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A meteogram is a quick way to view computer model data in a table format out in time for a site. Time is listed horizontally with the corresponding forecasted values displayed below in easy-to-read columns.


While meteogram tables are a powerful forecast tool, the most important thing to remember is that the data has NOT been reviewed by a WeatherFlow meteorologist prior to publication on the web. The values displayed are simply what the model expects to happen without any additional fine-tuning by a human.

The arrows point in the direction of the flow.

Several different meteogram options are available for viewing by clicking the tabs across the top of the product:


The default view for the meteogram is the "Extended Guidance" tab. This view incorporates two different medium-resolution models into one meteogram for a seamless view of weather data out to one week for those users wanting a longer term forecast. Clicking the "Show Additional Data" link will reveal additional weather parameters below the default parameters shown.
The main benefit of the Extended Guidance meteogram is the ability to view forecast data out for a long period of time. However, while this is appealing for making sailing plans well in advance, remember that computer model forecast accuracy drops considerably the further you go out in time. The best course of action is to monitor the Extended Guidance meteogram over the course of several days to see whether the forecasted winds are changing or staying relatively consistent. A large amount of variation in these trends from day to day should translate to low confidence in the accuracy of the model data, and vice-versa.


The "Short Guidance" tab shows meteogram data over a much shorter time period of 24 hours, but from the highest resolution model available for the site. Typically this will be the proprietary WeatherFlow RAMS (WRAMS) model, with the main benefit here being a unique data set not available anywhere else. Data is also shown hourly instead of every three hours.

The trade-off between the Extended and Short Guidance meteograms is model accuracy versus time. Given the tendency for higher resolution models to have higher accuracy, especially within the first 24 hours of a model run, the Short Guidance meteogram is an excellent choice for those users wanting to know the wind forecast for the current or next day.


In addition to the Extended and Short Guidance meteograms, all of the individual model meteograms are provided. This setup gives the user the ability to view even more model data (if desired) and compare the wind forecast across several different sources. The amount of data shown will vary and depend on the length of each model run. For example, the NAM 12km model will have data out to 84 hours, the GFS out to 180 hours, etc.

We present computer generated model data in several ways: on the graph as a faded line, on our forecast maps as colors and lines, and in the meteogram tables. There are many different sources for computer generated forecasts, and our goal is to provide you with our best automated forecast as well as give you tools to make your own forecast.

Our proprietary model, the WRAMS model (described below) is usually the best available model for short-term forecasts. WRAMS is run twice a day (00Z, 12Z) across much of North America, out about 36 hours, at a temporal resolution of one hour, and at various spatial resolutions as fine as 2km. Data from WRAMS is only available from WeatherFlow - you can't get it anywhere else.

Many parts of North America are covered by the 12km NAM (North American Model), produced by NOAA. The NAM, formerly known as ETA, is run by the National Centers for Environmental Prediction. This model is run four times a day (00,06,12,18Z), running out to 84 hours. It has a 12 km horizontal resolution and generates a forecast for every third hour.

NOAA also generates a global model, the Global Forecast System (GFS), which is run four times a day (00,06,12,18Z) and produces forecasts up to 16 days in advance, but with decreasing spatial and temporal resolution over time (it is widely accepted that beyond 7 days the forecast is little better than guesswork). It produces a forecast for every 3rd hour for the first 180 hours.

The ARW 5km- Hawaii Model is another model run from UCAR incorporating several different models in an attempt to get better accuracy in Hawaii and Alaska. Here is some technical information about this model. The higher resolution at 5km should enable this model to better pick out the intricacies of the islands.


Numerical Weather prediction (weather modeling) is an extremely complex and computer intensive process. Here are the fundamental steps:

1) Define an Area with appropriate grid Resolution

2) Gather Weather Readings.

3) Run Model- Complex series of equations

4) Repeat process

5) Analyze how accurately equations performed and revise equations accordingly.

Weatherflow has designed a modeling system that leverages it's mesonet, meteorologists, and modelers to create the most accurate model for the coastal environment. Below we will show how the different aspects of Weatherflow contribute and constantly improve the WRAMS Weatherflow model.


Why does the grid resolution of the model matter?

The coastal zone is where computer weather models perform the worst. The primary reason for this is the complexities between water and land temperatures as well as friction and topography. When choosing a model to try to predict the weather in this area it is important to use one that can actually "see" the body of water that your going to be on.

Below is a comparison between 12km resolution model (which is the standard resolution for most weather services) and the 2km RAMS model for San Francisco Bay. Note that the 12km doesn't even see the Bay! If it can't see it, how can it forecast for it??


What difference does this make? Below is the San Francisco forecast comparison between the 12km and 2km models for the exact same time. Notice the complexity that the 2km model is able to pick out compared to the coarse approach of the 12km model. Which would you choose for making your decision?


What good is running your own high resolution model if you can't verify if it's right?




The "backbone" of Weatherflow is our network of precision weather stations. With 350+ stations (and always growing) placed right in the land/sea interface, Weatherflow is able to see and log weather events and effectively verify the model's accuracy.

Note that: Since no other company/agency has such a dense and accurate coastal network, nobody else can verify their models!

In fact... since nobody else has this network, they aren't even aware that the models are wrong!


Regional Atmospheric Modeling System - (RAMS) + Weatherflow Feedback processing= WRAMS

RAMS is a state-of-the-art multipurpose, numerical prediction model designed to simulate atmospheric circulations spanning in scale from hemispheric scales down to large eddy simulations (LES) of the planetary boundary layer. It is at the core of the WeatherFlow Forecasting System. RAMS was primarily developed at Colorado State University and Mission Research Corporation, and now also by ATMET. The most frequent applications of RAMS are to simulate atmospheric phenomena on the mesoscale (horizontal scales from 2 km to 2000 km) for purposes such as:
- weather forecasting
- photochemical ozone modeling and precursor transport
- air quality studies
- acid deposition
- long range transport
- nuclear emergency response
- environmental and atmospheric research.

RAMS can drive advanced Lagrangian particle and hybrid Eulerian dispersion models which predict mesoscale pollution impacts in complex, time-dependent, mesoscale circulations.

RAMS is equipped with a multiple grid nesting scheme which allows the model equations to be solved simultaneously on any number of interacting computational meshes of differing spatial resolution. The highest resolution meshes are used to model the details of smaller-scale atmospheric systems, such as flow over complex terrain and surface-induced thermal circulations. The coarser meshes are used to model the environment of these smaller systems, thus providing boundary conditions to the fine mesh region. In addition, the coarser meshes are used to simulate larger scale atmospheric systems which interact with the mesoscale systems resolved on the finer grids.

RAMS Technical Details.


Weatherflow employs a full time staff of operational Meteorologists. With over 25+ combined years of forecasting the coastal areas our forecasters have learned (and still are learning) the nuances of the coastal weather. Using the Weatherflow sensor network to verify their theories, our Meteorologists are able to give the modelers direct feedback on where the models are wrong. Since Weatherflow runs it's own WRAMS model... we have the ability to alter the models based on this feedback.

No other weather company is able to know that their coastal forecasts are wrong... let alone have the ability to fix it!



Weatherflow provides several different models for our customers including the NAM(ETA) and GFS(AVN), which we download from the government just like all other forecast companies. We provide this data complementary on our commercial websites.

What differentiates Weatherflow is our use of our own proprietary model called the WRAMS model. This high resolution model is customized to run where all models have the most trouble... at the coastal interface.

WRAMS is a work in progress and by design...always will be. Weatherflow is the only company with the resources and expertise to make WRAMS successful. The exclusive mesonet of sensors, the team of coastal forecasters, and the technical team of programmers and modelers all work in concert to gradually improve the model's accuracy.



Numerical Weather prediction (weather modeling) is an extremely complex and computer intensive process. Here are the fundamental steps:

1) Define an Area with appropriate grid Resolution

2) Gather Weather Readings.

3) Run Model- Complex series of equations

4) Repeat process

5) Analyze how accurately equations performed and revise equations accordingly.

Weatherflow has designed a modeling system that leverages it's mesonet, meteorologists, and modelers to create the most accurate model for the coastal environment. Below we will show how the different aspects of Weatherflow contribute and constantly improve the WRAMS Weatherflow model.



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