AV Geeks 16mm Lunch 7-12-2024

is is I is hello everybody I'm skip alimer welcome to the avgeeks lunchtime streaming show where we watch old 16 mm films and that was a bunch of uh weather satellite footage made for NASA by different aerospace companies and unfortunately there's no soundtrack on that material cuz I'd love to hear it love to know more uh today we watch films about rain and flooding because that's what we're getting warnings about uh here in Raleigh North Carolina right now it's been a pretty nice drizzle but there's thunder and lightning so who knows what could happen we could lose power we could lose internet but we're just going to keep going uh right now it doesn't seem floody but um supposedly before 3:00 we're supposed to get a lot of um rain so I don't know what's going to happen but I have a lot of questions about weather and one of them is why why does it change let's find out [Music] we all know that weather changes that clear skies become cloudy that there are warm days and cold days dry times and Times of precipitation what makes the weather change the answer lies in air masses that form over different parts of our Earth in the polar regions air becomes cold the slatting Rays of the Polar Sun even in summer do not heat polar regions very much but in the tropics the nearly d direct rays of the sun keep the land warm all year round and the warm land heats the air that is over it our weather changes mainly because of air masses that drift away from the cold polar regions and the warm tropical regions Within These two regions there are six important areas where air masses develop air masses that form over land called Continental air masses are usually dry with less water vapor in them than maritime air masses which form over the water that surrounds our continent let's look more closely at each of these air masses one kind of Continental air mass is called polar Canadian Air this air mass usually travels Southeast across Canada to the Northern parts of the United States in summer polar Canadian air breaks heat waves bringing rain then cool fair weather but in Winter polar Canadian Air brings severe cold producing the cold waves that can affect much of North America while polar Canadian air masses form over land polar Pacific air masses form over water this air is not as cold as Polar Canadian Air but cool and full of water vapor from the North Pacific Ocean when the polar Pacific air masses reach the Pacific coast the water vapor forms clouds that drop rain or snow on the high Western mountains just as Polar Pacific air masses usually move east across North America polar Atlantic air masses usually drift East to Europe occasionally though polar Atlantic air masses move move west to the coast of Canada and the United States this cool moist maritime air often causes fogs in summer and heavy snows in Winter another kind of air mass the tropical Continental forms over Mexico and the southwestern United States in the summer air masses that form over this part of the continent are hot and dry as they move northeastward they usually bring clear skies tropical Gulf and Tropical Atlantic air masses form over regions of the warm Gulf of Mexico and South Atlantic Ocean and contain a great amount of water vapor in summer these tropical air masses are often the cause of severe heat waves as they travel northward across parts of the United States tropical Pacific air masses are also warm and humid they form over warm parts of the Pacific Ocean and travel Eastward to the Pacific coast of North America as they cross the mountains near the West Coast they often produce rain or snow moving on in an easterly Direction tropical and polar air masses from these six region are constantly in movement generally Eastward across most of the United States and Canada most changes in weather come about when different air masses come in contact with one another when a tropical Gulf air mass drifts northward and meets a cooler air mass we'll find the meeting marked on a weather map this line shows the boundary between the warm air mass on the left and the cooler on the right such a meeting where warm air replaces cold air is called a warm front as seen from the side the edge of the warm air mass slowly slides up over the cooler air mass pushing it back like this the first signs that a warm front is passing over you are high cirrus clouds then you see lower serratus and altostratus clouds thin and flat soon the clouds you see are Nimbo stratus clouds and finally rain begins to fall as the warm front continues to move past you pushing away the last of the cold air the clouds may get so low that they nearly touch the ground and there is fog with the rain when the warm front has passed and the warm air has completely replaced the cooler air the weather is usually clear warm and humid when a mass of cold polar air drifts South and meets a warm air mass pushing it back we may also find the meeting marked on a weather map this line shows the boundary between the cold air on the left and the warm air on the right such a meeting where cold air replaces warm air is called a cold front the edge of the warm air mass is tipped upward as the cold air pushes under it if a cold front were passing over you first you would probably see large fluffy cumulous clouds condensing out of the rapidly rising and cooling warm War moist air then you would see thick cumulonimbus rain clouds that often bring thunderstorms heavy rain and strong winds but soon the sky clears as the cold front passes and the cool air completely replaces the warm air now the air is cool or cold a warm air mass can sometimes become trapped between two cooler air masses this happens when a slow moving warm front is overtaken by a cold front the whole warm air mass is squeezed off the ground such a meeting of fronts is called an uded front High feathery cirrus clouds appear first then lower ones in layers then both Nimbo Stratus and cumulon nimbus clouds bring the storm and heavy rain or snow can fall [Applause] when the storm passes there are a few higher cumulus clouds and the weather is fair again and so across our continent move warm air masses from the south and cold air masses from the north changing our weather bringing us the variety of weather that most parts of North America experience [Music] meteorologists today are working to gain a better understanding of weather and what makes it [Music] [Applause] change I don't know if you can hear it I don't want to unplug the microphone you hear the the rain um blowing against the window uh so we're in the midst of it of all this rain uh so again uh if we lose power or Internet um it's great seeing you uh I don't know what the flooding situation is going to be like I don't think it's going to be bad here but I I don't know who knows um this next film I showed uh early on on the on our streaming show in like 2020 but it's still pretty great it's uh Thunderbolt Hunters enjoy [Music] deafening and terrible Ying is the voice of nature roused the violence in the thunderstorm devastating the blinding bolts that flash between sky and Earth smashing trees smashing homes smashing anything that offers resistance to their Unleashed par since time's beginning men have looked at Flaming SK first in uncomprehending fear ofy my later with the courage of curiosity Benjamin Franklin's true dangerous experiment may have proved a little scientific V but they did set the pattern for a new and strange profession of today dedicated to spying on the angry skies and resting from nature the truth about her Thunderbolt lightning protection for our Power Systems give these studies High significance for almost every modern activity depends in some way on the steady uninterrupted flow of electricity so nowadays in any one of many selected options it's the first Telltale Rumble which Heralds an approaching thunderstorm direction North Northeast velocity 35 okay thanks2 lot of fireworks moving in big step a dooy heading for New York City how about calling that that guy over there that that guy who's always looking for lightning now right after midnight say when a rip snorton storm's coming up hi Don't Mean a Thing To That Bird he's a thunderbolt Hunter thus from some distant airport or power company Outpost comes the warning for which our modern Thunderbolt Hunter has waited days weeks perhaps months welcome is the call in the dead of night for nighttime is best suited to successful operation of the traps by which this scientific Huntsman snares his game Empire State buing powering Darkly above New York's NightLight the steel framed spires of Manhattan serve as Myriad lightning blocks tallest of these and most effective for Gathering Thunder is the Empire State Building here the hunter goes into AMP one of his lightning STS is set way up in the very peak of the tower this TR is really a battery of special machines which measure and record the time duration and varying current of any lightning stroke which may hit the building here he is 104 floors above the street sprads his way through the Maze of Steel beams and Braes starts the machine tend them carefully while they warm up now everything is in Readiness to take the Fingerprints of any visiting license but this is only half the job he's off to another ambush half a mile away at the world's busiest Corner 39 floors up in the air is a battery of strange high-speed cameras especially designed to photograph lightning bolts at play at the throw of a switch Motors begin to wh voltage is precisely adjusted and as the storm sweeps over New York there's nothing to do but wait but not for long and and another portrait for the Thunderbolt Hunters picture gallery back in the laboratory these curious portraits are assembled for study how' you like to see the Fingerprints of a thunderbolt straight from the Empire State Building well there they are and Beauty a series of sharp Peaks on a chart and there's a perfect play byplay photograph of the same lightning stroke together these pictures provide a compl complete record and if they don't make sense to you and me it's only because we're not experienced Thunderbolt Hunters let's go back to the camera room and interpret these pictures in terms everybody can understand our eyes saw only this but here are some surprises revealed by the Thunderbolt Hunter's Ultra highspeed cameras what appeared as a single flash was in reality a series of Strokes starting with a St leader a sort of lightning Scout moving downward in a series of short rushes changing course with each Rush when this Advanced agent of lightning contacts the ground and establishes a conducting path a vicious high power return stroke climbs up the leader from the earth convert