Pacific Northwest Weather

[andrewr]

Currently 31F with some frost. Should be another cold one tonight and tomorrow morning.

[TT-SEA]

Everyone please remember... we are gaining close to 4 minutes of daylight every day! We have 20 minutes more daylight now than last week!!!

And will have 20 minutes more next week.

My point is... if its sunny we are going to get much warmer than 2 months ago.

[andycottle]

Viewing tonights run of the 00z GFS and MM5 model, we stay nice`n sunny through tomorrow and most of Friday with 850MB temps approaching +9C by Friday, then droping like a stone and going to near
-6C by Sunday. With light off shore winds and somewhat Southerly light winds, abundant sunshine the next two days, and 500MB vorticity heights of 564 to near 570...we could very well see surface temps near 60 or maybe even very low 60`s at the warmest. ETA, NGM, and GFS MOS for Seattle are much to chilly for my thinking as they have highs in the low-mid 50`s. For Saturday, look for showers and cooler conditions...followed by lingering showers in scattered form for Sunday into Monday.

Longer range...15th - 23rd, Strong high pressure out over the Pacific Ocean and off the Western U.S coast by SEVERAL hundered miles...keeps the Jet in a major split flow with the Northern branch going way up North and Southern branch over Oregon and Northern California. So while we up here in Western Wa. enjoy more spring-like weather, areas to our South may see clouds and scattered shower activity at times.

-- Andy

[snow_wizzard]

Andy...Keep in mind that we are going to have constant Fraser river outflow next week. That will keep things more winter like in the temperature department. The Canadian model looks even colder than the GFS, so below normal temps look good.

If you guys have not seen the latest sea surface temperature data, here it is. What a dramatic end to end to what little El Nino we had. Nino regions 1 + 2, and 3 are now below normal, with the crucial region 3.4 down to just a fraction above normal. Scroll to the bottom of the list you will see the latest SST's for the various regions and the departure from normal values. Dropping like a rock!

http://www.cpc.ncep.noaa.gov/data/indices/wksst.for

[andycottle]

snow wizzard....you mentioned the Canadain model and about it being cooler next week. I`m asumming you were looking at the ECMWF? -- Andy

[TT-SEA]

Andy... there is both a Canadian model and a European model (ECMWF).

Snow_Wizzard... based on the latest ECMWF next week will be a carbon copy of this week. Sunny and pleasant days... cool nights. Maybe a little warmer with the rapidly increasing length of daylight.

Nothing arctic. Northerly flow... but not arctic. No precipitation either.

[snow_wizzard]

Andy...I am saying colder as in the heights and configuration of the flow at the 500mb level. The Canadian shows a bit more amplitude with the offshore ridge and a sharper northerly flow along the 540 and 546 height lines. All of the models show the surface pressure will strongly slope from high over BC to low over Oregon next week. This could spell, a prolonged period of cold outflow from the Fraser River Valley. With this situation the dew points could get extremely low which could allow wind sheltered areas to plummet at night. The air will likely be cold enough to keep the highs below normal also, but that is a much harder call.

If we were to get some luck this time, we could be looking at a significant cold spell. The ingredients are there, but we will have to see if the trend toward colder model runs can continue. I am going to mention the "S" word just in case... I would hate to have it snow, and have everyone say I didn't mention the possiblity. How embarrassing would that be?

By the way...here is the Canadian early next week.

http://weatheroffice.ec.gc.ca/data/mode ... 136_50.gif

Currently 30 in Covington....

[snow_wizzard]

Here is a fun little map to look at! The Canadian spaghetti ensemble map for day 9. This is for the 546 contour. Notice how the operational model (solid black line) and the control model (dashed black line) both show a high amplitude ridge off the coast. Big time northerly flow!

http://weatheroffice.ec.gc.ca/data/ense ... 216_e.html

[TT-SEA]

SW - thats a very good point. You pretty much have to mention snow any time cold air is within 1,000 miles just to cover your bases and keep your standing in the group as the cold weather expert. It would be quite a disaster to have a snowstorm sneak up on YOU!!!

Anyways... you should be safe next week. The thrust of the cold air is WAY east and the models are likely too cold at 850mb at this point in the game.

If this were December or early January we could have highs in the 30's on Monday and Tuesday. But in mid-February we should be at least in the mid to upper 40's with any sun at all.

After that... the air mass will moderate and the flow will become more southeasterly and we should be in the 50's if we get sun.

[TT-SEA]

Here is a fun little map to look at! The Canadian spaghetti ensemble map for day 9. This is for the 546 contour. Notice how the operational model (solid black line) and the control model (dashed black line) both show a high amplitude ridge off the coast. Big time northerly flow!

Look at the solid red line.

[snow_wizzard]

Yeah...I noticed the mean line was not in line with the main models. It should be noted that the models themselves are alway more accurate than the other individual ensemble members. That having been said, there is certainly plenty of disagreement and the mean cannot be ruled out.

At this point it kind of seems like we are heading down the road toward a decent cold spell, the question is when. It could well be that the ridge will just slowly creep westward over time, and we may not get the good stuff until early March. On the other hand, it could happen very soon. The GFS repeatedly goes back to showing us being cold, and in all likelihood it will end up being right eventually. I would say that from here on out we need to look very closely every time the models show things turning cold, because the time is drawing near. The most likely scenario is that the ridging we have seen will simply move further west over time which will open the door to progressively colder and more moist weather. It will be fascintaing to see how this all plays out over the next two months or so.

[W13]

Currently 24 F as of 6:18 AM

[R-Dub]

A touch cooler then yesterday morning at this time.

2/10/05 LK Goodwin WA
6:20:46 AM CURRENT
Clear
Temperature (ºF) 30.0
Humidity (%) 99.3
Wind (mph) ESE 1.3
Daily Rain (") 0.00
Pressure ("Hg) 30.29
Dew Point: 29.8 ºF

[andycottle]

Currently clear skies at 7:19am with a temp of 27. Low was 26.

[snow_wizzard]

Justin...We are the coldest spot in western WA this morning! At least out of any of the official weather stations. 24 in Covington, and 24 where you live on the East Hill. I knew that would be the case, because the offshore pressure gradient was just a little bit stronger last night which makes this the prime area to get seepage of drier from eastern WA, but without wind. As I have mentioned before, the surface pressure maps are everything when it comes to predicting radiational cooling. This is one advantage I still have over TT. He has not been here long enough to know the really fine points of that just yet.

That having been said, I think that TT has really proven himself on here in many regards.

[andycottle]

Checking a few weather obs from the 7am hour....the central sound are having temp in the low-mid 30 with a few upper 30`s, but if if you go a bit northward...temps are in the 20`s. http://www.atmos.washington.edu/~ovens/ ... c_pgtsnd+1

-- Andy

[TT-SEA]

Thanks Snow_Wizzard.

Offshore flow kicked in and we are up to 46.2 degrees!! Should get into the upper 50's at our hosue today but the fog Sea-Tac is going to slow down the warm up there.

[andycottle]

At 9:02am we have a very thin layer of Cirrus clouds over us, and with temp of 30. -- Andy

[snow_wizzard]

TT...That east wind is the damndest thing. If you are just past the leading edge of it, you get the coldest low temps, and if you are in it, you are 20 degrees warmer.

I am sure liking the progs for early next week...very nippy indeed. This map is for day 5.

http://www.srh.noaa.gov/cwwd/models/12z ... 0_120m.htm

This is in combination with 850mb temps of -10, and a straight N to S surface pressure gradient, which means no compressional downslope heating.

[andycottle]

Good morning all. Taking a look at the 06 and 12z GFS, tomorrow should be another nice dry and for the most part, mostly sunny day as 850MB temp warm to near +9C and 500MB voriticity heights of 564DM. Expect increasing clouds toward late Friday afternoon into evening, and then showers by late Friday night into Saturday. A few hit and miss showers stick around for Sunday with maybe a sprinkle or two on Monday.

Long range...looks like were still in a split flow 15th - 22nd, but in a coolish dry Northely flow. This theme has been shown now for the past 6 runs of the GFS...so we can expect to see another nice strech of sunny days and very cool nights...well, maybe mid 20`s at the coldest.

-- Andy