Ice Storm Coming II

Satellite really shows us "in the squeeze" tonight as a fresh batch of cold/dry air is surging west across the Rockies into Eastern WA and moisture approaches from the SW.  We are in the middle, which is a classic ice or snow storm setup!  00z models have really come into agreement for no precip from system #1 Saturday night, but all have precip in here after sunset Sunday.  Not a lot, but that all day ice storm last January?  It only produced .17" of "rain" at PDX!  Doesn’t take much to make a mess when it’s freezing rain. 

We will probably not get above freezing Monday.  It’s a common error to bring the temp in Portland above freezing in the first 24 hours of an ice storm.  Very unlikely with air this dry.  As moisture falls into it heat in the atmosphere is used for evaporating the moisture.  For example, if it’s 32 with a dewpoint of 16 when the precip  starts Sunday evening, the temperature will probably drop to 27 and the dewpoint comes up close to 27 as the air saturates.  Then it takes a long time to raise the temperature 5 degrees as cold air continues to pour out of the Gorge.  It happens every time.

As mentioned last night, short term issue is cold and especially wind.  Speaking of "the squeeze".  PDX-DLS gradient is over 10 millibars this evening, and I would expect a 13-14 mb gradient Saturday night and again Sunday night.   This pattern in the past has produced 80+ mph winds at the west end of the Gorge, while it’s almost calm across 2/3 of the metro area. 

And just for you Longview folks:  Probably freezing rain or maybe briefly snow Sunday evening, then a change to rain by Monday midday.  High Monday near 34.

18 Responses to Ice Storm Coming II

  1. muxpux says:

    started snowing here in longview a bit before sundown. still snowing and just now starting to stick ont he roads. i believe this is because of our trmendous temp swing. i live near the lake in the heart of the city and my “somewhat” innacurate weather channel thermometer that has a sensor on our porch about 6′ high on a post said it was 19 this morning, and before noon it was about 44. so im assuming our ground was too warm to stick right away, however, the temp plunged when the clouds rolled in, and we were around 35 when the first flakes started falling. and true to form, no reports of snopw from the “official” stations here. go figure.
    the way this system is moving, im not sure how much longer we will be seeing snow, as the band of moisture has been thinning as it was moving north, but as long as we get something frozen tomorrow, and we dont get some freak warmup like normal, ill be happy.
    on a sidenote, my grandpa who lives in Albany had a stroke this morning, and my poor mom had to make the treaterous commute from longview, just as the precip was hitting vancouver. i heard from her a bit ago, and she said it was hell going through portland, but made it out of the worst, and was smooth 60+mph sailing around salem, and the roads were wet. the car thermo said 33. also, my grandpa said it was dry at his house in Albany.

  2. Marc says:

    between what elevations will the moisture fall as rain? and when will it start falling as freezing rain?
    in hockinson last monday, we recieved a quick 1/2 inch of snow, when an inversion was supposed to be in place. however, it was freezing from the valley floor to the highest elevations. how has this changed in these past couple days that will make it fall as freezing rain, instead of snow?

  3. Traci says:

    Started raining here in Lebanon about 8:30pm and my porch is all slick. Shows 27 degress outside. Brrr.

  4. Ryan says:

    I have noticed the other weather stations are a bit timid after making big time calls for snow last time. KATU has backed off their 3-days of winter weather to a ‘maybe’ for Monday. KGW so far doesn’t seemed all that convinced that anything is going to happen. I haven’t seen the latest from KOIN. Obviously here on the KPTV site the forcast hasn’t changed.
    If anything happens I only hope it is a one day event. I know Mark called for increase in wind and cold air and he nailed that forcast on the head. It’s back down to 32 here in Vancouver an only 5:30 we were still in the mid thirties yesterday. The winds have been whipping all day here in Vancouver also. Looks like Mard is dead on with the pre-storm forcast. I guess my only question is if this thing does fall apart as it tries to come in does that mean we could see even more dry & cold weather? I know the satellite shows two systems out in the pacific.

  5. Gary says:

    The wind is pounding us up here on MT Park

  6. Gary says:

    The wind is pounding us up here on MT Park

  7. Tami Mills says:

    I havent seen a temp for Mcminnville on the news in a few days. It say’s mcminnville but has no temp. I live in Amity and Mac is closest so I go by macs forcast. I have too much shopping I have to finish so please let me know if I am going to be able to leave my home….Thanks.

  8. Sean says:

    Well up here at my location 1400ft, about 3 miles east of Brightwood. It’s currently 26deg and a strong east wind blowing for the better part of 3 days now. Which hasn’t allowed the temperature to be above freezing here for 3 days now. Even still have snow on the ground from 2 weeks ago even.
    Looking at the camera up at Gov’t Camp, it showing 20 deg at 2pm. Then looking a bit further up at 6000′ 21deg then 7000′ was 24 so all those temps are below freezing. Of course this is at the Cascades, but I think it shows that the overall air is pretty cold. Plus without a strong southerly wind to scour out the cold air I could see it lasting more than just Monday here on the east side of town.
    Should be some good times and exciting weather (to watch from home)!

  9. Rob J. says:

    Mark you’re awesome, you predicted this ice storm days ago! Unlike the other news station who had no idea. I mean it hasn’t happened yet, but chances are very likely it will now. you also predicted the major heatwave we had last summmer, or maybe it was 04, like 7 days in advance while everyone else just had highs in the 80’s, you said it would be 100, and 102, and it turned out that way!!! I always look at your forecast first because you are by far the most accurate forecaster in the Portland media!! Keep up the good work.

  10. Derek says:

    Is it possible to get some so to speak “wet snow” before it turns to freezing rain. During the big storm two years ago when it was going from snow to sleet there was a short maybe 20 minute period when there was wet snow coming down but it was only 15 degrees. Is that a possibility for a short period during this storm?

  11. Andrew says:

    What do you think this storm will do for Portlands west hills? Will the higher elevation make any difference with this storm. Could we get more snow then freezing rain? Also, some forcasts call for the cold wintery mix to stick with us until Wednesday or possibly later, do you think this is possible?

  12. Jordan says:

    Mark, Finally an official just Longview forecast. Lol. But does that mean we have a better chance of seeing snow than freezing rain? Also does our topography here have to do with the tremendous rainfall rates we get with a southerly type flow.

  13. The wind guage on the top of the Corbett GS gym is online again. ( I’m waiting to see if it registers in the 80’s this weekend. Any burp in the power supply will stall the downloading until some one can set it straight. If it starts to ice, it might be difficult for anyone to do this.

  14. grslocum says:

    I just gotta say, this is going to be interesting, and maybe into the middle of the week!!! especially those in east county!!! I work for a grocery store, and the sales related to wintery type weather increase dramatically!!! This is the situation to panic(a lil bit). It’s christmas week, (lots of extra shopping), an ice storm-with high winds could knock out power for a few days. Add to that, the possibillity restocking the stores may be nearly impossible to do after the icing event begins as most of our local warehouses are located near troutdale where the weather is worse.
    So, long story short… You may have some supplies stocked up from the last snow (scare)… But, be weary!!! If you need candles, firewood-or-logs, flashlights and batteries, comfort food to get through a cold spell, PLEASE get out there TODAY!!! It may be 4-5 days till we (grocery stores) can catch up to demand on supplies…
    Otherwise, get the Christmas shopping done, and plan to enjoy some indoor wrapping, x-mas tree decorating, or x-mas card writing, family game playing stuff this week. (activities that don’t rely on electricity just in case)

  15. Tyler says:

    Great pics…I haven’t seen this much ice on the falls since 1996. If people remember pictures from Dallas last week, they had less than a tenth of an inch of freezing rain, and it caused streets to be a mess. Only thing about light freezing rain is that the trees likely won’t get too heavy so as to fall.
    I was going to head up in the gorge tomorrow, but alas, my anemometer is broke anyway. I’ve got to 83 mph at Crown Point, I’m sure it will be somwehere close to that or higher Saturday and Sunday.
    On a side note, I was wondering if I was the only one who had issues getting the blog to work. It wasn’t updating at all. Anyone else have problems?

  16. Kevin Beckman says:

    Yeh Mark, You seem to be getting this stuff down. I wonder if the cold boundary might slip a little further south so we could see some snow, along with Longview, as the front moves in.

  17. Kirk says:

    Hello Mark, Some friends and i were talking we think katu says snow as often as possible just for ratings. Looked at there ten day trend tonight and it looks like a three day snow storm. I am surprised how there is little consistency between forecasters. I value your forecast you seem to have a lot of local knowledge and that is important with the Gorge in our back yard. Last year the NWS forecast 12 inches of snow at our house and all we got was freezing rain what a disappointment. O K that’s plenty of two finger typing for now.

  18. Tony says:

    Something interesting. If Sunday night and monday are anything like it was today, it seems as though the ice may not come first, as conditions will favor snow. The depth of the non-freezzing air between the inversion and the actual freezing level was very very thin today. If the gap was that thin on monday, we could see the day start as snow and end as freezing rain, this kind of system can go either way, perhaps even lasting until wed. (there is a small chance, but don’t put your money on it). The winds here on the eastside have really picked up tonight as the front is approaching the coast, makes me scared to think what will happen with the front hits the coast and forces all that compressed air through the gorge…… not fun.
    I know Rod Hill over at KATU said one of the “wildcards” was if the moisture would even reach us. After looking at forecast models, it seems as though as long as the first set hits us (no matter how small) the air saturation will cause enough cooling for the next small wave (monday). The models are actually converging on this, but for some reason I am feeling that there is something off with this storm. Seems as though nobody really knows what to expect, or how much….
    Guide us Mark! This is the time of need for your fallowers, and we’re scared!

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