Amped Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 3:23 AM, losetoa6 said: Yea...the lower hieghts are a nice change . Also.. with the anomalous artic cold lurking so close by . Models have trended much quicker with the cold plunge starting with 18z suite. Sunday early morning now with the crash Expand GFS has a similar trend 18hrs. Link to comment Share on other sites More sharing options...
Ralph Wiggum Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 3:27 AM, nj2va said: Nice to see the RGEM continue the 00z trend. Getting excited for McHenry this weekend. Expand Rgem is torched at 2m Link to comment Share on other sites More sharing options...
high risk Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 3:25 AM, Bob Chill said: What's really off is the midlevels aren't even marginal. Not even close to a sleet sounding either but the snowmaps pile it up hour after hour. TT is using the JB algorithm tonight. Expand What'a going on, I think (based off the NAM3), is that you have a huge slug of precip occurring during the evening hours - looks like well over an inch between 00z and 06z when the "snow" really piles up. The soundings are really, really iffy in terms of sleet potential, but the model microphysics are allowing for some pingers to be mixed in with the rain. Let's say that we have 1.3" of liquid falling and the model thinks that it's 60% rain and 40% sleet pellets: we know that would not accumulate, but the tallying does 1.3" x 0.4 = 0.52" liquid of "snow (+ sleet) accumulation". TT slaps a 10:1 ratio on that and gets 5.2" of "snow", while the Ferrier method will assign a way lower SLR since it knows that the frozen component is sleet and not snow. Link to comment Share on other sites More sharing options...
aldie 22 Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 3:40 AM, high risk said: What'a going on, I think (based off the NAM3), is that you have a huge slug of precip occurring during the evening hours - looks like well over an inch between 00z and 06z when the "snow" really piles up. The soundings are really, really iffy in terms of sleet potential, but the model microphysics are allowing for some pingers to be mixed in with the rain. Let's say that we have 1.3" of liquid falling and the model thinks that it's 60% rain and 40% sleet pellets: we know that would not accumulate, but the tallying does 1.3" x 0.6 = 0.52" liquid of "snow (+ sleet) accumulation". TT slaps a 10:1 ratio on that and gets 5.2" of "snow", while the Ferrier method will assign a way lower SLR since it knows that the frozen component is sleet and not snow. Expand Man who does math at 11pm...yeesh lol Link to comment Share on other sites More sharing options...
Ji Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 2:56 AM, high risk said: a friendly reminder that when the NAM accumulated snow depth and Ferrier (from the nest) maps show much less than the 10:1 "snow" accumulation map, then the model is not predicting the snowfest that you think it is.....I know...just asking what model is seeing to print that out... Link to comment Share on other sites More sharing options...
Warm Nose Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 3:40 AM, high risk said: What'a going on, I think (based off the NAM3), is that you have a huge slug of precip occurring during the evening hours - looks like well over an inch between 00z and 06z when the "snow" really piles up. The soundings are really, really iffy in terms of sleet potential, but the model microphysics are allowing for some pingers to be mixed in with the rain. Let's say that we have 1.3" of liquid falling and the model thinks that it's 60% rain and 40% sleet pellets: we know that would not accumulate, but the tallying does 1.3" x 0.6 = 0.52" liquid of "snow (+ sleet) accumulation". TT slaps a 10:1 ratio on that and gets 5.2" of "snow", while the Ferrier method will assign a way lower SLR since it knows that the frozen component is sleet and not snow. Expand Link to comment Share on other sites More sharing options...
Fozz Posted January 18, 2019 Share Posted January 18, 2019 I don't know how much of this is snow, but it looks like the GFS has a nice surprise for northern MD. Link to comment Share on other sites More sharing options...
Amped Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 3:51 AM, Warm Nose said: Expand I simplified it and factored out some terms. 50% rain=100% rain Link to comment Share on other sites More sharing options...
87storms Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 3:40 AM, high risk said: What'a going on, I think (based off the NAM3), is that you have a huge slug of precip occurring during the evening hours - looks like well over an inch between 00z and 06z when the "snow" really piles up. The soundings are really, really iffy in terms of sleet potential, but the model microphysics are allowing for some pingers to be mixed in with the rain. Let's say that we have 1.3" of liquid falling and the model thinks that it's 60% rain and 40% sleet pellets: we know that would not accumulate, but the tallying does 1.3" x 0.6 = 0.52" liquid of "snow (+ sleet) accumulation". TT slaps a 10:1 ratio on that and gets 5.2" of "snow", while the Ferrier method will assign a way lower SLR since it knows that the frozen component is sleet and not snow. Expand I thought it would calculate the 40% instead. Either way, I can see why the snow maps would be off. This event might be too marginal to toss yet, at least for the northern tier. edit: nevermind, I think you meant (1.3”)x(0.4). Makes sense Link to comment Share on other sites More sharing options...
high risk Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 4:16 AM, 87storms said: I thought it would calculate the 40% instead. Either way, I can see why the snow maps would be off. This event might be too marginal to toss yet, at least for the northern tier. Expand ugh. Yes, I came out with the right "totals" but typed 0.6 where it should have been 0.4. I've edited the original post. People are right that math shouldn't be done at 11pm.... Link to comment Share on other sites More sharing options...
NorthArlington101 Posted January 18, 2019 Share Posted January 18, 2019 I’m heading the UKIE looks south and the JMA looks nice. For the two cents that is worth. Link to comment Share on other sites More sharing options...
WEATHER53 Posted January 18, 2019 Share Posted January 18, 2019 The slug of eroding warmth portrayed as entering into southwest PA well may not make it that far north. That’s the trend and that’s some spooky looking cold ready to pounce. Link to comment Share on other sites More sharing options...
yoda Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 4:34 AM, NorthArlington101 said: I’m heading the UKIE looks south and the JMA looks nice. For the two cents that is worth. Expand Ukie at 60 is over PHL... so nope lol Link to comment Share on other sites More sharing options...
NorthArlington101 Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 4:50 AM, yoda said: Ukie at 60 is over PHL... so nope lolWell, that’s why you don’t believe what you read onlineAt least we have the JMA and the NAMs Link to comment Share on other sites More sharing options...
Roger Smith Posted January 18, 2019 Share Posted January 18, 2019 Euro not very encouraging but you never know with these lows moving southeast away from the Rockies, they can stay wide and come up the coast. Thursday's overperforming snow might be a tip that cold is not giving up without a fight. Would see if 12z model runs start to show a coastal trend. Link to comment Share on other sites More sharing options...
Ralph Wiggum Posted January 18, 2019 Share Posted January 18, 2019 Nails coffin and all that stuff Link to comment Share on other sites More sharing options...
nj2va Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 10:25 AM, Ralph Wiggum said: Nails coffin and all that stuff Expand 3k NAM same time. Seems NWS Pitt isn’t favoring that look above given the text of the watch for the mountains. LWX posted watches for the I81 counties in NVA and MD. Link to comment Share on other sites More sharing options...
Ralph Wiggum Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 10:40 AM, nj2va said: 3k NAM same time. Seems NWS Pitt isn’t favoring that look above given the text of the watch for the mountains. LWX posted watches for the I81 counties in NVA and MD. Expand NAM is by itself. Either a major win coming or overdoing things as usual. Rgem is obviously warmest but fair support that says NAM is likely too cold. Link to comment Share on other sites More sharing options...
AfewUniversesBelowNormal Posted January 18, 2019 Share Posted January 18, 2019 Pretty big differences between the NAM and GFS still. NAM is almost all frozen here. Link to comment Share on other sites More sharing options...
cae Posted January 18, 2019 Share Posted January 18, 2019 RGEM ensemble got a little better for PA western MD, but still doesn't get much snow past Parr's Ridge. Link to comment Share on other sites More sharing options...
WVclimo Posted January 18, 2019 Share Posted January 18, 2019 LWX seems to be leaning their forecast toward climo. Point and click for my yard calls for 1 to 2 inches of snow tomorrow afternoon and 1 to 3 more tomorrow night, along with a quarter inch of ice. Hoping they nail the snowfall amounts. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted January 18, 2019 Share Posted January 18, 2019 Man what I'd give for a surprise 150 mile southeast shift. Link to comment Share on other sites More sharing options...
winterymix Posted January 18, 2019 Share Posted January 18, 2019 GEFS looks favorable for only six to 12 hours of pure liquid. Link to comment Share on other sites More sharing options...
AfewUniversesBelowNormal Posted January 18, 2019 Share Posted January 18, 2019 I knew this would happen.. the 12z NAM is going warmer in the Plains. Link to comment Share on other sites More sharing options...
T. August Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 1:50 PM, AfewUniversesBelowNormal said: I knew this would happen.. the 12z NAM is going warmer in the Plains. Expand I’m running out of fingernails Link to comment Share on other sites More sharing options...
paulythegun Posted January 18, 2019 Share Posted January 18, 2019 There are many fine plumes...on both sides Link to comment Share on other sites More sharing options...
lpaschall Posted January 18, 2019 Share Posted January 18, 2019 My faith is in the NAM now that we are in the short range. It has been consistent over the last few runs with minor timing differences. Link to comment Share on other sites More sharing options...
AfewUniversesBelowNormal Posted January 18, 2019 Share Posted January 18, 2019 NAM went to the GFS. Link to comment Share on other sites More sharing options...
nj2va Posted January 18, 2019 Share Posted January 18, 2019 On 1/18/2019 at 11:22 AM, Ralph Wiggum said: NAM is by itself. Either a major win coming or overdoing things as usual. Rgem is obviously warmest but fair support that says NAM is likely too cold. Expand I should have added, I'm not tracking this for Arlington...I'm tracking for McHenry/Garrett County as I'll be at my house there this weekend. I agree that the cities will see rain from this and the story will be the drop in temperatures. Euro is warmer than the NAM but is still colder than RGEM by a considerable amount. Link to comment Share on other sites More sharing options...
Scarlet Pimpernel Posted January 18, 2019 Share Posted January 18, 2019 Reduced to hoping for a few flakes as the Arctic air rushes in on Sunday! Well, that and perhaps still having a few piles of what's on the ground now still left over. Link to comment Share on other sites More sharing options...
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