World_Sep_2017_6hr
--September is the first month of meteorological autumn in the Northern Hemisphere, and of spring in the Southern Hemisphere. --By tracking the latest hours in white, the overhead sun can be seen moving east to west on a daily basis. --Thunderstorms travel west to east over the middle and higher latitudes in both hemispheres, and are stationary or move more slowly from varying directions in the tropics. ~Ron Holle
Oct 3, 2017 Webmaster Archive
Northern Hemisphere --Alaska, Canada, China, Europe, Russia, and the United States have less lightning than in August. --Most of the Indian subcontinent has frequent lightning throughout September. Thunderstorms form to the south and north of the Himalayas until late in the month. --Japan has frequent lightning throughout the month as strong systems arrive from the west. ~Ron Holle
Nov 3, 2017 10:54:13 PM Dave Fincher
Tropics --The east-west aligned equatorial trough, the Intertropical Convergence Zone, is moderately defined over the eastern North Pacific and western Atlantic during September, and sporadic over the western Pacific. --The major islands and land areas of tropical Southeast Asia have thunderstorms nearly every afternoon in sea breezes and along mountain slopes. Motion is generally from east to west near the equator. --Central America and Mexico have frequent thunderstorms. --Lightning over Africa is mostly south of the Sahara and moves southward during September. A steady progression of easterly waves forms over equatorial Africa that move west to the Atlantic coast at intervals of three to five days. --Thunderstorms over Brazil spread southward through the month. ~Ron Holle
Nov 3, 2017 10:54:25 PM Dave Fincher
Southern Hemisphere --Several storms form over South Africa, Australia, and Argentina and move offshore to the east. --Organized thunderstorms move steadily from west to east across the southern oceans. --The Andes south of the equator provide a sharp western boundary in a NNW-SSE line and no lightning occurs over the cold water offshore of the Andes. ~Ron Holle
Nov 3, 2017 10:54:50 PM Dave Fincher
Specific --03 to 05 September: Large cyclonic circulation over southeastern Europe. --05 to 07 September: Cold frontal boundary has a large amount of associated lightning from New England to Texas. --05 to 12 September: The circulation of Hurricane Irma is evident starting east of Puerto Rico while it moves to the west, then north over Florida. --07 to 10 September: Thunderstorms extend to the northwest United State and southwest British Columbia. --12 to 15 September: Typhoon Talim moves from east of Taipei to northwest, then north. --16 to 21 September: Large cyclonic circulation persists over eastern India and Bangladesh. --19 to 20 September: Long west-to-east line of lightning over western Russia.--10 to 12 September: Cold front aligned from west to east moves southward over southern China. --20 to 23 September: The circulation of Hurricane Maria is apparent over Puerto Rico while it moves to the west, then northwest to the Atlantic east of the United States. ~Ron Holle
Nov 3, 2017 10:55:01 PM Dave Fincher