Jump to content

high risk

Meteorologist
 View Profile  See their activity

  • Posts

    2,587

  • Joined

  • Last visited

 Content Type 

Everything posted by high risk

  1. high risk
    Trend in the NAM is really interesting. A slower arrival of the front allows for more heating Saturday and for moisture to return. 00Z run this evening has a good amount of CAPE, especially south of DC along with a not-too-shabby wind profile.
  2. high risk
    Completely understand the post, but the NAM doesn't give most of us 6". This is definitely a case to look at the snow depth maps, as the 10:1 is probably an overall too generous ratio, and the model is definitely showing some sleet which gets tallied in. There are flaws with the snow depth maps, but they (right or wrong) best represent what the model is actually predicting will be on the ground. That said, even the snow depth maps are 3-4" for many.
  3. high risk
    Thank God we're sneaking this event in just before the clock change......
  4. high risk
    Definitely faster with the arrival of the cold air, which is key. Mid 20s for most by early afternoon Saturday.
  5. high risk
    Great question! The issue you mentioned might be leading to slightly higher sleet amounts than justified by the model output, but I checked the forecast soundings, and the GFS does show profiles that favor sleet for a few hours Saturday morning.
  6. high risk
    pretty remarkable that we're too far south to get in on the good SVR threat for an early March event
  7. high risk
    There are reasonable questions about how far south the threat will extend, but there is a steady stream of wind damage reports coming in from central PA.
  8. high risk
    Absolutely. High rates would allow those us north of town to get some whitening for sure. I'm cautiously getting on board with the idea of seeing some accumulations on certain surfaces, as even the models which are typically too warm in these scenarios are close to showing this scenario. If I lived north of I-70, I'd be feeling good about about increasing chances for a few inches.
  9. high risk
    A number of the HRRR solutions today have shown these crappy pre-frontal showers and have been less enthusiastic for our SVR chances.
  10. high risk
    Too far out. Looks like a very strong system with an intense front, but verbatim, there isn't right now an impressive push of warmth and moisture in advance, and it comes through too quickly and too early. If that changes, and it becomes a slower system, we would have time to advect a more impressive air mass into our area ahead of the system, and it might come through at a better time of day. Both of these would open the door to SVR chances.
  11. high risk
    It's hard to get excited about an event with such a small chance for lightning, but I suppose that the showers later could mix down some intense gusts. Given that we're already gusting to 35-40 knots, some convective enhancement could certainly take us into the severe range.
  12. high risk
    I'm calling complete and total b.s. here. There isn't a model that gets 40 degrees to DC or even close by midnight tomorrow night, much less mid to upper 40s. This isn't some 995 sfc low blasting by to our northwest; it's a weak surface system with an accompanying weak pressure gradient, and the cold wedge will take time to erode.
  13. high risk
    Surface temps around the metro area tomorrow evening, and the precip totals won't be huge, but there is a pretty clear signal for a period of sleet or freezing rain for a lot of us. Even if sfc temps warm up above freezing, there is a still a cold layer immediately above in pretty much all guidance for at least a few hours.
  14. high risk
    I don't know for sure, but I think that they're at least using the precip type information directly from the models and not computing it themselves. Regardless, it's applying an instantaneous precip type to an accumulated precip.
  15. high risk
    Right! It's most pronounced for the NAM beyond 48 hours or the GFS beyond day 5, as those models have hourly output through those times, although that assumes that the various sites are actually pulling in the hourly data. The bottom line, though, is that it definitely inflates freezing rain and sleet totals.
  16. high risk
    This is a fair point. None of these accumulation computations is making any attempt to determine how efficiently the ice can accrete. They're just looking for freezing rain as the precip type at the top of the hour, and if that is found, all of the QPF from the past hour (or in some cases, 3 or 6 hours!) goes into the freezing rain bucket. In fact, only the RAP/HRRR actually have a true tallies of freezing rain and sleet.
  17. high risk
    I think I'm buying on sleet and freezing rain for at least a while in much of the area. Even if the sfc temps are too cold in the NAMs (and I'm not convinced that they are), it's pretty clear that there will be a fairly deep layer below freezing just above. Shows up really well on the NAM Nest: Even the GFS has the same idea - the cold layer isn't as cold or as deep, but it's there. The winds in that cold layer are southeast, so it won't be able to hold in for the whole night (until you get further north), but I think that the idea of a cold layer near the ground during the late afternoon and evening could very well be correct. The biggest wild card is actual precip, as there is still limited agreement on the QPF details.
  18. high risk
    A number of the CAMs either explicitly show a similar feature or hint at it. The Saturday front is really strong, and the environment ahead of it will have healthy lapse rates, so I think that the chance of a forced line of convection along the boundary is fairly high. Temperatures would support rain showers quickly changing to snow.
  19. high risk
    So nice to see this thread! Cheers to a great 2022 severe season! That said, I'm not very excited about later tonight. Temperatures should stay up overnight, but we need every degree we can get, and having the threat in the afternoon would have helped. The shear is awesome, but the lapse rates suck, and there just isn't much chance of getting even a few hundred joules of cape. There will be convective enhancement of the rain early Friday, but it seems like the SVR threat is really, really low.
  20. high risk
    Some reasonable agreement between the 18Z NAM Nest and GFS - my confidence level always goes up with they align.
  21. high risk
    The precip shield is pretty clearly going to extend further to the northwest than initially thought. The problem for weenies, however, is that even with "close" sfc temps, the forecasted soundings overall don't seem to support snow on the northwest edge. That said, some of the temperature profiles wouldn't require too much cooling to become wet snow, so I suppose that a few surprises are possible.
  22. high risk
    I can't argue with this thinking, and it seems like the 18Z NAM is moving towards that idea.
  23. high risk
    The 18Z HRRR laughs at our thread
  24. high risk
    FWIW, and I say this with every caveat about no two events being the same, the ARW and ARW2 Hi-Res Windows were the coldest (and most erroneously cold) models for the January 20 rush hour bust. The GFS and Hi-Res Window FV3 were the next coldest. NAM and NAM Nest were next "best" but still a bit cold. The Canadian models did the best. Again, it was a single case, but it did involve shallow cold air spilling into the area.
  25. high risk
    Oh, F*ck yes!
×
×
  • Create New...