Jump to content
  • Member Statistics

    17,609
    Total Members
    7,904
    Most Online
    Vesuvius
    Newest Member
    Vesuvius
    Joined

Feb 1-2 storm threat


ORH_wxman
 Share

Recommended Posts

1 minute ago, RUNNAWAYICEBERG said:

At this point, not sure a good 12z euro run will give us any more confidence that it’s coming. Could be another day or two before we close the book or drool all over it.

This one may need more time then originally thought, A lot to resolve.

Link to comment
Share on other sites

51 minutes ago, Typhoon Tip said:

It seems to be the whole ball of wax on this this thing - 

Just a quick critique - you mentioned earlier that the N/stream involvement didn't seem very plausible to you "because the flow is tipping progressive" - or words to that affect. 

I don't see how/why 'progressive' characteristic of the total flow behavior is a logical delimiter there. Progressive happens in either stream...it's just a tendency for r-wave rollouts to move actively west-toward east at mid latitudes..which can be endemic to either.  

That said, "phasing" per se is harder - not so much because it can't happen, but... because the models are not sophisticated enough to handle the narrowing margins for error down to finite scales, required to correctly assess whether there is syncing mechanics in the stream spacing and so forth.  

It's a bit advanced...but, it really has to do with the coriolis forcing in three-D.   2Ω (v sinφ - w cosφ), -2Ωu sinφ, and 2Ωu cosφ, which handles the west to east in U, north south in V and W of course being up down.  Anyway, as these are combined, if any one exceeds a critical value/threshold ...the velocity of the system overwhelms the forcing and the system doesn't "feel" the exertion to rotate...or 'curve' as much. That's why fast flow tends to curve less ... ? It doesn't mean it curves none - it curves less...These factor work out to decimal forcing when you put in values for latitude and wind velocity.  So, you have to do all that at the latitude, per wind and so forth, at different levels...to get to a "syncing" phase...  

That's why these thing are tougher to phase at higher speeds... And, it is why the models have been tending to correct phasing toward the upper/outer Maritimes ...when they were first doing so closer to home when they were in the extended. It's like it's getting better data into the f term and than the field corrects to a phasing further down stream because the curvature forcing could not take place in time to get us here.  

These runs are trying to over come that by digging the N-stream sort of calving west against the eastern slope of the western ridge ... as the ridge is pressing eastward in the progressive pattern no less. Oy.  Lot of juggling here.  This behavior might try to phase things soon...mainly because that digging further west earlier on. Increasing some space in which to phase is like giving some time back the system.  

I should have been clearer...I was referring to the idea that phasing is harder.

I've always wondered something about the Coriolis forcing and there is another equation or two (think one of them is the vorticity equation) but when you do scale analysis you "negate" terms which have a larger scale of magnitude b/c it is said that term is "negligible"...I wonder if even know its negligible if it actually still holds some degree of importance and perhaps if incorporated into these equations would maybe help with accuracy. 

Link to comment
Share on other sites

Just now, RUNNAWAYICEBERG said:

Certainly more than I did. I just can’t see computers simulating this cluster F of sw’s properly until they’re over the midwest...even then, could be a trick or two left. 

There scratching their mother boards like we are our heads..............:lol:

  • Haha 1
Link to comment
Share on other sites

First post since Dec 2... haven't seen any compelling threats + crazy busy at work... thanks for great discussion here by the usual players as always.

But I'm more on guard for a surprise on this one... good H5 setup, and conducive to an abrupt jump rather than gradual evolution of solutions. If all you had was this H5 map, you'd anticipate cyclogenesis ~ under that green circle... the trough is tilting nearly neutral, the flow is not compressed and there's room:

GFS_90hr.jpg.0597e23ce94c0d97f0266a9ab55ec46c.jpg

 

Instead 24 hrs earlier this lead energy is stealing the show, purple circle:

GFS_66hr.jpg.fe13653e892e2ca7bebd9fb2647bb9e9.jpg

 

I know overwhelming majority of OP and ENS guidance focuses on that lead energy shunting this well OTS, while the lagging stronger SWs end up doing nothing, but I'd remain vigilant for a surprise on this one, at least through 12z Thursday guidance.

 

 

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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

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