Search Results
1. Introduction Conventional observational data are inadequate in providing accurate initial and boundary conditions for numerical model simulations and forecasts of tropical cyclones (TCs), thus often leading to poor track and intensity forecasts ( Wu and Kuo 1999 ; Wu et al. 2005 ). Therefore, making additional observations in the critical areas that will have the maximum influence on numerical forecasts of TCs is an important task. Operational aircraft surveillance missions have been
1. Introduction Conventional observational data are inadequate in providing accurate initial and boundary conditions for numerical model simulations and forecasts of tropical cyclones (TCs), thus often leading to poor track and intensity forecasts ( Wu and Kuo 1999 ; Wu et al. 2005 ). Therefore, making additional observations in the critical areas that will have the maximum influence on numerical forecasts of TCs is an important task. Operational aircraft surveillance missions have been
the eyewall structure changes that are involved in intensity forecasting. The impact of RS winds in mesoscale model forecasts of tropical storms is described by Pu et al. (2008) . In section 2 , the procedure for deriving the RS winds is presented. A series of data assimilation and forecast experiments using NOGAPS and the Naval Research Laboratory (NRL) Atmospheric Variational Data Assimilation System (NAVDAS) will be described in section 3 . NOGAPS ( Hogan and Rosmond 1991 ) is a primitive
the eyewall structure changes that are involved in intensity forecasting. The impact of RS winds in mesoscale model forecasts of tropical storms is described by Pu et al. (2008) . In section 2 , the procedure for deriving the RS winds is presented. A series of data assimilation and forecast experiments using NOGAPS and the Naval Research Laboratory (NRL) Atmospheric Variational Data Assimilation System (NAVDAS) will be described in section 3 . NOGAPS ( Hogan and Rosmond 1991 ) is a primitive
( Houze et al. 2007 ). We thus have very limited skill in predicting tropical cyclone formation, rapid intensification, fluctuation, or decay ( Elsberry et al. 2007 ). High-resolution cloud-resolving mesoscale models, along with better initialization of the initial vortex, may be necessary to faithfully represent the internal dynamics that is crucial for hurricane intensity forecasts ( Houze et al. 2007 ; Chen et al. 2007 ; Davis et al. 2008 ). Despite improvements in using advanced data
( Houze et al. 2007 ). We thus have very limited skill in predicting tropical cyclone formation, rapid intensification, fluctuation, or decay ( Elsberry et al. 2007 ). High-resolution cloud-resolving mesoscale models, along with better initialization of the initial vortex, may be necessary to faithfully represent the internal dynamics that is crucial for hurricane intensity forecasts ( Houze et al. 2007 ; Chen et al. 2007 ; Davis et al. 2008 ). Despite improvements in using advanced data
operational hurricane track forecast models . Bull. Amer. Meteor. Soc. , 77 , 925 – 933 . Hodyss , D. , and S. J. Majumdar , 2007 : The contamination of ‘data impact’ in global models by rapidly growing mesoscale instabilities . Quart. J. Roy. Meteor. Soc. , 133 , 1865 – 1875 . Kleist , D. T. , D. F. Parrish , J. C. Derber , R. Treadon , W.-S. Wu , and S. Lord , 2009 : Introduction of the GSI into the NCEP Global Data Assimilation System . Wea. Forecasting , 24 , 1691
operational hurricane track forecast models . Bull. Amer. Meteor. Soc. , 77 , 925 – 933 . Hodyss , D. , and S. J. Majumdar , 2007 : The contamination of ‘data impact’ in global models by rapidly growing mesoscale instabilities . Quart. J. Roy. Meteor. Soc. , 133 , 1865 – 1875 . Kleist , D. T. , D. F. Parrish , J. C. Derber , R. Treadon , W.-S. Wu , and S. Lord , 2009 : Introduction of the GSI into the NCEP Global Data Assimilation System . Wea. Forecasting , 24 , 1691
track and intensity forecasts in a mesoscale model ( Chou and Wu 2008 ). In addition to the impact of DOTSTAR dropwindsonde data on TC track forecasts, detailed aspects such as targeted observations on TCs and validation of remote sensing data have also be studied ( Wu et al. 2007a , 2009a , b , c ; Yamaguchi et al. 2009 ; Chou et al. 2010 ). In summer 2008, the international THORPEX Pacific Asian Regional Campaign (T-PARC) was conducted in the western North Pacific. The aim of the multinational
track and intensity forecasts in a mesoscale model ( Chou and Wu 2008 ). In addition to the impact of DOTSTAR dropwindsonde data on TC track forecasts, detailed aspects such as targeted observations on TCs and validation of remote sensing data have also be studied ( Wu et al. 2007a , 2009a , b , c ; Yamaguchi et al. 2009 ; Chou et al. 2010 ). In summer 2008, the international THORPEX Pacific Asian Regional Campaign (T-PARC) was conducted in the western North Pacific. The aim of the multinational
sufficient horizontal resolution to accurately simulate mesoscale TC structure, which is problematic when observations resolve such features. For example, Aberson (2008) showed that assimilating eye and eyewall dropsonde data at coarse resolution can result in degraded track and intensity forecasts. Therefore observations from the NOAA P3 and NRL P3 are not assimilated on the outer domain. For similar reasons, TC minimum SLP data is not assimilated in these experiments. Small ensembles have a tendency
sufficient horizontal resolution to accurately simulate mesoscale TC structure, which is problematic when observations resolve such features. For example, Aberson (2008) showed that assimilating eye and eyewall dropsonde data at coarse resolution can result in degraded track and intensity forecasts. Therefore observations from the NOAA P3 and NRL P3 are not assimilated on the outer domain. For similar reasons, TC minimum SLP data is not assimilated in these experiments. Small ensembles have a tendency
1. Introduction The accuracy of tropical cyclone (TC) forecasts is of great concern to both civilian and military interests. The forecast of the TC itself is of obvious concern for regions that may be directly impacted by the storm, but in some cases the storm forecast may significantly affect remote regions as well. It has been shown that when TCs recurve into the midlatitudes, they can have a substantial impact on the midlatitude environment well downstream, and the extratropical transition
1. Introduction The accuracy of tropical cyclone (TC) forecasts is of great concern to both civilian and military interests. The forecast of the TC itself is of obvious concern for regions that may be directly impacted by the storm, but in some cases the storm forecast may significantly affect remote regions as well. It has been shown that when TCs recurve into the midlatitudes, they can have a substantial impact on the midlatitude environment well downstream, and the extratropical transition
using singular vectors. J. Atmos. Sci. , 56 , 2965 – 2985 . Burpee , R. W. , J. L. Franklin , S. J. Lord , R. E. Tuleya , and S. D. Aberson , 1996 : The impact of Omega dropwindsondes on operational hurricane track forecast models. Bull. Amer. Meteor. Soc. , 77 , 925 – 933 . Chou , K-H. , and C-C. Wu , 2008 : Development of the typhoon initialization in a mesoscale model: Combination of the bogused vortex with the dropwindsonde data in DOTSTAR. Mon. Wea. Rev. , 136
using singular vectors. J. Atmos. Sci. , 56 , 2965 – 2985 . Burpee , R. W. , J. L. Franklin , S. J. Lord , R. E. Tuleya , and S. D. Aberson , 1996 : The impact of Omega dropwindsondes on operational hurricane track forecast models. Bull. Amer. Meteor. Soc. , 77 , 925 – 933 . Chou , K-H. , and C-C. Wu , 2008 : Development of the typhoon initialization in a mesoscale model: Combination of the bogused vortex with the dropwindsonde data in DOTSTAR. Mon. Wea. Rev. , 136
. Mon. Wea. Rev. , 130 , 1552 – 1572 . Henderson , J. M. , R. N. Hoffman , S. M. Leidner , T. Nehrkorn , and C. Grassotti , 2005 : A 4D-VAR study on the potential of weather control and exigent weather forecasting. Quart. J. Roy. Meteor. Soc. , 131 , 3037 – 3052 . Hoffman , R. N. , 2006 : Using 4d-VAR to move a simulated tropical cyclone in a mesoscale model. Comput. Math. Appl. , 52 , (8–9) . 1193 – 1204 . Hoffman , R. N. , J. M. Henderson , S. M. Leidner , C
. Mon. Wea. Rev. , 130 , 1552 – 1572 . Henderson , J. M. , R. N. Hoffman , S. M. Leidner , T. Nehrkorn , and C. Grassotti , 2005 : A 4D-VAR study on the potential of weather control and exigent weather forecasting. Quart. J. Roy. Meteor. Soc. , 131 , 3037 – 3052 . Hoffman , R. N. , 2006 : Using 4d-VAR to move a simulated tropical cyclone in a mesoscale model. Comput. Math. Appl. , 52 , (8–9) . 1193 – 1204 . Hoffman , R. N. , J. M. Henderson , S. M. Leidner , C
current ADSSV is calculated based on the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5; Grell et al. 1995 ) adjoint modeling system. In the Atlantic Ocean basin, the TC track forecasts have been improved by 15%–20% within the 5-day forecast period for those missions designed by the targeted strategies ( Aberson 2008 ). In the western North Pacific Ocean basin, an average of 20% improvement for the 12–72-h track forecasts over the NCEP
current ADSSV is calculated based on the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5; Grell et al. 1995 ) adjoint modeling system. In the Atlantic Ocean basin, the TC track forecasts have been improved by 15%–20% within the 5-day forecast period for those missions designed by the targeted strategies ( Aberson 2008 ). In the western North Pacific Ocean basin, an average of 20% improvement for the 12–72-h track forecasts over the NCEP