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The temps aloft control the surface a majority of the time so if its warm above its warm below. It never works the opposite way. Meaning a cold surface doesn't make the mid levels cold. Also the mid levels don't fluctuate as fast as the surface so you can get a better sense of temps during a period looking at the 850mb level.
To nitpick, or rather clarify, the mid levels don't make the surface warm or cold, they just describe the general air mass better. Heat from the sun is always aborbed at the surface, the only way the atmosphere higher up warms is through circulation of surface air from the surface. But of course, local weather is just from local heating and cooling but from air masses from elsewhere moving in. The 850 mb level is less affected by the diurnal cycle of surface radiational and cooling and local geographic and topographic effects, it's better mixed. So that layer is a better description of the general weather. But it's not controlling the surface temperature.
To nitpick, or rather clarify, the mid levels don't make the surface warm or cold, they just describe the general air mass better. Heat from the sun is always aborbed at the surface, the only way the atmosphere higher up warms is through circulation of surface air from the surface. But of course, local weather is just from local heating and cooling but from air masses from elsewhere moving in. The 850 mb level is less affected by the diurnal cycle of surface radiational and cooling and local geographic and topographic effects, it's better mixed. So that layer is a better description of the general weather. But it's not controlling the surface temperature.
I "think" we'll agree but let me elaborate a bit more...
Once you follow it more you'll be amazed it does. Do you know why you're in the upper 20s/low 30s today with sunny skies?? Look at the 850mb temps.
Majority of time that level is the exact reason why we are warm or cold. You will never get to 50°F with a 850mb temp of below -10C. Had that level been above freezing then you have the chance.
The air mass above controls the surface temps but it's not an exact science.
Is it the reason why you're 30 and Albany is 26? Or You 30 and few miles away 34? NO. That's a surface related thing with other reasons which I think is what you mentioned.
Can the 850mb level be below freezing and you at 40F at same time? Maybe. There's some lag time just like when a front comes through it takes a while for surface to cool down vise versa with warm front.
Here's current 4pm temps in numbers and 850 temps shaded. You're in the purple.. That's cold above which is relating to cold at the surface. Not vise versa.
Now lets look at the actual numbers from the balloons. Saturday you hit low 50sF. Why? because the 850mb level warmed up and was above freezing.
On the left is the 7pm Friday data showing the warm airmass "above". 850 level was 4°C. That is above normal for this time of year and right as that SW flow airmass above warmed up, you temps at the surface went into upper 40s/low 50s. Saturday the 850 temps were above freezing still.
On the right is this morning. Cold above = cold below.
Lastly... it's the exact reason why NWS mentions it in their discussions...
NATIONAL WEATHER SERVICE ALBANY NY
341 PM EDT SUN MAR 16 2014
THE LATEST GFS HAS H850 TEMPS IN THE -12C TO -15C RANGE. HIGHS ON SUNDAY MAYBE IN THE 20S TO M30S ACROSS ERN NY AND WRN NEW ENGLAND WITH BLUSTERY CONDITIONS.
The snow forecast on Weather Underground was upgraded to 4 to 6 inches for me. It said 1 to 3 earlier in the day, which seemed consistent with the snowfall forecast maps posted by chicagogeorge and Cambium. Just got back from my bike ride-we've got full cloud cover and cold. Certainly feels like snow is coming.
Edit: There's a winter weather statement now as far north as Middlesex County in NJ. Earlier the statement only extended up to Camden County. I'm guessing the storm may have trended northward a bit.
The snow forecast on Weather Underground was upgraded to 4 to 6 inches for me. It said 1 to 3 earlier in the day, which seemed consistent with the snowfall forecast maps posted by chicagogeorge and Cambium. Just got back from my bike ride-we've got full cloud cover and cold. Certainly feels like snow is coming.
Edit: There's a winter weather statement now as far north as Middlesex County in NJ. Earlier the statement only extended up to Camden County. I'm guessing the storm may have trended northward a bit.
Nice. Here's NWS Snowfall total forecast. I'm in the white. 0"! LOL They are expecting 8-12" across Dover area.
I "think" we'll agree but let me elaborate a bit more...
Once you follow it more you'll be amazed it does. Do you know why you're in the upper 20s/low 30s today with sunny skies?? Look at the 850mb temps.
Majority of time that level is the exact reason why we are warm or cold. You will never get to 50°F with a 850mb temp of below -10C. Had that level been above freezing then you have the chance.
The air mass above controls the surface temps but it's not an exact science.
Is it the reason why you're 30 and Albany is 26? Or You 30 and few miles away 34? NO. That's a surface related thing with other reasons which I think is what you mentioned.
Can the 850mb level be below freezing and you at 40F at same time? Maybe. There's some lag time just like when a front comes through it takes a while for surface to cool down vise versa with warm front.
Here's current 4pm temps in numbers and 850 temps shaded. You're in the purple.. That's cold above which is relating to cold at the surface. Not vise versa.
Nice maps, and I'm not disagring they're not connected, just the language you're using about them being caused by another. You're making it sound like the 850 mb is the cause rather than just a good measure. Practically, it's about the same but a connection isn't the same as a cause. As for the bolded, it's true, but I could just as easily write: you'll never get a 850 mb temperature of below -10°C with a 50°F surface temperature. The temperature can't change with height more than the dry adibatic lapse rate (9.8°C/km), so the difference between sea level and the 850 mb can't be any more than about 15°C [in a humid atmosphere the difference will be less]. I don't know if you could see the 850mb is controlling the weather any more than the surface, it's just that diurnal and local geographic effects create more differences at the surface, while the 850 mb smooths out the noise.
I think you can also make a good arguement that the surface controls the upper atmosphere to a certain extent too. I found in the summer 700 mb temperatures in the mountain west are hotter than the rest of the country. Why? Because the surface to 700 mb distance is less than the elsewhere, so there's less cooling with height (heating occurs at the surface). But once you get high enough, the local difference disappears, the atmosphere becomes less well mixed. You're out of the boundary layer; the benefit of the 850 mb layer is it's just out of the boundary layer (except in mountains):
Here is the 500mb depiction of the cold shot coming in the 6-10 day period
Does anyone see even Spring showing up for the eastern 2/3rds anytime soon? Not me, nor do I see this pattern changing. I think we will be stuck in it for the next 23094584309845 months.
Nice maps, and I'm not disagring they're not connected, just the language you're using about them being caused by another. You're making it sound like the 850 mb is the cause rather than just a good measure. Practically, it's about the same but a connection isn't the same as a cause. As for the bolded, it's true, but I could just as easily write: you'll never get a 850 mb temperature of below -10°C with a 50°F surface temperature. The temperature can't change with height more than the dry adibatic lapse rate (9.8°C/km), so the difference between sea level and the 850 mb can't be any more than about 15°C [in a humid atmosphere the difference will be less]. I don't know if you could see the 850mb is controlling the weather any more than the surface, it's just that diurnal and local geographic effects create more differences at the surface, while the 850 mb smooths out the noise.
I think you can also make a good arguement that the surface controls the upper atmosphere to a certain extent too. I found in the summer 700 mb temperatures in the mountain west are hotter than the rest of the country. Why? Because the surface to 700 mb distance is less than the elsewhere, so there's less cooling with height (heating occurs at the surface). But once you get high enough, the local difference disappears, the atmosphere becomes less well mixed. You're out of the boundary layer; the benefit of the 850 mb layer is it's just out of the boundary layer (except in mountains):
I havent been following the whole conversation....but let me chime in here based on what I have seen forecasting. We use a top down approach in terms of winter precipitation types....hence look at temps at 500 mb....then thru 700 mb/850/925 mb to the surface. So to most degrees the temps above the surface do have a strong impact on temps the surface. A lot depends on the mixed layer....ie from the soundings.
For example....you can have a nighttime inversion develop with very warm air moving in at 900-800 mb layer and if you are mixed only to 900 mb the warm layer above that cannot mix to the surface. Thus in those instances you may have very warm 850 mb temps and be cool at the surface. Same token in a well mixed layer with mixing to 800 mb a 850 mb temp warmed by decent through the atmosphere can be a good approximation of the surface temp.
But it isnt that clear cut. The surface temp has a strong sun dependence. Meaning with a stronger sun in March at an 850 mb temp of -20C or 925 mb of -15C you will have warmer temps at the surface than corresponding temps given in mid January as the sun angle is lower.
Thus in the early and late winter season, using 850 mb temps or even 925 temps of zero to depict rain/snow line can not be used in many cases as the layer right near the surface is warmer than it would be in a similar situation in the dead of winter.
Dan
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It said 1 to 3 earlier in the day, which seemed consistent with the snowfall forecast maps posted by chicagogeorge and Cambium. Just got back from my bike ride-we've got full cloud cover and cold. Certainly feels like snow is coming.
Nice. Here's NWS Snowfall total forecast. I'm in the white. 0"! LOL They are expecting 8-12" across Dover area. 
