Brief description of the main models used?

[Rockin4NOLA]

Hey all,

Forgive me if this question has already been asked but I've been trying to understand the different model acronyms and was wondering if someone could give me a basic description of the main ones, for ex. BAMS? HWRF?

Thanks so much.

[clfenwi]

Here's a couple of links that you may find of interest

http://www.nhc.noaa.gov/modelsummary.shtml

http://www.srh.noaa.gov/ssd/nwpmodel/html/nhcmodel.htm

I was going to leave it at that, but I'll try to give you a very quick and dirty summary of the models that you may find mentioned.

Global forecast models:
These are general purpose weather forecasting models that are run 2-4 times a day, every day of the year.

GFS - Global Forecasting System: The model used by NOAA
CMC - aka "the Canadian", ran by the Canadian equivalent of the National Weather Service
UKMET - ran by the UK's Meteorological Office.
ECMWF - aka "the Euro" or "European", ran by the European Centre for Medium range Weather Forecasts.
NOGAPS - ran by the US Navy.

Limited Area models:
These models are designed specifically for hurricanes, and as such are run every six hours, when there is something to track (invest or tropical cyclone).

GFDL - designed by NOAA's Geophysical Fluid Dynamics Laboratory
HWRF - Hurricane Weather Research and Forecast model, was by NOAA to replace the GFDL. However, it has not shown sufficiently superior performance to do so.

Tropical models: Like the limited area models they are run every six hours when there is something to track. However, they are much less sophisticated.

BAMS
BAMM
BAMD are variations of the Beta and Advection Model. Each model plots the storm's forecast model assuming a particular vertical extent of the storm (Shallow, Medium, or Deep) and moves it along the predominant steering current at the particular level. (I.e. an undeveloped system with little vertical extent would tend to follow the track forcast by the Shallow Bam, while a fully developed storm would be better forcast by the Deep).

SHIPS - Statistical Hurricane Intensity Prediction Scheme - uses input from the GFS and satellite imagery, along with a track forecast from BAMM (or the NHC if available) to generate an intensity forecast.

[Rockin4NOLA]

Thanks so much! I've been wondering why certain models seemed to be referenced so often. Now I know what I'm looking at lol.

[brunota2003]

Also, as a side note, when the BAM models are in line, or fairly close to being in line, with one another...wind shear usually is not a problem for the system...but if the shallow model is going west and the medium or deep model is going north or in some other random direction, then that system is likely dealing with some hefty shear.

Likewise, when you see a graphic with the models posted, if the different models (GFS, BAM, NOGAPS, GFDL, HWRF, etc) tend to "spider" out, the steering currents are weak or are forecast to collapse, meaning the storm is going to meander around a bit and the models don't have a good handle on it.