1. Weather and its Impact on Aviation Operations National Weather Service Hastings, Nebraska Kearney Explorers Club November 21, 2006

2. High and Low Pressure Systems

8. Cold and Warm Fronts

15. Density Altitude

19. Wind Shear

20. Change in wind speed and direction as you go higher in the atmosphere – Changes are sometimes very abrupt Low level wind shear – Horizontal winds – Vertical winds

23. Aircraft Icing

24. Disrupts smooth flow of air over wing surfaces and around airplane parts that stick out – Decreases lift – Adds weight to aircraft Icing prevention – On the ground De-icing procedure – In the air Avoiding clouds with temperatures and humidities which lead to ice buildups

31. Thunderstorms

32. Thunderstorm Hazards Downburst winds Hail Reduced visibilities

46. Terminal Aerodrome Forecasts

47. Airport specific forecasts within 5 miles of the center of the airport for a 24-hour period Weather elements – Wind and wind shear – Cloud levels – Precipitation / fog / dust / sand – Visibility – Probability of precipitation toward the end of the forecast

48. Terminal Aerodrome Forecasts TAF GRI 191128Z 191212 25006KT P6SM SKC FM1600 30010KT P6SM SKC FM1900 33013KT P6SM SKC FM0000 32006KT P6SM FEW250 FM0400 VRB03KT P6SM SCT250

49. Regional Airports

50. NWS Hastings TAF Site Grand Island (KGRI) – Located 2 miles east-northeast of Grand Island – Elevation: 1846 ft. MSL

51. NWS Hastings TAF Site Grand Island (KGRI) – Airport is serviced by an ASOS Augmentation of observations is performed by Grand Island Control Tower personnel from 0600 to 2200 local time Occurrences of precipitation or thunderstorms are manually appended to observations as a remark

52. NWS Hastings TAF Site Grand Island (KGRI) – Main forecast considerations Diurnal pressure gradient winds Thunderstorm intensities during convective season Low ceilings/visibilities during stratiform precipitation events Radiation Fog

54. Transcribed Weather Broadcasts

55. Weather forecasts for expected conditions 25 miles on either side of specified routes of flight (50 mile-wide corridor) 12-hour forecast

56. Regional Airports

57. TWEB 261 KOMA-KGRI-KLBF

58. TWEB 261 KOMA-KGRI-KLBF TWEB 261 KOMA-KGRI-KLBF Combines regional surface observations (METARs) and terminal forecasts (TAFs) – METARs: Omaha, Offutt AFB, Council Bluffs (IA), Millard, Fremont, Lincoln, Columbus, York, Aurora, Grand Island, Hastings, Kearney, Broken Bow, Lexington, North Platte – TAFs: Omaha, Lincoln, Grand Island, North Plattte

59. TWEB 261 KOMA-KGRI-KLBF Prevailing conditions defined for entire route or portions of the route – Logical separation of meteorological occurrences Pre-frontal conditions Post-frontal conditions Airmass thunderstorms Surface gradient winds > 25 knots Low level wind shear

60. Questions? The End