Jump to content
  • Member Statistics

    17,894
    Total Members
    7,904
    Most Online
    WichitaChiefSam
    Newest Member
    WichitaChiefSam
    Joined

March 2-3 Disco, Part III


stormtracker

Recommended Posts

  • Replies 1.8k
  • Created
  • Last Reply

I'm mostly just reading but I have one question for you all, haven't seen it asked elsewhere: When the models show total snowfall maps are they taking into consideration ground conditions? In other words, is it just calculating total snowfall based on what falls from the sky and assuming everything sticks? Or does it account for some not accumulating intially based on it raining intially, warmer temps, etc. I believe they take virga into consideration but I wasn't sure how it handles situations like these, especially with a changeover.

Link to comment
Share on other sites

  On 3/2/2014 at 3:05 PM, ers-wxman1 said:

As I'm learning the forum ropes... What is a troll?

  
  On 3/2/2014 at 3:06 PM, Bob Chill said:

Basically any post thats designed to make your ears bleed and increase your urge to kill

A little clarification: a Troll is someone that makes such posts, Trolling is the action of making such posts, usually by someone that knows much better. Neither is suffered very well in here. Examples:

- How much IMBY (in my back yard) - Not trolling, just a stupid post in a model discussion

- Oh, no! The 12z NAM is south again and its superior resolution means it's picking up nuance that the Globals are missing! Oh, no! - definitely trolling

Link to comment
Share on other sites

  On 3/2/2014 at 3:31 PM, cgillesp said:

The NWS forecast is at 10.9" for DC. Seems a bit above consensus, and I've never known LWX to be bullish. What gives?

 

I was surprised by their max/min and expected value range, it sure seems higher than they usually go.  I've often wondered if they oscillate back and forth, going lower if they busted too high on a previous forecast, then going higher if they went too low previously (if that makes sense).  I do recall for the Feb. 12-13 storm, they seemed awfully low.  All guidance was giving the area probably 6-12" on average, with higher amounts farther west where it stayed snow longer.  But LWX was going 4-6" in the metro area.  They may have been swayed by the GFS, which was chronically light on that event until right near when it started.  It's really tricky in this area as you probably know, since the forecast will greatly affect millions of people (quite literally), and many decisions.  I've sometimes been down on them, but I do not at all envy their position given the high-profile location.

Link to comment
Share on other sites

  On 3/2/2014 at 3:32 PM, Noreastericane said:

I'm mostly just reading but I have one question for you all, haven't seen it asked elsewhere: When the models show total snowfall maps are they taking into consideration ground conditions? In other words, is it just calculating total snowfall based on what falls from the sky and assuming everything sticks? Or does it account for some not accumulating intially based on it raining intially, warmer temps, etc. I believe they take virga into consideration but I wasn't sure how it handles situations like these, especially with a changeover.

 

It's snowfall not snow depth.

Link to comment
Share on other sites

  On 3/2/2014 at 3:33 PM, cgillesp said:

On the other hand that suite of maps has DC in the 10-14 range. I think I'll stick with WPC for for their probabilistic maps. 

Those experimental (I think they're still listed that way on their site) plots are a fantastic resource, I think.  Both the probabilistic for various amounts and their percentile accumulation maps.

 

ETA:  I'm referring to the WPC maps in particular here, though I do like that LWX has been showing ranges and probabilities for the local area, too.

Link to comment
Share on other sites

  On 3/2/2014 at 3:31 PM, ers-wxman1 said:

Confidence factor for > 12 per probabilistic guidance.

http://www.erh.noaa.gov/lwx/winter/images/snowProbGT12.png

Wow. Bullseye I-66 corridor.

Hard to read on the phone but it looks like the RGEM expects more of a SE flow on the back end, giving RIC good back end while not suppressing as much as the NAM.

Link to comment
Share on other sites

  On 3/2/2014 at 3:42 PM, UVVmet84 said:

yeah GFS looks like 5-8" for Baltimore and surrounding burbs. QPF looks good, things came a bit north. As some are saying, a bit warmer, which leads to the more northern solution (at least minutely). 

 

Yep, still a very nice snowstorm for DC and Baltimore.  By 6z we are definitely frozen and by 9z all snow.

Link to comment
Share on other sites

  On 3/2/2014 at 3:41 PM, Bob Chill said:

Gfs is widespread 1 - 1.2 cities and burbs but .4 is definitely non-frozen verbatim

 

GFS still has the latest changeover of any model even though it goes below freezing earlier....I think a wildcard is how much frozen falls between midnight and 4am, and when does it change to snow..Euro has been on board with definitely getting some accumulating snow between 1am and 4am....if we have to wait until 5, then obviously we will get less snow....I am having trouble getting on board with any insane amounts as it looks like a 12 hour snow event tops....which is usually a good signal for 8" in a heavy snow event...

Link to comment
Share on other sites

  On 3/2/2014 at 3:44 PM, DCTeacherman said:

Yep, still a very nice snowstorm for DC and Baltimore. By 6z we are definitely frozen.

Ptype maps show some good sleet at 6z. Surface freezing down by pg/charles line so it prob goes to sleet between 11-midnight depending on location

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...