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Atlantic Tropical Action 2014


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Also has outrageous convection well NE of the system.

 

That's the main reason why it shows an out to sea solution.  The LLC follows the heaviest convection.  We've seen it before like with Debby in 2012 where the center kept reforming NE following the heaviest convection.  

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I understand that, but that shift east is from the 00z run to the 06z run. The map in question is listed as 12z guidance and I am just wondering why they include 06z model runs on that map.

This information is readily available not the NHC website:

b. Early versus Late Models

Forecast models are characterized as either early or late, depending on whether they are available to the forecaster during the forecast cycle. For example, consider the 1200 UTC forecast cycle, which begins with the 1200 UTC synoptic time and ends with the release of an official forecast at 1500 UTC. The 1200 UTC run of the NWS/Global Forecast System (GFS) model is not complete and available to the forecaster until about 1600 UTC, an hour after the forecast is released. Thus, the 1200 UTC GFS would be considered a "late" model since it could not be used to prepare the 1200 UTC official forecast. Conversely, the BAM models are generally available within a few minutes of the time they are initialized. Therefore, they are termed "early" models. Model timeliness is listed in Table 1.

 

Due to their complexity, dynamical models are generally, if not always, late models. Fortunately, a technique exists to take the latest available run of a late model and adjust its forecast so that it applies to the current synoptic time and initial conditions. In the example above, forecast data for hours 6-126 from the previous (0600 UTC) run of the GFS would be smoothed and then adjusted, or shifted, so that the 6-h forecast (valid at 1200 UTC) would match the observed 1200 UTC position and intensity of the TC. The adjustment process creates an "early" version of the GFS model that becomes part of the most current available guidance for the 1200 UTC forecast cycle. The adjusted versions of the late models are known, largely for historical reasons, as "interpolated" models.

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This information is readily available not the NHC website:

b. Early versus Late Models

Forecast models are characterized as either early or late, depending on whether they are available to the forecaster during the forecast cycle. For example, consider the 1200 UTC forecast cycle, which begins with the 1200 UTC synoptic time and ends with the release of an official forecast at 1500 UTC. The 1200 UTC run of the NWS/Global Forecast System (GFS) model is not complete and available to the forecaster until about 1600 UTC, an hour after the forecast is released. Thus, the 1200 UTC GFS would be considered a "late" model since it could not be used to prepare the 1200 UTC official forecast. Conversely, the BAM models are generally available within a few minutes of the time they are initialized. Therefore, they are termed "early" models. Model timeliness is listed in Table 1.

 

Due to their complexity, dynamical models are generally, if not always, late models. Fortunately, a technique exists to take the latest available run of a late model and adjust its forecast so that it applies to the current synoptic time and initial conditions. In the example above, forecast data for hours 6-126 from the previous (0600 UTC) run of the GFS would be smoothed and then adjusted, or shifted, so that the 6-h forecast (valid at 1200 UTC) would match the observed 1200 UTC position and intensity of the TC. The adjustment process creates an "early" version of the GFS model that becomes part of the most current available guidance for the 1200 UTC forecast cycle. The adjusted versions of the late models are known, largely for historical reasons, as "interpolated" models.

Thank you very much for that response! I guess that is why the "early" map model runs are nearly identical to the original 06z runs as the only change that would occur are observed differences from 0-6 hours out.

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Thank you very much for that response! I guess that is why the "early" map model runs are nearly identical to the original 06z runs as the only change that would occur are observed differences from 0-6 hours out.

Exactly, they simply do a correction (interpolation) based on the observed 06h error.

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This thing is racing westward. I'm not sure any model had a handle on how fast this is moving westward. They all seem to have him moving slower than 96L actually is.

 

 It's pretty clear when you look at the INVEST tracks (that are corrected to an observed position of the estimated center) that the global model init locations are behind the (apparent) actual location. This physically moves their whole forecast track west.

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 It's pretty clear when you look at the INVEST tracks (that are corrected to an observed position of the estimated center) that the global model init locations are behind the (apparent) actual location. This physically moves their whole forecast track west.

 

Add the faster motion and potential need to move the tracks west with the trough possibly dropping 96L off could raise concerns for people along the east coast. Gonna have to wait and see where a real center forms and start getting model runs that could be more reliable.

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Remarkably the UKMET (only thing available is the text product) at 12Z has it enter the GOM. It's not nearly as much of a crack-smoking purveyor of horrific tropical track forecasts the way the Canadian is:

 

 

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER  30 HOURS

                   FORECAST POSITION AT T+ 30 : 20.7N  72.6W

 

  VERIFYING TIME     POSITION     STRENGTH        TENDENCY

  --------------     --------     --------        --------

 00UTC 24.08.2014  21.6N  73.3W     WEAK    INTENSIFYING SLIGHTLY

 12UTC 24.08.2014  21.9N  75.4W     WEAK        LITTLE CHANGE

 00UTC 25.08.2014  21.8N  76.5W     WEAK        LITTLE CHANGE

 12UTC 25.08.2014  22.1N  77.9W     WEAK        LITTLE CHANGE

 00UTC 26.08.2014  21.5N  79.1W     WEAK    INTENSIFYING SLIGHTLY

 12UTC 26.08.2014  22.2N  80.3W     WEAK     WEAKENING SLIGHTLY

 00UTC 27.08.2014  23.8N  82.7W     WEAK        LITTLE CHANGE

 12UTC 27.08.2014  24.6N  85.7W     WEAK    INTENSIFYING SLIGHTLY

 00UTC 28.08.2014  25.5N  88.5W     WEAK        LITTLE CHANGE

 12UTC 28.08.2014  27.5N  90.4W     WEAK    INTENSIFYING SLIGHTLY

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Remarkably the UKMET (only thing available is the text product) at 12Z has it enter the GOM. It's not nearly as much of a crack-smoking purveyor of horrific tropical track forecasts the way the Canadian is:

 

 

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER  30 HOURS

                   FORECAST POSITION AT T+ 30 : 20.7N  72.6W

 

  VERIFYING TIME     POSITION     STRENGTH        TENDENCY

  --------------     --------     --------        --------

 00UTC 24.08.2014  21.6N  73.3W     WEAK    INTENSIFYING SLIGHTLY

 12UTC 24.08.2014  21.9N  75.4W     WEAK        LITTLE CHANGE

 00UTC 25.08.2014  21.8N  76.5W     WEAK        LITTLE CHANGE

 12UTC 25.08.2014  22.1N  77.9W     WEAK        LITTLE CHANGE

 00UTC 26.08.2014  21.5N  79.1W     WEAK    INTENSIFYING SLIGHTLY

 12UTC 26.08.2014  22.2N  80.3W     WEAK     WEAKENING SLIGHTLY

 00UTC 27.08.2014  23.8N  82.7W     WEAK        LITTLE CHANGE

 12UTC 27.08.2014  24.6N  85.7W     WEAK    INTENSIFYING SLIGHTLY

 00UTC 28.08.2014  25.5N  88.5W     WEAK        LITTLE CHANGE

 12UTC 28.08.2014  27.5N  90.4W     WEAK    INTENSIFYING SLIGHTLY

 

Interesting. The UKMET is, indeed, a respectable (top tier) model for the tropics unlike the CMC. This could be quite the surprise and a potentially dangerous setup for the US Gulf coast if this solution were to verify closely. Does the UKMET have the faster forward speed initiated more accurately than the GFS and Euro?

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Guest Imperator

Could this be Sandy II  for New Jersey ?

This what happens when you put too much raw information in unprofessional hands.... 

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The 12z ECMWF ensemble mean is still clustered between Florida and Cuba as of 18z Tuesday. This matches up well with the 00z ECMWF ensemble mean and keeps the window open for a further west solution. If the ridge is able to build to the north, 96L should find itself in a favorable upper level enviornment with warm SST.

 

By 00z Friday the 12z ECMWF ensemble mean is centered directly over Central Florida.

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The 12z ECMWF ensemble mean is still clustered between Florida and Cuba as of 18z Tuesday. This matches up well with the 00z ECMWF ensemble mean and keeps the window open for a further west solution. If the ridge is able to build to the north, 96L should find itself in a favorable upper level enviornment with warm SST.

 

By 00z Friday the 12z ECMWF ensemble mean is centered directly over Central Florida.

Just to illustrate this. Ensembles are still very much all over the place.

post-12104-0-56183000-1408738508_thumb.p

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