Pacific Northwest Weather

[AnthonyC]

FYI...Steve Malone gave an excellent lecture down at the UW last night. He talked about Mt. St. Helens past/present/future. I talked to him after the lecture...he's an interesting/intelligent man.

And tonight, there's another weather lecture sponsored by the Atmospheric Science department...it starts at 730pm. I would recommend going.

As for the weather, a blah day. Cloudy and mild.

Anthony

[andycottle]

Showery weekend possibly coming up

Good evening all. Getting a look at the latest models this evening....the GFS, NAM, ECMWF, MM5, and GEM models all seem to be pointing at what could be a coolish weekend. Late saturday especaily into sunday-monday time frame could be very cool and very showery as a trough of low pressure with 500MB temp of about -24C & height of 552DM comes down the canadian coast and finally on top us by monday. 850MB temps will be at 0 with a height of about 1440M.

ETA and MRF MOS has surface temps in the lower 60`s, but with westerly winds at the surface and strong 30 to 40kt northly winds, would expect highs in the lower to mid 50`s. Also...looks like there may be some minor instability with this oncoming system for the weekend. So will leave my outlook as is for tonight, and keep an eye on the models over the coming days.

-- Andy

[snow_wizzard]

There is no denying this low coming in is going to be unseasonably cold. This map for day 3 shows very cool air over us and a ton more off to the NW.

http://itg1.meteor.wisc.edu/wxp_images/ ... 50_h72.gif

With that cold of airmass and 500mb heights around 200 meters below normal, it is going to be very cool. The real key, though, is that the low is progged to move right on top of us (or at least very close). I see no way for us to escape thunderstorms out of this, unless there is absolutley no sunshine for Sunday through Tuesday!

I just looked at some June's that had periods with temps 7 or more degrees below normal, and found the key is for the low to track just to the NE of us. That gives us very cool temps, but limited moisture. Many of the lows this year have tracked just a bit too far SW of us, which is great for rain, but not as good for cool weather. This low appears it will track between the two scenarios, which should be good for temps 4 - 8 below normal and plenty of showers. The way things are trending we could easily see lows begin to track to our NE later in the month as it becomes incresingly difficult for them to go south of us.

It is also interesting to note, that the MJO has now become a non issue. Just in the past week that index has gone totally flat. Up until then, it had been gyrating from huge positive to huge negative anomolies. There is no doubt this will result in some changes, but who knows what they will be. My guess is that patterns will now become locked in for much longer periods.

[andycottle]

Note to snow wizzard:

I wanted to add mention of T-Storms in my weather outlook I posted, but didn`t want to go out on a limb just yet. But I do agree, it will be rather cool over the weekend. -- Andy

[snow_wizzard]

I understand your wanting to wait Andy.

This is for TT...I just stole this from another weather board. Enjoy!

Ice and snow piling up over a large area of Antarctica - 19 May 2005 -
According to a new study published in the online edition of Science, the East Antarctic
Ice Sheet gained about 45 billion tons of ice between 1992 and 2003. The ice sheets are
several kilometers thick in places, and contain about 90% of the world's ice.

Using data from the European Space Agency's radar satellites ERS-1 and ERS-2, a research
team from the University of Missouri , Columbia , measured changes in altitude over about
70% of Antarctica's interior. East Antarctica thickened at an average rate of about 1.8
centimeters per year over the time period studied, the researchers discovered.

The region comprises about 75% of Antarctica 's total land area and about 85% of the
total ice volume. The area in question covers more than 2.75 million square miles - roughly
the same size as the United States.

(This means that more than 90 percent of the world's glaciers are growing thicker …
while the media keeps yelling about the ones that are melting.)

http://www.nature.com/news/2005/050516/ ... 16-10.html
http://www.nytimes.com/2005/05/20/science/20ICE.html

[snow_wizzard]

I have some exciting news guys!

The SST forecasts continue to slowly drop, and now they are showing slightly below normal SST's by late December.

http://www.cpc.ncep.noaa.gov/products/a ... SSTMon.gif

Notice how the latest 6 forecast members are considerably lower than the earliest 6. We just might have a La Nina next winter!

[TT-SEA]

O.K... the high today at Sea-Tac was 65 degrees.

That is pretty warm considering the pattern today. It was northerly and cyclonic. An absolutely miserable combination. Snow_Wizzard was right about identifying the pattern. Though he is clinically insane for wanting this crap.

Still... I am surprised that it got up to 65 degrees.

Here in North Bend you would have thought it was January this morning.

To say that I hate the weather we had today is a massive understatement.

I am excited about the new upper low moving in just to stir things up again.

[andycottle]

Weather Outlook: Could be a pretty Active day sunday!

Ok folks, I`ll make this short here....but the newest run of the GFS seems to be more wet for sunday than what the ETA is showing. So from what I saw in earlier models, am betting late saturday into sunday could be especaily wet and cool. Anyway, it now looks like the first in a series of mini short wave-vort lobes will swing around main trough of low pressure come late this weekend. The first of vort lobes comes right on top us between 12z and 18z sunday morning, with the second one coming in sunday afternoon, but with main action heading in to SW Western, WA. and most Northern part of Western Oregon. So as mentined earlier, will keep a wacth on the weather.

[snow_wizzard]

I will admit today was not my number one choice for weather it was quite gloomy and dreary. Tomorrow could be even worse. The high in Covington was only 59 today. That is starting to get into the below normal side of things.

It looks decently possible that June could end up averaging below normal. The new GFS shows three toughs in the next two weeks. A couple of them look quite cool, and the third could be very wet, but that is way too far out to call yet. With the MJO dying out, we could get stuck in this pattern for quite some time. The extreme variability we have been seeing may not be so likely now.

[weather girl]

I think we're in this pattern for awhile (and I mean similar pattern through the summer,) although August is always a little tricky. Give it a couple of more weeks for things to really set in, but then watch it really heat up in Texas.

As for today, we've got a nice marine layer in here this morning, 54 degrees, but we should get some clearing this afternoon before topping out at about 67.

I really enjoy reading the weather debates here. Have a nice weekend!

[andycottle]

Good afternoon all.

Taking a look at the latest models.... it appears that sunday will be the coolest day of the weekend and very showery in nature, as a 1012 to 1016MB trough of low pressure comes down the B.C coast line and then swings at least two or three mini short wave - vorticity lobes right through Western Washington during the day sunday. GFS, NAM, and Canadain GEM model are in some sort of agreement about this oncoming system. Air mass will also be quite cool as MM5 model is showing 850MB temps of near 0C with 500MB temps of -24C and height of around 546 to 550DM. So with the air mass being rather cool for this time of season, and minor istability aloft per-CAPE values, isolated T-Storm showers and or just some rumbles of thunder looks alright for now. But as mentioned, with the cool dome of air in place.... believe all it would take to fire off thunder storms is some good solar day time heating along with the mini short waves to help further aid in the develoment of thoes storms.

-- Andy

[andycottle]

Hi again...!

Looks like little has changed since my latest weather outlook...per GFS & NAM. And so will keep my current thoughts for some isolated/scattered T-Storms through the day sunday as there appears to be plenty of showers behind the trough. And the 546DM mini short wave - vort lobe is still looking to come into our viewing area sunday morning. And after that passes over us, should see some sunbreaks with thoes above mentioned showers sunday afternoon. A PSCZ may also form, but time will tell.

-- Andy

[andycottle]

How quite the board is today! Where are you all?:) -- Andy

[TT-SEA]

Although active... the coming days offer very little chance for a cloudy all-day rain.

That means highs will reach 60 degrees on most days with occasional sun.

Maybe some thunderstorms though.

[andycottle]

Hey Tim...how`s it going? Finally someone eles posting tonight other than me.. -- Andy

[andycottle]

Latest models tonight are still in agreement about the cool trough of low pressure coming in for sunday morning, which should make for some very rainy and cool conditions. After a very rainy morning, a rather cool and fairly moist air mass -- up through 700MB -- comes over us for sunday afternoon that will have 850MB temps near 0C and 500MB temps of about -24C with height of 537 to 540DM. So should see some sunbreaks during this time, which should set the stage for at least some scattered T-Storm activity as possible weak impulses will be rotating around the main area of low pressure. And as mentioned earlier, it`s possible that a PSCZ may also form in it`s usual spot.

-- Andy

[AnthonyC]

It's the beginning of June? lol.

Sunday and Monday look interesting as a cold, upper level low swings down the Vancouver Island coast. Lapse rates are not incredibly steep, but with any sunbreaks and convective temperatures at a marginal 55F, it will not be difficult to fire up the afternoon thunderstorms.

Beyond Tuesday, models diverge...the GFS builds a ridge of high pressure off the west coast while the ETA parks the upper trough over the PNW. Considering there is an amplified ridge of high pressure in the center of the country...this cool/showery pattern may persist for awhile.

What happened to our 90-degree heat? Amazing the stark difference in one week.

Anthony

[andycottle]

Good morning folks.

Looking at the latest models, tomorrow should be a likely day for thunder storm activity as the GFS is showing a 546DM vorticity lobe moving through our area during the late morning and into early afternoon hours. Air mass will also be quite cool and moderately unstable with 850MB temps near 0C and 500MB of -26C. Per MM5 model, CAPE vlaues not really all that high either and at a minimal 200 J/KG. Now behind this front/ trough and with in the large showery cumulus field, lifted indices appear to be about a -2 to -3C with LAPSE getting on the steep side. GOES sounder imagery showing a marginal high end '8' to a low end '9'. And the TT(total total index - measure of T-Storm potential) is in the lower 50`s right in the main showery air mass. Convective temp for tomorrow afternoon is 57 degrees per MRF-MOS. On ther hand, NGM-MOS has a high of 63. Either way, upper 50`s to lower 60`s looks good...IF we can get plenty of sunbreaks. And if we do get a lot of sunbreaks, this should very likely aid in the further develoment of afternoon T-Storm activity. So for now....Thunder storms looks like a good bet.

-- Andy

[andycottle]

Good evening all...and hope every one had a great day.

Some interesting and exciting weather is on the way for tomorrow, especaily into the afternoon hours. Latest models tonight show a 540 to 546DM trough of low pressure right off the Washington coast. It is this trough that will be the fun weather maker as it looks like several short waves will be rotating around the main low in which they get spun off into our area. Air mass aloft will become QUITE cool and moderately unstable with 850MB temps of near 0C and 500MB temp of -26C. To further aid the develoment of T-Storms... lapse rate will be right around 8C/KM with lifted indices of around -3C. MRF-MOS also showing precip chance being very high over a 12 to 24hr period. So at any rate, and with plenty of sunbreaks inbetween the short waves, thunderstorms for late tomorrow morning into afternoon hours looks like a very good bet. Some of the more stronger storms may put down heavy amounts of rain in short span. Small hail is also a possiblity since the air mass will be so cool for so late in the season.

-- Andy

[snow_wizzard]

Yes indeed! It looks like we may have shifted gears into a solid below normal temperature pattern. We are now to the point where even 60 is well below normal. Needless to say, if either tomorrow or Monday fails to break out, we could come in well below 60. In actuality it looks like the next trough could be even cooler. This setup here is one that can bring well below normal temps in June.

http://www.srh.noaa.gov/cwwd/models/00z ... 0_180m.htm

That strong WNW flow simply rams the cold air from the Bering Sea area right into us.

As for the next two days. I am certainly expecting we will be seeing red on the radar again. The very wet spring continues!