Update at 10 PM. Looks like some mixed rain /snow and wet snow in the South Sound away from the water, increasing with elevation. Some accumulation above 500 ft.
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A very interesting forecast dilemma is before local meteorologists tonight.
On one hand, the U.S. high-resolution model (HRRR) is predicting as much as 8 inches over the South Sound and 5 inches at SeaTac Airport by 11 AM Friday morning. The U.S. GFS model is doing the same. Most of the snow will fall overnight.
In contrast, the European Center model, which is generally the most accurate (remember the missing bomb cyclone in December?), is NOT going for lowland snow. Zippo.
Keep in mind, this is snowfall, not snow depth. This is going to be very wet, melting snow in any case, and snow depths will be MUCH, MUCH less.
An interesting aspect of this event is the large north-south temperature change forecast over the region. Below is the forecast temperatures around 5000 ft (850 hPa pressure) at 5 AM tomorrow morning. Huge contrast over southern Washington (blue cold, green warmer). A small error in position would be significant.
Currently, the freezing level is around 1600 ft at SeaTac (see below), much too high for snow reaching sea level. The snow level (where all the snow has melted) is about 1000 ft below the freezing level. But it should decline slowly.
What about uncertainty in the forecasts? It is HUGE. The UW high-resolution model, forced by many global models, shows a wide range of possibilities. Many forecasts are for zero, others as much as 4 inches of snowfall (NOT SNOW DEPTH).I suspect the European Center projections will be closer to the truth. Near sea level, some of you may see some flakes tomorrow morning in the central and south Sound near sea level (500 ft and below elevation). But nothing significant. Snowfall will increase rapidly above 500 ft.
In contrast, the central and south Cascades will be hit hard (see accumulated snow through Sunday morning). Feet of fresh snow. The mountains of SE Washington will also get plentiful powder.
Perhaps one could dig out the Old Farmer's Almanac and get a forecast.
ReplyDeleteIt's been snowing heavily in West Seattle, near Alaska Junction (400ft). Still ongoing! Had to go outside for a night walk.
ReplyDeleteIt’s snowing in Capitol Hill Seattle! About a quarter inch.
ReplyDeleteIt’s snowing in Issaquah Highlands 500ft above. Accumulation is 1 inch. Temp +1C
ReplyDeleteWoke up to snow on east Capitol Hill this morning at 5:30 AM a few blocks west of the arboretum. Not much, maybe ½ inch, falling and sticking. The air was quite cold, but the thermostat (pulled from the internet) said it was 35˚F in the general area. This area is about 262 ft. in elevation.
ReplyDeletehttps://www.flickr.com/photos/bwellsea/55145388778/
Woke up to an inch of accumulated snow in somerset, elevation 800’. The kids are extremely excited.
ReplyDeleteStill snowing here Redmond area. Def didn't expect that though I know with our microclimates it is unpredictable.
ReplyDelete3 inches so far on Cougar Mountain (Issaquah) at 7:30. VERY wet & heavy snow weighing down tree limbs.
ReplyDeleteWe've gotten about 3" so far, and it's still snowing (560-ft MSL). That was after a 12-hr power outage due to yesterday's high winds. We have a generator, so we didn't freeze.
ReplyDeleteAbout 2” on grass and trees so far here in the forest halfway between Gig Harbor and Port Orchard. Temps currently around 33° with light snow falling.
ReplyDeleteEnough snow here in Olalla to sled on “according to our “resident expert”.
ReplyDeleteStill snowing near downtown Redmond!
ReplyDeleteSnow in Ballardia! Only sticking on the lawn and deck, and melting on contact with the road.
ReplyDeleteAs of the morning of March 13, mean statewide snowpack (SWE) for the 31 Washington subbasins currently shown on the NRCS Interactive Map is 55% of the 1991-2020 median for the date.
ReplyDeleteSnowing on Bainbridge, not really sticking but well below 500 feet
ReplyDeleteThis is exactly the kind of forecast where an experienced forecaster, with acquired knowledge of the region and its microclimates, earns their keep. A difference of 100’ in the accumulating snow level here will affect travel and utility outages for hundreds of thousands of people, and clearly that’s a call that the forecast models aren’t yet capable of making.
ReplyDeleteAnd if that human forecaster gets it wrong, we also get a human throat to choke*, so there’s a nice bonus.
(* note for the irony-impaired: simmer down. It’s just a saying, no meteorologists were harmed in the making of this comment.)
Also: check out those wacky isotherms! Temps are nearly identical right now on both sides of the Cascades, how often do you see that this time of the year?
ReplyDeleteAs of around 9:15 am, there’s 2” or so on the lawn and cars near me here in Shelton at 265’ elevation. We are under 1/2 mi from Oakland Bay. Less accumulation on the roads.
ReplyDeleteSnowing in Silverdale at 500 ft MSL. Barely sticking on the lawn and deck.
ReplyDelete3" on the ground here on Vashon, big flakes still falling at 9:30am. Some trees and limbs are starting to fall, power is out on the southern half of the island.
ReplyDeleteLooks like the HRR got it right, 1.5" on the ground North End Tacoma and still falling. Temp hovering right at freezing with the heavy precip. Started snowing around 6:00AM here.
ReplyDeleteThe much ballyhooed European model doesn't agree with the mass of white that is visible all around my neighborhood. Nobody bats 1000.
ReplyDeleteSnowing like crazy in Tacoma all morning. I'm not sad about it.
ReplyDeleteNORTH BEND at 11:15 am on Friday the 13th. At my “microclimate” we have a total of 5” and a steady light snowfall continuing. This after a 16 hour power outage overnight and some pretty good gusts on Wednesday-Thursday.
ReplyDeleteA good week
for a weather geek.
❄️We appreciate you, Professor Cliff.👏🏼 ❄️❄️❄️❄️❄️❄️❄️❄️❄️❄️❄️❄️❄️
❄️❄️❄️❄️☃️❄️❄️❄️❄️
ReplyDeleteFederal Way An inch (eteballing it while clearing steps) on the ground, heavy, wet, icy slush on concrete. Still snowing.
ReplyDeleteDown in Boston Harbor, about seven miles north of Olympia, still snowing with a couple inches of snow on grass AND roads. Would add a picture but don’t know how.
ReplyDeleteStill snowing lightly at noon on the Key Peninsula. two to three inches accumulation.
ReplyDeleteIt rained a bit for the last hour, but back to snowing at sea level in Brown’s Point Tacoma at 1:30pm. Pavement is slushy but an inch plus still on the trees and shrubs.
ReplyDeleteStill snowing at Brown’s Point Tacoma at 1:30. Rained a bit early but now back to snow.1-1.5 inches still on the ground despite the rain.
ReplyDeleteHI Cliff, here in Thurston county 6 miles out on the Steamboat peninsula between Eld and Totton inlet, as of 2;45 pm we have 4 plus inches of the white stuff and still dumping the 25 -50Cent size flakes like it has done since 8 AM, its like an amazing Mico climate here.
ReplyDeleteLiving in the Central area of Tacoma, streets were bare and wet, but some snow mixed in the rain at 6AM this morning, so headed east to Sprague to SR 16 to interchange onto I-5 NB and it stayed that way until about SR 18/340th before it began to change to virtually all snow.
ReplyDeleteHighway remained bare and wet, and it wasn't until I pulled off onto 516/Kent Des Moines Rd and some slush on the exit ramp and Kent Des Moines, but once past Military Rd S and began to descend into the Kent valley, the slush quickly disappeared and it was again, bare and wet.
It snowed all day in Kent, and now am home, and at 4:56PM, it's big wet flakes and just checked the Weather Channel and they say, 33 and rain, it's almost all snow at this point.
Slush in places, and along the sides of streets, maybe 2" there, but it's purdy while it lasts.
Wasn't expecting this! East Renton Highlands at about 600': started about midnight and hasn't stopped. We've got about 4" and it's on the pavement and everehere! Power failed overnight. Couldn't make it to work: Cough, Cough, Cough!
ReplyDeleteMeanwhile on mynorthwest.com
ReplyDeleteDROUGHT, this storm does nothing for our DROUGHT. Even talking about how in 2015 hydropower in columbia basin was less due to lack of water, implying this year might be same. Last I knew, Revelstoke had some great if not epic snow, according to a youtuber that snowmobiles up there.
Ugh. Cliff please set them straight.
https://mynorthwest.com/pacific-northwest-weather/northwest-drought/4216093
This has been catastrophic for PSE customers. And the snow has been constant for 14 hours here. This kind of failure is not acceptable. What went wrong ??.
ReplyDeleteJust landed at SeaTac, 7:15 pm Sat. Holding for gate while they clean about 4 inches of snow.
ReplyDeleteAlaska Air had 3 hour gate delays at SeaTac:
DeleteI truly apologize to hear this. Snow was not expected in the Seattle area and our deicing crew at the Seatac airport is working hard to make it safe for our flights to depart. I truly apologize for the delay. https://x.com/AlaskaAir/status/2032517450093240497
Our Aer Lingus flight EI053 landed from Dublin after 9.5 hours and experienced 1.5 hour delay to find a gate; apparently all gate push backs needed deicing. Do airports employ weather forecasters...
I'm in Olalla at 400 feet elevation. It snowed all day, but the temperature remained above freezing, reaching 39 as a high. It finally quit snowing about dark. Maybe it will freeze tonight....
ReplyDeleteNice convergence zone moving over Mukilteo/Edmonds right now. Sticking to the roads we have about an inch.
ReplyDeleteBetween the hilly topography, marginal temperatures, relatively warm water, and odd convergence zones, sometimes the best thing local meteorologists can do is say "watch out for snow" and let things play out from there. It's tough when 300 feet of elevation and a couple of miles is the difference between nothing and a few inches of snow.
ReplyDeleteFor the record: Moderate to heavy snow nearly all day at 4th/Lucile in Georgetown. In spite of that, we never saw more than some slush on the streets that melted any time the snow let up.Some light accumulation on trees and shrubs, and 2”-4” on some nearby cars that stayed parked and cold all day. An interesting baseline for measuring that snowfall vs snow accumulation delta that made such a big difference today.
ReplyDelete