Our 'Table Talk' comes into play now.
    Dec 18 - 23
    Arctic Cold.  The E-NE winds will subside briefly early on Saturday the 17th right before the leading edge of an Arctic Cold air mass begins to shift south out of eastern Alaska & The Yukon.  Barometric pressure is charting well above 1050 mb (we find it hard to fathom the forecast of 1060s plus mb on the GFS charts).  With a surface Low possible along the BC coast following a similar track, SNOW is probable in the Sunday / Monday Dec 18,19 period.  The system may not carry much moisture, but it doesn’t take a lot to witness The White.  Areas with snow would be Salem north.  The air could cool down rapidly west of the Cascades, if the Low trajectory is just right.  Generally, though, the coldest event of the season is charting to drop into the PNW and the middle of the U.S. starting this weekend.
    The E-NE winds will HOWL Monday through Friday Dec 19-23.  A second shot of colder Arctic Air arrives.  Seriously, wind damage possible for some trees, as very cold HEAVY air settles into the eastern basins of WA, OR and to the east.  The week should be DRY & cold.  Single digits temperatures possible east of the Cascades; upper teens to low 20s west side, out of the wind.  Right now, the models build such a High Dome of pressure, that cold air will really smash west out of the Gaps.
    Another scenario in the Dec 18-23 period is that the first ‘drop’ of cold air from the north skirts east of the Continental Divide, keeping the PNW on the chilly side, with no threat for snow showers on Sunday the 18.  However, that second, colder blast from the Yukon, if it happens, would greatly intensify the pressure difference east & west of the Cascades on Canadian Coastal Mountains with WINDS notably stronger than the first shot.  Stay tuned
    Christmas weekend.
    With either scenario, models bring Pacific storms into the region from the west during the holiday weekend.  That means the transition from cold to mild will be quite messy.  Bad timing.  We could experience a day or two of snow, then freezing rain, then rain. The degree of each type of precipitation we have will depend on how which of the forecast discussed above pans out.  For now, we are suggesting that snow/freezing rain is possible on Christmas Eve (more snow than freezing rain for NW WA, to start with anyway).  Valley RAIN on Christmas Day for west of the Cascades. W-SW winds.  
    After Christmas - windy and wet, with Pacific storms arriving Mon and Wed Dec 26 & 28.
    —> We will keep everyone informed with special statements, if all of the above comes into play
    “Have the courage to let go of the things not worth sticking to."
    -Rufus
    Copyright © 1994-2022 - All Rights Reserved - The Weather Café ®
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    East instead of South

    Posted by Rufus La Lone on

    Friday December 9
    The threat for strong winds has changed, as the track of the storms will remain offshore; however, strong east-to-NE winds over the Puget Sound & out of the Columbia Gorge will be in play, at times, so Mug up & read on.
    A Low center pressure Pacific storm is charting to drop to approx 979 mb as it approaches north Vancouver Island; however, the storm center will NOT move onshore; instead it will track off the coasts of WA & OR, slowly ‘filling in’ (weakening) as it moves onshore into California late Sunday.  Hence, southerly WINDS will be nominal; however, E to NE winds in the Puget Sound will get noticed.  We will get some precipitation out of this storm, today (Fri) lasting through much of Saturday.  The air mass will cool down as the weekend unfolds, so snow levels will drop below the passes.  Quite wet & windy in the far southern portions of OR and into northern CA.  Localized fog could reform on Sunday & Monday as winds diminish; temps will be close to, if not below, freezing is the sky clears.
    The Tuesday storm, which we mentioned last time a possible wind producer, is now likely to track offshore, posing no threat for wind or much precip on Tue & Wed.  In fact, High pressure will build east of the Cascades and set up a STRONG east wind situation as next week progresses.  Fraser wind should increase a bit late Tue night, and be a factor for a few days.   For east Portland & the Columbia Gorge, the wind will increase daily so that by Fri & Sat Dec 16,17 it could be quite strong.  Other than a few showers late Tue into Wed, DRY weather will be the main feature of next week.  The winds will ease up by Sunday the 18th.
    Our next period of rain could begin during the week of Dec 19-23.  Model runs have trended two different ways; 1) a pattern brings another COLD High pressure dome down from interior of Canada setting up a cold & wet, low-elevation-snow threat during that week; or 2) a chilly & damp system drops in from the NW on Tue, followed by a series of  stronger, much wetter storms for mid-to-late week Dec 21,22, drenching the PNW before and during the Christmas weekend.  Plenty of time to refine this outlook next week.
    A White Christmas is not indicated, as of yet, on the long-range charts.  
    “Money may talk, but today’s dollar doesn’t have enough cents to say very much."
    -Rufus
    Copyright © 1994-2022 - All Rights Reserved - The Weather Café ®
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