Pacific Northwest Weather

[TT-SEA]

The 00Z run of the GFS continues to show an active period from Sunday - Wednesday and then a change to a relatively calm pattern as the jet stream weakens and shifts north. Eventually.... it looks like a pattern that favors a few weak cut-off lows wandering around the Eastern Pacific or the Western U.S. This is usually a very pleasant and generally warm pattern.

Should be cool early next week with frequent showers (and many sun breaks) and some pretty awesome convergence zones. Highs mostly in the low 50's.

The last half of April should feature some warm periods (highs in the 60's and low 70's) broken up by a few weak systems.

R-Dub... you will get some days on the lake soon!!

[andycottle]

My view on the 00z GFS is that tomorrow and Sunday look like some nice weather days, though it will be a little chilly. Should see increasing clouds late Sunday. However come Monday, a rather strong cold front comes through our area during the early-late morning time frame. In which that cold front will probably be followed by a very active PSCZ as the front comes through. After the passage of the front, 850 temps fall down to around/near -4C with heights of 1410M. And 500MB vorticity heights come down to around 534DM with temps possibly falling as low as the mid -30`sC to slightly colder values. MRF and ETA showing lifted indicies of only 0 to +1. CAPE values are pretty nil for when the system comes in on Monday. MM5 model has surface temps in the low-mid 50`s while the Seattle MOS has temp in the low 50`s for Monday. So any sunbreaks that we do get once the front passes by, should help with development of shower activity.

-- Andy

[snow_wizzard]

TT...I am not seeing the kind of readings you are talking about for the second half of the month. The GFS shows another very strong trough digging in after a short break in the 7 - 8 day time frame. Until the MJO shifts back to a positive phase, any warm periods will be short lived. Even when it does go to positive there is usually about a one week lag time for our weather to react. This month is going to average well below normal in temperature. In fact I would say the entire spring could be pretty active, but I am not sure of that yet.

When we are seeing analogs from 1953, 1955, 1999, etc, the odds do not favor recovery any time soon. Those years all had abnoramlly cool Apr - Jun periods. Right now, I am just going to commit to this month remaining cool. This year has been too weird to go any further than that!

[R-Dub]

Nice to wake up to a bright sunny morning

A few clouds have since moved in, but still Partly Sunny with a temp of 40 degrees.

[AnthonyC]

Lost another 20 bucks at poker last night...lol. I should really learn my lesson.

As for the weather, Sunday thru Tuesday looks fairly active as an upper level trough meanders off the coast. Each model run isn't as extreme with this feature...not as cold, wet or strong...but it's a decent trough for the middle of April. Mountain snow, lowland rain will be the case...hopefully we can pile up another 2 feet because this might be it for the season.

As for the extended, I have to agree with TT-SEA. Latest models indicate very tranquil pattern as the jet stream shifts north and we are left with pleasant conditions. A cut off low sits off the northern California coast...this should generate warm temperatures and at least partly sunny conditions.

The last few weeks have been nice, but I'm ready for a return to sunny/warm weather.

Anthony

[snow_wizzard]

The 12z run continues to build on the idea of another cold trough digging down on us in the 7 - 10 day period. That, of course, is after the deep cold trough that will dominate our weather for the Sunday night - Wednesday night time frame. I say there is little chance of any big change in the pattern, at least until the 20th. Even then it's doubtful.

Certianly no doubt that things have been chilly! We had a low of 33 yesterday and 36 today. Solidly below normal! Even with the sunshine the highs are remaining below normal also.

We are going to end up with two months averaging below normal in a three month period (Feb & Apr). That is the first time we have done that in quite some time! Furthermore, it makes the relentless above normal forecasts that the NCDC is putting out, look a bit suspect....

[snow_wizzard]

Another interesting note...Normally the last cold trough in a series ends up being the coldest of the group. Just something to look forward to.

[invisible]

I predict that precipitation will be above normal in April and May. I bet that precipitation will be well under average with above normal temperature in June. I am not cocerned about drought this june because in July and August will have normal temperature and precipitation. I bet this prediction will be right because the pattern we has right now is wet. It will become drier in June. Mother nature just wants to keep the weather balance.

[andycottle]

Hi guys! I`m home....! Not too bad of day a here in Woodinville. Partly sunny skies through mid afternoon with some building of puffy cumulus up around 15,000, 20,000ft or so. In the last couple hours skies have became cloudy, and with some spotty visable virga falling from the clouds.
My high today was 61 with a low of 36. Had some very light precip over night, but was not measureable.

-- Andy

[andycottle]

Hi again! Here`s a few pics I took of the cumulus and swelling cumulus while at work today. By watching the clouds earlier today, would say the cloud tops rose no higher than about 20,000ft or so. No precip was generated by these clouds shown in the pics. -- Andy

http://pg.photos.yahoo.com/ph/ajc192004 ... pg&.src=ph

http://pg.photos.yahoo.com/ph/ajc192004 ... pg&.src=ph

http://pg.photos.yahoo.com/ph/ajc192004 ... pg&.src=ph

http://pg.photos.yahoo.com/ph/ajc192004 ... pg&.src=ph


These clouds really caught my eye because of the formation, and the way it looked. Though maybe they were going to show some sort of interesting weather, but saw nothing come out of the clouds.
http://pg.photos.yahoo.com/ph/ajc192004 ... pg&.src=ph

[andycottle]

Viewing the latest GFS along with a few other models, it still appears that a deep and cool upper trough will settel over us by Monday, that 850MB temps of around -4C and heights of 1380 to near 1410M. 500MB vorticity heights are near 540DM, however temps at that level are pretty chilly and at about -34C. Lifted indicies looking near +1 to +2, but CAPE values for monday early-late evening are in the 200 to near 300 J/KG. So if this holds ture, and we get a rather good active PSCZ....T-Storm activity should at best be marginal. Could even see some small hail and gusty winds.

This very cool upper level trough sticks with us through the 15th in which we will have a continued threat of showers and a few isolated storms. though we should see some partical clearing at times inbetween showers.

-- Andy

[R-Dub]

Spectacular pics Andy!!!

Currently Mostly Cloudy with a temp of 44.9 degrees at 8:50PM

[andycottle]

Thanks Randy!

[andycottle]

Latest GFS still showing the cool trough setteling over our area for the Monday through late Thursday early Friday time frame. Then guess what? The fun starts again as we yet again have another very cool trough settel over our region for next Monday. This one looks VERY showery. So....the active weather continues! -- Andy

[W13]

Currently 38 F after a low this morning of 33 F. Should be a fairly nice day with some increasing cloudiness late this afternoon. Overall, a good weather day.

I can't wait to see how strong the PSCZ's this week will be and if they will drift more southwest than usual.

[andycottle]

Good morning all. Currently we have mostly sunny skies with a temp of 43 and humidity 91% and DP 41. Baro is 30.03 and steady. My low this morning was 38.

-- Andy

[W13]

Great pics Andy!

[andycottle]

Viewing this mornings 6Z GFS...our showery and active weather will last till about the middel late part of the upcoming week. This is all thanks to a deep and very cool upper level trough setteling over our area that will have day time temps feeling a bit coolish and with some breezy winds. Along with this trough, especaily tomorrow - Wednesday, is the likely possibily of a PSCZ that should fire off T-Storm showers since the airmass will be moderatly unstable.

Yet another cool and showery trough settles over our area by late next weekend and into Monday to give us more active weather. -- Andy

[andycottle]

Great pics Andy!

Thanks Justin! Glad you liked them.

[AnthonyC]

Dude, what I would give to be in Denver today!! I want warmer/sunnier weather, but one last blast of heavy snow would be awesome!!

As for the weather in Seattle, fairly active the next week. A decent cold front is located off the coast...nothing significant, but I guess it's April. With a 130+ jet streak, a nice surface low is starting to take shape...unfortunately it's headed up into central BC having little impact on Western Washington. A decent shot of rainfall tonight...a few inches of snow for the mountains. The mountains should get about 6 inches tomorrow morning with moderate orographic lift and a decent westerly flow. Snow levels will be low for this time of year...possibly below 2k.

Monday thru Thursday morning looks active as an upper level trough lingers off the PNW coast. Expect showers/thunderstorms in the lowlands, moderate snow in the cascades. Snow levels will be very low will cold air aloft...below 2k through this period...but not much orographic lift. Hopefully we can manage a foot by Thursday.

And the extended...looking at latest GFS trends, the progressive pattern in the Eastern Pacific is starting to wane which is indicative of a transition from Winter to Spring. The jet stream is less powerful and is shunted north. The GFS indicates another weaker trough by late next weekend, but a cutoff low forms in northern California which would shove the jet stream north and bring partly sunny conditions, and very mild readings. We'll see.

I'll be gone the rest of today thru Tuesday night...I'm off to visit Willamette and Gonzaga Universities. I won't be posting during this time frame.

Anthony