Winter 2013-14 Pattern Discussion III

[Cold Rain]

Below are two images cleverly labled 1 and 2.  Image 1 is the Euro 216 from yesterday at 12z.  Image 2 is the Euro 216 from 0z today.  Given the coarse maps on eWall, I can't compare apples to apples with respect to time, so obviously, the second map is 12 hours after the first, out in time.

 

The green circles represent features that are pretty much the same on each map (with only minor differences in placement/orientation/strength).  The red circles 1, 2, and 3 represent key features that make all the difference between a winter storm and a rainstorm.

 

1 is the 50/50 feature that I mentioned yesterday.  Yesterday, I opined that instead of energy moving due east to establish a true 50/50, creating confluence over the NE US, locking in high pressure, more times than not, we have seen this feature slide NE into Greenland, moving the confluence zone out of the NE US, allowing HP to slide out or move north.  In Image 1, you see a nice 50/50.  In Image 2, you see that feature instead moving NE into Greenland.  You have to account for the 12 hr time difference in the maps here, but what's really the main driver is the lack of -NAO blocking.  The energy has no reason to go straight out into the Atlantic.  Instead, it goes toward Greenland, as has been the predominant path most of the winter.  And surprise...no high pressure in a favorable position to usher in cold for a winter storm.  As a result, the Waycross Heat Ridge takes over, and the 850s are way north.  Rainstorm.

 

Now, we could really just stop right there since that's game, set, match.  But since I circled more things, we'll forge ahead.  Red circle 2 is the other northern stream wave moving in from the west.  Yesterday's run had it stronger and farther east, allowing reinforcing high pressure behind it to move in from the northwest.  Today's run has it much weaker and much farther west, even 12 hours later!  So we get no high pressure over the northeast and no high pressure moving in from the west.

 

Feature 3 is the southern stream energy responsible for the storm.  As you can see, it has moved farther east in Image 2, consistent with what we'd expect from the 12 hour time step.  However, it appears much stronger.  A low pressure forms over the coastal plain of NC and strengthens as it moves out to sea.  That's a big difference as well from the 12z run from yesterday.  That's not a classic winter storm track for the majority of the SE.

 

So, a very good winter storm setup has devolved into a very hostile winter storm setup in just 12 hours, mainly due to the northern stream and how H5 over Canada evolves.  Is it right?  Who knows.  But we know what to look for, going forward, if we want to see a background H5 environment that is supportive of a winter storm.

 

There are still many model runs before this is resolved, and it could go either way.  My instinct aligns with what Burger posted....without a very strong and consistent signal for anomalous cold, cool March temps will not get the job done.  We'll see.

 

On another note, I saw some graupel on the way to work this morning, so that was nice.

 

 

[superjames1992]

Beautiful maps, as always, Cold Rain.

FWIW, ths EPS seemed to support a colder solution than the operational last night from what I could gather in a quick look this morning. Now, they did back off a little and could back off more at 12z today. We'll see.

Also, the 06z GFS had a funky looking storm on 3/6, as well. Looked like all snow in N NC with mixing further south.

We're still over a week out, though.

[WSNC]

It's the NAM over 48 hours so probably nothing, but it does show about .10" frozen qpf for NC Saturday. It seems like a lot of people are down on our chances, but I'm hopeful the next couple of weeks with so much cold high pressure to north and an active southern storm track.

[deltadog03]

Models are going to highly struggle in this pattern...Remember that.  In fact, with 2 jets in play, the GFS will prolly do terrible until about day 5 or less.  It can't handle 2 streams very well.  CMC will throw out or up some wild solutions as well.  I do think there is a storm around that time, but I DONT think its going to give much wintry weather south of NC...*as usual*

[FLweather]

It's the NAM over 48 hours so probably nothing, but it does show about .10" frozen qpf for NC Saturday. It seems like a lot of people are down on our chances, but I'm hopeful the next couple of weeks with so much cold high pressure to north and an active southern storm track.

 

Yeah that run does look intriguing and eye candy. Strong disturbance at the h7 level and slows down the HP to allow for a mostly snow insitu CAD event. Not likely to happen as all snow. One possibility I see for Saturday though considering the strong disturbance and the WAA that will occur with it is a nuisance sleet/freezing rain event for CAD Favored areas of NC/VA.  There appears to be enough damming for the surface and below 850 to stay cold enough. But once you get above 850 into the 700mb range the warm nose becomes evident.

[Shawn]

Models are going to highly struggle in this pattern...Remember that.  In fact, with 2 jets in play, the GFS will prolly do terrible until about day 5 or less.  It can't handle 2 streams very well.  CMC will throw out or up some wild solutions as well.  I do think there is a storm around that time, but I DONT think its going to give much wintry weather south of NC...*as usual*

 

Well said Chris.  There are 9 EPS members from the 00z Euro showing Winter weather down in Macon.  Pretty much all just "trace" amounts.  In KCAE, we are down to 15 from 20.  Although the Canadian isn't the worst model in the world, you'd think the EPS would start honking soon if the threat was real.

[burgertime]

12z GFS is actually really close to a big winter storm in NC @144. 1048 high coming across the plains with plenty of moisture. Looks like an I-40 special on the surface maps. 

[Hvward]

12z GFS is actually really close to a big winter storm in NC @144. 1048 high coming across the plains with plenty of moisture. Looks like an I-40 special on the surface maps. 

 

 

Yeah night and day difference between the 6z and 12z.  Like delta said the gfs is going to throw out some crazy solutions but I really hope that this one is right, it looks to be at least an I-40 special.

[packbacker]

12z GFS is actually really close to a big winter storm in NC @144. 1048 high coming across the plains with plenty of moisture. Looks like an I-40 special on the surface maps. 

 

Yeah, all models are bringing in the HP a little further south and east and stronger each run, GFS is really close, and it's still 6 days away, interesting...

Edit:  Let me preface, this GFS run is the furthest south, so take with grain of salt.

[burgertime]

Yeah, all models are bringing in the HP a little further south and east and stronger each run, GFS is really close, and it's still 6 days away, interesting...

 

It's also bringing in record cold (I would think anyways) into the US for March. I'll believe it when I see it. 

[packbacker]

It's also bringing in record cold (I would think anyways) into the US for March. I'll believe it when I see it. 

 

Agreed…verbatim it's rain to sleet to snow for central NC, if Euro shows it inside day 5 that will be another story.  This is still 5+ days out.

[packbacker]

MA get's 40+ hours of sleet/snow per 12z GFS 

[superjames1992]

The GFS showed 0.1-0.25" QPF worth of ZR for the NC CAD regions on 3/1, too. It was similar to the NAM, but warmer at the mid-levels.

[Tacoma]

MA get's 40+ hours of sleet/snow per 12z GFS 

i hope MA stands for my area and not mid atlantic.  

[packfan98]

I think that the storm will definitely end up further south than the Euro has been showing.  A dead giveaway is when it was trying to show a cutter and then it suddenly turns right or even ends up southeast of where it was in earlier frames.  I believe that's what both the Euro and EPS mean has shown over the past day or so.  Now will it end up as far south as the GFS....probably not.

[packbacker]

i hope MA stands for my area and not mid atlantic.  

 

LOL, unfortunately not.  It's the mid-atlantic, the snow capital of the US.

[packbacker]

Per GFS central NC doesn't get above Freezing Tue/Wed/Thursday.  Well actually we start above freezing Monday night into Tuesday but then drop like a rock.  Obviously GFS is to cold but's funny to see.

[Hvward]

12z gfs and 12z ggem have the low placement very similar. The ggem looks to have a little bit more backside moisture.

[FLweather]

The GFS showed 0.1-0.25" QPF worth of ZR for the NC CAD regions on 3/1, too. It was similar to the NAM, but warmer at the mid-levels.

Considering the blip from NAM it puts down that amount too but more widespread. Though it was dry with the 6z.

 

But whatever starts to fall from the clouds around dawn Saturday will be sleet/freezing rain. 

 

Surface temps for Nam

 

 

Surface of GFS.

[superjames1992]

BTW, looking at the 12z GGEM meteogram for RDU, it appears to show IP/ZR and RN mix with the 3/3 system (lots of pingers, actually) and continues to show the 3/6 system, which is a wintry mix in RDU, but probably all-snow further west.

The 3/3 system appears to bear watching again, though we shall see. Long way to go... Neither of these will probably work out, but there's a chance. The 3/3 system seems especially difficult to see working out at this point.

[Isopycnic]

So the Canadien looks good, the GFS is dry, and the Euro was completely different from the previous run to the last. Unless the models start showing the same thing consistently, I think more likely than not there isn't going to be a winter storm next week.

The models create the weather.

[Brick Tamland]

The models create the weather.

 

Yeah, that's totally what I said.

[Cold Rain]

Euro looks like dumpster fire for winter weather through 144.  However, a big HP is getting ready to drop into the US and there is some weak southern stream energy hanging around.

[deltadog03]

I bet the euro has a storm this run...energy diving over western rockies SE

[Jon]

I bet the euro has a storm this run...energy diving over western rockies SE

based on the ensemble members it's a matter of time before it shows the big dog and the whole board freaks out

[tnweathernut]

Looks like a nicely developed rain storm for everyone in the southeast, with a low in west central Alabama at 192.

[mackerel_sky]

Euro looks like dumpster fire for winter weather through 144. However, a big HP is getting ready to drop into the US and there is some weak southern stream energy hanging around.

Sometimes you have to sacrifice a storm to the apps runner gods to bring down the cold for the trailing systems. We've had three small potentials that have panned out to rain or nothing. I'm in until the 6th storm goes poof or cutter!

[deltadog03]

Yup, rain for everyone it appears.  Seems like the right solution *or the closest one as of now*

[Cold Rain]

Yeah, there is just no cold around anywhere at all.  Just terrible.

 

For Mack:

 

 

[Lookout]

lol at the 12z gfs showing nearly -40F lows in Missouri. Gfs likes to go crazy sometimes with surface temps when there is snow on the ground under strong (and sometimes not strong) HPs.  We've all seen this before and it almost never verifies..But this one might take the cake as one of the most extreme cases of it being way too cold at the surface.

 

Meanwhile the euro has surface temps in northern mo at around 20. Only around a 60 degree difference but  what's 60 degrees among friends though? But just to drive home how big that difference is..think about having a low of around 80 on one model while the other says it's going to be 20. Or how about 100 degrees on one and 40 on the other? Or having a low of 50 while the gfs says "FU,  you european trash..I say it's going to be 10 below!" Plug in any temps we are familiar with and you see just how extreme and laughable their differences are.

 

 

meanwhile closer to home, some more laughs...with  the gfs showing teens for a large portion of north ga and sc, with single digits for nc. While the euro has temps in the 20s in north carolina and only around freezing for us. lol..I think this might be one of the biggest differences in temperatures I have ever seen between the two models.  Someone had to be drunk or  stoned and brutally attacked the gfs, knocking it completely silly.