all right all now that we're through the hurricane stuff I want to talk a little bit about North nor easers and then wrap up by comparing hurricanes to some of the other severe weather events just so you make sure you have everything down before we get ready to take the next exam and then there will be one more lecture set to watch on flooding so the type of storm that we're talking about here are nor easers this is where we have a low pressure center that's located up just off of the New England area in the northeastern United States there's a little article here at the bottom that you can click to read more about these different events okay but the reason I'm talking about them here is because some of the damage impacts can be similar to what we see with our smaller hurricane type events now you'll notice here that I'm saying the left front quadrant is one of the stronger parts of a nor Easter so that's different than what I just talked about with hurricanes and the right front quadrant being the strongest one so again I'm talking about this because some of the characteristics are similar although they form in a different manner so here's a typical pressure map setup of where the nor Easter is located up in the northeastern United States so here's our low pressure center right up here okay you see the warm front out ahead in this part and then you see the cold front in behind so you'll notice right away that's different than what we've talked about with hurricanes because hurricanes are weakened by strong upper level winds and frontal systems that interact with them okay so nor easers are different in that they are more strong frontal systems that wind up with strong cyclonic circulation or counterclockwise circulation in the Northern Hemisphere and this takes place just off of the East Coast when we talk about them as nor easers and helps to bring in moisture from the Atlantic okay it can cause big snowstorms and big storm surge and things like that during certain times of year so one of the ways that these are talked about sometimes is talking about nor Easter as cold core storms because they're forming more up there by New England and the northeastern us and again we're talking about these being associated with frontal system so here is our cold front again right in here okay and the temperatures in these areas are going to be colder than what we find in the middle of our tropical systems remember tropical systems you have to have that 80° water fueling those systems this is very different very rarely do we have the nor easers over any type of water that would ever get to that temperature because of where they're located so even though the low pressure doesn't get to the level that it does with our hurricanes you know talking about pressures getting down below 920 mbars or something like that for for a category 5 hurricane even though that doesn't happen these big storm systems associated with these large low pressure waves can impact areas that are larger in total size so you can see here this system right how far it extends all the way from Canada down to pulling moisture actually up from the Caribbean itself okay now what does this have in common with hurricanes even though they're forming differently through these front systems and low pressure centers up in the northeastern part of the us well because they have that onshore flow of winds you can get lots of flooding carrying that moisture Inland and you can also get storm surge and Coastal damage that is similar to some of our smaller hurricanes that we can see along the Gulf Coast in fact there's actually a storm that occurred a famous storm an Ash Wednesday storm that occurred along the Atlantic coast that actually impacted 700 miles of the coastline itself and some of the open ocean waves that were documented were 30 ft high and so you can see the amount of property loss here and the types of damage even though these aren't as big as some of the most intense hurricanes because they hit really populated areas of the Northeast they can cause some extensive extensive damage so just looking at again what the Ash Wednesday storm looked like and if I didn't tell you where this picture picture was from or what caused it you could look at this and think it was a hurricane that impacted these different areas but in this case it was a nor Easter storm so in some cases there's been Storm surges that have been documented as high as 16 ft related to nor easers and similar to some of our hurricane events a lot of the damage is concentrated along the coastline itself because of that water surging Inland as a result of the storm now one of the storms you may have heard about in the past is actually super storm Sandy which caused all that damage in New York and New Jersey in those areas and so you can see the path that that took here is the tropical storm and it actually trapped North this way follow along the track and it actually got caught up and fed into this nor Easter type of setup okay so this really was kind of a perfect storm of conditions and something that we don't see all that of often but in this case we had a lot of moisture that got carried up from the tropics and then got wrapped around that low pressure system of fronts that's more associated with nor easers and so you had that nor Easter onsh onshore flow plus extr tropical moisture getting carried into the center of it which led to Major flood events up there in the northeastern part of the United States so just going back to compare some things and make sure you're reviewing what you need to for the exam and stuff over the severe weather part before we get to the flooding itself as its own lecture make sure that you are comparing the difference in size how the different events form how long they last how big they are and how many times you actually see these things so that's all listed here and is for you to review as well in the PDF but remember for example hurricanes are much larger okay and they last a lot longer than tornadoes however tornadoes occur many more times per year even though a lot of those are smaller tornadoes and not our biggest events make sure you also know the differences between hurricanes and how our big thunderstorm waves form in those systems of fronts that move across the us remember that hurricanes are part of waves that come out of the tropics and that frontal systems do not interact well with hurricanes remember frontal systems are associated with strong winds a loft or strong upper level winds we might also say and remember that would tear apart A hurricane's circulation around that low pressure center theat to wave Cyclones form in the mid latitudes just like it says so they're forming more out of the tropics and forming more in the northern United States and then moving across with that system of fronts as the Westerly direct that Central low pressure wave when we think about hurricanes remember their strongest winds are at the surface themselves where they're causing damage and storm surge and things like that and remember we want light upper level winds with our hurricanes if we're going to see them form and persist mlad to wave Cyclones on the other hand are different because their strongest winds are a loft because the jet stream overlies these and that helps intensify mid latitude wave Cyclones and thunderstorm systems remember if the stream system were present over hurricanes remember that would create more single Direction flow and decrease the likelihood of having that strong rotation around a hurricane system in a hurricane we have sinking air right in the middle in a midl two- wave Cyclone the air is rising right along the middle of that frontal system where the air is getting forced up along that boundary between the two different types of air and lastly when we look at hurricanes compared to our other systems if you're going to find them on a weather map remember that hurricanes have a very strong pressure gradient Force which means the change in pressure is very high over a small distance and so when you see this mapped out you see the isobars or the lines of equal pressure space closer together and that's what indicates big changes in pressure over a small distance okay that's the main wrapup up for our severe weather portion and the last thing we're going to cover during the severe weather portion related to exam 3 is flooding so make sure you watch that last lecture before you take your exam