RT Journal Article
T1 On the impact of initial conditions in the forecast of Hurricane Leslie extratropical transition
A1 López Reyes, Mauricio
A1 González Alemán, Juan Jesús
A1 Sastre Marugán, Mariano
A1 Insua Costa, Damián
A1 Bolgiani, Pedro Mariano
A1 Martín, M.L.
AB Hurricane Leslie (2018) was a non-tropical system that lasted for a long time undergoing several transitions between tropical and extratropical states. Its trajectory was highly uncertain and difficult to predict. Here the extratropical transition of Leslie is simulated using the Model for Prediction Across Scales (MPAS) with two different sets of initial conditions (IC): the operational analysis of the Integrate Forecast System (IFS) and the Global Forecast System (GFS). Discrepancies in Leslie position are found in the IC patterns, and in the intensity and amplitude of the dorsaltrough system in which Leslie is found. Differences are identified both in the geopotential height at 300 hPa and the geopotential thickness. Potential temperature in the dynamic tropopause shows a broader, more intense trough displaced western when using the IC-IFS. The IC-IFS simulation shows lesser trajectory errors but wind speed overestimation than the IC-GFS one. The complex situation of the extratropical transition, where Leslie interacts with a trough, increases the uncertainty associated with the intensification process.The disparities observed in the simulations are attributed to inaccuracies in generating the ICs. Both ICs generate different atmospheric configurations when propagated in time. Results suggest that during an extratropical transition in a highly baroclinic atmosphere, the IFS model’s data assimilation method produced a more precise analysis than GFS due to the greater number of observations assimilated by the IFS, the greater spatial resolution of the model and the continuous adjustment of the simulations with the field of observations.
PB Elservier
SN 0169-8095
YR 2023
FD 2023-09-15
LK https://hdl.handle.net/20.500.14352/101758
UL https://hdl.handle.net/20.500.14352/101758
LA eng
NO López-Reyes, M., Gónzalez-Alemán, J. J., Sastre, M., Insua-Costa, D., Bolgiani, P., & Martín, M. L. (2023). On the impact of initial conditions in the forecast of Hurricane Leslie extratropical transition. Atmospheric Research, 295, 107020.
NO ECMWF
NO Instituto Frontera
DS Docta Complutense
RD 8 oct 2024