March 5-6 Storm Discussion

[Poimen]

Let's reel this one in guys and gals.

[WeatherNC]

I do not see any real trends over the past 24-36 hours, while some may be analyzing each little jog north or south, all of this is acceptable noise at this range, with above average agreement in the guidance.  Envelop currently resides about 100 miles n-s either side of I-64 in VA.  That certainly puts RDU and GSO in play so to speak, but on the southern fringe.  EPS control jackpots Farmville - Roxboro with the pivot point, >1' along that line in a 12hr period, cranking east to about Roanoke Rapids - Petersburg.  Henderson and Oxford get thumped verbatum.  A 50 miles shift north or south may seem like a big jump, or trend, and while the impacts could be sig, were still >96hrs out and trying to nail down a track, which already probably falls within the envelope I mentioned above.  Too close to call ATM.

[RevDodd]

Let's reel this one in guys and gals.

Brave man, Poimen! Bring the mojo home for everyone!

[Poimen]

I do not see any real trends over the past 24-36 hours, while some may be analyzing each little jog north or south, all of this is acceptable noise at this range, with above average agreement in the guidance.  Envelop currently resides about 100 miles n-s either side of I-64 in VA.  That certainly puts RDU and GSO in play so to speak, but on the southern fringe.  EPS control jackpots Farmville - Roxboro with the pivot point, >1' along that line in a 12hr period, cranking east to about Roanoke Rapids - Petersburg.  Henderson and Oxford get thumped verbatum.  A 50 miles shift north or south may seem like a big jump, or trend, and while the impacts could be sig, were still >96hrs out and trying to nail down a track, which already probably falls within the envelope I mentioned above.  Too close to call ATM.

 

Going to be close, for sure.

[burgertime]

I do not see any real trends over the past 24-36 hours, while some may be analyzing each little jog north or south, all of this is acceptable noise at this range, with above average agreement in the guidance.  Envelop currently resides about 100 miles n-s either side of I-64 in VA.  That certainly puts RDU and GSO in play so to speak, but on the southern fringe.  EPS control jackpots Farmville - Roxboro with the pivot point, >1' along that line in a 12hr period, cranking east to about Roanoke Rapids - Petersburg.  Henderson and Oxford get thumped verbatum.  A 50 miles shift north or south may seem like a big jump, or trend, and while the impacts could be sig, were still >96hrs out and trying to nail down a track, which already probably falls within the envelope I mentioned above.  Too close to call ATM.

 

This is very true. I think right now we are seeing "wobbles" however I do think because of the blocking we see as what Brandon said a shift east which should hopefully equate to a more southern track. Only time will tell. Can't read too much into the 12z NAM but it seems to be picking up on this now. Either way I-40 and up as usual look to be in ideal spots no matter what. MBY is going to be in Crying Game territory. The coach may turn into a pumpkin very fast. 

[Poimen]

Brave man, Poimen! Bring the mojo home for everyone!

 

Thanks, Rev. I'm going to do my best.

[packfan98]

The 12z nam ended up with a 3 contour closed ULL about 50 miles NNE of the 06z GFS at the same time period.  The main difference is that the blocking looked STRONGER than the GFS.  If this is true, one would think that the low would be shunted further south.  

[RevDodd]

I do not see any real trends over the past 24-36 hours, while some may be analyzing each little jog north or south, all of this is acceptable noise at this range, with above average agreement in the guidance.  Envelop currently resides about 100 miles n-s either side of I-64 in VA.  That certainly puts RDU and GSO in play so to speak, but on the southern fringe.  EPS control jackpots Farmville - Roxboro with the pivot point, >1' along that line in a 12hr period, cranking east to about Roanoke Rapids - Petersburg.  Henderson and Oxford get thumped verbatum.  A 50 miles shift north or south may seem like a big jump, or trend, and while the impacts could be sig, were still >96hrs out and trying to nail down a track, which already probably falls within the envelope I mentioned above.  Too close to call ATM.

Weathernc: Speaking for the folks who live on the fringe of that southern fringe, is the bigger wildcard for eventual track the storm's strength or the strength of the blocking? Obviously the stronger the blck, the more likely we are to see a more southward slide. But how would increased strength factor into things.

 

Not trying to wish the storm one way or the other, but hoping to have a more reasoned expectation as events develop over the weekend. Thanks!

[Poimen]

The 12z nam ended up with a 3 contour closed ULL about 50 miles NNE of the 06z GFS at the same time period.  The main difference it that the blocking looked STRONGER than the GFS.  If this is true, one would think that the low would be shunted further south.  

 

Yeah, the NAM may be too north with the vort initially. We'll see.

[CaryWx]

I do not see any real trends over the past 24-36 hours, while some may be analyzing each little jog north or south, all of this is acceptable noise at this range, with above average agreement in the guidance.  Envelop currently resides about 100 miles n-s either side of I-64 in VA.  That certainly puts RDU and GSO in play so to speak, but on the southern fringe.  EPS control jackpots Farmville - Roxboro with the pivot point, >1' along that line in a 12hr period, cranking east to about Roanoke Rapids - Petersburg.  Henderson and Oxford get thumped verbatum.  A 50 miles shift north or south may seem like a big jump, or trend, and while the impacts could be sig, were still >96hrs out and trying to nail down a track, which already probably falls within the envelope I mentioned above.  Too close to call ATM.

This is where the better sampling comes in once this system gets on shore tomorrow morning. I look for the 12z Sunday models to get this nailed down, at least with more reliability if not accuracy.

[Cold Rain]

This is where the better sampling comes in once this system gets on shore tomorrow morning. I look for the 12z Sunday models to get this nailed down, at least with more reliability if not accuracy.

I agree. I think this is going to play a significant role here. We could see a shift big enough in either direction based on better sampling. I still think the block is the main key here...and I guess that area should be well sampled. Hopefully, it can trend stronger.

[CaryWx]

I agree. I think this is going to play a significant role here. We could see a shift big enough in either direction based on better sampling. I still think the block is the main key here...and I guess that area should be well sampled. Hopefully, it can trend stronger.

I only believe this is where WeatherNC locks down his forecast envelop projection. More exact path will not be known until this thing begins its very sharp and somewhat unusual steep dive in the Midwest. By then we should know with good confidence just where the path will be.

[downeastnc]

Are they running some recons flights off the west coast to get a better sample, I know I saw where they were talking about doing that. ULL are notoriously hard to pin down so 100-150 miles this far out is not that big of a jump in track, lots of little things with how it all comes together will have big effects on who ends up getting the worst of it, and typically we would be waiting for the energy to get sampled before locking in on a track. 

[CaryWx]

Are they running some recons flights off the west coast to get a better sample, I know I saw where they were talking about doing that. ULL are notoriously hard to pin down so 100-150 miles this far out is not that big of a jump in track, lots of little things with how it all comes together will have big effects on who ends up getting the worst of it, and typically we would be waiting for the energy to get sampled before locking in on a track. 

Only if they believe DC and north are in play.

[burgertime]

Are they running some recons flights off the west coast to get a better sample, I know I saw where they were talking about doing that. ULL are notoriously hard to pin down so 100-150 miles this far out is not that big of a jump in track, lots of little things with how it all comes together will have big effects on who ends up getting the worst of it, and typically we would be waiting for the energy to get sampled before locking in on a track. 

 

I would say that is likely but it probably won't happen until 00z. 

[packbacker]

The 12z nam ended up with a 3 contour closed ULL about 50 miles NNE of the 06z GFS at the same time period. The main difference is that the blocking looked STRONGER than the GFS. If this is true, one would think that the low would be shunted further south.

The NAM is close to the Euro at hour 84, just 6 hours faster. Although the NAM is fairly useless outside 48-60 hours, this was the first I have looked so not sure what its been doing on previous runs.

[mackerel_sky]

All the models are showing the block being stronger each run.I think the models still are not showing how this affects the track.I feel,imo,that a 100 mile shift S,or more is not impossible,I feel it is likely.

[packbacker]

All the models are showing the block being stronger each run.I think the models still are not showing how this affects the track.I feel,imo,that a 100 mile shift,or more is not impossible,I feel it is likely.

I agree we are still in the +- 100 mile track range, but still feel easier to shift north than south.

[downeastnc]

I agree we are still in the +- 100 mile track range, but still feel easier to shift north than south.

With the blocking showing up stronger each run not sure why that would make you think a north jog in track was more likely? 

[packbacker]

With the blocking showing up stronger each run not sure why that would make you think a north jog in track was more likely? 

 

If the blocking weakens or if it happens to phase with any energy up at the lakes, the northern model runs had some phasing/interaction, they have now backed off on that, but that could come back.

[packbacker]

The differences between the GFS and the Euro at just 84 hours is amazing, the ULL must be 300 miles south on GFS.  Granted they both eventually get to the same spot by day 4/5 which is good.

 

 

 

 

 

 

[tarheelwx]

Rather than being a difference in position, isn't it more a difference in timing?

TW

[Brick Tamland]

All the models are showing the block being stronger each run.I think the models still are not showing how this affects the track.I feel,imo,that a 100 mile shift S,or more is not impossible,I feel it is likely.

 

I feel the same way. I know 50 or 100 miles can make a big difference with this. But if it moves, I think it moves more south a little bit. Been saying all along it first went more and more south, then more and more north, and now it's settling in the middle. Still thinking at least 6 inches of snow for me.

[packbacker]

Rather than being a difference in position, isn't it more a difference in timing?

TW

 

No, the GFS drops it south through the KS/MO state line and than heads east, the Euro drops it from MN to KY.

[DCMetroWinston]

WXeastern
Good morning..the European and American guidance models are now in good agreement with each other and a late season significant snow storm has now become likely for the Mid Atlantic and southern Appalachian regions between March 6th and 7th. This is my general thinking as of now which will likely change a little but not a whole lot. I will fine tune this graphic over the next couple of days with specific amounts. Right now it's still too early to try and discuss numerical totals this early in the game so please dont ask how many inches. Find your county and see snow scale for possible amounts. Another update coming later tonight!

 

[Buddy1987]

Idk but the GFS looks different already at 39hrs on the 500 setup with the energy ejecting out of California. 45 hr GFS has it back over toward western Cali where as at 39 now it has it over extreme southeastern Nevada. Have no idea what consequences this will have.

[WeatherNC]

Weathernc: Speaking for the folks who live on the fringe of that southern fringe, is the bigger wildcard for eventual track the storm's strength or the strength of the blocking? Obviously the stronger the blck, the more likely we are to see a more southward slide. But how would increased strength factor into things.

 

Not trying to wish the storm one way or the other, but hoping to have a more reasoned expectation as events develop over the weekend. Thanks!

 

There are several wildcards, strength and placement of the block being one.  Its influence is most important when the low is over SD/IL/IA as it prevents the system from moving due east and must dive underneath of it, hence the SE track thereafter.  The GEFS, after peaking the west based NAO in the next day, has another small spike around the 5th, before relaxing.  Would like to see that verify as that indicates the ridge at-least maintaining in north eastern Canada through the next 3-4 days.  Another uncertainty, and this could likely account for a 50 mile or so correction in the last 48 is the vort interactions as the ULL begins the maturation process.  Of note, the 12z NAM has a very distinct pva tail on the western flank of the ULL extending almost due n-s through the northern plains.  As that energy moves down, and is ingested by the low, the torque exerted on the low will be altered from varying directions, depending on how it all evolves.  The 0z GFS took that vortmax through AL/MS, something to watch as force was being applied from the south.  There is also a double barrel look with surface features, a weak low pressure over WV and another over SC as the system moves east.  That jacks up the flow as we have weak waa in advance typically seen with transfers to the coast.  The Euro hints at a dominant low trying to form over Central GA, it still does have a weak low pressure over WV, but the isobars indicate the primary is coming out of the mid south, to near south eastern NC, and temporarily stalling over HAT as the mid, upper and surface centers meet.

[burgertime]

Out to 57 GFS at 5h looks like a mix between 00z and 6z of the GFS though the energy is weaker.

[Buddy1987]

And at 48 its not too far off with its 54 hr image from 6z imo.

[Buddy1987]

Out to 57 GFS at 5h looks like a mix between 00z and 6z of the GFS though the energy is weaker.

Yea I def agree with this looks pretty much the same still.