Shad Posted February 20 Share Posted February 20 RGEM a touch too warm similar to ICON Link to comment Share on other sites More sharing options...
LP08 Posted February 20 Share Posted February 20 It’s not a great model but the fv3 is a beatdown and still going at 60 8 Link to comment Share on other sites More sharing options...
psuhoffman Posted February 20 Share Posted February 20 Why are the Icon and rgem soooo warm! It’s Feb with a sub 990 low off the Delmarva and moderate precip. And it’s close to 40! WTF 7 Link to comment Share on other sites More sharing options...
NorthArlington101 Posted February 20 Share Posted February 20 Just now, psuhoffman said: Why are the Icon and rgem soooo warm! It’s Feb with a sub 990 low off the Delmarva and moderate precip. And it’s close to 40! WTF I'd say we bust low on temps as we have all week but we know that's not likely Link to comment Share on other sites More sharing options...
Scraff Posted February 20 Share Posted February 20 Goofy GooFuS time! LFG!! 2 Link to comment Share on other sites More sharing options...
WxUSAF Posted February 20 Share Posted February 20 1 minute ago, psuhoffman said: Why are the Icon and rgem soooo warm! It’s Feb with a sub 990 low off the Delmarva and moderate precip. And it’s close to 40! WTF Cuz it’s an absolute dog shit antecedent airmass? RGEM overall has a lot to like. Better H5, closer tuck to the coastal, and a really nice IVT that gets most everyone in the metro area and east. Sorry CHO area… 4 Link to comment Share on other sites More sharing options...
Shad Posted February 20 Share Posted February 20 The King is running.....let it cook 1 1 Link to comment Share on other sites More sharing options...
SomeguyfromTakomaPark Posted February 20 Share Posted February 20 Still feels like some trending to go before the actual storm but it's nice to see the the total whiff solutions from the euro/icon a few days ago are basically gone. Link to comment Share on other sites More sharing options...
arlwx12 Posted February 20 Share Posted February 20 I'd be surprised if any watches get issued before the 00z runs. Maybe after the 12z runs tomorrow? Link to comment Share on other sites More sharing options...
Terpeast Posted February 20 Share Posted February 20 1 minute ago, WxUSAF said: Cuz it’s an absolute dog shit antecedent airmass? RGEM overall has a lot to like. Better H5, closer tuck to the coastal, and a really nice IVT that gets most everyone in the metro area and east. Sorry CHO area… Yep, we've been in a -PNA regime for weeks now. We're lucky we're even talking about snow at all rn 1 Link to comment Share on other sites More sharing options...
Nomz Posted February 20 Share Posted February 20 All hail 1 Link to comment Share on other sites More sharing options...
Terpeast Posted February 20 Share Posted February 20 Still changes with the SW canada shortwave on gfs even at hour 18 1 Link to comment Share on other sites More sharing options...
TowsonWeather Posted February 20 Share Posted February 20 1 minute ago, Terpeast said: Still changes with the SW canada shortwave on gfs even at hour 18 As subtle as they are, I would THINK they might bode well downstream? At least in theory. No point speculating, I guess, just too complex to say at this point. Could just as easily go sideways on us. 1 Link to comment Share on other sites More sharing options...
arlwx12 Posted February 20 Share Posted February 20 Slightly updated wording from LWX's AFD at 1029... If the upstream ridge-building event takes place a bit further west near 120 W longitude on Saturday, downstream trough amplification would be favorable for phasing over the mid MS Valley into the OH/TN Valleys Saturday night. A subsequent low track hugging the coast would become more likely in this scenario, aided by downstream blocking and a potential source of cold air given the upper lows over Maritime Canada and surface high pressure attempting to ridge into northern New England. There is also an appearance of an inverted trough signature in a subset of model guidance over the last couple cycles, given interaction between a more amplified northern stream wave and a bit more distant offshore southern stream low. This could factor into precipitation amounts and placement. After reviewing the 00z model guidance suite, some subtle consistency has been noted although subtle uncertainty remains. Most of the models has a low tracking up from GA/AL toward the NC coast and off the Delmarva coast during the late Saturday night into late Sunday timeframe. The question remains in the proximity toward the coast along with cold air availability, and the overall scope of the precip shield pending the placement/intensity of the system. 25 to 50 miles could make a huge difference between seeing little to no wintry precip or impactful precip, especially for those east of the mountains where the confidence remains low due to thermal issues especially below elevations of 1500 feet. The 00z GFS/GEFS solutions have come down a tad, but still produce measurements on the order of 10+" of snow over a large chunk of the area. Meanwhile, the 12z EPS ensembles came up some, but at much more conservative levels which align with deterministic runs of the NAM, RDPS, GDPS, GEM, CMC, EURO/EURO AIFS, and UKMET. The latest NBM also came up a bit and aligns with the majority compared to the GFS/GEFS outliers, especially along and east of I-95. With that said, the 6/12z model suites should put the remaining puzzle pieces together as we will sit 60 hours from the event. Three scenarios remain: 1) The phase of all of these upper level features occurs too late, with low development offshore and too far southeast. 2) Similar to scenario 1, but an inverted trough on the back side of the low brings snow to eastern portions of the region. 3) Low develops closer to shore and strengthens along Delmarva Peninsula, resulting in the most snow for our areas. We still remain in the "wait and see" period with this storm, so just take precautions now, should the worst case scenario play out. Having a preparedness kit stocked up is never a bad idea. Lastly, no matter what plays out further east, it seems much more likely that the mountains will see another round of upslope snow. The key here will be with how much we manage to get. That will depend on the storm track as well, but it seems much more likely for at least advisory to perhaps warning level accumulations through the Sunday/Monday period along/west of the Allegheny Front. Of note, the higher sun angle later in the season becomes a factor especially for lower elevations if precip occurs during the day. Cold air will also be filtering into the region as the storm in question approaches, rather than being locked-in beforehand, which offers another layer of uncertainty in p-type. Link to comment Share on other sites More sharing options...
EstorilM Posted February 20 Share Posted February 20 1 minute ago, arlwx12 said: Slightly updated wording from LWX's AFD at 1029... If the upstream ridge-building event takes place a bit further west near 120 W longitude on Saturday, downstream trough amplification would be favorable for phasing over the mid MS Valley into the OH/TN Valleys Saturday night. A subsequent low track hugging the coast would become more likely in this scenario, aided by downstream blocking and a potential source of cold air given the upper lows over Maritime Canada and surface high pressure attempting to ridge into northern New England. There is also an appearance of an inverted trough signature in a subset of model guidance over the last couple cycles, given interaction between a more amplified northern stream wave and a bit more distant offshore southern stream low. This could factor into precipitation amounts and placement. After reviewing the 00z model guidance suite, some subtle consistency has been noted although subtle uncertainty remains. Most of the models has a low tracking up from GA/AL toward the NC coast and off the Delmarva coast during the late Saturday night into late Sunday timeframe. The question remains in the proximity toward the coast along with cold air availability, and the overall scope of the precip shield pending the placement/intensity of the system. 25 to 50 miles could make a huge difference between seeing little to no wintry precip or impactful precip, especially for those east of the mountains where the confidence remains low due to thermal issues especially below elevations of 1500 feet. The 00z GFS/GEFS solutions have come down a tad, but still produce measurements on the order of 10+" of snow over a large chunk of the area. Meanwhile, the 12z EPS ensembles came up some, but at much more conservative levels which align with deterministic runs of the NAM, RDPS, GDPS, GEM, CMC, EURO/EURO AIFS, and UKMET. The latest NBM also came up a bit and aligns with the majority compared to the GFS/GEFS outliers, especially along and east of I-95. With that said, the 6/12z model suites should put the remaining puzzle pieces together as we will sit 60 hours from the event. Three scenarios remain: 1) The phase of all of these upper level features occurs too late, with low development offshore and too far southeast. 2) Similar to scenario 1, but an inverted trough on the back side of the low brings snow to eastern portions of the region. 3) Low develops closer to shore and strengthens along Delmarva Peninsula, resulting in the most snow for our areas. We still remain in the "wait and see" period with this storm, so just take precautions now, should the worst case scenario play out. Having a preparedness kit stocked up is never a bad idea. Lastly, no matter what plays out further east, it seems much more likely that the mountains will see another round of upslope snow. The key here will be with how much we manage to get. That will depend on the storm track as well, but it seems much more likely for at least advisory to perhaps warning level accumulations through the Sunday/Monday period along/west of the Allegheny Front. Of note, the higher sun angle later in the season becomes a factor especially for lower elevations if precip occurs during the day. Cold air will also be filtering into the region as the storm in question approaches, rather than being locked-in beforehand, which offers another layer of uncertainty in p-type. Haha I just clicked refresh on that as well and saw it was "updated" but it doesn't seem like they even touched the stuff regarding the storm potential. Link to comment Share on other sites More sharing options...
Interstate Posted February 20 Share Posted February 20 I don't think I am liking the change... I could be wrong 1 1 1 Link to comment Share on other sites More sharing options...
TowsonWeather Posted February 20 Share Posted February 20 At 30h, not quite as diggy out west, but the leading vort is slower, leading to more interaction between the vorts. Heights very slightly higher. Link to comment Share on other sites More sharing options...
LP08 Posted February 20 Share Posted February 20 Definitely a broader Trof through 36 Link to comment Share on other sites More sharing options...
LeesburgWx Posted February 20 Share Posted February 20 1 minute ago, Interstate said: I don't think I am liking the change... I could be wrong I thought the changes look better. Who knows at this point. Let's see it play out Link to comment Share on other sites More sharing options...
Nomz Posted February 20 Share Posted February 20 Maybe more of the 00z solution than the earlier ones Link to comment Share on other sites More sharing options...
TowsonWeather Posted February 20 Share Posted February 20 1 minute ago, Interstate said: I don't think I am liking the change... I could be wrong Yeah, I was on the fence at 30h, I'm in the "don't like this" camp now for 36h. Shallower trough, not quite as diggy. Link to comment Share on other sites More sharing options...
SnowenOutThere Posted February 20 Share Posted February 20 13 minutes ago, WxUSAF said: Cuz it’s an absolute dog shit antecedent airmass? RGEM overall has a lot to like. Better H5, closer tuck to the coastal, and a really nice IVT that gets most everyone in the metro area and east. Sorry CHO area… Eh it’s get Shenandoah nice and good Link to comment Share on other sites More sharing options...
arlwx12 Posted February 20 Share Posted February 20 The next AFD should be out a bit before 4 pm. 1 Link to comment Share on other sites More sharing options...
Interstate Posted February 20 Share Posted February 20 it is all about it going negative tilt now 1 Link to comment Share on other sites More sharing options...
SnowenOutThere Posted February 20 Share Posted February 20 I actually don’t hate the GFS so far 1 Link to comment Share on other sites More sharing options...
Jersey_Snowhole Posted February 20 Share Posted February 20 1 minute ago, Interstate said: it is all about it going negative tilt now It’s negative at hr 57 Link to comment Share on other sites More sharing options...
stormtracker Posted February 20 Share Posted February 20 3 minutes ago, Interstate said: I don't think I am liking the change... I could be wrong Still seems decent. Seems a bit more progressive. Link to comment Share on other sites More sharing options...
Interstate Posted February 20 Share Posted February 20 it is way positive at 48 compared to 54@6Z 1 Link to comment Share on other sites More sharing options...
TowsonWeather Posted February 20 Share Posted February 20 42h, the theme of shallower trough and more consolidated energy remains, but more energy rounding the back-side. Link to comment Share on other sites More sharing options...
mitchnick Posted February 20 Share Posted February 20 Just now, SnowenOutThere said: I actually don’t hate the GFS so far This has become a love-hate relationship here. Link to comment Share on other sites More sharing options...
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