Feb 12-13 Sleet/Snow/ZR Event

[BIG FROSTY]

Just think only 7or 8 more Euro runs to go and it's underway! lol

[burgertime]

if I had to guess, I'd say the city is safe for the most part. Probably 8 or 9 tenths of all snow, followed by .4 of either IP or ZR. In other words, perfect sledding conditions.

 

Just got to look at the Euro. I swear my business meetings are out out to get me. My gut tells me it would be all snow with a switch over to heavy sleet for an hour or two then probably going to a -ZR. You're also talking about a wet heavy snow. Getting 7 inches of big fat flakes and then some IP and ZR on top would be amazing. Now that's what you go sledding on. 

[Brick Tamland]

WxSouth showing almost all of NC above the snow line for Wednesday morning on his last facebook post.

[Jon]

I just took a look at the horrible snow maps.. and it's a bit worrisome to still see "snow" here in KCAE.. when we all know that won't verify as the white stuff.

 

Wondering if as the precip/cold enters or is pulling out the temps drop for some reason to show it?  Hm.. maybe I'm a bit overly optimistic saying KCAE looks good for no ice...  weird...

 

ATL has it / very close too..

Yeah, none of that snow on the Euro is actually snowfall outside of the immediate foothills and appalachians, unfortunately. The 850s are ugly nevermind other temps. For KCAE I don't have soundings for the 12z Euro but the "Snowfall" is more like ZR/IP/Rain. I wouldn't be surprised if it's all rain. 850's are 5-9 degrees during "snowfall" Ground temps are slightly at or above freezing, rising as storm moves through.

 

Not a fun event by any means for most, It's hard to believe all of a sudden the models will just develop a ton of cold out of nowhere inside a few days. Whether a storm trends weaker, the high doesn't move out as slow, etc. It's hard for me to get excited about this one. I never like relying on rates to generate frozen precip, most of the time it doesn't work out here in the SE.

[Cheeznado]

On balance most of the runs are barely too warm for a major ice event in ATL proper, it may be one of those 31-33 degree rains with some icing but not a road problem and not that many power issues, we get a lot of those here. I hope that is the case, but it will be a close one I think. The farther NE, like up towards Gainesville it looks ominous. This is still a complex situation with the zonal flow, so we have a long way to go to really pin anything down too specifically but I do like the slightly warmer trend. Again I usually root for winter storms, major ice, no thanks.

[burgertime]

Yeah, none of that snow on the Euro is actually snowfall outside of the immediate foothills and appalachians, unfortunately. The 850s are ugly nevermind other temps. For KCAE I don't have soundings for the 12z Euro but the "Snowfall" is more like ZR/IP/Rain. I wouldn't be surprised if it's all rain. 850's are 5-9 degrees during "snowfall" Ground temps are slightly at or above freezing, rising as storm moves through.

 

Not a fun event by any means for most, It's hard to believe all of a sudden the models will just develop a ton of cold out of nowhere inside a few days. Whether a storm trends weaker, the high doesn't move out as slow, etc. It's hard for me to get excited about this one. I never like relying on rates to generate frozen precip, most of the time it doesn't work out here in the SE.

 

For a good example of why many are excited look at hour 30 of the 12z run and note the 850 line where it runs. That's getting it done with a 1026 high in retreat. Euro is bad at realizing how cold the CAD is from a distance. IF and big IF the Euro is correct there will be a battle with the warm nose but IF the Euro is that strong with the wedge it's gonna be a big dog. 

[Jon]

WxSouth showing almost all of NC above the snow line for Wednesday morning on his last facebook post.

Now now, lets not only tell half the story. There's no way most of NC gets snow from the currently modeled setup and he knows that.

 

Same WxSouth post, "That dotted blue zone is the rough guide for snow to sleet transition. A very rough guide. Many times in this setup, the snow line will be further north of that line, thanks to warm nose aloft, but we'll worry about that later"

[Brick Tamland]

Now now, lets not only tell half the story. There's no way most of NC gets snow from the currently modeled setup and he knows that.

 

Same WxSouth post, "That dotted blue zone is the rough guide for snow to sleet transition. A very rough guide. Many times in this setup, the snow line will be further north of that line, thanks to warm nose aloft, but we'll worry about that later"

 

 

Still looks like a lot of snow and ice, though, even if it does turn over to rain at the end.

[GaWx]

My tally for 2/11-13 period: 6 Euro runs in a row with somewhat widespread winter storm; 14 of 16 GFS runs; one of two failures was this last run (12Z 2/7).

[Pilotwx]

Note also all winter and most of the fall temps have been modeled to warm 3 to 5 days out

[Pilotwx]

Is there any differences between the control vs Ens runs

[Jon]

For a good example of why many are excited look at hour 30 of the 12z run and note the 850 line where it runs. That's getting it done with a 1026 high in retreat. Euro is bad at realizing how cold the CAD is from a distance. IF and big IF the Euro is correct there will be a battle with the warm nose but IF the Euro is that strong with the wedge it's gonna be a big dog. 

Hour 30 or 130?

 

I did notice the OP Euro is much warmer than it's ensemble mean outside of the mountains...especially over NC and into NW SC. Most of NC save some SE counties are at least 0 during the duration of the system. Euro may, in fact, be under doing the CAD as you said.

[burgertime]

Now now, lets not only tell half the story. There's no way most of NC gets snow from the currently modeled setup and he knows that.

 

Same WxSouth post, "That dotted blue zone is the rough guide for snow to sleet transition. A very rough guide. Many times in this setup, the snow line will be further north of that line, thanks to warm nose aloft, but we'll worry about that later"

 

Just to further elaborate check out this map from Feb 2010. CLT got around 3 - 4 inches of snow with like an inch of sleet. This lines up well with the Euro. You had a retreating high and the Euro was seeing what should have been nothing but ZR for my back yard 120 hours out. Now below you can see how there is a good PV in the NE that helped keep that low south but over all it's kind of a close setup.   Turns out it wasn't close at all. 

[burgertime]

Hour 30 or 130?

 

I did notice the OP Euro is much warmer than it's ensemble mean outside of the mountains...especially over NC and into NW SC. Most of NC save some SE counties are at least 0 during the duration of the system. Euro may, in fact, be under doing the CAD as you said.

 

I was saying hour 30. Not a real "CAD" but with the high retreating and another weaker high out around the lakes 850 line is running the border of NC/SC. A few days ago it had us much warmer. 

[packbacker]

Hour 72 on the Euro ENS mean just looks like a us nice setup for a winter storm, let's see where it goes.

[burgertime]

There's no retreating high off the NE coast...there's a banana high over the midwest.

 

Good catch. On the next couple of frames that 1028 slides out but I do see that high out in the midwest is hanging strong. Didn't even notice that. 

[burgertime]

Hour 72 on the Euro ENS mean just looks like a us nice setup for a winter storm, let's see where it goes.

 

@120 it looks good then warms up after that. Still showing a CAD signature though. 

[packbacker]

@120 it looks good then warms up after that. Still showing a CAD signature though. 

 

Yep, but the overrunning precip that starts hour 84 through 120 is what I am hoping, that may be able to give a lot of places 1-3".  The "big" ice storm is getting really close to being a big rain storm.

[burgertime]

Yep, but the overrunning precip that starts hour 84 through 120 is what I am hoping, that may be able to give a lot of places 1-3".  The "big" ice storm is getting really close to being a big rain storm.

 

I don't look at the Euro ENS much as I didn't realize I had access to it till just now (lol). I would imagine though anything that's in that .10 area is just spread though right? Looking at the GEFS or the SREF I always look for anything over .10 and if it has .25 then it's a good sign. I could be wrong with that though. 

[packbacker]

ENS mean looks a lot like the Op, but more favored for western NC, 85 and points west.

[packbacker]

ENS mean looks to have about 0.1-0.25" of precip for bulk of NC that would be mostly snow.  After that the HP is off the coast and just the western part of NC is below freezing which would be frzn.

[packbacker]

Finally looking at the Ens Means of the GEFS and CMC, see the big difference.  The CMC is able to get a banana high going, although weak and the GFS obviously doesn't, and the CMC has the low to the north I would guess a 1000 miles to the west...

 

GEFS mean….

 

 

 

CMC Mean...

 

[NoDa-wx]

Gsp disco

 

That was the overnight disco...here's this afternoon.  GSP is getting more confident about some type of hit but like all of us here the temps are the wild card

 

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

AS OF 305 PM EST FRIDAY...THE EXTENDED RANGE PERIOD KICKS OF MONDAY

EVENING WITH A MID/UPPER LEVEL WAVE EJECTING ACROSS THE MIDSOUTH AND

INTO THE SOUTHERN APPALACHIANS.  MEANWHILE...CANADIAN HIGH PRESSURE

WILL PUSH SOUTHWARD THROUGH THE UPPER MIDWEST AND START SLIDING EAST

TOWARDS NEW ENGLAND.  SURFACE CYCLOGENESIS IN THE WESTERN GULF WILL

ALSO BE ONGOING WITH AN H85 WARM FRONT SLOWLY SPREADING TO THE NORTH

ACROSS THE SOUTHEAST.  AT THE SURFACE...CAA WILL PREVAIL AS ABOVE

MENTIONED HIGH PRESSURE BEGINS TO ANCHOR IN PLACE ACROSS THE

NORTHEAST AMIDST CONFLUENT UPPER FLOW.  WEAK ISENTROPIC LIFT

ASSOCIATED WITH THE ADVANCING WARM FRONT WILL INITIATE LIGHT SHOWERS

ACROSS THE REGION LATE MONDAY NIGHT INTO TUESDAY MORNING.  THERMAL

PROFILES WILL BE SUPPORTIVE OF ALL RAIN AT ONSET WITH A TRANSITION

TO A WINTRY MIX BY LATE MORNING FOR AREAS ALONG THE I85 CORRIDOR. 

THE AIRMASS NORTH OF I85...ALONG WITH THE HIGHER TERRAIN OF WESTERN

NC...WILL LIKELY REMAIN COOL ENOUGH THROUGH THE PROFILE TO SUPPORT

MOSTLY SNOW.  LATEST QPF GUIDANCE WITH THIS INITIAL SYSTEM INDICATES

THE POSSIBILITY OF ACCUMULATING SNOWFALL IN THE ABOVE MENTIONED

SNOWFALL FAVORED REGIONS.  ACCUMULATIONS OF UP TO 3 INCHES ARE

POSSIBLE ALONG THE HIGH TERRAIN WITH GENERALLY LESS THAN AN INCH IN

THE VALLEY FLOORS...EASTWARD INTO THE NC FOOTHILLS/PIEDMONT. 

MEANWHILE THE ABOVE MENTIONED SURFACE CYCLONE WILL BE DEEPENING

ACROSS THE NORTHERN GULF AND WILL EJECT TO THE NORTHEAST OVER THE

SOUTHERN APPALACHIANS AS PREVIOUSLY FORECAST.  OTHER THAN A

CONSENSUS ON A MILLER A CONFIGURATION...MODELS REMAIN IN

DISAGREEMENT WITH REGARDS TO THERMAL PROFILES AND

INTENSITY/PLACEMENT OF THE SURFACE LOW. ALTHOUGH STILL BLENDING THE

OPERATIONAL MODELS...DUE TO RUN TO RUN CONSISTENCY DECIDED TO LEAN

MORE HEAVILY ON THE ECMWF SOLUTION WHICH IS COOLER IN THE LOWER

LEVELS WITH A STRONG MORE PERSISTENT CAD WEDGE.  THUS...PTYPE

REMAINS A CONCERN WEDNESDAY AND THROUGH WEDNESDAY EVENING.  USING

THE ECMWF AS THE PREDOMINATE SOLUTION...PTYPE NOMOGRAM YIELDS MORE

OF A WINTRY MIX WITH FREEZING RAIN BEING THE MAIN CONCERN.

CONFIDENCE OF A WINTER WEATHER EVENT SEEMS TO BE ON THE RISE AS

LIKELY POPS WERE INTRODUCED.  BUT AS MENTIONED ABOVE...THE OVERALL

THREAT IS STILL UNDETERMINED AT THIS TIME DUE TO MODEL UNCERTAINTY. 

WILL CONTINUE TO MONITOR THIS PERIOD FOR MORE SOLID CONCLUSIONS ON

PREDOMINATE WINTER WEATHER THREATS.

 

[SN_Lover]

looking at 1000-500 and 850-700 thickness only the northern fringes of NC will get snow from the Euro. The rest of the areas looks like a mixed bag of precipitation. 

[MichaelJ]

What we should be looking at is the trend of the models and the EURO started trending a little warmer the last run which is worrying for those that want sn as we were all pretty borderline for temps to begin with. Still a lot of time for the model waffling to continue and I suspect they will like Robert said.

[superjames1992]

Finally looking at the Ens Means of the GEFS and CMC, see the big difference.  The CMC is able to get a banana high going, although weak and the GFS obviously doesn't, and the CMC has the low to the north I would guess a 1000 miles to the west...

 

GEFS mean….

 

[iMAGE SNIPPED}

 

 

CMC Mean...

 

[iMAGE SNIPPED]

 

 

Wowzers... just small differences. 

 

Looks like the CMC mean is quite a bit faster (more in line with the Euro), as well.

 

 

What we should be looking at is the trend of the models and the EURO started trending a little warmer the last run which is worrying for those that want sn as we were all pretty borderline for temps to begin with. Still a lot of time for the model waffling to continue and I suspect they will like Robert said.

 

 

I don't know if there's a noticeable trend with the Euro.  Last night's 00z run was colder than yesterday's 12z run while the 12z run today warmed a tad, more in line with yesterday's 12z run.

[packbacker]

Wowzers... just small differences. 

 

 

 

 

I don't know if there's a noticeable trend with the Euro.  Last night's 00z run was colder than yesterday's 12z run while the 12z run today warmed a tad, more in line with yesterday's 12z run.

 

Yep, and the Euro ENS looks more like the CMC Ens.

[packbacker]

JMA give us the nice over-running precip/snow on day 4-5.

 

[Cold Rain]

 

JMA give us the nice over-running precip/snow on day 4-5.

 

That's encouraging. This is where I think we score farther east IF surface temps cooperate. If we could sneak out 3-4 inches in the pre-event, I'd call that a win, regardless of what happens later on.

[deltadog03]

I would think, as of now, its looking like ATL-AHN looks like a mega ZR storm.  NE GA to GSP could be crippled with snow/sleet/zr  and snow/sleet in NC.  I would say MCN would be just a very cold rain, but I still think that could/would trend colder with time as we get closer.  I don't like how the high sits in the NE, I wish it was stronger as well.  With that said, its very impressive for being a 103 something high.  its in a very good spot.