Jump to content
  • Member Statistics

    17,751
    Total Members
    7,904
    Most Online
    Fuji Kapesta
    Newest Member
    Fuji Kapesta
    Joined

The January 5/6 Thing


stormtracker
 Share

Recommended Posts

1 minute ago, stormtracker said:

I mean...there really are no huge differences right now.   DC metro got a hair warmer so, as we know our climo, we flirt.  But all in all...nothing panic inducing imo

Tried to get a lil coastal going also.

The coastal does a great deal for the subforum - would love to see that feature continue to improve

  • Like 4
  • Thanks 1
Link to comment
Share on other sites

1 minute ago, mitchnick said:

That's because of this vort at 96. It opens up 6 hours later, but still vigorous. 

500h_anom.us_ma.png

This is a beauty. It's more amped and more neg tilted. That enhancement as this passes is where we can really stack fluff with good growth in the DGZ and 15-20:1 type ratios. As some have said, let's get 5-6" OTG before that part and then play with house money. 

  • Like 3
  • yes 1
Link to comment
Share on other sites

2 minutes ago, NorthArlington101 said:

The coastal does a great deal for the subforum - would love to see that feature continue to improve

GFS hangs onto the primarily low. Did this a bit at 12z but a little more pronounced this run. Not sure I buy it. Either way not a huge difference but explains some of the mixy issues getting closer for a time.

1736197200-UJRSct1eBqk.png

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Just now, high risk said:

Worth noting that, given the amount of green on the 18Z GFS p-type maps, the GFS is terrible at maintaining cold air damming.   If it's in the mid 20s at 7AM, and the sfc winds stay E/NE all day, areas around DC won't get into the mid 30s.

Sounds good to me.   I'm actually not worrying about significant mixing attm.   Matt and I always kinda factor it in anyway, but not sure it's gonna be as "bad" as shown.

  • Like 2
Link to comment
Share on other sites

1 minute ago, CAPE said:

GFS hangs onto the primarily low. Did this a bit at 12z but a little more pronounced this run. Not sure I buy it. Either way not a huge difference but explains some of the mixy issues getting closer for a time.

1736197200-UJRSct1eBqk.png

I feel like things have been trending that way - would certainly help you out. It throws D.C. an extra 2" that get lost during the dry slot... could maybe end up a win-win, as I think @WxUSAF mentioned earlier.

Link to comment
Share on other sites

9 minutes ago, wxmvpete said:

One of my favorite products in assessing the potential for extreme events is the ECMWF's Extreme Forecast Index (EFI). The link for the page is here: https://satable.ncep.noaa.gov/efi/. To read up on it more from the ECMWF, you can visit here: https://confluence.ecmwf.int/display/FUG/Section+8.1.9+Extreme+Forecast+Index+-+EFI%2C+and+Shift+of+Tails+-+SOT. If you haven't seen it before, in quoting the ECMWF page, the EFI "compares the medium range ensemble forecast probability distribution of an event to the M-climate distribution for the chosen location, time of year and forecast lead time.  The underlying assumption is that, if a forecast is anomalous or extreme with respect to the M-climate (re-forecast database over the past 20 years), the real weather is also likely to be anomalous or extreme compared to the real climate.   Simple probabilities derived from the ensemble (e.g. the probability that forecast temperature >32°C) do not highlight the differences in the distributions of forecast.  However, EFI will do so because it accounts for the distribution of all the ensemble members.  EFI takes values between +1 and -1.

Experience suggests: EFI values between 0.5 to 0.8 (irrespective of sign) can be generally regarded as signifying that ““unusual”” weather is likely,

EFI values above 0.8 (irrespective of sign) as usually signifying that ““very unusual”” or extreme weather is likely. "

In this case using the new 12Z ECMWF EFI, maybe it is because it's been so long, but we do have some >0.8 values in northern VA that I can't recall seeing before (granted this product is still fairly new). Note as well is the Shift of Tails area. The Shift of Tails according to ECMWF "...compares the tails of both distributions of M-climate and ensemble based on the 90th and 99th (upper tail) percentiles...The SOT index complements EFI by providing information about how extreme an event could potentially be.  Specifically, it compares the tails of the ensemble and M-climate distributions." Usually, my eyebrows rise some when we have a ~0.7 and >1 SoT look. We have a >0.8 and even a 5 SoT in Northern VA. This tool can be used to show the event that the ECMWF ENS distribution suggests a very unusual snow event is likely based off the 20-year running climo, but some of the members are on the more extreme side given the higher SoT. 

ECMWF EFI.png

Yep, it was the January 3-4, 2022 event. Here's what it looked like the day before for an example, and we know what it ultimately did in those areas.

ens_2022010200_midatl_24h_sfi_SFC_48.png

  • Like 6
  • Thanks 3
Link to comment
Share on other sites

Just now, stormtracker said:

Sounds good to me.   I'm actually not worrying about significant mixing attm.   Matt and I always kinda factor it in anyway, but not sure it's gonna be as "bad" as shown.

I agree. And I'm likely not using the GFS thermals for any indication of what mixing could occur. A setup like this with the flow scheme as High Risk said isn't sending sfc temps into the mid 30's. There might be a ML warm nose if the primary drives up into C WV and is a bit more amped, but I'd expect some kind of CAD wedge to counter it. 

Link to comment
Share on other sites

1 minute ago, stormtracker said:

I'm still trying to figure what they are trying to convey.  I mean, did I say something wrong?  Looks as described? 

sorry - I wasn't trying to disagree with you. Just posing the WxBell maps since you've said yourself the SV ones are bad. Added the context of previous runs since I didn't think it could hurt.

Link to comment
Share on other sites

Just now, NorthArlington101 said:

sorry - I wasn't trying to disagree with you. Just posing the WxBell maps since you've said yourself the SV ones was bad. Added the context of previous runs since I didn't think it could hurt.

Ah, ok.  lol.  I was just confused for a sec.  And thanks.   WB maps are so much better

  • Like 1
Link to comment
Share on other sites

1 minute ago, NorthArlington101 said:

I feel like things have been trending that way - would certainly help you out. It throws D.C. an extra 2" that get lost during the dry slot... could maybe end up a win-win, as I think @WxUSAF mentioned earlier.

Eh I will take 12z all day over this run verbatim lol.

Very nice run for the southern PA folks though.

 

  • Like 3
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...