The “I bring the mojo” Jan 30-Feb 1 potential winter storm

[BornAgain13]

That NAM run was wonky lol

[BooneWX]

18 minutes ago, Upstate Tiger said:

Now that I’ve seen the surface depiction, it seems like it might be having some feedback issues like the Canadian last night. You can see it trying to pop the low well east of the isobars it should be located at. Thus the paltry snow shield.

[WXNewton]

NWS blend

[BornAgain13]

I might be wrong but isn't the National Blend like a run or 2 behind? Wondering if its picking up on 18z or 0z last night. 

[BooneWX]

Just now, BornAgain13 said:

I might be wrong but isn't the National Blend like a run or 2 behind? Wondering if its picking up on 18z or 0z last night. 

I believe it ingested 6z data

[SUNYGRAD]

I hope nothing happens with any model data being delayed today or tomorrow.  What would one do?

[USCG RS]

3 hours ago, eyewall said:

There are a few failure modes for this setup which would result in
less precipitation over central NC. The first is the placement and
the latitude the mid/upper level low closes; minor adjustments will
have potentially significant ramifications on if/when/where the
deformation band sets up. The second is that some degree of
cyclogenesis will occur along the primary baroclinic zone over the
Bahamas and may draw stronger ascent, moisture, and related liquid
equivalent and snow amounts away from the instant occlusion-type,
nearer-shore coastal low.

 

37 minutes ago, Upstate Tiger said:

I wish one of the mets would explain that Low in the bahamas.  GFS has that feature as well.  Just shown up in the last day.

We are not seeing the earlier phasing or negative tilt we saw at 18z.  Probably all noise at this point any way...

Please see above 

What the discussion is saying is that the larger temperature gradient is over the Bahamas and therefore more baroclinicity is in this zone. Normally it's just off the coast, however, this time it's over the Bahamas. This means the greatest potential forcing and development is towards that area and therefore may be where the physics take this storm and development. 

Low pressures develop along (for mid latitude storms) temperature gradients. These gradients are large changes in temperature over a short distance. This causes a spin to develop, especially as warm air is forced to rise and cool air is shunted to the ground. That change in temperature causes a vertical wind shear and allows the potential energy between the temperatures to be converted to kinetic energy, allowing a low pressure to form and allowing the low pressure system to vent itself as the shear creates a bend back in heights (as an LP develops it needs venting so the pressure can be evacuated - this shear aids in that through concentrating each LP in each layer of the atmosphere at a slightly different horizontal placement. Essentially as you go through h85/7/5, the LP in each layer is west of the LP below it. This allows venting of the storm).

So the models are picking up that the energy potential is greater in the Bahamas and if that's the case, the baroclinicity over the Bahamas may rob the energy from the LP attempting to develop along the coast. 

[UpstateSCBud]

19 minutes ago, lilj4425 said:

To the cliff diving thread.

Easy my friend. You’re gonna have a rough couple of days if you let one run of the NAM at this range send you cliff diving 

[WXNewton]

Does anyone remember the website for cmc-collaboration model. I remember it used to have a cool look to it!

[Buddy1987]

2 minutes ago, BornAgain13 said:

I might be wrong but isn't the National Blend like a run or 2 behind? Wondering if its picking up on 18z or 0z last night. 

Yea one of the Mets who is tied to NWS or CPC highlighted this a couple times in the MA forum. We really can't afford for the GFS to trend the wrong way here.. as is imo we're already on the western edge of the fence.

[strongwxnc]

1 minute ago, UpstateSCBud said:

Easy my friend. You’re gonna have a rough couple of days if you let one run of the NAM at this range send you cliff diving 

Fact is we are always one step away from the cliff. 

[Snowncanes]

RDPS closes off the upper low all the way up in Iowa… way earlier than everything else 

[WinstonSalemArlington]

9 minutes ago, WXNewton said:

NWS blend

Me gusta mucho 

[StantonParkHoya]

Raleigh NWS forecast. FRAME IT

[olafminesaw]

8 minutes ago, USCG RS said:

 

Please see above 

What the discussion is saying is that the larger temperature gradient is over the Bahamas and therefore more baroclinicity is in this zone. Normally it's just off the coast, however, this time it's over the Bahamas. This means the greatest potential forcing and development is towards that area and therefore may be where the physics take this storm and development. 

Low pressures develop along (for mid latitude storms) temperature gradients. These gradients are large changes in temperature over a short distance. This causes a spin to develop, especially as warm air is forced to rise and cool air is shunted to the ground. That change in temperature causes a vertical wind shear and allows the potential energy between the temperatures to be converted to kinetic energy, allowing a low pressure to form and allowing the low pressure system to vent itself as the shear creates a bend back in heights (as an LP developed or needs venting so the pressure can be evacuated - this shear aids in that through concentrating each LP in each layer of the atmosphere at a slightly different horizontal placement. Essentially as you go through h85/7/5, the LP in each layer is west of the LP below it. This allows venting of the storm).

So the models are picking up that the energy potential is greater in the Bahamas and if that's the case, the baroclinicity over the Bahamas may rob the energy from the LP attempting to develop along the coast. 

I am thinking the sooner the trough digs and tilts negative the better shot the coastal low will have to become dominant and cause both lows to consolidate further west?

[Snowncanes]

3 minutes ago, Snowncanes said:

RDPS closes off the upper low all the way up in Iowa… way earlier than everything else 

Dives down into N Alabama before working its way east. May give our GA peeps a little something

[olafminesaw]

RGEM is a big hit

[wncsnow]

RGEM (still going most areas)

[BornAgain13]

RGEM  a big hit especially for the Carolinas. Little to south for @Buddy1987 and myself.

But its not done

[BornAgain13]

I would think RGEM would climb the coast if it continued? Good sign for the 12z CMC.?

[lilj4425]

4 minutes ago, wncsnow said:

RGEM (still going most areas)

Gives Atlanta over five inches. Wow.

[BornAgain13]

Icon still not their but its decent for NC

[Snowncanes]

Should mean the Canadian looks nice. I just wonder if that upper low is going to close off that far north. A pretty far outlier right now versus everything else. But not impossible I suppose 

[olafminesaw]

4 minutes ago, StantonParkHoya said:

Raleigh NWS forecast. FRAME IT

My hourly forecast in Greensboro is showing 8". The highest I've seen this far out since moving here in 2018

[mstr4j]

RGEM, PLEASE VERIFY!!!!!! PLEASE, us UPSTATE SNOW STARVED PEOPLE ARE BEGGING YOU! I might even sell a kidney

[Upstate Tiger]

14 minutes ago, USCG RS said:

 

Please see above 

What the discussion is saying is that the larger temperature gradient is over the Bahamas and therefore more baroclinicity is in this zone. Normally it's just off the coast, however, this time it's over the Bahamas. This means the greatest potential forcing and development is towards that area and therefore may be where the physics take this storm and development. 

Low pressures develop along (for mid latitude storms) temperature gradients. These gradients are large changes in temperature over a short distance. This causes a spin to develop, especially as warm air is forced to rise and cool air is shunted to the ground. That change in temperature causes a vertical wind shear and allows the potential energy between the temperatures to be converted to kinetic energy, allowing a low pressure to form and allowing the low pressure system to vent itself as the shear creates a bend back in heights (as an LP developed or needs venting so the pressure can be evacuated - this shear aids in that through concentrating each LP in each layer of the atmosphere at a slightly different horizontal placement. Essentially as you go through h85/7/5, the LP in each layer is west of the LP below it. This allows venting of the storm).

So the models are picking up that the energy potential is greater in the Bahamas and if that's the case, the baroclinicity over the Bahamas may rob the energy from the LP attempting to develop along the coast. 

Thanks!  I had not seen that.

Good grief...now we have to worry about a Low in the Bahamas.  If there is a way to screw the SE, no matter how crazy, it seems to happen.

[Buddy1987]

2 minutes ago, BornAgain13 said:

I would think RGEM would climb the coast if it continued? Good sign for the 12z CMC.?

That is one HELL of a bowling ball.. looks to tuck the low super close to the coast by the end of it's run.

[Snowncanes]

So we have the far west RGEM and the far east ICON with pretty much everything else smack in the middle. 

[Buddy1987]

Just now, Snowncanes said:

So we have the far west RGEM and the far east ICON with pretty much everything else smack in the middle. 

Time for the GFS to confuse us even more lol

[neatlburbwthrguy]

4 minutes ago, lilj4425 said:

Gives Atlanta over five inches. Wow.

Is RGem ever accurate?