Capt. Adam Posted March 11, 2013 Share Posted March 11, 2013 I'll focus on today since I'm pretty confident in the next 6 hours. Temps here have "skyrocketed" here, up 16 degrees in less than 2 hours. We've gone from freezing fog this morning to good visibility, sun and a South wind building in now. Link to comment Share on other sites More sharing options...
Quakertown needs snow Posted March 11, 2013 Author Share Posted March 11, 2013 Time change has me all messed up with model run times, driving to work in the dark and pending driving home in full sun plus its in the 50's, it must be #MOrach Link to comment Share on other sites More sharing options...
blinkers88 Posted March 11, 2013 Share Posted March 11, 2013 Here comes the rain Link to comment Share on other sites More sharing options...
DerekZ Posted March 12, 2013 Share Posted March 12, 2013 Figured this could be a good discussion starter in the banter thread ... This time of year, there is a lot of discussion about sun angle and how it can hamper snow accumulation. Of course, March sun and surface temperatures above freezing can be overcome with heavy enough rates. My question is this: has anyone seen any kind of formula that incorporates all of the variables to determine the likelihood of snow accumulating on various surfaces? How would one weigh the different variables? Am I missing anything critical? Maybe there is some kind of table to illustrate these considerations? For instance (all numbers hypothetical based on my limited understanding and assume all levels of atmosphere above 900 mb are below freezing): Jan 8 * 4 am * surface temps at 25 degrees F * 900 mb at 20 degrees F * visibility of 1/4 mile = 100% chance of snow accumulating on all surfaces March 21 * 12 noon * surface temps at 34 degrees F * 900 mb at 30 degrees F * visibility of 1/4 mile = 50% chance of snow accumulating on pavement, 75% on grass Link to comment Share on other sites More sharing options...
famartin Posted March 12, 2013 Share Posted March 12, 2013 Figured this could be a good discussion starter in the banter thread ... This time of year, there is a lot of discussion about sun angle and how it can hamper snow accumulation. Of course, March sun and surface temperatures above freezing can be overcome with heavy enough rates. My question is this: has anyone seen any kind of formula that incorporates all of the variables to determine the likelihood of snow accumulating on various surfaces? How would one weigh the different variables? Am I missing anything critical? Maybe there is some kind of table to illustrate these considerations? For instance (all numbers hypothetical based on my limited understanding and assume all levels of atmosphere above 900 mb are below freezing): Jan 8 * 4 am * surface temps at 25 degrees F * 900 mb at 20 degrees F * visibility of 1/4 mile = 100% chance of snow accumulating on all surfaces March 21 * 12 noon * surface temps at 34 degrees F * 900 mb at 30 degrees F * visibility of 1/4 mile = 50% chance of snow accumulating on pavement, 75% on grass This could be handled scientifically, assuming one knew all the variables, which I would think would include: Precipitation rate Air temperature Insolation Surface temperature of surface Internal temperature of surface Type of surface That's just a wild-ass stab at how you could calculate that. There's probably a published formula somewhere. Link to comment Share on other sites More sharing options...
Grothar Posted March 12, 2013 Share Posted March 12, 2013 This could be handled scientifically, assuming one knew all the variables, which I would think would include: Precipitation rate Air temperature Insolation Surface temperature of surface Internal temperature of surface Type of surface That's just a wild-ass stab at how you could calculate that. There's probably a published formula somewhere. Would salt on the road surface, amount and type of moisture on the existing surface, soil temperature, and wind speed play be considered variables as well? Link to comment Share on other sites More sharing options...
famartin Posted March 12, 2013 Share Posted March 12, 2013 Would salt on the road surface, amount and type of moisture on the existing surface, soil temperature, and wind speed play be considered variables as well? Salt certainly. Now that I think about it, duration would also matter, both with and without salt. I don't think moisture would matter much. If the surface is above freezing, the first thing the snow will do upon impact will be to melt, thus making the surface wet. Soil temperature kinda goes along with "internal temperature" which I listed already. Wind speed would matter more if the air is significantly cooler than the surface. Link to comment Share on other sites More sharing options...
fsu_wxgirl Posted March 12, 2013 Share Posted March 12, 2013 Thundering here in Berwyn Link to comment Share on other sites More sharing options...
chubbs Posted March 12, 2013 Share Posted March 12, 2013 Heavy rain this AM just passed the 1" mark. Link to comment Share on other sites More sharing options...
Voyager Posted March 12, 2013 Share Posted March 12, 2013 Heavy rain this AM just passed the 1" mark. 1.79" here. Link to comment Share on other sites More sharing options...
Grothar Posted March 12, 2013 Share Posted March 12, 2013 1.54 here in Trexlertown/Macungie area Link to comment Share on other sites More sharing options...
wederwarrior Posted March 12, 2013 Share Posted March 12, 2013 Does that clearing come up our way from VA for sunset? Big nerdy show tonight! PANstars and a crescent moon. Link to comment Share on other sites More sharing options...
ChescoWx Posted March 12, 2013 Share Posted March 12, 2013 0.95" of rain today in NW Chesco Link to comment Share on other sites More sharing options...
chubbs Posted March 12, 2013 Share Posted March 12, 2013 1.59" nice pre-spring soaking. Link to comment Share on other sites More sharing options...
NaoPos Posted March 13, 2013 Share Posted March 13, 2013 Anyone know if that new comet is visible? If so, viewing details? Link to comment Share on other sites More sharing options...
RedSky Posted March 13, 2013 Share Posted March 13, 2013 i would like to know if it was visible as i didn't bother looking because i was expecting clouds but it looks like they might have broke in time Link to comment Share on other sites More sharing options...
wederwarrior Posted March 13, 2013 Share Posted March 13, 2013 Clouds broke just as dusk settled in. Comet panstarrs was visible with binos low in the west, going in and out of clouds There are some great pics from DC area on space weather.com Next 3 nights it will be visible just after sunset 7:30-8, low to the horizon. All cloud cover pending of course. Link to comment Share on other sites More sharing options...
Porsche Posted March 13, 2013 Share Posted March 13, 2013 Mini flizzard here. Link to comment Share on other sites More sharing options...
ChescoWx Posted March 13, 2013 Share Posted March 13, 2013 Brief snow squall just came through NW Chester County Temp dropped to 38.3 Link to comment Share on other sites More sharing options...
NaoPos Posted March 13, 2013 Share Posted March 13, 2013 Link to comment Share on other sites More sharing options...
Voyager Posted March 13, 2013 Share Posted March 13, 2013 So why the hell do we have to have this bull**** pattern now as we head into spring???? This sucks... Link to comment Share on other sites More sharing options...
Quakertown needs snow Posted March 14, 2013 Author Share Posted March 14, 2013 So why the hell do we have to have this bull**** pattern now as we head into spring???? This sucks... steve, dont look at the 12z euro, Link to comment Share on other sites More sharing options...
Voyager Posted March 14, 2013 Share Posted March 14, 2013 steve, dont look at the 12z euro, LOL...I won't, and sorry guys for the rant. I'd just rather have this pattern in December/January as we are heading into winter, not in March/April as we are heading out of it. Link to comment Share on other sites More sharing options...
johnc Posted March 14, 2013 Share Posted March 14, 2013 I love rainy days like we had yesterday. More of that please. Link to comment Share on other sites More sharing options...
Quakertown needs snow Posted March 14, 2013 Author Share Posted March 14, 2013 driving into work this am, nice dusting in hatfield / lansdale area. congrats! Link to comment Share on other sites More sharing options...
JERSEYSNOWROB Posted March 14, 2013 Share Posted March 14, 2013 Very scattered snow flurries here in Marlboro, NJ this morning. I mean I can literally count the flakes falling right now, thats how scattered it is. Hahaha Link to comment Share on other sites More sharing options...
HM Posted March 14, 2013 Share Posted March 14, 2013 So why the hell do we have to have this bull**** pattern now as we head into spring???? This sucks... The last few springs have been awesome and maybe even a little too summer-like. It certainly was nice and I'm definitely looking forward to convective season. Unfortunately, it looks like this is the kind of spring that starts off with a nor'easter or two. The "return to a blocking state around astronomical spring" idea is looking better and better. While we always get brief bouts of warmth (like earlier this week) this time of year, it seems like cold temperatures will be able to plow southward through mid-April. Link to comment Share on other sites More sharing options...
Capt. Adam Posted March 14, 2013 Share Posted March 14, 2013 Flurries here as I was taking the kids to school, enough to make the windshield wet. Oh, the sun was out at the same time. Link to comment Share on other sites More sharing options...
RedSky Posted March 14, 2013 Share Posted March 14, 2013 Snow squalls had whitened the ground in harleysville this am enough to make some roads slick Link to comment Share on other sites More sharing options...
RowanBrandon Posted March 14, 2013 Share Posted March 14, 2013 Had some flurries come through earlier. Link to comment Share on other sites More sharing options...
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