RJisLiving Posted April 28, 2011 Share Posted April 28, 2011 I'll check those out, thanks! Link to comment Share on other sites More sharing options...
hm8 Posted April 29, 2011 Share Posted April 29, 2011 http://cimss.ssec.wisc.edu/goes/blog/archives/7898 As the title asks....what the heck is this? Link to comment Share on other sites More sharing options...
isohume Posted April 29, 2011 Share Posted April 29, 2011 http://cimss.ssec.wi...g/archives/7898 As the title asks....what the heck is this? That's whats known in the meteorological world as creepy. Idk...it looks more menacing on the 6.5 µm than the visible. On the visible loop the accompanying cirrus is also spinning to some degree. Probably just some meso circ leftover from deep convection would be my guess. Neat. Link to comment Share on other sites More sharing options...
Ed Lizard Posted May 6, 2011 Share Posted May 6, 2011 Is Total-Totals still a good indication of mid level instability when 850 mb temps are extra warm due to the cap? Link to comment Share on other sites More sharing options...
isohume Posted May 6, 2011 Share Posted May 6, 2011 Is Total-Totals still a good indication of mid level instability when 850 mb temps are extra warm due to the cap? If you expect the cap to be broken, TTs can give a decent estimate of mlvl instability. If you don't expect the cap to be broken, other indices like ELCAPE, el-mixed layers, mlvl dry air, caa aloft, etc can give an indication of the elevated convective potential. Usually if the H85 temps are too high (cap) it could cause an unrealistically high TT based on the lapse rate alone. Link to comment Share on other sites More sharing options...
patrick05 Posted May 18, 2011 Share Posted May 18, 2011 sorry to bump the thread but there's a tstorm right now and i just remembered when i was still in the Philippines... we used to get a lot of thunderstorms there especially during afternoon... my grandparents used to say that the indication that the storm is ending is if i hear continuous rumbles of thunder... how true is this do you think?? when i was there it seemed to be true but i don't know that's why i ask... thanks! Link to comment Share on other sites More sharing options...
isohume Posted May 18, 2011 Share Posted May 18, 2011 sorry to bump the thread but there's a tstorm right now and i just remembered when i was still in the Philippines... we used to get a lot of thunderstorms there especially during afternoon... my grandparents used to say that the indication that the storm is ending is if i hear continuous rumbles of thunder... how true is this do you think?? when i was there it seemed to be true but i don't know that's why i ask... thanks! The continuous rumbling you hear from tstms moving away is due to the combination of shock waves reaching you from different lightning strikes. On a normal day (non-inversion) shock waves can have an audible range up to 10 miles, however ctg lightning has been known to travel 10 miles from it's parent storm. Therefore, it is never truly safe when you can still hear thunder. The NWS recommends you stay indoors for 30 minutes after the last clap of thunder is heard. Link to comment Share on other sites More sharing options...
Analog96 Posted May 18, 2011 Share Posted May 18, 2011 The continuous rumbling you hear from tstms moving away is due to the combination of shock waves reaching you from different lightning strikes. On a normal day (non-inversion) shock waves can have an audible range up to 10 miles, however ctg lightning has been known to travel 10 miles from it's parent storm. Therefore, it is never truly safe when you can still hear thunder. The NWS recommends you stay indoors for 30 minutes after the last clap of thunder is heard. That's basically very similar to the rules we had when I umpired baseball. 35 minutes after thunder. Delay the game, but if there's no shelter, go home. Link to comment Share on other sites More sharing options...
isohume Posted May 18, 2011 Share Posted May 18, 2011 That's basically very similar to the rules we had when I umpired baseball. 35 minutes after thunder. Delay the game, but if there's no shelter, go home. The NWS used to promote the 30/30 rule, which said take shelter when you can count 30 seconds or less between lightning and thunder and remain there for 30 minutes after the last thunder. This was too confusing of a message and if you can hear thunder, lightning can kill you. So basically now we're saying if thunder is heard, take shelter and remain there for 30 mins until aft last thunder is heard. Link to comment Share on other sites More sharing options...
Analog96 Posted May 18, 2011 Share Posted May 18, 2011 The NWS used to promote the 30/30 rule, which said take shelter when you can count 30 seconds or less between lightning and thunder and remain there for 30 minutes after the last thunder. This was too confusing of a message and if you can hear thunder, lightning can kill you. So basically now we're saying if thunder is heard, take shelter and remain there for 30 mins until aft last thunder is heard. It's basically safer. There were times when I violated the rule. I mean, if I KNEW it was a solid line of storms coming thru and it cleared rapidly, I might start them playing in 20 minutes, but that was rare. Link to comment Share on other sites More sharing options...
Ed Lizard Posted May 19, 2011 Share Posted May 19, 2011 Can one of the more knowledgable mets explain how to tell what kind of tornado we are viewing when watching a U-Tube video. I guess we can all tell the multi-vortex monsters from a supercell, but tropical funnels, land spouts, water spouts, and how to tell which is which. How high into the parent clouds structure they go. Are gustnadoes and land spouts the same animal? If some pro-met was really motivated, they could even link U-Tubes of the various types of tornadoes. Bonus question- if tropical funnels generally form in low shear conditions, than a tornado in a hurricane's rain band wouldn't be a tropical funnel, no? Link to comment Share on other sites More sharing options...
MJW155 Posted May 20, 2011 Share Posted May 20, 2011 Why is the SW coast of Florida more vulnerable to a hurricane storm surge than the SE coast of Florida? I know the continental shelf is just offshore on the eastern side but how is something below the water protecting the shoreline? If you look at the evacuation area for Collier County it's much larger than Broward County. http://www.floridadisaster.org/PublicMapping/2010/COLLIER.pdf http://www.floridadisaster.org/publicmapping/2010/BROWARD.pdf Link to comment Share on other sites More sharing options...
isohume Posted May 20, 2011 Share Posted May 20, 2011 Why is the SW coast of Florida more vulnerable to a hurricane storm surge than the SE coast of Florida? I know the continental shelf is just offshore on the eastern side but how is something below the water protecting the shoreline? If you look at the evacuation area for Collier County it's much larger than Broward County. http://www.floridadi...010/COLLIER.pdf http://www.floridadi...010/BROWARD.pdf One of the factors affecting storm surge is the slope and width of the continental shelf. The less steep and more wide the continental shelf is the more of a factor storm surge will be. Basically...less work needs to be done by the storm to bring a large mass of water upward and inland. These two graphics depict a shallow and steep continental shelf and the general effects on storm surge. Here is the continental shelf around srn FL. Note how steep it is around Miami and shallow and wide it is on the SW side. Link to comment Share on other sites More sharing options...
tmagan Posted May 21, 2011 Share Posted May 21, 2011 In addition, there is a Geology article that states the Bahamas platform is a barrier which limits the distance to which the hurricane can pile up the water. Link to comment Share on other sites More sharing options...
MJW155 Posted May 21, 2011 Share Posted May 21, 2011 One of the factors affecting storm surge is the slope and width of the continental shelf. The less steep and more wide the continental shelf is the more of a factor storm surge will be. Basically...less work needs to be done by the storm to bring a large mass of water upward and inland. Nice explantion. The graphics basically show it's harder for water to go uphill which makes sense. Link to comment Share on other sites More sharing options...
Metsfan Posted June 8, 2011 Share Posted June 8, 2011 Can any Met chime in on this. The NWS in OKX said this in thier morning forecast, and can't seem to figure out why this would occur. 850 MB DEWPOINTS NEAR 10C SHOULD ALLOW SURFACE DEWPOINTS TO DROP AS WE HEAT UP. How is this possible? Link to comment Share on other sites More sharing options...
tornadojay Posted June 8, 2011 Share Posted June 8, 2011 Can any Met chime in on this. The NWS in OKX said this in thier morning forecast, and can't seem to figure out why this would occur. 850 MB DEWPOINTS NEAR 10C SHOULD ALLOW SURFACE DEWPOINTS TO DROP AS WE HEAT UP. How is this possible? this is due to atmospheric mixing that takes place during the day. In the morning, there is generally an inversion, where there could be a higher dew point value near the surface with lower dew points up above. During this time of year, the atmosphere generally mixes down dry adiabically from 850 mb, such that the lower dew point values will mix downward toward the surface. Link to comment Share on other sites More sharing options...
Metsfan Posted June 8, 2011 Share Posted June 8, 2011 this is due to atmospheric mixing that takes place during the day. In the morning, there is generally an inversion, where there could be a higher dew point value near the surface with lower dew points up above. During this time of year, the atmosphere generally mixes down dry adiabically from 850 mb, such that the lower dew point values will mix downward toward the surface. good explaination thanks. Link to comment Share on other sites More sharing options...
Metsfan Posted June 8, 2011 Share Posted June 8, 2011 Can a Met chime in on this process, I am having difficulties understanding. 5.4 Squall Line Evolution When estimating the shear environment of a squall line, that component of the low-level environmental shear oriented perpendicular to the line exerts the most control on the line’s structure and evolution. This graphic shows three squall lines evolving in environments with identical shear profiles. Yet, because of their orientations, the squall lines are unlikely to evolve in the same way. The uppermost line will likely be a strong, long-lived system because all the wind shear is perpendicular to the line. On the other hand, the bottom system experiences no line-normal shear, so it will likely be a weaker, shorter-lived system. http://www.meted.ucar.edu/mesoprim/shear/print.htm Link to comment Share on other sites More sharing options...
Mencken_Fan Posted June 11, 2011 Share Posted June 11, 2011 How can one forecast beyond the range of the GFS? Worse yet, and do so for Scandinavia? If one was going to Scandinavia (or anywhere else) for the month of July; how would one in June make any guess at all as to whether it would be warmer/cooler or wetter/dryer than normal? Thanks. Link to comment Share on other sites More sharing options...
isohume Posted June 11, 2011 Share Posted June 11, 2011 Can a Met chime in on this process, I am having difficulties understanding. 5.4 Squall Line Evolution When estimating the shear environment of a squall line, that component of the low-level environmental shear oriented perpendicular to the line exerts the most control on the line’s structure and evolution. This graphic shows three squall lines evolving in environments with identical shear profiles. Yet, because of their orientations, the squall lines are unlikely to evolve in the same way. The uppermost line will likely be a strong, long-lived system because all the wind shear is perpendicular to the line. On the other hand, the bottom system experiences no line-normal shear, so it will likely be a weaker, shorter-lived system. http://www.meted.uca...shear/print.htm The are basically saying that an MCS will have better organization and maintenance the higher the shear magnitude is. The more perpendicular the shear magnitude is to the storm's orientation...the greater percentage of the shear will be available to the storm. They are using a vector and vector components to define the shear magnitude. The 0-3 km shear vector points in the NE direction in this example. The top squall line is aligned perpendicular (NW-SE) to the shear vector and thus receives all of the shear enhancement and theoretically it will be the strongest. The middle storm is align at 45 degree angle (N-S) to the shear vector thus it only receives a vector component of the shear. In this case, it is only benefiting from the u component, since that is the component that is perpendicular to the storm's orientation. The bottom storm is aligned parallel (SW-NE) to the shear vector so it will not benefit from the shear and it will most likely die out soon. Link to comment Share on other sites More sharing options...
LithiaWx Posted June 11, 2011 Share Posted June 11, 2011 General Question : Can someone link me a site that has searchable by date/month averages for temps and precipitation? I'm looking for SE records and Upstate NY records. Thanks in advance! Link to comment Share on other sites More sharing options...
Analog96 Posted June 11, 2011 Share Posted June 11, 2011 General Question : Can someone link me a site that has searchable by date/month averages for temps and precipitation? I'm looking for SE records and Upstate NY records. Thanks in advance! Try the NWS pages' climo sections. www.nws.noaa.gov Link to comment Share on other sites More sharing options...
hm8 Posted June 20, 2011 Share Posted June 20, 2011 So here's something I've always wondered about how radars work....(My vocabulary on the subject is weak but I'll try to describe it the best I can, bare with me) When looking at a radar's returns without smoothing, the shape of the "pixel" that's returned changes as you get further away from the radar. Closer to the radar, the "pixels" are longer in the radial direction then then are in the tangential direction. Further away, the opposite is true. Why is this? Link to comment Share on other sites More sharing options...
AtticaFanatica Posted June 20, 2011 Share Posted June 20, 2011 So here's something I've always wondered about how radars work....(My vocabulary on the subject is weak but I'll try to describe it the best I can, bare with me) When looking at a radar's returns without smoothing, the shape of the "pixel" that's returned changes as you get further away from the radar. Closer to the radar, the "pixels" are longer in the radial direction then then are in the tangential direction. Further away, the opposite is true. Why is this? The pixel represents the resolution volume of the radar (just the volume of air being sampled). A radar beam has a beamwidth (technically a half-power beamwidth) such that as you get farther away from the radar, the area covered by that beam is greater, so the "width" and therefore the radar volume being sampled is getting bigger and resolution is getting worse (think of two lines that form an angle, as you get farther away from where the two lines meet, the distance between the two lines increases no matter what the angle is). This does not happen in the radial direction, the same "length" is always being sampled because it's a product of something else (the radar's pulse width, among other things). So, as you move away from the radar, the radial resolution stays the same as the azimuthal resolution degrades and you see the change in pixel size as you've described. Link to comment Share on other sites More sharing options...
LithiaWx Posted July 1, 2011 Share Posted July 1, 2011 I was watching the radar today and noticed that a storm was moving south but the outflow from it was moving north. How is this possible? Was the outflow possibly in all directions and for some reason the radar was not picking up on the rest of it? Link to comment Share on other sites More sharing options...
isohume Posted July 1, 2011 Share Posted July 1, 2011 I was watching the radar today and noticed that a storm was moving south but the outflow from it was moving north. How is this possible? Was the outflow possibly in all directions and for some reason the radar was not picking up on the rest of it? The outflow from a downburst can go in any direction and usually goes in all directions. If there is weak SR flow then you will see the outflow in all directions like a concentric circle. If there is signif SR flow, then you'll see less outflow up-shear. It's simple physics. Also... the degree of outflow movement perpendicular or parallel to the 88D radial you are sampling will determine how strong a signal is returned to the RDA. Link to comment Share on other sites More sharing options...
metalicwx366 Posted July 2, 2011 Share Posted July 2, 2011 I got a handful of questions. How does a Mesoscale convective system form a tropical cyclone sometimes? How do annular hurricanes be able to survive hostile conditions (Epsilon) and what gives them the ability to do that? How do derechos or bowechoes sometimes form areas of low pressure? Why did erin intensify over land lol? Why is it so hard for miami to reach 100 degrees? Link to comment Share on other sites More sharing options...
River Card Posted July 2, 2011 Share Posted July 2, 2011 Hi, I have always had an interest and admire all the factoring when looking into long range seasonal outlooks. This year I really want to immerse myself deeper into it and although it is way early to even think winter, are there a few analog years that might be worth looking into for my area this winter? It has been ages since we have had a neutral condition, and was wondering what history would suggest after the last 4 or 5 winters being so active around here, inevitably we are due for a dud. So does it look cold and snowy or cold and dry....would appreciate any tidbit of info if there is even any to offer at this juncture. Thank you. Link to comment Share on other sites More sharing options...
am19psu Posted July 2, 2011 Author Share Posted July 2, 2011 I got a handful of questions. How does a Mesoscale convective system form a tropical cyclone sometimes? Latent heat release generating vorticity How do annular hurricanes be able to survive hostile conditions (Epsilon) and what gives them the ability to do that? Small Rossby radii due to high angular momentum and efficient generation of mechanical energy from thermal energy How do derechos or bowechoes sometimes form areas of low pressure? Latent heat release generating vorticity Why did erin intensify over land lol? Frictional convergence and non-hostile land (marshes) Why is it so hard for miami to reach 100 degrees? The ocean. Link to comment Share on other sites More sharing options...
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