Sunday, February 1, 2009

Warm Front Approoaching


The skies are clouding up right now as a warm front approaches. Take a look at the infrared satellite picture (attached). The band of clouds stretching from the NW nearly due west is associated with the front. Then the clouds take a sharp bend (near the low center) and then heads SW to just north of Hawaii (the latter band is the cold front). In a low-level temperature analysis (with sea level pressure and surface winds), you can see many of these features (see attached), as well as the cooler air still in place over us right now (blue colors).
The clouds will thicken today and showers will reach us very late this afternoon and this evening ( you were going to watch the superbowl anyway, right?). Tomorrow will be the transition day, becoming dry and warmer during the afternoon. Tuesday should be sunny and warm (in the 50s).
Winter really ends here the third week of February, with the risks of major storms of any type dropping rapidly after that. The first third of the remaining winter looks pretty benign.

23 comments:

I Love Weather! said...

Cool! I think I'll spend the afternoon and evening outside with the nice clouds and showers - much better than watching the Super Bowl!

Anonymous said...

Cliff, the GFS is still insisting, as it has been for several days, on a pattern change on February 9 headed into the middle of the month that looks a lot like the second half of December. I know it's still pretty far out, but considering how the GFS has been consistently showing this for a few days, how much trust can we put into it? I'm really looking forward to it if it does happen.

CherryCherryBoomBoom said...

I was hoping for another storm. :(

Anonymous said...

Anon, I'm sure Cliff knows about the GFS predictions, but he might regret mentioning them. After all, the chance of the models being correct a week out is pretty slim.

Anonymous said...

Anonymous, actually the GFS is fairly decent in forecasting long-range patterns IF it is consistent as it has been. Contrary to what the last anonymous poster said, the chance of models being correct a week out is pretty good if that consistency is there - I've seen it many times.

I bet we see cooler weather with maybe even some snow chances next week. The ECMWF is not as aggressive but still suggest something similar. Well, it would be nice at least. Besides, after such a depressing winter, we're due for something like that again. We need to get SOMETHING in here before the long summer/dry season starts in March.

Anonymous said...

If I remember correctly, the GFS was insisting on a major pattern change around January 23rd that was supposed to be a lot like December 13-26. I remember seeing the 18Z show abundant snowfall for Seattle on January 30th, on January 19th. In the end, all we got out of it was a dusting of snow. Don't get your hopes too high...

Cliff Mass Weather Blog said...

One can not take big regime changes seriously beyond seven days...PARTICULARLY those associated with snow. They rarely pan out due to the way the modeling is done (resolution of the models decline at around 7 days)...cliff

Anonymous said...

So Cliff, I noticed your answer and it made me wonder...why are models even run past 7 days then?

Josh-B said...

Anonymous, aka, indistinguishable. Wondering where you live when the dry season begins. Even Northern Cal can have some wetting rains into April and mid May.

andycottle said...

Hey Cliff... When you post new blogs, you usually post images for us readers to see. So for us readers here, are we some how able to post actual images like you do, or do we just have to keep posting links to images when we want to share with other readers here?

Anonymous said...

Hey Josh-B,

I live in the eastern suburbs of Seattle.

Brian said...

To Anon wondering about pattern change, KOMO mentions rain/snow next Sunday (could be the start?) and KING 5's Plus Five More forecasts shows snow not this week, but next week with highs in the upper 30s.

See how it pans out.

andycottle said...

For all wondering about the latest 18zGFS, here`s what I am seeing..

I see the latest 18zGFS continues to have us dry through at least Wed into perhaps Thurs as weak high pressure builds into our region along with split-flow at the upper levels. This will have any systems splitting apart and going north and south of us. Should also be fairly mild and at least partly cloudy to mostly sunny, though may see some high clouds at times as a cut-off low looks to dive south along the west coast of the near off-shore waters for later this week. Thicknesses will be in the lowe 550`s with 500mb heights un the upper 550`s to lower 560`s. SW-SSW flow also looks to be present with 850mb temps of around +6 to maybe +7c, so should see highs in the low to mid 50`s. However by later in the week, about Thurs or Fri, showers look to be back in the forecast as weakening trough passes through our region. Thicknesses also lower back down to around 546m. Sat looks dry at this point, though cool with on-shore flow. But come Sun and into Mon of next week, we look to be unsettled as a cool and deep trough with 522m thicknesses is over the PNW and giving us a showery start to the beginning of the work week with NW flow just above the surface.

Long term shows that the GFS is not so cold and not very arctic as it was showing in previous runs. However, next Tue and beyond looks cool and continued unsettled as series of some what deep troughs slide through our region under WNW flow aloft.

Josh-B said...

I wonder if the GFS had the Steelers or the Cardinals? I think the Euro had the Steelers.

Josh-B said...
This comment has been removed by the author.
Cliff Mass Weather Blog said...

Why are models run past 7 days when their skill is marginal? A good question. This period is one where we are learning what long-range predictions can and cannot do for us. Sometimes there is skill beyond 7 days and we need to learn when they occur.

Regarding adding figures to comments...I don't know..you could check with google...but I don't see how you might do it....cliff

Anonymous said...

I want to learn to do weather like andycottle because I want to sail offshore and figure out my own weather from obscure locations so I don't die.

andycottle said...

Looking at several models here.... I see that today through at least Thursday should be mainly dry with highs in the low-mid 50`s as thicknesses rise into the low 550`s with SSW flow and upper level 500mb heights rise into the low-mid 560`s. And with rising heights and weak high pressure at the surface and aloft, this should lead to partly to mostly sunny skies, though some high clouds may drift by us as cut-off low dives south along the west coast for later in the week. In fact, the forecasted cut-off may be close enough the put some showers over Oregon and maybe SW WA by Fri. However, this wont be the main cause of showers. The main cause of showers for the Fri-Sun period will be a weakening trough passing through our region which may give some showers at times as thicknesses lower back down to around 546m. And the 6zGFS/GEM/ Canadain and MRF models all seem to roughly agree about precip being back in the picture for late in the week.

The longer term for next Tue and beyond, it looks like an unsettled weather pattern will be with us as it appears that several and coolish troughs will swing through our region from the NW with thicknesses between 522 and 528m. And it`s not looking as cold either like yesterdays models were showing as 850mb temps for next week and beyond never really get below -6c. So coolish and showery pattern with snow in the mountains looks reasonable for right now.

Anonymous said...

Hey Cliff, are we still ENSO neutral or has it shifted to a weak El Nino?

The kind of patterns we've been having for the last month seem more like an El Nino.

In fact, this whole winter seems out of whack. It seems like we've had almost no normal weather in the last three months.

Josh-B said...

Happy Cross-quarter day everyone!

Anonymous said...

I'm no weatherman but I've lived in Washington long enough to know that any forcast more than a few days out, and sometimes even 1 day out, can change dramatically! I think the local channel weathermen/women are crazy! They are forcasting cooler weather and possible lowland snow for mid to late next week....I'll take Cliff's day to day forcast.....And Cliff...just wondering....we didn't get any good windstorms this year.....What does the El Nino, La Nina weather pattern look like it's shaping up to be for next winter....or can you tell this early....and if you can, does it look like it's shaping up to be a mild or wild 2009/2010 winter as far as wind storms go? The snow this year was fun, and the flooding nervewracking, but I love a good windstorm!

Chas. R. said...

Cliff: Thank you!
this blog is a terrific community resource. I am looking for info on predicting the warmest, driest time to cross the Olympics on foot this summer from Hood Canal (Duckabush area) to the ocean via the Hoh valley and Mt Olympus. My guess is anytime in August, and possibly earlier for benefit of the longer days. At most we might catch an inch or two of rain in a storm during the summer drought, correct?

Anonymous said...

Based on the temperature differences at the NW passes, I was wondering if we're still in a weather inversion? And if so when will it end?