World_24hr_May_2018
--May is the last month of meteorological spring in the Northern Hemisphere, and of autumn 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 move slowly from varying directions in the tropics. ~Ron Holle
Jun 2, 2018 Webmaster Archive
Northern Hemisphere -- May lightning over the United States occurs in both large and small systems, clusters, and lines across nearly all of the country. --Major lightning-producing squall lines move from the northwest to southeast across northeast India and Bangladesh, especially early in the month. --Extensive lightning occurs over Saudi Arabia, including the southern Red Sea coast. --The Mediterranean coasts of Morocco, Algeria, and Tunisia have thunderstorms on many days. --Alaska, Canada, China, Europe, and Russia have very few strokes until later in May. --Central America and Mexico lightning increases significantly during May. ~Ron Holle
Jun 6, 2018 8:49:56 PM Dave Fincher
Tropics --The equatorial trough, the Intertropical Convergence Zone, is in an east-northeast/west-southwest alignment over the Atlantic Ocean, well defined in an east-west swath over the Eastern North Pacific, but difficult to identify over the Indian and Western Pacific Oceans. --The major islands and land areas of tropical Southeast Asia, including New Guinea, have daily thunderstorms in sea breezes and along mountain slopes; they are mostly stationary. --Storms develop on many May days over Ethiopia and move to the west-southwest. --Madagascar has thunderstorms on only a few days in May, while the Sahara and South Atlantic are nearly free of lightning. --Thunderstorms are frequent over the Indian subcontinent, Cambodia, Laos, Thailand, and Vietnam. --Lightning activity shifts to the north of 10 degrees South latitude over Brazil by the end of May. --The southern boundary of thunderstorms over Africa steadily shifts northward during May. ~Ron Holle
Jun 6, 2018 8:51:50 PM Dave Fincher
Southern Hemisphere --The Andes provide a sharp western boundary in a NNW-SSE line and no lightning occurs over the cold water offshore of the Andes. --The South Atlantic and South Pacific Oceans away from the continent have few thunderstorms. -- Australia and New Zealand lightning is in a few large organized systems in May. ~Ron Holle
Jun 6, 2018 8:52:02 PM Dave Fincher
--01 to 11 May: Numerous squall lines race from north to south over Bangladesh. --03 to 04 May: Continuous line of lightning from Texas to Ohio. --04 to 08 May: Several large organized north-south squall lines form over Cameroon and surrounding regions, move offshore over the Atlantic, then dissipate. --18 to 19 May: A cold front clears thunderstorms over land areas from south to north from Argentina to central Brazil. --19 to 26 May: Tropical Cyclone Mekunu develops over Arabian Sea and moves northwest onshore to Yemen and Oman. --24 to 30 May: Tropical Storm Alberto moves inland along Florida Gulf Coast. --26 to 27 May: Frequent lightning over the United Kingdom. ~Ron Holle
Jun 6, 2018 8:52:15 PM Dave Fincher