Application of the WRF and HWRF models for tropical cyclone development

Luis M. Farfán
CICESE, Mexico
Noon October 2 in Room 2155

Tropical cyclones from the eastern Pacific basin may have tracks that approach northwest Mexico and cause an impact on the population as well as on the surrounding environment. In particular, during the last 66 years more than 40 cyclones moved over land across the Baja California peninsula and most of them occurred in September. Therefore, they are an important group of weather systems to monitor and forecast.

As part of the outreach activities provided by CICESE, we provide support to emergency managers to better understand the observations of storm structure and estimates of intensity changes. This includes the analysis of real-time, high-resolution imagery from geostationary satellites. Another component of this support is an interpretation of the forecasts provided by the U.S. National Hurricane Center and the Mexican Meteorological Service. This includes explaining the benefits, limitations and cautions to be exercised with the information stated in the official forecasts. Also, it implies a revision of the available information (advisories, discussions and probabilities) as well as the predictions derived from global-and regional-scale models in the ATCF database.

Beginning with the season of 2014, simulations from the WRF (from ARW, version 3.5) and HWRF (from DTC, version 3.5a) models are used to predict weather conditions in Baja California. The input data is from the GFS model and, because of limitations on computer and network resources, the simulations are performed only once per day, with data from 00 UTC for prediction times up to 120 hours. Basically, we concentrate on making graphical products to show the spatial distribution of wind fields as well as the evolution of precipitation over the southern peninsula: 23-28°N. Also, there are comparisons between our tracks and those derived from ATCF including the official forecasts.

During this talk, examples from the HWRF model performance with respect to landfall events from the period 2006-2010 will be provided. Also, we will discuss preliminary results from 2014 as well as future plans for upcoming seasons.