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Febuary 22-24


Chrisjmcjr

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Thanks. I dont know much, so I appreciate you guys who do. Can you explain real quick the definitions of 850's, 540's etc. I hear them mentioned alot.

more detailed if u want to read it

 

850mb in forecasting winter weather

So what's the deal with 850mb? In the winter, you have to look at the layers from the surface up to around 700mb to determine the type of precip you will get at the surface - the most important of these usually being the 850mb layer. Above 500-700mb, the temperatures are typically below freezing year-round. If 850mb and higher are below freezing, snow can develop and begin falling through the boundary layer. If the surface (boundary layer) is above freezing and 850mb is below freezing, snow will usually melt before it reaches the ground (as rain), or if it makes it to the ground will melt quickly. If the boundary layer is also below freezing, the snow can make it to the ground and stick. In many cases, falling precip will bring some of the 850mb temps down to the boundary layer, causing it to cool. So even if the surface is above freezing, heavy snow falling from a very cold 850mb layer can cool the boundary layer below freezing in a relatively short time. It's almost like dropping trillions of little ice cubes down into a huge cooler.

Conversely, if 850mb is above freezing and the boundary layer is below freezing, liquid raindrops falling into the boundary layer (or partially melted snowflakes) will either freeze into ice pellets before reaching the ground (sleet) or will freeze on contact with the ground (freezing rain).

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if the NAM is too warm then NW of NYC say 25-30 its not so bad...

The mid level lows develop too late for almost all of us and the primary is too powerful. Even for much of CT, the precip is over before the cold air can work back in. This isn't a storm for our subforum. :(

 

Adjust the blizzard about 100 miles NE and that's about what you get here.

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Yea even northwest of nyc is rain, the entire metro area is too warm per the nam, and the qpf rates and lifting is not going to be strong enough to dynamically cool down to the surface

Look where the 700/850 lows develop and close off, and how far NE that happens. North of that is where strong lift occurs, cold air is forced down due to dynamics, and very heavy snow breaks out. It pretty much becomes another storm at that point. West and south of that has to deal with the dryslot. In keeping with the horrendously progressive/Nina pattern this winter, this happens way too late for just about anybody in this subforum. Even Hartford looks like they get the shaft for the most part. Face it-winter is pretty much over for us unless we can develop a blocking regime which can slow the pattern down and stop these primaries from taking over. This is eastern New England's pattern for sure.

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Look where the 700/850 lows develop and close off, and how far NE that happens. North of that is where strong lift occurs, cold air is forced down due to dynamics, and very heavy snow breaks out. It pretty much becomes another storm at that point. West and south of that has to deal with the dryslot. In keeping with the horrendously progressive/Nina pattern this winter, this happens way too late for just about anybody in this subforum. Even Hartford looks like they get the shaft for the most part. Face it-winter is pretty much over for us unless we can develop a blocking regime which can slow the pattern down and stop these primaries from taking over. This is eastern New England's pattern for sure.

I agree yes, the storm deepens too late and in the wrong spot to get us into the unstable convective banding that would "drop down" the cold aloft to the surface. The synoptic pattern is horrid right now
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Look where the 700/850 lows develop and close off, and how far NE that happens. North of that is where strong lift occurs, cold air is forced down due to dynamics, and very heavy snow breaks out. It pretty much becomes another storm at that point. West and south of that has to deal with the dryslot. In keeping with the horrendously progressive/Nina pattern this winter, this happens way too late for just about anybody in this subforum. Even Hartford looks like they get the shaft for the most part. Face it-winter is pretty much over for us unless we can develop a blocking regime which can slow the pattern down and stop these primaries from taking over. This is eastern New England's pattern for sure.

 

well congrats to them i guess LOL..... they might end up with over 100 inches in spots if the pattern keeps up.  Some places have over 60" already.  BTW any chance North of the city to get a couple inches or no?

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well congrats to them i guess LOL..... they might end up with over 100 inches in spots if the pattern keeps up.  Some places have over 60" already.  BTW any chance North of the city to get a couple inches or no?

Probably a good if not very good chance Boston ends up with 3X or more Central Park's total for the winter. In 07-08 Boston ended with something like 4 or 5 times what Central Park had and we're in a very similar regime now. NAM nailed them with 2"+ liquid, almost all snow this run. I wouldn't be confident in much snow unless you're in Hartford or northeast. West of the city gets screwed by the primary and late-developing low. This is yet another north and east snow event.

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