A good weather site if you’re looking

This weather site is way above average and probably has more information than you need or even want.  It has four weather models (NAM, GFS, ECMWF AND METEOBLUE) that pretty much cover what you need to know and you can compare them all nicely lined up.  Just type the location you want in the search window in the upper left of the screen and take off ….  Also for a good discussion of the models in case you missed the posting a few days ago you might read it for a decent understanding of the strengths and weaknesses of the models Windy uses …   enjoy

rŌbert

Here’s a Frequently Asked Question site to help …

~~~  CHECK Windy OUT  ~~~

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So, what exactly are the European and American weather models? ~ The Washington Post

The European model depicted Hurricane Sandy’s extremely unusual left turn into the New Jersey coastline as much as seven days in advance. The American model aimed Sandy out to sea up until three or four days before. (WeatherBell.com)

November 22

We hear it every winter: “The American model says …” or “But, isn’t the European model most accurate?” But what’s behind the computer weather models that guide a forecast?

Computer models are, by far, the most important tools weather forecasters use for making predictions. They are able to process infinitely more information than the human brain in a fraction of the time and keep improving.

Because of progress made in computer modeling, weather forecasts have improved by about one day per decade. In other words, a five-day forecast today is about as accurate as a three-day forecast was in the 1990s.

Forecasters generally rely on two primary types of models: those that cover the globe and high-resolution models that key in on smaller areas to capture more detail.

Global models

Global models, it comes as no surprise, are run globally. They’re the models that capture the sprawling weather systems that can stretch across a continent, such as cold fronts and massive storms. If you’re looking to accurately forecast systems of the largest scale, then you have to go big. So big, in fact, that your model spans the entire planet.

The two global models you hear the most about are likely the American and European models. Each has its own strengths and weaknesses.

The American model is officially known as the Global Forecast System model or GFS. It is created and operated by the U.S. National Weather Service. It’s run four times a day and churns out predictions up to 16 days in the future.

The computing power behind the American model has grown tenfold in the past four years, with the model now able to process eight quadrillion calculations per second. The supercomputer running it is one of the 30 fastest in the world, according to the National Oceanic and Atmospheric Administration.


The American GFS model depicts a plume of deep moisture heading toward New England in October. It brought a nudge of heavy rain and localized flooding. (WeatherBell.com)

The European model is officially known as the European Center for Medium-Range Weather Forecasts model or ECMWF. It is named after its operating agency in Europe, stemming from a partnership between 34 different nations with a need for weather modeling.


A look at a small section of the enormous supercomputer running the ECMWF model. (ECMWF)

The European model is more computationally powerful than the American and is generally regarded as an all-around better model. That’s due to the way data is organized and processed by the model’s “under-the-hood” math and physics, in addition to the raw power of the supercomputer running it.

In 1979, the first ECMWF forecast rolled off a “supercomputer” about a tenth as powerful as a modern-day smartphone, according to the center, and the current computing array is about as powerful as a stack of smartphonesmore than 20 miles tall.

Instead of running to 16 days into the future, like the American model, the European makes predictions only 10 days out. The nine- to 10-day range has been shown as the “practical limit” of accurate weather forecasts. Model forecasts are most accurate one or two days into the future, moderately accurate three to five days out, and become increasingly less reliable beyond.

Other global models that forecasters frequently review include Canada’s Global Environmental Multiscale Model (GEM), which runs out to 16 days, as well as the U.K. Met model, which runs out to a week. On occasion, the German ICON model and Australia’s model enter the conversation as well.

Both the American and European models have shown substantial forecast improvement over the years, although — evaluated objectively — the European has consistently demonstrated somewhat superior performance.

Ryan Maue

@RyanMaue

Skill comparison between NOAA GFS & ECMWF last 14-years.

1. Both models continue to improve
2. ECMWF has made considerable gains in summer-time skill
3. ECMWF minus GFS shows consistent & widening gap over the past several years.

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While the European is, on average, the more accurate model, the American sometimes produces better forecasts. Skilled meteorologists review the forecasts of both models, along with others, understand their strengths and weaknesses, and understand in what circumstances to place more or less weight on a specific prediction.

When forecasts between models disagree, meteorologists can look at even more simulations of weather, known as ensemble forecasts, to gain further insight into the range of possibilities.


A look at individual ensemble forecasts from the American GFS model for a snowstorm that targeted the Washington region last December. (WeatherBell.com)

When these ensemble forecasts differ by a lot, this tells forecasters that there is high uncertainty in the model predictions. In such a situation, forecasters are wise to project low confidence and communicate a range of possibilities.

High-resolution models


A simulation of thunderstorms from the High Resolution Rapid Refresh (HRRR) model from August. (PivotalWeather.com)

Sometimes, you might see more detailed-looking models such as the high-resolution NAM (North American Mesoscale model) or the HRRR (High-Resolution Rapid Refresh model). These are “convective-allowing models.”

Think thunderstorms. They’re pretty small. Too small, oftentimes, to be adequately resolved in the global models’ six-to-10-mile-wide grid boxes. A thunderstorm updraft may be only two or three miles across.

The bottom line

While they keep improving and are the state-of-the-art tools for weather forecasting, there are no perfect computer models.

This winter, you might see a specific model forecast posted on social media many days into the future, when these predictions aren’t that reliable.

As a general rule, wait until at least a few days before a winter storm to make decisions based on specific predictions and find a trusted meteorologist to help you interpret model forecasts.

SNOTEL Snow/Water Equivalent for Colo

Remember the reading this early in the winter season of snow/water information is a bit misleading.  The South Platt for instance @ 141% might mean there is 10″ of snow and maybe 1″ of water equivalent rather than 3″ of snow and .03″ of water (normal). It’s way too early to get excited about how big the winter will be when the information is the first sampling of SNOTEL sites and can drop the other direction just as quickly.

rŌbert

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NOAA calls for mild winter but one with big mood swings

Ice forms on the window of a Chicago Transit Authority train while a commuter hustles to board as a winter storm makes its way through several Midwestern states on Feb. 9, 2018. (Charles Rex Arbogast/AP)

October 17

Don’t expect a particularly harsh winter, but a volatile one. That’s the essence of the National Oceanic and Atmospheric Administration’s winter outlook, released Thursday.

The agency is forecasting warmer-than-average temperatures over a large part of the nation, in keeping with recent trends. Winters are warming up because of climate change, and the overwhelming majority of recent years have tended to be mild on balance.

But even with winters trending milder, they have still unleashed brutal cold snaps and blockbuster storms, and there’s no reason this year won’t be different.

The temperature forecast


NOAA winter-temperature outlook.

Most of the nation is favored to be warmer than normal, but “cold weather is anticipated and some areas could still experience a colder-than-average winter,” the outlook said.

Areas least likely to be cold, relative to average, are Alaska and Hawaii, where the outlook highlights high chances for above-average temperatures. Abnormally warm oceans surround both of these states, which have experienced record-breaking temperatures at times since the summer.

Rick Thoman@AlaskaWx

The sea surface temperatures in the Chukchi and Beaufort Seas off the north and northwest coasts of Alaska were, by far, the warmest of record this past summer, due in part to very early sea ice loss. H/T @Climatologist49 @CinderBDT907 @ajatnuvuk @amy_holman

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The Upper Midwest, which endured a brutally cold second half of winter last year, is the only part of the Lower 48 where above-normal temperatures are not favored. Instead, the outlook calls for equal chances of below-, normal and above-normal temperatures.

The precipitation forecast

 


NOAA winter precipitation outlook.

NOAA’s outlook paints a sprawling zone with elevated chances for above-normal precipitation from Montana to the northern Mid-Atlantic. Within this zone, it’s especially likely to be wet in the northern plains and Upper Midwest. These areas also had a very wet second half of winter last year, which led to historic spring and summer flooding, and the situation could repeat next year if this forecast is correct.

Drier-than-normal weather is favored in parts of the Deep South and central California, where NOAA is calling for the onset of drought conditions.

Ocean temperatures are abnormally high off the California coast, forming a zone some scientists have referred to as “the blob.” Although some scientists have attempted to link this warm water with elevated chances for drought in California, Mike Halpert, deputy director of NOAA’s Climate Prediction Center, told reporters Thursday that he’s unconvinced.

The blob “usually doesn’t play a large role in climate outcomes over North America,” he said.

Halpert made clear that NOAA’s forecast for drought in California is based on computer model forecasts, not the high offshore temperatures.

Rō’bear Re’por going to the dark side

Unknown.pngDear Readers

Rō’bear is going to the Dark side for a few weeks beginning Sept. 14th. Traveling south to check out rumors of a Deep State in the Central Andes along with some fly fishing and of course observance of the daily Pisco Hour.  He will procure assistance from local personas de mala reputación y conferencistas invitados residing in Rio Blanco, Portillo & Papudo Chile  …  then hopefully return with a few stories early October to share with rŌbert devotees.

While the jefe is visiting the Dark Side you can go to the bottom of each page in the Re’por to Older Posts which will take you back in time to past stories from the bad old days.

“It’s the truth even if it didn’t happen”  Ken Kesey

Seguro, 

The Management

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