Pacific Northwest Weather

[AnthonyC]

There's SUN on the horizon...

Another day of rain...esp. in the last hour with a PSCZ. Nothing too strong or organized, thus thunderstorms are eliminated from the forecast. One last front...albeit rather strong for this time of year...to plow through the PNW tomorrow and Wednesday. Alot of the dynamics...main jet streak and surface trough...are headed into northern Oregon but Western Washington will see a solid shot of rain...breezy winds...and cooler temperatures.

And then the pattern FINALLY breaks...this weekend looks awesome as 850 mb heights approach +12C and 500 mb heights approach 580. Temperatures in the middle 70s will be common across Western Washington...and SOMEONE will finally crack that 80-degree mark.

Anthony

[weather girl]

I'm looking for analog years to this one. I don't think this is the same pattern we saw last year at this time. Summer will set up differently, but I agree that the ridge of high pressure will get going here pretty soon. (Maybe this coming weekend???) I'm going to predict 82 here in Salem on Sunday or Monday.

Anyway, I've been looking at 1965 and 1983. Both look good to me right now. I'm holding out on 1968....it's just not cold enough, but it has been in the semi-sorta iffy zone. Will have to wait until the summer plays out. Good news: I think Bastardi thinks we'll go El Nino neutral. Sounds good to me. Australia's El Nino outlook comes out on Wednesday. Woo-hoo!!!

[andycottle]

Anthony... looks like and you are seeing the same for next week as WARM temps could be a real possiblity. No real exciting weather here today. Just showers and sunbreaks at times.

-- Andy

[snow_wizzard]

Weather Girl...I think you have something with 1983. I have been seeing a lot of parallels to that year all of the sudden! As you may know, December was TREMENDOUSLY cold later that year. One really big parallel to 1983 is in the 500mb temperature anomaly in the tropics. There are only a few years that have had the huge positive anomaly that we have had this year, and 1983 was one of them. Oddly enough 1998 was one of the other years and it also had a serious Arctic blast in December. As for 1968...we are having very similar temperatures in Seattle to what that year had.

A word of caution for the possible warm spell for Sunday and Monday. The ECMWF is not showing a ridge anything near what the GFS is showing so don't get your hopes real high. Even the GFS shows a very strong onshore flow developing after about two warm days so this is not going to be days on end of sunny and warm weather.

[AnthonyC]

After viewing latest satellite pics, the next system looks very impressive for this time of year...a nice surface low is developing, the classic comma-shape is forming and a nice jet streak is energizing the system. But after this system, we should be done for awhile...hopefully a long while...

Snow_Wizzard,

I do trust the GFS with this pattern change. Although the model can sometimes be drastic, it usually does well when the pattern is shifting from cooler/wetter to warmer/drier...esp. with the blocking ridges we've experienced this winter. I will go out on a limb and say some places will surpass the 80-degree mark by Monday.

Anthony

[andycottle]

Taking a look at the latest GFS this evening... tomorrow is appearing to be quite a very wet day as an active but vigerours trough and cold front comes through our area during the 12z - 18z period. 48hr precip totals are near 1.25" for the coastal inland areas, while further inland and into the Puget Sound region, may end up easily seeing close to an inch of rain. Rest of the day tomorrow continues the very showery theme. In fact, could even a PSCZ develope after the frontal passage as 500MB winds be strong and about 40kts from the SW.

For rest of this week....our showery continues through this coming Saturday as short waves will be affecting our region. Sunday the 22nd - Sunday the 29th... a large ridge of high pressure still looking to take shape to give us some really nice sunny weather. High temps should pretty WARM as 850 Temps appear to be in the +12C to +15C and 500MB heights running anywhere from 570 to near 580DM.

So incase you`ve put thoes shades away, they`ll be in use really soon!

-- Andy

[andycottle]

Question here: Do any of you know any weather sites that show the Precipital Water values? You know....to get a sence or idea of just how much rain a weather might put down.

-- Andy

[snow_wizzard]

Andy...I do not know of any really good sites for precipitable water value. If you find one it would be great if you could post it.

It certainly does look like much of Western Washington could see anywhere from 1 - 2 inches of rain from all of the fronts, short waves, convergence zones, showers, and all of that this week. Little doubt this will be our second very wet month in a row.

I still think the GFS may be overdoing the ridging next week, but it is a safe bet we will see some sunny and warm weather, especially on Sunday. The offshore flow will last for less than two days, so it will be back to low clouds by Monday or certainly Tuesday. We must remember how even the warm periods this spring have been cloudy, it may be hard to break out of that rut. I would love to see a long stretch of clear weather, but I just don't see it yet. We can only hope that the thing does not completely fall through. The ECMWF showed 850mb temps would only get modestly warm on Saturday and Sunday and then fall back to 4 or so.

I have almost come up with my final list of analog years. It has been extremely difficult to choose the years, because this year has had such a bizarre sequence of events. Once I have all of the years, I can run the numbers and come up with an outlook for this summer, fall, and next winter. The two things that appear to be clear are we will not have a really hot summer, and December is very likely to have a major Arctic outbreak. I have been blown away by how many signs are pointing to the December cold spell! More details later.

[andycottle]

Hi folks. Just now took a look at the new run of the GFS...and not much has changed and looks very similar to what I said in my evening weather outlook.

So as mentioned....very wet and rainy tomorrow, then continued showery through rest of the work week and into saturday. And about sunday through next week....big ridge of high pressure builds in, along with high 850MB temps and 500MB heights 570+DM. All in all...much nicer and a lot more sunnier weather should be in store toward the begining of next week.

-- Andy

[andycottle]

Well if I knew of a really good site that showes precipitable water values...I would certainly post it.

And snow wizzard, great job on keep up with ALL of your analogs and seeing how they may tell the weather for rest of this year. Job well done! For me, I think it would take a math wiz to do all the stuff you do to keep track of thoes analogs. -- Andy

[snow_wizzard]

Wow! It must be a boring day across the nation today. There has not been a new post in the US weather section for 12 hours.

We are finally going to have a below normal daily average temp today. The low at Sea - Tac was 1 degree below normal, and the high should be a bit below normal too. The low at my place was 42 this morning and it felt awesome!

The NWS is beginning to hint that this could be a really big rain. The jetcore is stronger than the models had indicated it would be and there is some hint the front could stall as it becomes more N to S oriented. At any rate a very wet week looks like a good bet.

[andycottle]

Viewing latest GFS this afternoon....ridge of high pressure still looks on track for the up coming weekend, to which we should see improving weather. About mid-week of next work week looks like that may the warmest time as 850MB temps approach near +12C and 500MB heights near or at 570DM. Temps probably warming into mid-upper 70`s. Toward end of next week, temps should cool back down some as a few showers and onshore flow try to make there way back into our region. This ridge of high pressure dose it`s best to hang on to dry weather....but weakens as a weak trough enters the PNW with main energy heading into Oregon around frist of next month, but with still enough 'bang' for us to have scattered showers.

-- Andy

[weather girl]

Thanks for all the research, snow_wizard. It's really good stuff, and I enjoy reading it. I'm liking 83 a lot, too.

I'm going to revise my earlier guess and say we hit 80 before the end of next week....maybe Friday? I don't think we're talking heat low quite yet. But I do think the southwest is warming up nicely. If we get a shift in those winds..... I'm kinda going back and forth with how quickly and how strong the seasonal ridge will be. Last spring, I thought it would be soft, but it really built in nicely.

It was 54 on my way home yesterday. It's 57 right now and winds at 13 mph. A little cooler tomorrow, I expect. This is kind of a strong storm for this late, isn't it.

[AnthonyC]

The system off the coast looks mighty impressive for the middle of May. A deep surface low is curving north into the Gulf of Alaska as another surface low develops off the Oregon coast...thus small craft advisories have been issued for the Puget Sound and Camano Island region...gale warnings continue for the coast.

After the initial front passes by, a broad surface trough should linger off the coast thru Thursday...and then finally a surface ridge begins to form. I still say some places will crack the 80-degree mark by Sunday.

Anthony

[andycottle]

Latest GFS this evening still on the idea with a ridge of high pressure building in this weekend and lasting through most of next work week. Next threat of showers comes around the 26th/27th time frame as a weak 540DM trough at 500MB comes down the BC coast line that will give us some showers by time it reaches Western Wa.

-- Andy

[TT-SEA]

I was in Salt Lake City the last two days.

Incredible thunderstorm last night that had heavy wet snow mixed in towards the end. There was 60 mph winds as well.

They definitely get some wild weather there. I was there last May and the same thing happened.

Came home to a sunny and very pleasant Seattle this evening. I thought it would be cold and wet.

[TT-SEA]

I finally had time to look at the models and I am still NOT seeing a big ridge for this coming weekend.

I am sure what all the talk is about!!

Here is the latest GFS for Sunday afternoon. That is NOT a ridge over us...



Tomorrow could get pretty wild. Thunderstorms a pretty good bet.

[AnthonyC]

The operational and ensemble runs of the GFS models have been in great disagreement the past few days...but I am surprised that the last few runs have almost eliminated the "big ridge" for this weekend. Hopefully they are gliches.

Tonight looks very wet and breezy as a weak surface low tracks into northern Washington...definitely not a high wind event, but unusual for the middle of May.

Anthony

[snow_wizzard]

Just as I thought! The previous runs of the GFS greatly overdid the ridge for Sunday and early next. The big question now is, what ridge! The new ECMWF shows nothing but below normal temps for the next week. I must admit, I thought there would be some ridge. This fits my wish list nicely, but I do say a couple of sunny days would have been nice.

What is my wish list you might ask? As wet as possible through June. After that a nice July would be quite welcome!

[TT-SEA]

Is that your wish because its good for our water supply and makes our landscape look very lush and healthy??

Or is that your wish because it might mean a 10-day cold period in 8 months?

No ridge this weekend.

Looks kinda cool and wet into June.