18Z GFS IS MUCH FARTHER EAST! SNOWSTORM FOR I-95 POSSIBLE

[truballer#1]

[jkt21787]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

[wxwatcher91]

YAY!!!!!!!

judging by those qpfs, all of southern New England could be in for over a foot with this storm...

the forecast right now is for rain for most of southern New England except inland MA and NH will have a bit of snow...

oh I would be soo happy to get just snow out of this... even if it wasnt that much I just dont want rain on Christmas

[wxwatcher91]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

actually it appears by that run that even the cities would be in for mostly snow. you see anywhere within the blues lines and outside the red it is snow

[jkt21787]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

actually it appears by that run that even the cities would be in for mostly snow. you see anywhere within the blues lines and outside the red it is snow

NO!! There is where you are mistaken, and this is such a common misconception. People think the 5400m 1000-500 mb thickness line is ALWAYS the rain/snow line! That is so NOT true!! There is no magic number at all for snow.

You MUST investigate vertical temperature profiles from surface all the way up to 200/300 mb to see what precip is most likely, and if you do so, you will see the low levels are still too warm for snow.

The 540 line is a guideline, not a mandate.

[truballer#1]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

I said "POSSIBLE" I-95 snowstorm!

[Tyler]

Actually, its still mostly rain for the I-95 cities. Bounday layer temperatures are too warm to support snow. Temps above freezing 2000ft - 3000ft. Plus, the 18z GFS is a pretty big outlier, it's the coldest run with the best sfc low track for snow and still has temps too warm for the I-95 cities at the surface.

[Tyler]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

I said "POSSIBLE" I-95 snowstorm!

Its not really "POSSIBLE" since this model run isn't even showing snow for I-95. Hopefully though, the models will trend colder for ya!

[WindRunner]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

actually it appears by that run that even the cities would be in for mostly snow. you see anywhere within the blues lines and outside the red it is snow

NO!! There is where you are mistaken, and this is such a common misconception. People think the 5400m 1000-500 mb thickness line is ALWAYS the rain/snow line! That is so NOT true!! There is no magic number at all for snow.

You MUST investigate vertical temperature profiles from surface all the way up to 200/300 mb to see what precip is most likely, and if you do so, you will see the low levels are still too warm for snow.

The 540 line is a guideline, not a mandate.

I might be missing something, but wouldn't 200-300mb be the upper levels here, and the 850mb temp the lowest the GFS has with the excpetion of the surface readout?

[jkt21787]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

actually it appears by that run that even the cities would be in for mostly snow. you see anywhere within the blues lines and outside the red it is snow

NO!! There is where you are mistaken, and this is such a common misconception. People think the 5400m 1000-500 mb thickness line is ALWAYS the rain/snow line! That is so NOT true!! There is no magic number at all for snow.

You MUST investigate vertical temperature profiles from surface all the way up to 200/300 mb to see what precip is most likely, and if you do so, you will see the low levels are still too warm for snow.

The 540 line is a guideline, not a mandate.

I might be missing something, but wouldn't 200-300mb be the upper levels here, and the 850mb temp the lowest the GFS has with the excpetion of the surface readout?

Yes, but again you need to look at the ENTIRE atmospheric profile, from top down. Of course the 200/300 mb will be below freezing in almost all situations, but its part of the profile. The PBL is the most important, and as Tyler said, that region is above freezing 2000 to 3000 feet up even. Thats enough to melt any frozen precip before reaching the surface, so again we're still looking at a rain event AT THIS TIME. Bottom line, 18z GFS isn't even a possible snowstorm for the I-95 corridor.

[carve]

Accuweather who i don't trust a whole lot has that storm giving us snow here in central ohio for christmas..Has the storm moving through the tennesse valley,,moving northeast.

[WindRunner]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

actually it appears by that run that even the cities would be in for mostly snow. you see anywhere within the blues lines and outside the red it is snow

NO!! There is where you are mistaken, and this is such a common misconception. People think the 5400m 1000-500 mb thickness line is ALWAYS the rain/snow line! That is so NOT true!! There is no magic number at all for snow.

You MUST investigate vertical temperature profiles from surface all the way up to 200/300 mb to see what precip is most likely, and if you do so, you will see the low levels are still too warm for snow.

The 540 line is a guideline, not a mandate.

I might be missing something, but wouldn't 200-300mb be the upper levels here, and the 850mb temp the lowest the GFS has with the excpetion of the surface readout?

Yes, but again you need to look at the ENTIRE atmospheric profile, from top down. Of course the 200/300 mb will be below freezing in almost all situations, but its part of the profile. The PBL is the most important, and as Tyler said, that region is above freezing 2000 to 3000 feet up even. Thats enough to melt any frozen precip before reaching the surface, so again we're still looking at a rain event AT THIS TIME. Bottom line, 18z GFS isn't even a possible snowstorm for the I-95 corridor.

Whoa, I'm not saying anything either way right now, I'm just asking a question of you to try and clear things up. I see what you are saying now, but not thanks to that post.

[jkt21787]

I'm not sure I understand. You are taking one run of the GFS, and specfically an intermediate run, and declaring a snowstorm for I-95. Not to mention if you really investigate this model, you will see its still too warm for the big cities, except maybe a brief changeover at the end. Not much accumulation.

actually it appears by that run that even the cities would be in for mostly snow. you see anywhere within the blues lines and outside the red it is snow

NO!! There is where you are mistaken, and this is such a common misconception. People think the 5400m 1000-500 mb thickness line is ALWAYS the rain/snow line! That is so NOT true!! There is no magic number at all for snow.

You MUST investigate vertical temperature profiles from surface all the way up to 200/300 mb to see what precip is most likely, and if you do so, you will see the low levels are still too warm for snow.

The 540 line is a guideline, not a mandate.

I might be missing something, but wouldn't 200-300mb be the upper levels here, and the 850mb temp the lowest the GFS has with the excpetion of the surface readout?

Yes, but again you need to look at the ENTIRE atmospheric profile, from top down. Of course the 200/300 mb will be below freezing in almost all situations, but its part of the profile. The PBL is the most important, and as Tyler said, that region is above freezing 2000 to 3000 feet up even. Thats enough to melt any frozen precip before reaching the surface, so again we're still looking at a rain event AT THIS TIME. Bottom line, 18z GFS isn't even a possible snowstorm for the I-95 corridor.

Whoa, I'm not saying anything either way right now, I'm just asking a question of you to try and clear things up. I see what you are saying now, but not thanks to that post.

The rest of my answer wasn't really intended for you, lol. It was more of a follow up to my original post. I see now it didn't come off that way. Sorry!

But anyway, I was just trying to clear up a common misconception that occurs about precipitation type. Its become one of my pet peeves, if you will. Honestly, because I used to be the same way, and want to make sure others don't make the same mistakes.

Again, sorry...

[Nimbus]

Less than a week out the accuracy of the GFS starts to improve.

The east west wag makes a big difference but is tough to nail down until the low starts deepening off the coast.

Potential is certainly there for a major northeaster.