Tropical Storm List

Transcription

1 Tropical Storm List Tropical-Storms is a mailing list only for those who are professionally active in either the research or forecasting of tropical storms worldwide. Monsoon is a mailing list for those who are professionally active in the research or forecasting of monsoons worldwide.

2 Tropical Cyclogenesis: Operational Forecasting Perspective International Workshop on Tropical Cyclones Jeju Island, South Korea Working group: Chris Landsea (RSMC Miami), Lixion Avila (RSMC Miami), Thierry Dupont (RSMC La Reunion), S. D. Kotal (RSMC New Delhi), and M. Mohapatra (RSMC New Delhi)

3 Accurate tropical cyclone genesis forecasting is important because of The need to provide extended community response planning, especially in remote or large communities The need to provide advisories at extended forecast ranges for offshore and onshore commercial activities The requirement for National Meteorological Services to manage forecasting and reconnaissance resources The potential to reduce future track, intensity, and size errors by more accurately defining the likely genesis location

4 Accurate tropical cyclone genesis forecasting is important because of The need to provide extended community response planning, especially in remote or large communities The need to provide advisories at extended forecast ranges for offshore and onshore commercial activities The requirement for National Meteorological Services to manage forecasting and reconnaissance resources The potential to reduce future track, intensity, and size errors by more accurately defining the likely genesis location

5 Accurate tropical cyclone genesis forecasting is important because of The need to provide extended community response planning, especially in remote or large communities The need to provide advisories at extended forecast ranges for offshore and onshore commercial activities The requirement for National Meteorological Services to manage forecasting and reconnaissance resources The potential to reduce future track, intensity, and size errors by more accurately defining the likely genesis location

6 Accurate tropical cyclone genesis forecasting is important because of The need to provide extended community response planning, especially in remote or large communities The need to provide advisories at extended forecast ranges for offshore and onshore commercial activities The requirement for National Meteorological Services to manage forecasting and reconnaissance resources The potential to reduce future track, intensity, and size errors by more accurately defining the likely genesis location

7 Within the 2010 IWTC report there was a substantial optimism that genesis forecasting was becoming a solvable problem: Both Ensemble Prediction Systems (EPS) and deterministic Numerical Weather Prediction (NWP) models were routinely capturing TC formation. Improvement in formation forecasts from operational numerical models were expected given advances in various aspects of numerical weather prediction systems, which includes increased resolution, improved parameterization schemes, and improved use of observations, especially satellite data to improve initial conditions. However, tropical cyclone genesis forecast continued to remain a challenging aspect of operational forecasting in the major tropical forecasting centers, as there was still no effective systematic approach in place for genesis forecasting, especially with respect to NWP guidance.

8 Within the 2010 IWTC report there was a substantial optimism that genesis forecasting was becoming a solvable problem: Both Ensemble Prediction Systems (EPS) and deterministic Numerical Weather Prediction (NWP) models were routinely capturing TC formation. Improvement in formation forecasts from operational numerical models were expected given advances in various aspects of numerical weather prediction systems, which includes increased resolution, improved parameterization schemes, and improved use of observations, especially satellite data to improve initial conditions. However, tropical cyclone genesis forecast continued to remain a challenging aspect of operational forecasting in the major tropical forecasting centers, as there was still no effective systematic approach in place for genesis forecasting, especially with respect to NWP guidance.

9 Within the 2010 IWTC report there was a substantial optimism that genesis forecasting was becoming a solvable problem: Both Ensemble Prediction Systems (EPS) and deterministic Numerical Weather Prediction (NWP) models were routinely capturing TC formation. Improvement in formation forecasts from operational numerical models were expected given advances in various aspects of numerical weather prediction systems, which includes increased resolution, improved parameterization schemes, and improved use of observations, especially satellite data to improve initial conditions. However, tropical cyclone genesis forecast continued to remain a challenging aspect of operational forecasting in the major tropical forecasting centers, as there was still no effective systematic approach in place for genesis forecasting, especially with respect to NWP guidance.

10 Definition of Tropical Cyclone A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and closed surface wind circulation about a well-defined center. - RSMC Miami/Honolulu (Atlantic/Northeast and North Central Pacific)

11 Definition of Tropical Cyclone A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and closed surface wind circulation about a well-defined center. - RSMC Miami/Honolulu (Atlantic/Northeast and North Central Pacific)

12 Definition of Tropical Cyclone A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and closed surface wind circulation about a well-defined center. - RSMC Miami/Honolulu (Atlantic/Northeast and North Central Pacific)

13 Definition of Tropical Cyclone A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and closed surface wind circulation about a well-defined center. - RSMC Miami/Honolulu (Atlantic/Northeast and North Central Pacific)

14 Definition of Tropical Cyclone A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and closed surface wind circulation about a well-defined center. - RSMC Miami/Honolulu (Atlantic/Northeast and North Central Pacific)

15 Definition of Tropical Cyclone A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and closed surface wind circulation about a well-defined center. - RSMC Miami/Honolulu (Atlantic/Northeast and North Central Pacific)

16 Definition of Tropical Cyclone A warm-core, non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and closed surface wind circulation about a well-defined center. - RSMC Miami/Honolulu (Atlantic/Northeast and North Central Pacific) NOTE: No lower bound of sustained winds

17 Various Definitions of Tropical Cyclone RSMC La Reunion (Southwestern Indian Ocean) - the maximum of the average wind speed has to be at least 28 kt before a tropical disturbance can be considered a tropical depression. RSMC New Delhi (North Indian Ocean) - 17 kt. RSMC Fiji and TCWCs of the Southeastern Indian Ocean and Southwestern Pacific Ocean) - 34 kt. RSMC Tokyo (Northwest Pacific Ocean)- has no lower bound wind speed threshold

18 Forecasting Genesis when Definitions Differ Makes intercomparison of genesis across basins problematic Decision of if/when genesis occurs remains subjective Role of human forecaster is crucial for genesis prediction Genesis of Phanfone, 18W, 2014

19 Genesis Predictions Observations and Analyses Statistical Approaches Deterministic Global Models Ensemble Prediction Systems Statistical-Dynamical Hybrid Approaches

20 Genesis Predictions Observations and Analyses Statistical Approaches Deterministic Global Models Ensemble Prediction Systems Statistical-Dynamical Hybrid Approaches

21 Genesis Forecasting: Observations and Analyses A pre-existing disturbance containing abundant deep convection Latitudes poleward ~5 o SST > 26 o C A sufficiently unstable atmosphere & deep layer of moist air

22 Genesis Forecasting: Observations and Analyses (cont.) Small vertical shear of the horizontal wind Upper-tropospheric anticyclonic outflow Enhanced lower tropospheric relative vorticity Appearance of curved banding features in the deep convection Falling surface pressure: 24-hour pressure changes (falls) of usually 3 mb or more

23 Genesis Predictions Observations and Analyses Statistical Approaches Deterministic Global Models Ensemble Prediction Systems Statistical-Dynamical Hybrid Approaches

24 Cossuth et al. (2013) moe.met.fsu.edu/genesis

25 0-48h Tropical Cyclone Formation Probability Schumacher et al. (2009) 0-24h /TROP/TCFP/index.html 24-48h

26 Genesis Predictions Observations and Analyses Statistical Approaches Deterministic Global Models Ensemble Prediction Systems Statistical-Dynamical Hybrid Approaches

27 Examining Global Model Output for Genesis At least one closed isobar (at 4 mb interval) with lowered central pressure Reasonable structure (closed circulation center, warm core, deep vertical extent, non-baroclinic) Longevity of the vortex for at least a day

28 Very Good Global Model Predictions of Genesis GFS forecasts verifying at genesis time of Hurricane Arthur 28

29 Not so Good Global Model Predictions of Genesis GFS forecasts verifying at genesis time of Hurricane Sandy F168 F156 F144 F132 F120 F108 F96 F84 F72 F60 F48 F36 F24 F00

30 Genesis Predictions Observations and Analyses Statistical Approaches Deterministic Global Models Ensemble Prediction Systems Statistical-Dynamical Hybrid Approaches

31 GFS Ensemble-based Probabilities of Genesis

32 Composite track of tropical cyclone before genesis Elsberry et al. (2011a,b)

33 Genesis Predictions Observations and Analyses Statistical Approaches Deterministic Global Models Ensemble Prediction Systems Statistical-Dynamical Hybrid Approaches

34 Tropical Cyclone Genesis Index Predictors: 1) Dvorak classification 2) 850 mb divergence 3) 850 mb vorticity change 4) mb shear 5) 600 mb humidity 6) Deep convection Dunion (2013)

35 Blending deterministic global models for genesis probabilities Halperin et al. (2013) -

36 Blending deterministic global models for genesis probabilities Halperin et al. (2013) -

37 Tropical Weather Outlook

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41 Pre-Genesis Tropical Cyclone Advisories at RSMC Miami To be issued for systems with at least a medium likelihood of genesis within 48 h 72 hr track, intensity, size forecast Only to be issued when a Tropical Storm Warning, Hurricane Watch, or Hurricane Warning needed Beginning in 2016 experimentally

42 Example of Pre-Genesis Advisory

43 Possible Recommendations Researchers should develop methods for providing quantitative (probabilistic) genesis prediction guidance via deterministic, ensemble, and statistical-dynamical models Researchers should develop methods for provide methods for providing pre-genesis prediction guidance of TC track, intensity and size via deterministic, ensemble, and statistical-dynamical models RSMCs/TCWCs should explore issuing quantitative genesis predictions to the public RSMCs/TCWCs should explore increasing lead-time of existing quantitative genesis predictions to the public RSMCs/TCWCs should explore the possibility of issuing pregenesis tropical cyclone track, intensity, and size forecasts

44 Possible Recommendations Researchers should develop methods for providing quantitative (probabilistic) genesis prediction guidance via deterministic, ensemble, and statistical-dynamical models Researchers should develop methods for provide methods for providing pre-genesis prediction guidance of TC track, intensity and size via deterministic, ensemble, and statistical-dynamical models RSMCs/TCWCs should explore issuing quantitative genesis predictions to the public RSMCs/TCWCs should explore increasing lead-time of existing quantitative genesis predictions to the public RSMCs/TCWCs should explore the possibility of issuing pregenesis tropical cyclone track, intensity, and size forecasts

45 Possible Recommendations Researchers should develop methods for providing quantitative (probabilistic) genesis prediction guidance via deterministic, ensemble, and statistical-dynamical models Researchers should develop methods for provide methods for providing pre-genesis prediction guidance of TC track, intensity and size via deterministic, ensemble, and statistical-dynamical models RSMCs/TCWCs should explore issuing quantitative genesis predictions to the public RSMCs/TCWCs should explore increasing lead-time of existing quantitative genesis predictions to the public RSMCs/TCWCs should explore the possibility of issuing pregenesis tropical cyclone track, intensity, and size forecasts

46 Possible Recommendations Researchers should develop methods for providing quantitative (probabilistic) genesis prediction guidance via deterministic, ensemble, and statistical-dynamical models Researchers should develop methods for provide methods for providing pre-genesis prediction guidance of TC track, intensity and size via deterministic, ensemble, and statistical-dynamical models RSMCs/TCWCs should explore issuing quantitative genesis predictions to the public RSMCs/TCWCs should explore increasing lead-time of existing quantitative genesis predictions to the public RSMCs/TCWCs should explore the possibility of issuing pregenesis tropical cyclone track, intensity, and size forecasts

47 Possible Recommendations Researchers should develop methods for providing quantitative (probabilistic) genesis prediction guidance via deterministic, ensemble, and statistical-dynamical models Researchers should develop methods for provide methods for providing pre-genesis prediction guidance of TC track, intensity and size via deterministic, ensemble, and statistical-dynamical models RSMCs/TCWCs should explore issuing quantitative genesis predictions to the public RSMCs/TCWCs should explore increasing lead-time of existing quantitative genesis predictions to the public RSMCs/TCWCs should explore the possibility of issuing pregenesis tropical cyclone track, intensity, and size forecasts

48 Tropical Cyclogenesis: Operational Forecasting Perspective International Workshop on Tropical Cyclones Jeju Island, South Korea Working group: Chris Landsea (RSMC Miami), Lixion Avila (RSMC Miami), Thierry Dupont (RSMC La Reunion), S. D. Kotal (RSMC New Delhi), and M. Mohapatra (RSMC New Delhi)