BullCityWx Posted February 20, 2020 Share Posted February 20, 2020 The NAM initialized dewpoints too warm in the Triangle. 2 Link to comment Share on other sites More sharing options...
DC2Winston Posted February 20, 2020 Share Posted February 20, 2020 Were dew points modeled to drop this low in the Triad area? I'm seeing lots of low 20's... I understand that helps a quick changeover to snow - but isn't it a double-edge sword with lower QPF and accumulation? 1 Link to comment Share on other sites More sharing options...
olafminesaw Posted February 20, 2020 Share Posted February 20, 2020 Just now, DC2Winston said: Were dew points modeled to drop this low in the Triad area? I'm seeing lots of low 20's... I understand that helps a quick changeover to snow - but isn't it a double-edge sword with lower QPF and accumulation? Yeah, definitely seems to align with models trending towards less moisture pushing North. It should help us though if a good band does move through early on. 1 1 Link to comment Share on other sites More sharing options...
Tony Sisk Posted February 20, 2020 Share Posted February 20, 2020 10 minutes ago, Billypg70 said: Someone just posted snowing steadily at lake Toxaway just on the otherside of the border. Looks to heading south. webcam neat Lake Toxaway 1 Link to comment Share on other sites More sharing options...
mcblimp95 Posted February 20, 2020 Share Posted February 20, 2020 9 minutes ago, BullCityWx said: The NAM initialized dewpoints too warm in the Triangle. It did a pretty bad job with the position of the 850 line as well. Especially along highway 74 and east. Link to comment Share on other sites More sharing options...
mcblimp95 Posted February 20, 2020 Share Posted February 20, 2020 The HRRR is taking the supposed rain/snow line and plopping it further and further south every run this morning. The 06Z run at the same time frame had it North of Rockingham, and the 13Z had it south of the county into South Carolina. Current observations looking at CC would suggest this is very likely the case. Link to comment Share on other sites More sharing options...
NorthHillsWx Posted February 20, 2020 Share Posted February 20, 2020 We got down to 38 and are already up to 45. I'm not going to sugarcoat it, that's not a good place to be with precip set to move in in the next 3 hours. Good news is DP's have FINALLY tanked into the 20's. That was a painful fall but they are crashing with the NE wind. I'm not model watching anymore they will bounce around with their clown maps until the very end but temp wise, we are running a couple degrees above where the globals (and NAM) had us yesterday and are in line with the HRRR. I did not think we'd exceed 41-42 today. Radar looks very NAM-like which is good but I am worried about folks west of the influence of the coastal. West of the Triangle may have more precip issues than we thought as even the NAM has trended more to the globals on that western cutoff. Radar watching will be the only way to confirm that. I would hit the panic button if precip is not gaining more of a WSW to ENE movement and pushing up into the Triad area by lunchtime. I like my forecast from yesterday and am sticking to it. I think RDU is a lock for 2-3 in and the coastal plain looks to be good for 4+ in. If we had better temps (as always) I think Max snow potential would be doubled at least but I know we will waste at least 0.25" here on wetbulbing and white rain. CLT-Upstate, I still don't think anyone outside of elevation will see any accumulation. Just not those areas' storm, unfortunately. 1 Link to comment Share on other sites More sharing options...
CaryWx Posted February 20, 2020 Share Posted February 20, 2020 15 minutes ago, BullCityWx said: The NAM initialized dewpoints too warm in the Triangle. Bull, WRAL is forecasting a changeover between 5-7pm for Triangle. Does that square with what we’re seeing here? From what I’m reading it would be much sooner 1 Link to comment Share on other sites More sharing options...
NorthHillsWx Posted February 20, 2020 Share Posted February 20, 2020 Just now, CaryWx said: Bull, WRAL is forecasting a changeover between 5-7pm for Triangle. Does that square with what we’re seeing here? From what I’m reading it would be much sooner WRAL's model has persistently pushed the start of snow back and the onset of rain earlier. Last night, for what it's worth, that model had the snow start time for Raleigh proper around 1-2. While I think it's bringing the rain in too early, especially based on downstream reports, it also may be capturing the fact that it is in the mid 40's at 9:30 AM and will probably rise a couple more degrees until precip sets in. I would not bank on an earlier switch to snow at this time given the warm BL that will take an army to overcome. That is the big change and I think some of the globals handled that better and were putting out lower snow totals accordingly. This is not all doom and gloom. I think current forecasts are right on track for this area and points east. This is ONLY in reference to being able to pick up the upper ends of some of the models we saw yesterday and last night (6 inch snows). 1 Link to comment Share on other sites More sharing options...
BullCityWx Posted February 20, 2020 Share Posted February 20, 2020 3 minutes ago, CaryWx said: Bull, WRAL is forecasting a changeover between 5-7pm for Triangle. Does that square with what we’re seeing here? From what I’m reading it would be much sooner As long as we hang around where we're at now, I expect a quicker changeover. Link to comment Share on other sites More sharing options...
BullCityWx Posted February 20, 2020 Share Posted February 20, 2020 Just now, NorthHillsWx said: WRAL's model has persistently pushed the start of snow back and the onset of rain earlier. Last night, for what it's worth, that model had the snow start time for Raleigh proper around 1-2. While I think it's bringing the rain in too early, especially based on downstream reports, it also may be capturing the fact that it is in the mid 40's at 9:30 AM and will probably rise a couple more degrees until precip sets in. I would not bank on an earlier switch to snow at this time given the warm BL that will take an army to overcome. That is the big change and I think some of the globals handled that better and were putting out lower snow totals accordingly. This is not all doom and gloom. I think current forecasts are right on track for this area and points east. This is ONLY in reference to being able to pick up the upper ends of some of the models we saw yesterday and last night (6 inch snows). RDU Metar is 41/29 Link to comment Share on other sites More sharing options...
Tar Heel Snow Posted February 20, 2020 Author Share Posted February 20, 2020 7 minutes ago, NorthHillsWx said: We got down to 38 and are already up to 45. I'm not going to sugarcoat it, that's not a good place to be with precip set to move in in the next 3 hours. Good news is DP's have FINALLY tanked into the 20's. That was a painful fall but they are crashing with the NE wind. I'm not model watching anymore they will bounce around with their clown maps until the very end but temp wise, we are running a couple degrees above where the globals (and NAM) had us yesterday and are in line with the HRRR. I did not think we'd exceed 41-42 today. Radar looks very NAM-like which is good but I am worried about folks west of the influence of the coastal. West of the Triangle may have more precip issues than we thought as even the NAM has trended more to the globals on that western cutoff. Radar watching will be the only way to confirm that. I would hit the panic button if precip is not gaining more of a WSW to ENE movement and pushing up into the Triad area by lunchtime. I like my forecast from yesterday and am sticking to it. I think RDU is a lock for 2-3 in and the coastal plain looks to be good for 4+ in. If we had better temps (as always) I think Max snow potential would be doubled at least but I know we will waste at least 0.25" here on wetbulbing and white rain. CLT-Upstate, I still don't think anyone outside of elevation will see any accumulation. Just not those areas' storm, unfortunately. At this rate, RDU definitely means more Raleigh than Durham/Chapel Hill. Just need that precip to be a smidge west for mby. It’ll be close, especially living closer to Carrboro. Link to comment Share on other sites More sharing options...
FatherNature Posted February 20, 2020 Share Posted February 20, 2020 2 minutes ago, NorthHillsWx said: WRAL's model has persistently pushed the start of snow back and the onset of rain earlier. Last night, for what it's worth, that model had the snow start time for Raleigh proper around 1-2. While I think it's bringing the rain in too early, especially based on downstream reports, it also may be capturing the fact that it is in the mid 40's at 9:30 AM and will probably rise a couple more degrees until precip sets in. I would not bank on an earlier switch to snow at this time given the warm BL that will take an army to overcome. That is the big change and I think some of the globals handled that better and were putting out lower snow totals accordingly. This is not all doom and gloom. I think current forecasts are right on track for this area and points east. This is ONLY in reference to being able to pick up the upper ends of some of the models we saw yesterday and last night (6 inch snows). Where is it 45 degrees in Raleigh? I have upper 30s/low 40s right now in multiple spots. 1 Link to comment Share on other sites More sharing options...
CaryWx Posted February 20, 2020 Share Posted February 20, 2020 With 41/29 the dewpoint will likely come up above freezing as the surface temp slowly drops. My guess is they meet around 37 and the surface temp drags it back down troughout the day/evening Link to comment Share on other sites More sharing options...
burrel2 Posted February 20, 2020 Share Posted February 20, 2020 Surface temps have dropped to 38 degree's just northeast of atlanta where heavy rain has set in. They've got 1/3 inch of liquid so far. Keep in mind they are +5C at 850mb right now. Seems like area's to the Northeast of here already have lower dew points to start and colder temps aloft, should have no problem dropping down to 34/35 when heavy precip moves in, and then hopefully go to 32/33 as half dollar flakes slam down. 3 1 Link to comment Share on other sites More sharing options...
NorthHillsWx Posted February 20, 2020 Share Posted February 20, 2020 Just now, FatherNature said: Where is it 45 degrees in Raleigh? I have upper 30s/low 40s right now in multiple spots. At work in Garner and my house is 44. Link to comment Share on other sites More sharing options...
downeastnc Posted February 20, 2020 Share Posted February 20, 2020 Latest HRRR has 8" down here and still snowing decent at hr 18 with several more to go....starting to think 6-10" is doable would be the biggest snow here in a solid 10 years if we get 8" or more....still would feel better if the temps would crash a bit lol....still the 925/850's are going to be plenty cold once we get the heavier banding setting up it should go all snow fast and surface temps will crash. Link to comment Share on other sites More sharing options...
Bryan63 Posted February 20, 2020 Share Posted February 20, 2020 In Garner near Lake Benson, sitting at 42 currently. 1 Link to comment Share on other sites More sharing options...
NCsandhills Posted February 20, 2020 Share Posted February 20, 2020 4 minutes ago, FatherNature said: Where is it 45 degrees in Raleigh? I have upper 30s/low 40s right now in multiple spots. FWIW my car said it was 46 degrees when I was arriving at work half an hour ago. The temp gauge outside the building had 43 degrees. Weather.gov has us at 41 and TWC has us at 42. Low to mid 40s seems to be where we're at. Link to comment Share on other sites More sharing options...
mackerel_sky Posted February 20, 2020 Share Posted February 20, 2020 6 minutes ago, burrel2 said: Surface temps have dropped to 38 degree's just northeast of atlanta where heavy rain has set in. They've got 1/3 inch of liquid so far. Keep in mind they are +5C at 850mb right now. Seems like area's to the Northeast of here already have lower dew points to start and colder temps aloft, should have no problem dropping down to 34/35 when heavy precip moves in, and then hopefully go to 32/33 as half dollar flakes slam down. I swear the heaviest precip in GA/AL, looks to be moving ESE! I think we skim by with some heavy precip, just don’t know if 850s will ever get right!? Link to comment Share on other sites More sharing options...
DC2Winston Posted February 20, 2020 Share Posted February 20, 2020 18 minutes ago, NorthHillsWx said: We got down to 38 and are already up to 45. I'm not going to sugarcoat it, that's not a good place to be with precip set to move in in the next 3 hours. Good news is DP's have FINALLY tanked into the 20's. That was a painful fall but they are crashing with the NE wind. I'm not model watching anymore they will bounce around with their clown maps until the very end but temp wise, we are running a couple degrees above where the globals (and NAM) had us yesterday and are in line with the HRRR. I did not think we'd exceed 41-42 today. Radar looks very NAM-like which is good but I am worried about folks west of the influence of the coastal. West of the Triangle may have more precip issues than we thought as even the NAM has trended more to the globals on that western cutoff. Radar watching will be the only way to confirm that. I would hit the panic button if precip is not gaining more of a WSW to ENE movement and pushing up into the Triad area by lunchtime. I like my forecast from yesterday and am sticking to it. I think RDU is a lock for 2-3 in and the coastal plain looks to be good for 4+ in. If we had better temps (as always) I think Max snow potential would be doubled at least but I know we will waste at least 0.25" here on wetbulbing and white rain. CLT-Upstate, I still don't think anyone outside of elevation will see any accumulation. Just not those areas' storm, unfortunately. Thanks, I agree. I'm remembering the over-running orientation from the December 2018 big storm. Definitely had a WSW to ENE movement. Our air is super dry here now. Maybe I'll storm chase to Rocky Mount or Greenville Link to comment Share on other sites More sharing options...
burrel2 Posted February 20, 2020 Share Posted February 20, 2020 Going on surface obs and radar extreme Northern Alabama is going to get accumulations over the next 2 hours. Surface has dropped to 33/34 there and continuing to go down and the rain/snow line has pushed south of them. 2 Link to comment Share on other sites More sharing options...
ILMRoss Posted February 20, 2020 Share Posted February 20, 2020 Here’s why I and other mets aren’t trusting the HRRR; this is a pretty unrealistic profile for an overcast day; with a super adiabatic lapse rate at the surface this is a sounding you’d usually get if it were sunny! Sometimes even short term models struggle with the boundary layer and potential solar radiation. 1 3 1 Link to comment Share on other sites More sharing options...
Isopycnic Posted February 20, 2020 Share Posted February 20, 2020 40/31f dp Link to comment Share on other sites More sharing options...
PackGrad05 Posted February 20, 2020 Share Posted February 20, 2020 FWIW, the new run of WRAL futurecast model is now showing 2-3 inches for most of the triangle. This is in line with the NAM. Their futurecast is usually pretty conservative so I think that's a good sign. 4 Link to comment Share on other sites More sharing options...
strongwxnc Posted February 20, 2020 Share Posted February 20, 2020 2 minutes ago, burrel2 said: Going on surface obs and radar extreme Northern Alabama is going to get accumulations over the next 2 hours. Surface has dropped to 33/34 there and continuing to go down and the rain/snow line has pushed south of them. Just need rates to make it go boom. Link to comment Share on other sites More sharing options...
SCSteel Posted February 20, 2020 Share Posted February 20, 2020 925 line is diving south as well the last hour. Does that indicate further cooling? 1 Link to comment Share on other sites More sharing options...
olafminesaw Posted February 20, 2020 Share Posted February 20, 2020 Good tends on the HRRR in terms of QPF for N and W, FWIW 2 1 Link to comment Share on other sites More sharing options...
NorthHillsWx Posted February 20, 2020 Share Posted February 20, 2020 22 minutes ago, burrel2 said: Going on surface obs and radar extreme Northern Alabama is going to get accumulations over the next 2 hours. Surface has dropped to 33/34 there and continuing to go down and the rain/snow line has pushed south of them. Where are you getting that? Huntsville and Florence are reading 39 each with Heavy Rain Link to comment Share on other sites More sharing options...
CaryWx Posted February 20, 2020 Share Posted February 20, 2020 Dewpoints crashing in the Triangle? Would have thought influx of moisture would bring them up. We changeover to -sn more quickly then? Link to comment Share on other sites More sharing options...
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