March Pattern and Discussion

[SnowNiner]

Right.

You know, we talk about a "north trend" as if it were arbitrary, but it's really a "climo trend." Given that the GFS has a cold bias, it just seems so obvious what's going to happen here. The closed low will end up moving through Kentucky-ish transfer over somewhere off the NC coast and then it will just be a matter of whether it phases and comes up the coast or not.

 

That's the whole reason we want suppression 5 days out on the GFS, because we know it's going to come north eventually.  We'll see what happens, but again, I still haven't seen a clown map showing snow for the piedmont with a GOOD southern track.  Too warm.  I know we're not supposed to worry about temps but I just don't believe that.  Gotta have cold to get snow.  I too this is probably a mid-atlantic storm; maybe east NC gets in on the coastal that forms, I don't know.

[MotoWeatherman]

Well the 12z CMC Global ditched it's idea of a northern path.  It moved way south...not enough to give anything but rain but none the less..way south.  And at 144 it's a raging nor'easter.

[beanskip]

When I read this, I nodded my head, but decided to check the soundings to confirm.

Whoops!

Here is 120 hours in Shelby, when it looks like bulk of precip falls -- pretty close!

 

Date: 5 day AVN valid 12Z WED  6 MAR 13
Station: KEHO
Latitude:   35.26
Longitude: -81.60
-------------------------------------------------------------------------------
LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W
     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg
-------------------------------------------------------------------------------
  0 1000    71                                                                
SFC  976   270   0.4  -1.9  85  2.3  -0.5 326  11 275.5 276.1 273.9 284.8  3.41
  2  950   484   0.6  -4.5  69  5.1  -1.3 333  29 277.8 278.3 274.5 285.8  2.88
  3  900   917   0.1  -7.0  59  7.1  -2.5 341  48 281.6 282.0 276.0 288.7  2.51
  4  850  1374  -0.5  -8.7  54  8.3  -3.4 350  52 285.6 286.1 277.9 292.4  2.32
  5  800  1859  -0.3 -10.4  46 10.1  -3.9 360  42 290.8 291.2 280.1 297.2  2.16
  6  750  2373  -3.0 -11.8  51  8.8  -6.0 358  35 293.3 293.7 281.1 299.6  2.07
  7  700  2916  -6.7 -14.8  52  8.2  -9.2 349  34 295.1 295.4 281.5 300.4  1.73
  8  650  3491 -10.1 -19.7  45  9.6 -12.6 339  32 297.6 297.8 282.0 301.5  1.24
  9  600  4102 -14.8 -23.6  47  8.8 -16.8 333  32 298.9 299.1 282.2 302.0  0.95
10  550  4754 -19.6 -28.1  47  8.5 -21.1 324  33 300.8 300.9 282.6 303.1  0.69
11  500  5454 -24.8 -34.8  39 10.0 -26.1 316  35 302.8 302.8 283.1 304.1  0.40
12  450  6211 -30.9 -40.8  37 10.0 -31.8 318  41 304.4 304.5 283.5 305.3  0.24
13  400  7034 -37.5 -45.8  42  8.3 -38.0 323  54 306.3 306.3 284.1 306.8  0.16
14  350  7943 -43.6 -53.8  32 10.2 -44.0 327  67 309.9 309.9 285.4 310.1  0.07
15  300  8968 -47.8 -59.8  24 12.0 -48.1 325  70 318.0 318.0 288.1 318.1  0.04
16  250 10168 -48.5 -64.3  14 15.8 -48.9 317  64 334.0 334.0 292.8 334.1  0.03
17  200 11637 -47.6 -69.1   7 21.5 -48.2 299  54 357.4 357.4 298.2 357.5  0.02
18  150 13528 -50.4 -73.5   5 23.1 -51.0 281  53 383.2 383.2 302.8 383.3  0.01
19  100 16120 -58.7 -80.6   4 21.9 -59.0 274  48 414.3 414.3 307.0 414.3  0.01
TRP                                             0                             
WND                                             0       

 

 

CLT, RDU, GSO, INT, are not even close to snow, your not overcoming +6 on 850's, we need this to track alot further SE.

[griteater]

Looks like UKMet is a touch south of previous run

[MotoWeatherman]

When I read this, I nodded my head, but decided to check the soundings to confirm.

Whoops!

Here is 120 hours in Shelby, when it looks like bulk of precip falls -- pretty close!

 

Date: 5 day AVN valid 12Z WED  6 MAR 13

Station: KEHO

Latitude:   35.26

Longitude: -81.60

-------------------------------------------------------------------------------

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W

     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg

-------------------------------------------------------------------------------

  0 1000    71                                                                

SFC  976   270   0.4  -1.9  85  2.3  -0.5 326  11 275.5 276.1 273.9 284.8  3.41

  2  950   484   0.6  -4.5  69  5.1  -1.3 333  29 277.8 278.3 274.5 285.8  2.88

  3  900   917   0.1  -7.0  59  7.1  -2.5 341  48 281.6 282.0 276.0 288.7  2.51

  4  850  1374  -0.5  -8.7  54  8.3  -3.4 350  52 285.6 286.1 277.9 292.4  2.32

  5  800  1859  -0.3 -10.4  46 10.1  -3.9 360  42 290.8 291.2 280.1 297.2  2.16

  6  750  2373  -3.0 -11.8  51  8.8  -6.0 358  35 293.3 293.7 281.1 299.6  2.07

  7  700  2916  -6.7 -14.8  52  8.2  -9.2 349  34 295.1 295.4 281.5 300.4  1.73

  8  650  3491 -10.1 -19.7  45  9.6 -12.6 339  32 297.6 297.8 282.0 301.5  1.24

  9  600  4102 -14.8 -23.6  47  8.8 -16.8 333  32 298.9 299.1 282.2 302.0  0.95

10  550  4754 -19.6 -28.1  47  8.5 -21.1 324  33 300.8 300.9 282.6 303.1  0.69

11  500  5454 -24.8 -34.8  39 10.0 -26.1 316  35 302.8 302.8 283.1 304.1  0.40

12  450  6211 -30.9 -40.8  37 10.0 -31.8 318  41 304.4 304.5 283.5 305.3  0.24

13  400  7034 -37.5 -45.8  42  8.3 -38.0 323  54 306.3 306.3 284.1 306.8  0.16

14  350  7943 -43.6 -53.8  32 10.2 -44.0 327  67 309.9 309.9 285.4 310.1  0.07

15  300  8968 -47.8 -59.8  24 12.0 -48.1 325  70 318.0 318.0 288.1 318.1  0.04

16  250 10168 -48.5 -64.3  14 15.8 -48.9 317  64 334.0 334.0 292.8 334.1  0.03

17  200 11637 -47.6 -69.1   7 21.5 -48.2 299  54 357.4 357.4 298.2 357.5  0.02

18  150 13528 -50.4 -73.5   5 23.1 -51.0 281  53 383.2 383.2 302.8 383.3  0.01

19  100 16120 -58.7 -80.6   4 21.9 -59.0 274  48 414.3 414.3 307.0 414.3  0.01

TRP                                             0                             

WND                                             0       

 

Looking at that sounding it looks like your precip is already over at that point.  RH at 850 and 700mb are only around 55%.  What would be more interesting is to see the 6z sounding.

[beanskip]

Ahhhh -- OK. Thanks. Guess that's where the 6/12 hours increments always burn me. Guess there could still be some snow in there 3-6 hours earlier.....

Looking at that sounding it looks like your precip is already over at that point.  RH at 850 and 700mb are only around 55%.

[beanskip]

Well, definitely some tightening of the envelope -- need to get it extended south for more of us to be in the game. Man, just once for Dr. No to come through for us....

[Brick Tamland]

It sure would be nice to have Matthew East and Allan Huffman here to give their thoughts on the model runs.

[Bevo]

Fair point -- I always try to offer a comparision with prior runs (although I didn't do that with the 850 temp observation).

I wasn't really even looking the precip maps, just wanted to know if the GFS was going to start trending north, which it did.

 

And I really do appreciate your input.  I know most of us are well aware of the nothern tick (not the insect).  I do expect that to occur.  But this run still held NW SC in the game - and has been that way for several runs, so it get's murky when other posts are concluding that the MA and north will be the winners.  That very well may happen (truthfully I expect it too as well, but I put it in parenthesis so it's off the record - ha!).  I just get so friggin' suspicious and gun shy with a ULL like this. 

[rduwx]

Right when it was getting good I get slammed at work and now trying to play catch up.

Overall this was not too bad of a run for NC folks. We have to remember we are still 5 days out and we're in the game. I know burger and a few others think I'm crazy but still worried about BL issues but that's just me.

[wake4est]

An interesting note on the always-rock-solid clown maps, is that in places where snow does fall, it vanishes very quickly within only a few hours. 

[beanskip]

I guess I just have never thought ULL's were immune to the north/climo trending that seems to infect our weather. I remember at least two that trended north to my BENEFIT in the past years. Can't ever remember one that really trended significantly south within 5 days. Always a first, though!

And I really do appreciate your input.  I know most of us are well aware of the nothern tick (not the insect).  I do expect that to occur.  But this run still held NW SC in the game - and has been that way for several runs, so it get's murky when other posts are concluding that the MA and north will be the winners.  That very well may happen (truthfully I expect it too as well, but I put it in parenthesis so it's off the record - ha!).  I just get so friggin' suspicious and gun shy with a ULL like this. 

[griteater]

I think this probably trends north, but for broad brush comparison sake, here's Mar '09 vs. Mar '13 (12z GFS)

 

MAR '09

 

MAR '13 (12z GFS)

[burgertime]

I guess I just have never thought ULL's were immune to the north/climo trending that seems to infect our weather. I remember at least two that trended north to my BENEFIT in the past years. Can't ever remember one that really trended significantly south within 5 days. Always a first, though!

 

You're def. correct about that. I remember one on the NAM coming to get us and it ended up in western KY. I think we do have some things working in our favor but you just never know with these. 

[Bevo]

I guess I just have never thought ULL's were immune to the north/climo trending that seems to infect our weather. I remember at least two that trended north to my BENEFIT in the past years. Can't ever remember one that really trended significantly south within 5 days. Always a first, though!

 

I think you're probably right to think that.  I really wanted to go back and look more closely at March 2009 since it came in very close to where this one is progged, and followed a very simlar track.  That ULL however, was more potent.  I don't know if this one will develop more contours or not - it would be nice.  I'm sure someone here has that information on the 2009 storm, and where it began trending north...or south.  I can't remember.

[MotoWeatherman]

Right when it was getting good I get slammed at work and now trying to play catch up. Overall this was not too bad of a run for NC folks. We have to remember we are still 5 days out and we're in the game. I know burger and a few others think I'm crazy but still worried about BL issues but that's just me.

 I don't think your crazy.  BL is always an issue with ULL's.  Yeah some can be in the sweet spot and cash in but there is much more shaft opportunity.  That ULL we had at the end of January gave me a nice cold rain.  Yeah synoptics said all should go well but model soundings said otherwise so synoptics lost out on that one for NGA.

[Bevo]

I think this probably trends north, but for broad brush comparison sake, here's Mar '09 vs. Mar '13 (12z GFS)

 

You really are a Jedi, aren't you.  As soon as I hit "Add Reply" I see your post winking at me.

[Snowless in Carrollton]

Today's GFS run sits and spins just east of the Delmarva where is yesterday it was NC/SC border.  I don't think it's going to go to much north, as there is a strong but somewhat weaking block there.  I still think NC/VA border will be in play and down I-85 south.  Pretty much the track of the March 2009 storm but slightly more west.

If the track is similar to March 2009 that would be good for Central GA.

[Southern Track]

Robert has an outstanding breakdown of March 09 storm on his Public forum at WxSouth.com if you wanna check it out

[griteater]

You really are a Jedi, aren't you.  As soon as I hit "Add Reply" I see your post winking at me.

 

Nice...I know the Euro was on that one (Mar '09) from 6-7 days out...and it did trend north a bit

[Isopycnic]

Robert has an outstanding breakdown of March 09 storm on his Public forum at WxSouth.com if you wanna check it out

and?.... or is this spam?

[Bevo]

Nice...I know the Euro was on that one (Mar '09) from 6-7 days out...and it did trend north a bit

 

Yeah - looking at those comparisons shows that low clearly more south before it started moving up.

[packfan98]

GFS ensemble mean might be a little further south than the op.  Hard to tell.

[Southern Track]

and?.... or is this spam?

Huh?

[franklin NCwx]

Franklin....what are you all expecting up there tomorrow?  I see where GSP has you in the 1 - 2" area.  I'm thinking about making the trip up to Cashiers or Highlands from Greenville.

I would say 2 tops here. Highlands has some snow on the ground now and I could see them getting 3 maybe even four up around 4500 ft.

[packfan98]

OK, at hr 132 there is a noticeable difference.

[griteater]

Good write-up from GSP on the overnight / early morning flizzard...

 

TONIGHT...SHORT RANGE MODELS INDICATE THAT THE H5 TROF WILL CLOSEOFF AND PIVOT ACROSS THE SOUTHERN APPALACHIANS. AS THE MID LEVEL LOWAPPROACHES AND CROSSES THE MTNS...A FIELD OF H7 OMEGA SHOULD SPREADEAST ACROSS THE FORECAST AREA. FORECAST SOUNDINGS INDICATE THAT THECLOUD DEPTH ACROSS THE REGION WILL EXTEND UP TO AROUND 12KFT...RESULTING IN SEVERAL THOUSAND FEET OF THE CLOUD WITHIN THEOPTIMAL DENDRITIC ICE CRYSTAL GROWTH TEMPERATURES. BASED ON THETIMING OF THE MOISTURE AND LIFT...SHSN SHOULD INCREASE ACROSS THEWEST FACING MTNS LATE THIS EVENING...THEN SPREADING ACROSS THE UPPERSAVANNAH RIVER VALLEY AND THE UPSTATE OF SC DURING THE PRE DAWNHOURS. NIGHTTIME SNOWFALL IS EXPECTED TO RANGE FROM 2-3 INCHESACROSS THE FAVORED NWFS AREAS TO A DUSTING UP TO A FEW TENTHS ACROSSTHE UPSTATE WEST OF I-26 AND NE GA. LOWS TONIGHT ARE FORECAST TORANGE FROM THE 20S ACROSS THE MTNS TO LOW 30S ACROSS THE FOOTHILLSAND PIEDMONT.

 

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...AS OF 245 AM EST FRI...THE MODELS FEATURE GOOD AGREEMENT ON A 537 DM500 MB LOW CENTER MOVING THROUGH THE HEART OF THE FORECAST AREA SATMORNING. THE LOW WILL BE ACCOMPANIED BY AN UPPER COLD POOL OF MINUS30 DEGREE C TEMPS...PRODUCING FAIRLY STEEP LAPSE RATES IN EXCESS OF6 DEG C/KM. HOWEVER...THE QG FORCING WITH THE SYSTEM IS NOTESPECIALLY STRONG OVER THE FORECAST AREA...AND THERE IS NO APPARENTPOOL OF NEGATIVE SATURATED EPV VALUES ALOFT TO SUPPORT MORE INTENSESNOW SHOWER RATES. THE GFS AND ECMWF DO SUPPORT LIQUID EQUIVALENTPRECIP AMOUNTS ON THE ORDER OF 0.05 TO 0.10 SAT...BUT THE NAM ANDSREF MEAN VALUES ARE LESS. ALL THINGS CONSIDERED WILL KEEP VERYSOLID CHC COVERAGE OF SHOWERS ACROSS THE AREA...WITH LIKELY POPS INSW SECTIONS UNDER THE BETTER LAPSE RATES. OUTSIDE OF THE MTNS...NEARSFC TEMP/WET BULB PROFILES REMAIN PROBLEMATIC FOR RAIN VERSUS SNOWPTYPES...WITH A MIX POSSIBLE FOR MUCH OF THE EPISODE. THIS WILLLIKELY LIMIT ACCUMULATIONS...BUT A QUICK DUSTING TO AN INCH WOULD BEPOSSIBLE WITH ANY HEAVIER SNOW SHOWERS. GIVEN THE LOW CONFIDENCE ONLOCATING ANY ONE INCH ACCUMULATIONS AT THIS POINT...WILL CONFINE THEWINTER WEATHER ADVISORY TO THE TN BORDER ZONES WHERE MOIST NWUPSLOPE FLOW CONTINUES. LEANED TOWARD THE COOLEST MODEL GUIDANCE FORTEMPS GIVEN THE CLOUDS AND EXPECTED PRECIPITATION.

[MotoWeatherman]

12z UKIE is north of GFS.  At this point in the game the GFS is the furthest south.

[franklin NCwx]

Looks like UKMet is a touch south of previous run

 

 

 

Sure is!

 

 

 

 

[burgertime]

12z UKIE is north of GFS.  At this point in the game the GFS is the furthest south.

 

Ukie might be slower. If you look at 105 on the GFS and hour 96 on the UKIE which you posted they are practically identical.