The FNMOC is another version of the THE SIGNIFICANT SWELL HEIGHT FORECAST charts, which shows us a full 7-day forecast of SWELL/SEA HEIGHTS occurring in smaller scale maps, giving us a tighter resolution. With some slightly different tweaking to get a better view of a smaller area the FNMOC model works the same way the bigger models work… using a wind model to determine surface wind speeds and then doing the math; processing the duration, intensity, as well as the path/track of those winds, and then crunching out a numerical picture of how big the seas will be anywhere in the assigned (nested) area. Again these models use colorized maps to show sea-heights and the movement of the storm tracks.top
Again the FNMOC is a smaller, more focused version of the swell-period forecast charts that you can see globally, by ocean, regionally, and sub-regionally. They track swell in swell period form as the energy moves away from the storm source. This tracking, particularly at this tighter resolution allows you to see how the incoming swell moves through the region…and in cases like Southern California or Central America, you can see how it may take a swell an extra day to move completely from Central America to Southern Mexico. Again this is a good tool to use in tandem with other models…using the wave heights, sea-level-pressure, and swell period forecast models you can paint a very vivid picture on how a swell will be affecting your favorite breaks.top
Yet another swell tighter resolution version of the sea-level-pressure chart…still gives you the 7-day forecast but since the FNMOC charts we are normally using, are targeted at the tropical regions, it gives us more of a heads up on potential tropical storms. If we see a tightly wound ball of low-pressure, and lots of green-to-red/purple colors swirling around the low, there is a good chance at some intense rainfall, thunderstorms, which generally indicate we could see some deeper convection and potentially a tropical storm forming in the region.top
This chart looks very much like the COAMPS model but don’t mistake them for each other. The FNMOC wind-stream forecast model shows the surface winds, and even pulls out areas where the winds get intense by using color blobs and wind flow with those same directional areas. The main difference is that the COAMPS uses a grid that creates a point every 10-meters while the FNMOC model, to save processing power, has grid points as far as 10-15 miles apart…it makes for less “dialed in” focus that you see on the COAMPS but it saves a lot of time crunching the numbers and will update faster and more often throughout the day.
Ahhh the Shear forecast…this chart is for extreme hurricane junkies and pilots that don’t like their planes torn in half. There is so much happening on this chart that it almost gives you a seizure the first time you look at it…but once you start to understand the color scheme a bit and what it is trying to tell you it starts to make some sense. To get a good grip on this chart the first thing you need to do is start thinking of the atmosphere in layers like a big cake with lots of flavors. You have winds moving in a dynamic fashion both horizontally and vertically…now the majority of the time the vertical motion is less dynamic than winds moving on the same layer…but there is a little crossover which can help change the direction of the layers above or below. The second important part of this chart is the conditions needed for tropical storm formation, one of which is the amount of shear that is occurring in the area the storm is trying to develop in. In this chart, blue stands for heavy shear, which means the winds in the layers are blowing in opposite directions. Yellow is for medium shear, so winds aren’t totally blowing against each other but they aren’t helping either. Green means are all layers are blowing the same direction and there is little no shear…these are the ideal conditions for tropical storm/hurricane formation.top