Tuesday, December 30, 2008

Quiet Day

Well, another forecast problem. The NWS was going for rain today...and I can't figure out why. Anyway, they just shifted the forecast today to a dry one for most of region.

The late Thursday/Friday storm is still uncertain. The best model...the National Weather Service GFS (Global Forecast System) model still has it in the latest runs...but weaker. The NWS NAM model (less skillful in general) doesn't have it at all. Comparing the forecasts of major international modeling systems...there is a lot of variability...but most are going for a weaker event. In contrast, in December 2006 the various modeling systems were really locking in and showing substantial agreement this far out (roughly 66-72 hr in the future). In short, for a confident forecast I look for temporal consistency in the solution and consistency among major modeling systems.

So at this point, I would certainly back off in predicting a major event and wait until tomorrow to see if the model solutions lock on a common prediction. There is large uncertainty and the trend of even the most severe outlier (GFS) is to weaken the event.

31 comments:

Jamie on BI said...

Cliff, some forcasters are predicting another strong (undefined) wind event tonight. What's your take? Thanks!

Jamie on BI said...
This comment has been removed by a blog administrator.
Scott K said...

Thanks for the blog update. After reading a lot of info about this Thursday's low I started coming to the same conclusion you are headed for as well. I think it'll be all hype and no blow. :)

Anonymous said...

Dear Cliff - I'm a big fan, and I do my part to spread the Cliff Mass word. I'm a checker at Fred Meyer and my customers think I'm a shaman when it comes to the weather forecast! I always listen to NPR on Friday mornings to hear you, and now I can learn the forecast every day. Thank you for teaching me the "why's". I like that part.
Ballard Fred Meyer Checker

Michael said...

FYI there is a coastal radar cause and Cliff Mass fan site on Facebook now

JewelyaZ said...
This comment has been removed by the author.
JewelyaZ said...

Michael,
Can you post the link to the Facebook group?

Here's a link to the Yahoo group for PNWest weather discussion and information. PNWeather Yahoo group

Glad to hear that the low for late this week will not be such a big deal here (probably). Yesterday's wind was enough excitement for me for one week. :-)

Dena said...

Well, we were out fixing our fence that blew down yesterday and just while we were outside, the winds picked up fairly dramatically to about 26 mph. (We're on Sunset Beach, Whidbey.) I see the NWS still has a wind warning for this evening.

Kevin Purcell said...

Cliff: you comment on the NAM being the least skillful of the models.

Do you have an ordering of models from most to least skillful?

Do they have systematic variations?

Thanks, Kevin

Anonymous said...

Cliff, I enjoy reading your predictions and post event analysis.

I am wondering, besides the information you have provided to you by the NWS, do you follow other websites to monitor live weather? For instance the WSDOT and Weatherunderground.com have stations all over the state.
Do those stations help you generate data for future research, or are those stations not accurate enough to be considered?

I ask this because I've considered adding a weather station to my home, and obviously it won't be a NWS/NOAA type set-up, but I would love to know if you or your counterparts look at this while fronts and cells move through the region.

Thanks again for your blog.

Scott K said...

I'm also wondering about today/tonight's wind event. Jamie asked the question in the first comment....Cliff what's your observation on tonight's chance at a wind storm?

Joseph Ratliff said...

From what I have seen on Wunderground.com for my area (Lacey, WA)...the Southwest Interior (and my area as well) are still on for some type of breezy to windy conditions. The National Weather Service site specifically has Lacey "breezy" with gusts to 30mph

You can type your zip code into the site below to get your "point forecast"...

http://forecast.weather.gov/MapClick.php?CityName=Lacey&state=WA&site=SEW&textField1=47.0257&textField2=-122.797

Anonymous said...

So very disappointing to see the models weakening the Thursday/Friday system... :(

Anonymous said...

I think the "point and click" forecasts from the NWS are absolutely worthless. The best forecasts are the ones with human input, as in the zone area forecasts. I have seen the computer call for rain with temperatures in the mid 20's. I have seen the real forecast call for 4-6 inches of snow, where the point and click forecast for where I live says less then an inch (I usually get more then most in my area). Someday these may be useful, but for now, ignore them.

Anonymous said...

Today was a rather pleasant day in Seattle-- dry, calm and relatively mild. After what happened in the last two weeks, maybe the weather forecasters were too caught up in storm sensationalism to warn us that a day of good weather was coming. Missing a good weather forecast is almost as bad as blowing a stormy one in this climate!

Michael said...

Coastal Radar Cause on Facebook

Michael said...

Cliff Mass Fansite on Facebook

Anonymous said...

This is a very useful blog. I've been checking it several times a day since I found it last week.

Scott Sistek's blog on KOMO is also pretty informative, though it doesn't seem to have as many commenters as this one. He has some interesting explanations of the different forecasting models for the possible windstorm at the end of this week.

http://www.komonews.com/weather/blog/36887209.html

Anonymous said...

Cliff your post is now outdated as the latest NWS info and model runs seem to reconfirm a strong wind event...with it most likely that a rather deep sub-980mb system will impact somewhere between Hoquiam and the middle of Vancouver Island. If todays GFS run panned out exactly as predicted, the PDX-BLI gradient would be in the 20+ mb range, suggesting a major wind event...unlike yesterdays PDX-BLI which peaked at 15mb...still substantial, but nowhere near the 22mb we hit during the Hanukah Eve storm.

Anonymous said...

Today was NOT pleasant and NOT a good weather day. Some of us LIKE weather, so a day with no weather is a bad weather day. I wish people would realize that.

Chris said...

And after two weeks of snow and ice, wind, power outages and trees falling on homes,some of us LIKE quiet weather days and would like a respite from some of the "fun". I wish people would realize that.

Mikey said...

Yeah. :) I'm nursing a sore back from shoveling snow.

DaveC said...

Cliff-- as of 7:45 pm it is really blowing on the Miller Peninsula east of Sequim. I don't have any instruments, but I would guess steady at 25-30 mph with higher gusts.

Anonymous said...

The 00z GFS has really taken the punch out of Thursday's system. It's pretty much following the trend of the NAM (I thought the GFS was the better model - it sure seems to have blown this one). I guess there's plenty of time left for things to change though.

I'm wondering if the models keep trending south with this storm, if that means a greater chance of snow, and if more cold air might follow in the wake of the storm.

Rob said...

I noticed that also. It will be interesting to see in the next couple of runs if it starts tracking with the NAM or if it changes back to a 970ish low. Personally I would like to see some more crazy weather. It doesn't appear that there is much cold air to work with even if this system tracks to our south.

Joseph Ratliff said...

Personally...I am with Chris...I could use the "respite" from bad weather for awhile.

There will be plenty of time for more SW windstorms that gust over 60mph next decade. :)

Anonymous said...

That's one of the problems. It's always referred to as "bad" weather. Why is that?

Anonymous said...

Oh, but Chris, but you do have lots of people who realize that. All the news on TV, the radio, and in newspapers; a vast majority of the public; the National Weather Service(!); even Cliff here talks about any and all weather in a negative light. It's the point of view of the vast minority of us that people don't realize and fail to even try.

Anonymous said...

the KPDX WFO just issued a special weather statement. Looks like they're more impressed with Thursday's storm than Cliff. Any thoughts?

Chris said...

I'm not trying to start a war here, I understand your point because of course there are two sides to every coin. However, when severe weather events send people to emergency shelters or hospitals, I will forgive the hype and the bias. I'm sure the people who lived through Katrina would have been grateful for less exciting weather. And I'm sure they would have called the term "bad" an understatement. Just the other side of the coin.

Anonymous said...

Yes I know, but 1) Katrina is an extreme event you don't see every day. People call every day weather bad things. 2) In the case of Katrina, there were many people who had the choice of whether to live through it or not. That isn't the case in things like F5 tornadoes that unpredictably move into a city, but a little breeze now and then and some drizzle or cloudy skies or any other so-called "bad" weather are hardly comparable to an F5 tornado or a Katrina.