Tropical cyclone forecast model: Difference between revisions

Revision as of 04:51, 24 August 2007

Revision as of 02:27, 3 September 2007

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*'''A98E''' is a statistical-dynamical prediction model using geopotential heights from the GFS forecast to modify the CLIPER forecast. It incorporates portions of the NHC90 and NHC98 Atlantic forecast models.

*'''GFS''' ([[National Weather Service]] [[Global Forecast System]]) is the main meteorological model for the United States. The model is run four times a day (six hours apart). It is a merger and expansion of the AVN and MRF models and is extended out to 384 hours.

In [[2007]], the [[National Centers for Environmental Prediction|NCEP]]*'''HWRF''' [[Hurricane Weather Research and Forecasting model|Hurricane-WRF]] becameis operationala anddynamical nested model that uses the NAM as a source of its background data. HWRF is usedintended to helpeventually forecastreplace the GFDL as the main nested model for hurricane prediction, but also aides in the forecasting of track, intensity, and rainfall from tropical cyclones. .<ref>http://www.noaanews.noaa.gov/stories2007/s2885.htm</ref><ref>WRF Program Coordinator. [http://wrf-model.org/development/wexob/meetings/Monthly-PC-Report-31Oct04.pdf Monthly Report of the WRF Program Coordinator.] Retrieved on [[2007-04-10]].</ref> The HWRF was introduced at the beginning of the 2007 hurricane season.

In [[2007]], the [[National Centers for Environmental Prediction|NCEP]] [[Hurricane Weather Research and Forecasting model|Hurricane-WRF]] became operational and is used to help forecast track, intensity, and rainfall from tropical cyclones.<ref>http://www.noaanews.noaa.gov/stories2007/s2885.htm</ref><ref>WRF Program Coordinator. [http://wrf-model.org/development/wexob/meetings/Monthly-PC-Report-31Oct04.pdf Monthly Report of the WRF Program Coordinator.] Retrieved on [[2007-04-10]].</ref>

Some models do not produce output quickly enough to be used for the forecast cycle immediately after the model starts running. Most of the above track models (except CLIPER) require data from global weather models, which produce output about four hours after [[synoptic time]]. However, for half of their forecasts, the NHC issues forecasts only three hours after that time, so some "early" models - NHC90, BAM, and LBAR - are run using a 12-hour-old forecast for the current time. "Late" models, such as the GFS and GFDL, finish after the advisory has already been issued. These models are [[interpolation|interpolated]] to the current storm position for use in the following forecast cycle - for example, GFDI.<ref name="NHCsummary_DeMaria"/><ref name="2005_Verification"/>