We are in for a stretch of beautiful fall weather, but many of our days will start off with low clouds and fog. And that is absolutely typical for this time of the year. In fact, we are now in the foggiest time of the year for central Puget Sound.Why?Night is getting fairly long, giving a good opportunity for the surface to cool off by emitting infrared...
Incredible Humidity
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Today the humidity has been extraordinary around western Washington and Oregon. I mean sticky. Feels like the southeast U.S. during the summer--and for good reason: we are experiencing very, very high humidities with dew points in the mid to upper 60s in many locations.(Remember dew point is a very good measure of humidity...high dew points mean...
The Rain Cometh
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Today was as close to perfect as weather can get around here. In Seattle: no clouds, high in the mid-70s, nice breeze. The air was clean and visibility was excellent.But this will be a weekend with a different ending and the change is moving in right now.Here is the latest radar image from the NWS Camano Is. radar. You see all those greens and yellows...
The First Atmospheric River of the Season
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Some of the most important wintertime weather features of our region are the plumes of moisture that stream northeastward out of the tropics and subtropics. In the discipline these plumes are often called "atmospheric rivers" and the atmospheric river that is often discussed in the media is the "pineapple express." This weekend the first major...
Northwest Monsoon
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I have been amazed by the amount of rainfall falling around here over the past two days, with a number of locations getting the equivalent of an entire September's rainfall in 48hr! Warm, humid, and tropical. At my home in north Seattle I had 1.1 inches the first day and 1.05 inches the second! The ground is saturated.Take a look at the 48-h rainfall...
Forecasting's Achilles Heel
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Today we are experiencing a noticeable forecast failure and one that in some sense is self-inflicted.Here is Puget Sound country it is going to be a beautiful day...lots of sun and temps rising into the 70s. Look outside or view the latest visible satellite picture.On the other hand the National Weather Service forecast RELEASED THIS MORNING paints...
How Bad Has It Been?
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Another round of rain struck today and the grumbling has increased..."The worst summer I can remember""I thought Septembers were good around here"and other comments that cannot be repeated on a family friendly blog.Looking at the temperature versus normal for the past four weeks, tells the recent tale (see below). Except for a few brief warm periods,...
The Birds Are Back
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I have mentioned before that birds can be viewed on weather radar, and we have a great example tonight.It seems like the big migrations tend to occur at night (less chance of being caught by predators?). Here is the radar image that shows the amount scattered by targets in the atmosphere (we call this reflectivity) at 5 PM. Not much there, just ground...
Go South for Sun! Wine weather.
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During the fall, the jet stream and its associated weather strengthen and move southward. As a result our region gets increasingly "clipped", starting with the north. Today and late yesterday are a classic cases.A weak front is now bringing clouds, rain, and cooler temperatures north of Seattle, while to the south it is dry and much warmer. Head...
The Long-Term Forecast
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Many of you have asked for the details of the long-term forecast: what is expected for this fall and winter. OK, you asked for it--and some of you may not like what you hear.The most powerful tool we have for predicting months ahead of time is the correlation between El Nino/ La Nina and Northwest weather. You have heard me talk about this frequently...
Cloudy and Cool
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I got back from a meeting at Lake Tahoe yesterday (American Meteorological Society Mountain Meteorology conference) and I am ready to get back on the plane to Reno. For September, which has often been a very good month around here, we are seeing cool, cloudy, and wet conditions west of the Cascade crest and north of Salem. Look at the latest satellite...
Hurricanes and Uncertainty
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Now that Northwest weather has returned to the more usual and benign September fare, lets turn to hurricane forecasting.An interesting factoid: My profession has made huge progress in predicting hurricane tracks, but there has been little headway with hurricane intensity predictions.Here are the official statistics for Atlantic hurricanes. First,...
