high risk

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Everything posted by high risk

  1. that's just an 80 km output grid which is a terrible way to view totals on a storm like this with a tight gradient
  2. I would think so, but based on the 9z SREF, I expected the 12z NAM to be north, and that didn't really happen. That said, the NAM nest is not chopping off the northwest corner of the precip shield like the parent NAM is; the 12z NAM solution probably should have been wetter than it was. The simulated reflectivity product looked much better than the QPF did.
  3. It's worth noting in the 15z SREF that only 4 of 21 members have less than 0.1" liquid for DC. But they're all NMM members, which are initialized off of the GFS. And of the 3 "wet" NMM members, they're all under 0.2". So if the GFS is right, the overall wet SREF solution *may* be meaningless. That said, all of the ARW and NMB members (initialized off of the RAP and NAM, respectively) are at least 0.25" for DC.
  4. you should clarify that this is a 6-hr total
  5. The 15 SREF mean did move the 0.25" and 0.5" lines south a little, but DC Metro is well within the 0.25-0.5" range. Big hit for southeast Virginia.
  6. Looking at the 3z SREF plumes, the members that have pretty much nothing for DC are all members that are initialized off of the GFS. This is completely consistent with the dry solution of the GFS run. Whatever the GFS is or isn't picking up in the initial state is influencing most of its SREF members. Maybe the GFS is right, but it's hard to ignore that most of the members initialized off of the NAM and RAP are wetter. Given that the 6z GFS seemed to be finally picking up on a north trend, it will be interesting to see if the 9z SREF mean is wetter. Edit: I see that the 9z SREF mean just came in with the 0.5" line up to DC.
  7. They certainly do show that, but I really don't like the snow plumes, as the way they convert liquid to snow ends up with some very high numbers in "cold" events. IMHO, looking at the QPF has more utility.
  8. You can't classify the SREF as a "high resolution" ensemble. But I overall agree that the overall SREF utility is limited. As users, though, we have to be careful looking at means without getting a sense of what's driving them, as they're not all equal. For example, last night's 21z SREF mean suggested a northward trend, but it was based on 3 or so members with huge hits. Today's 15z has a few wet members but a significant number of members with 0.1". It could easily still end up as 0 for DC, but I don't think we can discount the chances for at least 1" in DC. But in the bigger picture, it sure would be nice if the SREF didn't show so much inconsistency from cycle to cycle.....
  9. 15z SREF is interesting with the 0.25" line up to Fredericksburg. But looking at the plumes, the liquid mean for DCA is 0.2". It's inflated a bit by a few members with crazy wet solutions, but roughly half of the members have at least 0.1" liquid.
  10. 00z NAM did not come north. excellent discovery by Yoda that the 21z SREF mean hinting at a northward trend was caused by a few aggressive members.
  11. 21z SREF mean made a jump north for the Wednesday night system with the 0.10" line now north of DC. Will this be the start of a northward trend in the guidance??
  12. from what I know about the products they like to use, they really lean on the WPC winter weather ensemble products at longer time ranges. It's that super-ensemble-thingy, and it is incredibly unenthusiastic right now about the event along the I-95 corridor, although those products often have to play catch-up to model trends.
  13. 45 dbz in the simulated reflectivity from the NAM fire wx (1.33 km) nest: http://www.emc.ncep.noaa.gov/mmb/mmbpll/firewx/firewx_12z_refd1000_animate_1h.html
  14. This really isn't about amounts. We're obviously all looking to add to our totals for the season, but regardless of whether it's a dusting or 1.5", it will be a high-impact event as the temperatures crash right behind the band of precip and turn the roads into an icy mess.
  15. We've seen the HRRR struggle a lot in these synoptic snow situations. Part of the problem is that the radar reflectivity assimilation is tuned for warm-season convective events with higher reflectivity values, and when it tries to assimilate these "weaker" radar signatures, it seems to get messed up a bit.
  16. I'm nitpicking here, but there is no such thing as the RUC anymore. perhaps some site never updated its labels when the RAP replaced the RUC a few years ago.
  17. the hi-res windows can be good - the precip verification scores for them are actually pretty good and on par with the 4 km NAM, although they have a very slight wet bias http://www.emc.ncep.noaa.gov/mmb/ylin/pcpverif/scores/2015/201501/hiresw.201501.gif they're initialized off of the RAP, so if the RAP is funky, the hi-res windows will be similar. There is definitely something going on in the past 24 hours in the analysis that is leading the RAP to be "healthier" with this system. All of the SREF members initialized off of the RAP are by far the wettest for central and northern MD, and the hi-res windows look similar. I just can't be sure whether it's correct.
  18. Word of caution with the SREF plumes: they use a formula to calculate snow-to-liquid ratios that ends up VERY generous in "cold" events. We're going to get good ratios for sure with this event, but the snow plumes will likely look way too healthy. I prefer to look at the QPF plumes and apply my own ratio.
  19. well, if the initial conditions are the drivers of the solution, then any models initialized off of the same analysis will have similar evolutions. The HRRR is initialized from the RAP, so I would expect the upper levels to evolve similarly in almost all cases.
  20. remember that the ARW members are initialized off of the RAP, so the agreement there is not surprising.
  21. under the area of 35 dbz in southern Howard County. the ground has quickly whitened beneath moderate snow.
  22. The 1.33 km NAM fire wx nest will be placed over DC Metro for the 18z and 00z cycles today for a nice view of this event. The output will be available at http://www.emc.ncep.noaa.gov/mmb/mmbpll/firewx/
  23. yes. with most clippers, we get a few hours of steady snowfall in more of a warm advection pattern. Tomorrow, the low is passing to our north, and we get basically get a narrow corridor of very intense lift right along the cold front. This is clearly depicted in the simulated reflectivity products.