Jump to content

Holston_River_Rambler

Members
 View Profile  See their activity

  • Posts

    5,560

  • Joined

  • Last visited

 Content Type 

Everything posted by Holston_River_Rambler

  1. Holston_River_Rambler
    Looks like I should be at 35 by 1PM at the rate the cold air is moving in. Re: Carver's that last ripple has consistently been modeled as the best one, I think whoever gets that one may get a quick inch. Has been projected up towards your area, but I also think the precip is being underdone by the models to an extent. Does precip continue to slightly overperform, no idea, lol. On the local radar sites to the west, you definitely see the dry air trying to intrude.
  2. Holston_River_Rambler
    The NAM though is still not doing so hot with its precip depiction:
  3. Holston_River_Rambler
    Looks like the NAM is back on board for the plateau and points east.
  4. Holston_River_Rambler
    Could be some sleet starting to mix in up that way. I know one of the radar products had a giant blog of graupnel over that area when that bright banding was going on. Maybe that helped cool the column a bit.
  5. Holston_River_Rambler
    NAMs aren't doing so well with the precip. 6z 3km and 12 km NAM radar projections for 7 AM: Radar as of 730 AM RGEM and latest HRRR look better but the HRRR has also been trending better the past few runs, maybe playing catchup with radar presentation?
  6. Holston_River_Rambler
    Cold air starting to move in now in my neck of the woods. Wundergound stations showing a sharp drop in the past hour. Wind has also picked up outside.
  7. Holston_River_Rambler
    I think the front itself is still moving, but there's still enough moisture being lifted behind it to keep things going for now.
  8. Holston_River_Rambler
    I see a 37 on Wunderground near Cottontown, but lots of 34s north near Protland
  9. Holston_River_Rambler
    What's your temp right now?
  10. Holston_River_Rambler
    I was actually kind of wondering if that was the case with that blue color. That was a color I don't see too often.
  11. Holston_River_Rambler
    The rain/ snow line is getting close to Nashville. I know many of you know about the correlation coefficient, but if you are wondering what in the world this weird looking radar is, it's part of a dual polarization radar that can help identify rain and snow because of how it scans what's falling through the air. First you can see the front pass south of Nashville and then the brighter colors show the transition to snow. When it is in a circle around a radar site at a pretty uniform distance it is usually because the radar is not aimed straight out, but at an angle up and it is seeing the transition to snow, but waaaaayyyyy up. Notice here how it starts to crawl in to Nashville as the loop continues. That is the rain/snow line creeping closer and down in the atmosphere. I'm not sure exactly how high it is right now, but it is moving in. There is still some moisture lingering back that way too and I bet those enhanced echoes north of Nashville over s. KY are some bright banding as the snow is melting in the atmosphere.
  12. Holston_River_Rambler
    Yeah, it's already got me in snow by 4 PM with 1.5"
  13. Holston_River_Rambler
    I'm not sure if that speed is accurate or not. Just my estimate at that time and was so unsure of it I didn't want to post it at first. Nothing to impede it on the Plains unlike here though and closer to the low/ high gradient there maybe?
  14. Holston_River_Rambler
    Yeah that's what I was wondering too, this is the first time I've tried to time one, so no idea.
  15. Holston_River_Rambler
    I had it clocked at 110 mph, but couldn't believe it. But like you said, our terrain and distance from what's driving south will have an effect here. That's a two hour loop
  16. Holston_River_Rambler
    Decided to tweak the gif above to make the cold show up sharper. Blue line is the approximate 32 degree line based on surface temps. I tried to estimate the arrival time, based on the above, but my calculations put it in Nashville in 5 hours, lol, so back to the drawing board.
  17. Holston_River_Rambler
    Here comes the cold:
  18. Holston_River_Rambler
    AFD with some interesting tidbits: " Temperatures will be on the decline through the day on Tuesday as the front moves through and colder air from the northwest begins to funnel into the area. With a non-diurnal temperature trend the "daytime high" temperatures on Tuesday will actually come early in the morning as temperatures only decrease through the daytime hours. The transition to wintry weather will begin in the Cumberland Plateau during the afternoon hours. Biggest questions at this point will be the warm nose and how quickly surface temperatures drop below freezing. In the plateau counties these may combine to bring a period of rain/snow/freezing rain/ice pellets mix before finally transitioning to all snow during the evening hours. All models are showing this general trend, but some of the details between models are still up in the air. One parameter to keep an eye on is the dendritic growth zone on the plateau. The NAM wants to keep the -12 to -18 C zone drier, longer than the GFS. This is the region of the atmosphere that needs to be saturated to create good dendritic growth. A drier dendritic growth zone would mean a delayed transition to snow, and possibly and longer duration of the wintry mix. The GFS keeps this dendritic growth zone saturated much quicker meaning that the transition to snow would be much faster. Have gone with a top down methodology across the area that is a general blend of GFS/NAM/HREF. The end result is rain, then wintry mix, then snow in the Cumberland Plateau. In the Valley and Southern Appalachian Mountains, expect there to be a much quicker transition to snow as the colder air at the surface gets caught along the Cumberland Plateau and has trouble making it further east, until after the warm nose has dissipated. That being said, am continuing with most of the area transitioned to snow during the overnight hours, which then leads to a snowfall accumulation forecast. Not many major changes have been made to the snowfall accumulation forecast, with the highest amounts expected in Northeast Tennessee/Southwest Virginia and the nearby higher elevations. Expect snowfall to struggle to accumulate on the roads, due to temperatures recently being in the 50/60`s. So most accumulations will occur on grassy and elevated surfaces, hopefully keeping travel impacts somewhat isolated.
  19. Holston_River_Rambler
    I'm getting suspicious now that the whole first half, if I can call it that, may fizzle out and a lot will just depend on timing that second wave. The HRRR shows this idea. Not saying it will be right this far out, more to show a type of progression that might occur and it would fit with your reasoning quite well:
  20. Holston_River_Rambler
    The Euro has definitely back off from the past few days, but not much change to me from 6z as far as I can tell. Of course as you said it does depend on where you're at. The push from the second piece of energy that Jeff mentioned seems to be key now. Euro doesn't seem to have it as much as the 3k NAM and RGEM. HRRR, waaayyy out in its la la land has it too. If that materializes there will probably be a narrow band somewhere of more accumulation.
  21. Holston_River_Rambler
    12z Euro looks about the same too.
  22. Holston_River_Rambler
    Snowfall looks pretty realistic on the 6z Euro: But the RGEM has won a few battles with storm evolution in the past. I think it is now kind of a watch and see now, but then again, I'm sure I'll be looking at the SREFs in 45 min. lol
  23. Holston_River_Rambler
    6z Euro continues to struggle with the southern energy, but does seem to be picking out a very quick moving northern stream pulse (almost like a clipper) that sort of cuts the head off the southern energy but also provides a bit of extra lift as it races toward the TN Valley: 0z Euro: 6z Euro: On both runs the energy races in and sweeps out the northern part of the souther wave, but the 6z run keeps it more consolidated toward the Gulf coast. Not sure that would help us at all, but interesting to see that there's still variability even 36 hours out. 6z Euro precip. result You can actually see the second piece of energy producing precip and racing down the front range of the Rockies in the early frames. I think the 6z RGEM did a better job pulling more of the energy north and in the RGEMs version of events, the second piece of energy does more to help than hurt. But right now it is on its own with that evolution.
  24. Holston_River_Rambler
    GFS especially sees some tropical foring moving into the dreaded Maritime Continent, but out in (admittedly) its la-la land, realyy cranks it up over the Western Hemisphere: EPS on the other hand like restrengthening it near the (cue dramatic music du...du...DUUUUUUU) the Western Indian Ocean: Right now the Western Indian Ocean looks pretty tame and most of the convection is in fact in the 4/5/6 regions: There's some a little further east, but it is also south of the equator. I wonder how much the less positive pattern depicted by NWP in the long range has to do with current convection location?
  25. Holston_River_Rambler
    We've been RGEM'd NAM suite has backed off from its wild runs, but it seems like this is because A. it s the NAM and B. it has the energy passing south of us flatter. 12km NAM flattens it, but 3km NAM brings out a second piece. Looks like it depends on exactly how that energy behaves: RGEM: NAM 12km: It should be getting sampled pretty well as of 10z, its right over a major sounding site in souther CA:
×
×
  • Create New...