Tiburon Posted January 26, 2011 Share Posted January 26, 2011 Ok, folks. I'm in for a nice, general 5-10" snowfall for the general PHL area, with the jackpot being about 10-20 miles to the N/W of I-95. Let's talk why, and let's talk why it's going to have a helluva time snowing and sticking by the AM rush hour--also known as why this is slop to snow for most. First, surface temps: The shore area is already above freezing, with WWD reporting 37/34 and ACY reporting 36/30. This is no surprise. PHL is at 34, PNE is 31, and Pottstown is 33 with some drier air around. Dews are in the mid-to-upper 20s. Further south, you have ILG and DOV at 34, Patuxent at 36 with rain, Wallops Island is at 38 with rain, and it's 39 and raining at SBY. After yesterday's highs in the low and mid 30s, anything that falls without a significant rate is melting on contact even once the column gets saturated. Move up the column to 925mb. Checking mesoanalysis, the 0C line at 925 mb runs currently through Pittsburgh-->Reading-->Allentown-->Northern 1/3 of Long Island, so anything that falls is partially melting through the column. Continue up to 850mb. The 0C line at 850mb runs through Williamsburg, VA to Ocean City, MD right now, with a westerly flow the whole way. Once the coastal gets going, that flow will change and advect warm air even up to that layer. Not being negative, but I wouldn't expect squat by daybreak, and there's almost no way in hell anybody SE of a Lancaster-->Reading-->Allentown line should expect any accumulation until the coastal gets really going. The damage from this is happening after sunset tonight. It may being snowing, but nothing's going to lay. Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 Ok, folks. I'm in for a nice, general 5-10" snowfall for the general PHL area, with the jackpot being about 10-20 miles to the N/W of I-95. Let's talk why, and let's talk why it's going to have a helluva time snowing and sticking by the AM rush hour--also known as why this is slop to snow for most. First, surface temps: The shore area is already above freezing, with WWD reporting 37/34 and ACY reporting 36/30. This is no surprise. PHL is at 34, PNE is 31, and Pottstown is 33 with some drier air around. Dews are in the mid-to-upper 20s. Further south, you have ILG and DOV at 34, Patuxent at 36 with rain, Wallops Island is at 38 with rain, and it's 39 and raining at SBY. After yesterday's highs in the low and mid 30s, anything that falls without a significant rate is melting on contact even once the column gets saturated. Move up the column to 925mb. Checking mesoanalysis, the 0C line at 925 mb runs currently through Pittsburgh-->Reading-->Allentown-->Northern 1/3 of Long Island, so anything that falls is partially melting through the column. Continue up to 850mb. The 0C line at 850mb runs through Williamsburg, VA to Ocean City, MD right now, with a westerly flow the whole way. Once the coastal gets going, that flow will change and advect warm air even up to that layer. Not being negative, but I wouldn't expect squat by daybreak, and there's almost no way in hell anybody SE of a Lancaster-->Reading-->Allentown line should expect any accumulation until the coastal gets really going. The damage from this is happening after sunset tonight. It may being snowing, but nothing's going to lay. meso analysis has dc at +4 925 and they are snowing with snow accumulating, read the obs down there. Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 OK now its light snow at Andrews and DCA... SPECI KADW 260750Z AUTO 05005KT 2 1/2SM R01R/5000VP6000FT -SN OVC021 00/M02 A3001 RMK AO2 UPB0657E0659SNB0732RAB0659E0732 OVC V BKN SLP168 $ METAR KDCA 260751Z 04006KT 1 3/4SM -SN BKN018 OVC024 02/M02 A3004 RMK AO2 SNB07 SLP173 P0000 T00171022 Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 meso analysis has dc at +4 925 and they are snowing with snow accumulating, read the obs down there. Dry air at the same level is likely allowing the snowflakes to make it through. Wetbulb temps are below freezing throughout. Once it saturates they'll change over. Link to comment Share on other sites More sharing options...
Tiburon Posted January 26, 2011 Share Posted January 26, 2011 meso analysis has dc at +4 925 and they are snowing with snow accumulating, read the obs down there. I can imagine snow, but I can't see accumulation with that temperature profile, especially since at 2am KADW reported 34/27 with -RN. Hey, I'm in for a doozy tonight. I just don't want to come on the boards and hear "bust!" all morning when nobody within 15 miles of downtown PHL sees accumulating snow before 4pm...It's all about expectation. Link to comment Share on other sites More sharing options...
Tiburon Posted January 26, 2011 Share Posted January 26, 2011 Dry air at the same level is likely allowing the snowflakes to make it through. Wetbulb temps are below freezing throughout. Once it saturates they'll change over. especially with the E and SE fetch up to the 900mb level. That's WAA. Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 I can imagine snow, but I can't see accumulation with that temperature profile, especially since at 2am KADW reported 34/27 with -RN. Hey, I'm in for a doozy tonight. I just don't want to come on the boards and hear "bust!" all morning when nobody within 15 miles of downtown PHL sees accumulating snow before 4pm...It's all about expectation. i dont think anyone is expecting any snow of much in the morning. Everyone knows tomorrow eve is the show. Link to comment Share on other sites More sharing options...
Tiburon Posted January 26, 2011 Share Posted January 26, 2011 i dont think anyone is expecting any snow of much in the morning. Everyone knows tomorrow eve is the show. Check out some of the posts a page or two back... Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 this is impressive composite radar Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 Check out some of the posts a page or two back... ooo yea going off the hrrr. We will see what happens. Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 nam total qpf Link to comment Share on other sites More sharing options...
Tiburon Posted January 26, 2011 Share Posted January 26, 2011 this is impressive composite radar Yeah Tom, I'm looking very forward to that band tonight. Fun stuff ahead. Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 Even with the 6Z NAM bumping up QPF it still relatively screws the areas just NW of I-95 with that gradient from hell... Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 3z eta Link to comment Share on other sites More sharing options...
johnc Posted January 26, 2011 Share Posted January 26, 2011 Precip should be entering South Jersey shortly. Crazy line down near Georgetown. Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 Precip should be entering South Jersey shortly. Crazy line down near Georgetown. Bright band due to melting (its rain in Georgetown) Link to comment Share on other sites More sharing options...
Tiburon Posted January 26, 2011 Share Posted January 26, 2011 3z eta That star in the upper right hand map (3 hr precip at 3Z) is practically over my house. With 10:1 ratios that's what 5-6" of snow? I think that is the definition of "puking snow." Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 Bright band due to melting (its rain in Georgetown) also, in clear air mode, so mod precip is going to seem like the earth is ending. Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 also, in clear air mode, so mod precip is going to seem like the earth is ending. More the bright band though, check out DOX which is in precip mode: http://radar.weather.gov/ridge/radar_lite.php?rid=dox&product=N0R&loop=yes Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 That star in the upper right hand map (3 hr precip at 3Z) is practically over my house. With 10:1 ratios that's what 5-6" of snow? I think that is the definition of "puking snow." lol Link to comment Share on other sites More sharing options...
johnc Posted January 26, 2011 Share Posted January 26, 2011 Bright band due to melting (its rain in Georgetown) still looks purdy though Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 More the bright band though, check out DOX which is in precip mode: http://radar.weather...ct=N0R&loop=yes ray, you gotta be a little impressed with how the radar looks right now, from that batch...im getting all i need a drink Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 still looks purdy though Not when it signals the death of snow Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 ray, you gotta be a little impressed with how the radar looks right now, from that batch...im getting all i need a drink I don't get impressed about radar signatures which equate to the death of snow Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 I don't get impressed about radar signatures which equate to the death of snow lol wtf... should we hold a memorial in its memory? Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 Mixing with rain at Dulles... SPECI KIAD 260820Z 03004KT 1 3/4SM -RASN BKN018 OVC030 01/M03 A3001 RMK AO2 RAB19 P0000 Link to comment Share on other sites More sharing options...
johnc Posted January 26, 2011 Share Posted January 26, 2011 lol @ the new Storm Total Snow Forecast map poor suckers in the NW... Though somehow I end up with the same amount so oh well. Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 lol wtf... should we hold a memorial in its memory? Always Link to comment Share on other sites More sharing options...
tombo82685 Posted January 26, 2011 Share Posted January 26, 2011 Mixing with rain at Dulles... SPECI KIAD 260820Z 03004KT 1 3/4SM -RASN BKN018 OVC030 01/M03 A3001 RMK AO2 RAB19 P0000 going off the obs down there. They have mod snow with half inch accum in spots, that one was from alexandria. Link to comment Share on other sites More sharing options...
famartin Posted January 26, 2011 Share Posted January 26, 2011 My goodness. Somebody needs some Halo Farm ice cream. Well if you can deliver it 2300 miles west Link to comment Share on other sites More sharing options...
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