6. Roll or Arcus Cloud

11. Supercell Thunderstorms

28. Squall Lines

35. Bow Echos

39. Often Associated with Strong Straight Line Winds Known as “Derechos” Can reach 100-150 mph http://www.youtube.com/watch?v=EGJmO eDEBtwhttp://www.youtube.com/watch?v=EGJmO eDEBtw Great Derecho Website: http://www.spc.noaa.gov/misc/AbtDerechos/d erechofacts.htm

40. Climatology (Events over 1980- 2001

41. High Resolution Numerical Prediction of Convection

42. Explicit Convective Prediction Requires high resolution (4km or less grid spacing) Requires high-resolution analysis of current situation, using radar, surface observations and all other assets. NCAR (WRF model) and CAPS (Oklahoma, ARPS model) are two leading efforts.

43. Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) Using the WRF Model Goal: Study the lifecycles of mesoscale convective vortices and bow echoes in and around the St. Louis MO area 10 km WRF forecast domain 4 km WRF forecast domain Field program conducted 20 May – 6 July 2003

44. Real-time WRF 4 km BAMEX Forecast Composite NEXRAD RadarReflectivity forecast Initialized 00 UTC 9 June 03

45. Real-time WRF 4 km BAMEX Forecast Composite NEXRAD Radar 4 km BAMEX forecast 36 h Reflectivity 4 km BAMEX forecast 12 h Reflectivity Valid 6/10/03 12Z

46. 27h WRF BAMEX Forecast Valid 6/10/03 03Z 4 km Max Reflectivity 10 km Max Reflectivity

47. 30h WRF BAMEX Forecast Valid 6/10/03 06Z 4 km Max Reflectivity 10 km Max Reflectivity

48. Real-time WRF 4 km BAMEX Forecast Initialized 00 UTC 10 June 03 Reflectivity forecastComposite NEXRAD Radar

49. Real-time 12 h WRF Reflectivity Forecast Composite NEXRAD Radar 4 km BAMEX forecast Valid 6/10/03 12Z 10 km BAMEX forecast 22 km CONUS forecast

50. Composite NEXRAD RadarReflectivity forecast Real-time WRF 4 km BAMEX Forecast Initialized 00 UTC 30 May 03

51. Real-time WRF 4 km BAMEX Forecast Composite NEXRAD Radar23 h Reflectivity Forecast Line of Supercells Valid 5/30/03 23Z

52. Realtime WRF 4 km BAMEX Forecast Composite NEXRAD Radar30 h Reflectivity Forecast Squall line 6” hail 00Z Valid 6/23/03 06Z

53. Real-time WRF 4 km BAMEX Forecast Initialized 00 UTC 11 June 03 Reflectivity forecastComposite NEXRAD Radar

54. Realtime WRF 4 km BAMEX Forecast Composite NEXRAD Radar30 h Reflectivity Forecast Missed Valid 6/12/03 06Z

55. Real-time WRF 4 km BAMEX Forecast Initialized 00 UTC 24 May 03 Reflectivity forecastComposite NEXRAD Radar

56. Realtime WRF 4 km BAMEX Forecast Composite NEXRAD RadarReflectivity Forecast 12 h 24 h Squall line PersistsDissipates Initialized 5/24/03 00Z

57. Preliminary BAMEX Forecast Verification (Done, Davis, and Weisman) Mode for corresponding convective systems For Convective Mode 2 or 3 Cases Observed YesNo Cases Predicted 6125 1621 Yes No Probability of detection (POD) = 79% False alarm rate (FAR) = 29%

58. A High-Resolution Modeling Study of the 24 May 2002 Dryline Case during IHOP (Xue and Martin 2006a,b MWR) Goal: Understand exactly WHEN, WHERE, HOW convection is initiated

59. Time and Location of Initiation (Loop time: 17UTC – 22 UTC)

60. Surface analysis + satellite images From Wakimoto et al. (2006 MWR). 1900 2000 2200 2100

61. 20:02UTC

62. 19:32UTC

63. 20:32UTC

64. 21:02UTC

65. 21:32UTC

66. 22:02UTC

67. 22:58UTC

68. 23:58UTC

69. 18 UTC May 24, 2002 I.C. 3 km / 1km grid

70. Model Configurations ARPS model with full physics, including ice microphysics + soil model + PBL and TKE-SGS turbulence 1200 UTC 1800 UTC 0006 UTC 1km 3km CI ~ 2000UTC 0000 UTC ADAS

71. Surface analysis plus obs at 18 Z

72. t=3h, 2100 UTC sfc. winds, qv, and composite reflectivity

73. t=4h, 2200 UTC

74. t=5h, 2300 UTC

75. Animation of 1 km forecast

76. t=3h, 2100 UTC

77. t=2h t=2h 15min t=2h 30min t=2h 45min A A A B B B C C C B A 2000 UTC 2015 UTC 2030 UTC 2045 UTC