heavy_wx Posted December 29, 2015 Share Posted December 29, 2015 Nice signature of refreezing in the ZDR field from KBOX. If you look at the 2.4/3.4 degree elevation scans, you can see the outer ring of enhanced ZDR associated with the melting layer, and an inner ring of slightly enhanced ZDR. We think that inner enhancement is due to the preferential freezing of smaller raindrops first; the larger raindrops (more oblate with higher ZDR) therefore contribute more to the returned ZDR by remaining liquid at the height of the radar beam. The smaller and more spherical frozen drops (with lower ZDR) contribute less to the total ZDR because ice scatters less power back to the radar than liquid water. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 29, 2015 Share Posted December 29, 2015 That's cool heavywx. Thanks for that. Link to comment Share on other sites More sharing options...
dendrite Posted December 29, 2015 Share Posted December 29, 2015 Sleet here. lol GFS...is it still showing snow here until 2pm? Link to comment Share on other sites More sharing options...
CoastalWx Posted December 29, 2015 Share Posted December 29, 2015 So why would the layer in between the inner and outer circle be lower ZDR? Because that's all liquid and no ice? Link to comment Share on other sites More sharing options...
mahk_webstah Posted December 29, 2015 Share Posted December 29, 2015 Sleet here. lol GFS...is it still showing snow here until 2pm?If I am seeing it right looking at my snow stick in the dark it looks like 4-5 inches with light mixed precip now Link to comment Share on other sites More sharing options...
Lava Rock Posted December 29, 2015 Share Posted December 29, 2015 12.8f. 1.5". Link to comment Share on other sites More sharing options...
qg_omega Posted December 29, 2015 Share Posted December 29, 2015 Maybe 4 inches here heavy sleet now Link to comment Share on other sites More sharing options...
heavy_wx Posted December 29, 2015 Share Posted December 29, 2015 So why would the layer in between the inner and outer circle be lower ZDR? Because that's all liquid and no ice? Yeah because there are likely many small (and thus nearly spherical) raindrops below the melting layer that have ZDR close to 0 dB. The total returns to the radar are therefore dominated by the scattering from the many small raindrops so the radar sees the total ZDR signal as close to the value for the small drops. Effectively, the larger, higher ZDR raindrops are masked by the many smaller ones until the smaller ones freeze and return less power back to the radar. Link to comment Share on other sites More sharing options...
MarkO Posted December 29, 2015 Share Posted December 29, 2015 3.5", and now snow/sleet mix. 15.2/13 Link to comment Share on other sites More sharing options...
dendrite Posted December 29, 2015 Share Posted December 29, 2015 If I am seeing it right looking at my snow stick in the dark it looks like 4-5 inches with light mixed precip nowPounding sleet here. 4.1" new...0.68" from a core. This is dense shiat. I'm glad I stayed up for it to start to actually see snow falling. Growth sucked then and it definitely sucks now. Link to comment Share on other sites More sharing options...
powderfreak Posted December 29, 2015 Share Posted December 29, 2015 Pounding sleet here. 4.1" new...0.68" from a core. This is dense shiat. I'm glad I stayed up for it to start to actually see snow falling. Growth sucked then and it definitely sucks now. CoCoRAHS report near you showing the opposite, like 6" of snow out of 4/10th of an inch QPF. I was wondering if you guys were getting better ratios, it's dense over here too. Link to comment Share on other sites More sharing options...
S&P Posted December 29, 2015 Share Posted December 29, 2015 about .5" of sleet / graupel. edging above freezing now most spots around here 32/30. Link to comment Share on other sites More sharing options...
qg_omega Posted December 29, 2015 Share Posted December 29, 2015 CoCoRAHS report near you showing the opposite, like 6" of snow out of 4/10th of an inch QPF. I was wondering if you guys were getting better ratios, it's dense over here too.Radar doesn't show much left, anyone hear how Montreal did I doubt anyone saw the foot plus predicted Link to comment Share on other sites More sharing options...
Damage In Tolland Posted December 29, 2015 Share Posted December 29, 2015 Scalping all night long and still ongoing. 25.9 Interior probably won't sniff 32 Link to comment Share on other sites More sharing options...
powderfreak Posted December 29, 2015 Share Posted December 29, 2015 We keep going back and forth from SN to IP. I see MPV was UP but back to -SN. Link to comment Share on other sites More sharing options...
dendrite Posted December 29, 2015 Share Posted December 29, 2015 CoCoRAHS report near you showing the opposite, like 6" of snow out of 4/10th of an inch QPF. I was wondering if you guys were getting better ratios, it's dense over here too.No way in hell. Sleet may have knocked it down some, but not 2"...maybe a couple tenths? Link to comment Share on other sites More sharing options...
powderfreak Posted December 29, 2015 Share Posted December 29, 2015 Radar doesn't show much left, anyone hear how Montreal did I doubt anyone saw the foot plus predicted They will snow most of the day north of the border...looks like plenty to go up there with precip still back to northern Michigan. Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 29, 2015 Share Posted December 29, 2015 .5 mix sleet snow currently pixie dust Link to comment Share on other sites More sharing options...
powderfreak Posted December 29, 2015 Share Posted December 29, 2015 No way in hell. Sleet may have knocked it down some, but not 2"...maybe a couple tenths? Yeah agreed. I think my stack is still growing with the sleet, it was dense to begin with. Pure needles all night. Link to comment Share on other sites More sharing options...
dendrite Posted December 29, 2015 Share Posted December 29, 2015 6z GFS still has almost all snow here through midday although it is somewhat closer with the warm tongue. Time to rebuild that model from scratch. 1000 vertical levels wouldn't have helped it. I bet the NGM would've had at least one torch level on it. lol Link to comment Share on other sites More sharing options...
Lava Rock Posted December 29, 2015 Share Posted December 29, 2015 Reports from kennebunk sleeting at 16f. Link to comment Share on other sites More sharing options...
moneypitmike Posted December 29, 2015 Share Posted December 29, 2015 Quite the pinging going on. I'm guessing 2". Still on the cool side. 20.4* Link to comment Share on other sites More sharing options...
MarkO Posted December 29, 2015 Share Posted December 29, 2015 MWN at 8.7F. That's got to be why I'm seeing some small flakes mixed in). Just measured 4.2" on the deck, and tried to get a core with the most cylindrical glass I have (totally unofficial) but appears to be between 0.5 and 0.6" qpf. Temp 15.4 @ 1100', 18.1@ 700', 13.1@1800' Link to comment Share on other sites More sharing options...
powderfreak Posted December 29, 2015 Share Posted December 29, 2015 4.0" on the nose measurement right after it changed to sleet....will be interesting if we can pick up an inch of sleet or so today. Link to comment Share on other sites More sharing options...
dendrite Posted December 29, 2015 Share Posted December 29, 2015 CoCoRAHS report near you showing the opposite, like 6" of snow out of 4/10th of an inch QPF. I was wondering if you guys were getting better ratios, it's dense over here too.I'll guess CON had 0.35"ish near the flip. That's about 3-3.5" of dense warm tongue snow. They're at 0.66" now so that's about another 1" or so...4-4.5" then? Will be curious to see what the "airport" total is. Link to comment Share on other sites More sharing options...
dendrite Posted December 29, 2015 Share Posted December 29, 2015 MWN at 8.7F. That's got to be why I'm seeing some small flakes mixed in). Just measured 4.2" on the deck, and tried to get a core with the most cylindrical glass I have (totally unofficial) but appears to be between 0.5 and 0.6" qpf. Temp 15.4 @ 1100', 18.1@ 700', 13.1@1800'Nice...that at least backs my numbers up a bit even though your numbers are crude. Link to comment Share on other sites More sharing options...
Dan Posted December 29, 2015 Share Posted December 29, 2015 2" in Methuen....moderate sleet. 25 Sent from my SM-N910V using Tapatalk Link to comment Share on other sites More sharing options...
dendrite Posted December 29, 2015 Share Posted December 29, 2015 I wonder if Gene could take the drone out in this peltfest to find the height of the warm tongue. Link to comment Share on other sites More sharing options...
J.Spin Posted December 29, 2015 Share Posted December 29, 2015 Event totals: 4.3” Snow/0.56” L.E. Snow started up here a bit after midnight, and it’s very dense stuff comprised of small flakes. Density of this morning’s stack from the snowboard was 13.0% H2O. Details from the 6:00 A.M. Waterbury observations: New Snow: 4.3 inches New Liquid: 0.56 inches Snow/Water Ratio: 7.7 Snow Density: 13.0% H2O Temperature: 19.9 F Sky: Snow (1-3 mm flakes) Snow at the stake: 4.5 inches Link to comment Share on other sites More sharing options...
CoastalWx Posted December 29, 2015 Share Posted December 29, 2015 Scalping all night long and still ongoing. 25.9 Interior probably won't sniff 32 You will. Others won't. Link to comment Share on other sites More sharing options...
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