February Pattern and Storm Discussion

[ColdRainsStr8cashhomey]

Really Great post, especially the bold.

 

Lookout, I know you have scrolled over your fair share of forecast models, soundings and analysis

 

maybe you'll agree, but the thing is this:  if a person can eliminate some of the analysis prior to a storm's arrival (the NAM, DGEX, crazy Jap model, Canadian sometimes)... a clouded picture of what may or may not happen becomes a lot more clear, does it not?

 

so by reducing how much **** model output gets archived into my brain prior to a storm event, the stress level which comes with forecasting is much easier to regulate... although, for the short-range, I will say that I am a fan of the 4km NAM mainly because of the finer resolution (4km NAM simulated radar nailed the snow development here in Upstate SC on Saturday the 16th)

[metalicwx366]

Lookout, I know you have scrolled over your fair share of forecast models, soundings and analysis

maybe you'll agree, but the thing is this: if a person can eliminate some of the analysis prior to a storm system arrival (the NAM, DGEX, crazy Jap model, Canadian sometimes)... a clouded picture of what may or may not happen becomes a lot more clear, does it not?

so by reducing how much **** model output gets archived into my brain prior to a storm event, the stress level which comes with forecasting is much easier to regulate... although, for the short-range, I will say that I am a fan of the 4km NAM

+1 This guy is freaking awesome. But then some folks will but X and X model got it right back in X with X storm for North Carolina wheen none of the other models showed it.

[RevDodd]

Gulf of Mexico effect snow shower chance at 192. Too early for a thread Florida folks.

 

Not at all likely, but certainly possible. I reference April of 1983 in Myrtle Beach (or was it '84? Dang I'm getting old!) when up to 2 inches fell along the Strand from about 28th up to Near where Barefoot Traders is now. Enough moisture and cold enough air aloft can work wonders.

[nchighcountrywx]

@wxbrad: A potent storm system moves over us Monday night into Wednesday. Cold air aloft could really make for some wet heavy snow in the mountains. http://t.co/w3QSdnYosX

[Tacoma]

@wxbrad: A potent storm system moves over us Monday night into Wednesday. Cold air aloft could really make for some wet heavy snow in the mountains. http://t.co/w3QSdnYosX

looks like there is a hole over buncombe county again.  what is it with this snow hole all the time.  use to not be this way. 

[Carvers Gap]

Not at all likely, but certainly possible. I reference April of 1983 in Myrtle Beach (or was it '84? Dang I'm getting old!) when up to 2 inches fell along the Strand from about 28th up to Near where Barefoot Traders is now. Enough moisture and cold enough air aloft can work wonders.

I would almost give up snow in TN to see it snow a couple of inches in Tampa. The cold air really goes pretty far south into Florida. When we have seen late season cold in the southeast, usually somebody gets some late season snow. Should be a fun couple of weeks. Last year it was hot in March. The GFS has had a real habit of driving cold too far south for the past several months, though.

[GaWx]

How cold could 3/1-5 be relative to history in the SE? I have the KATL stats. Keeping in mind the GFS cold bias, the 6Z GFS per MeteoStar has KATL at 31 F, which would be a whopping 20 below normal and 11 below the mid Jan. normal!! The coldest single day to date this winter has been only down to 36 F.

 

 Here are the coldest 3/1-5's 1930-2012:

 

**Normal is 51***

 

-28 1960 major ZR and 0.8" S/IP

-37 1943 0.4" S/IP

-37 1975

-37 1978 T of S/IP

-37 1980 2.7" of S/IP

-38 1947 2 T's of S/IP

-38 2002

-39 1942 3.7" S/IP

-39 1962 2 T's of S/IP

-40 1930

-40 1954

-40 2009 4.2" S/IP

 

Even if the 6Z GFS is off by 5 F (very possible considering the cold bias), it would still be 36 F, the 2nd coldest since 1930! Keep in mind that KATL's median total S/IP in the entire season is only 1" and mean 2". Based on the above, I'd think that a T of S/IP would be likely at the very least.

[tarheelwx]

Here's the 12z nam for Boone.  Basically 1.5" qpf of zr and pl

 Station ID: KTNB Lat:   36.20 Long:  -81.65                                                         NAM Model Run: 12Z 23FEB 2013  HR Valid     2m Tmp 2m Dpt 10m Dir 10m Spd TPrcp CPrcp 1000-500 500mb 850mb 500mb MSLP TCC PRS WX   Tot    Snowfall  Vis                Deg F  Deg F   deg      kt    in.   in.     Thk    GPH   Tmp   Tmp   mb   %  TEXT    Clouds      in    SM   0 02/23 12Z   35     34     319       2    0.00  0.00    553    566    6.5 -13.8 1016 100 RA    061OVC394    0.0    6.6   3 02/23 15Z   46     43     269       3    0.03  0.00    553    565    6.3 -15.0 1012 100       085OVC393    0.0   15.1   6 02/23 18Z   49     43     243       4    0.01  0.00    552    563    6.7 -15.6 1011 100       040OVC355    0.0   15.0   9 02/23 21Z   54     44     262       6    0.00  0.00    552    562    7.6 -16.8 1009 100       163OVC392    0.0   15.1  12 02/24 00Z   48     42     285       4    0.00  0.00    551    560    6.1 -18.8 1010 100       148OVC356    0.0   15.0  15 02/24 03Z   43     40     298       5    0.00  0.00    548    559    4.5 -21.0 1012 100       105OVC334    0.0   15.0  18 02/24 06Z   42     39     303       6    0.00  0.00    544    555    4.6 -21.9 1012 100       115OVC198    0.0   15.2  21 02/24 09Z   37     34     308      10    0.00  0.00    542    552    1.8 -20.5 1012  25       090SCT137    0.0   15.2  24 02/24 12Z   32     30     308      10    0.00  0.00    543    556    0.4 -16.9 1015  30       103SCT132    0.0    6.1  27 02/24 15Z   40     23     306      14    0.00  0.00    546    560   -1.2 -16.5 1016   2       032FEW090    0.0   15.1  30 02/24 18Z   45     21     306      13    0.00  0.00    549    562    0.3 -16.5 1015   7       041FEW077    0.0   15.0  33 02/24 21Z   45     22     306      12    0.00  0.00    550    562    0.9 -17.3 1015   5       055FEW107    0.0   15.1  36 02/25 00Z   37     21     314       8    0.00  0.00    549    563    0.1 -18.0 1018   3       022FEW071    0.0   15.0  39 02/25 03Z   33     21     318       6    0.00  0.00    548    564    0.1 -18.4 1020   0          CLR       0.0   15.1  42 02/25 06Z   29     20     323       6    0.00  0.00    547    564    1.6 -18.2 1021   0          CLR       0.0   15.1  45 02/25 09Z   30     20     317       4    0.00  0.00    547    564    2.2 -18.4 1021   6       042FEW105    0.0   15.1  48 02/25 12Z   31     19     173       2    0.00  0.00    546    564    0.6 -18.8 1021  21       263FEW328    0.0   15.1  51 02/25 15Z   36     22     137       7    0.00  0.00    547    566    0.7 -18.9 1022 100       224OVC367    0.0   15.1  54 02/25 18Z   35     24     149       9    0.00  0.00    548    565    0.1 -18.1 1021 100       168OVC371    0.0   15.0  57 02/25 21Z   34     24     134       8    0.00  0.00    548    564    1.4 -15.0 1020 100       093OVC390    0.0   15.0  60 02/26 00Z   31     25     101       8    0.00  0.00    548    564    2.0 -14.5 1019 100       076OVC371    0.0   13.7  63 02/26 03Z   29     28     110      12    0.25  0.00    548    565   -1.2 -15.1 1020 100 FZRN  030OVC390    0.0    0.7  66 02/26 06Z   29     28     107      14    0.26  0.00    549    563    0.2 -15.5 1017 100 FZRN  029OVC305    0.0    0.8  69 02/26 09Z   28     27     106      15    0.31  0.00    549    560   -2.4 -14.0 1014 100 FZRN  028OVC254    0.0    1.3  72 02/26 12Z   30     29      98      14    0.34  0.00    550    560    0.4 -15.9 1011 100 FZRN  028OVC153    0.0    0.9  75 02/26 15Z   31     29     111       7    0.33  0.02    548    556    1.6 -14.9 1009 100 -TSPL 033OVC162    0.0    0.4  78 02/26 18Z   36     33     172       6    0.06  0.02    546    552    1.9 -15.9 1006  98 -TSRA 032BKN067    0.0   15.0  81 02/26 21Z   42     38     232       6    0.00  0.00    543    548    2.0 -18.1 1004  59 -RA   069BKN138    0.0   14.5  84 02/27 00Z   38     36     242       4    0.03  0.00    541    548    1.3 -19.5 1007  75       065BKN117    0.0   15.1

[jmundie]

this... although meager warm advection will kill a major ice event from being possible as that warm air mixes down dynamically... it's interesting how easy it is to forget that dynamic warming also happens as warm air is pulled down from a warm pocket above as heavy precip falls

 

it's pure gold that the NAM is given so much weight on this board... if one looks at comparisons, it's easy to see this model is shaky... 12z NAM is displaced 300 miles with the core of the upper-low in Oklahoma compared to the 0z NAM valid the same hour... I just looked for S & G, but when are we going to agree to stop looking at that disgraceful model outside of 24 hours in advance? 

 

to add, I must admit that I usually wait for Wilkes to post before I determine what p-type will fall over my head

 

hell, I normally wait on a Wilkesborodude-post for confirmation that the coast is clear to attempt to walk out of my house in a safe manner

This happened in Nashville in one of our events that was supposed to be an ice storm. Surface temps were hovering at freezing with a decent dew point depression, heavy precip started falling and the temp went up, because the air at 925 was insanely warm, like 10c. 

[packbacker]

I thought the 12z GFS looked much better for a day 8 threat, alot better than yesterdays run.

 

 

[Inudaw]

GFS had a nice looking system in the plains at 240 hours.  Only to crush it before it gets to the Mississippi River.  ^^;

[rduwx]

I thought the 12z GFS looked much better for a day 8 threat, alot better than yesterdays run.

 

I was just getting ready to comment on this same thing.  There is a lot of energy coming down and digging far to the south.  If the trough axis was just a tad farther west we would of had a storm imo.

[packbacker]

GFS had a nice looking system in the plains at 240 hours.  Only to crush it before it gets to the Mississippi River.  ^^;

 

Yeah, this run definitely seemed more active, which is very nice to see.

[packbacker]

I was just getting ready to comment on this same thing.  There is a lot of energy coming down and digging far to the south.  If the trough axis was just a tad farther west we would of had a storm imo.

 

The 0z Euro was similar, had a threat.

[buckeyefan1]

Lookout, I know you have scrolled over your fair share of forecast models, soundings and analysis

 

maybe you'll agree, but the thing is this:  if a person can eliminate some of the analysis prior to a storm's arrival (the NAM, DGEX, crazy Jap model, Canadian sometimes)... a clouded picture of what may or may not happen becomes a lot more clear, does it not?

 

so by reducing how much **** model output gets archived into my brain prior to a storm event, the stress level which comes with forecasting is much easier to regulate... although, for the short-range, I will say that I am a fan of the 4km NAM mainly because of the finer resolution (4km NAM simulated radar nailed the snow development here in Upstate SC on Saturday the 16th)

+1  

 

GFS had a nice looking system in the plains at 240 hours.  Only to crush it before it gets to the Mississippi River.  ^^;

 Hasn't that been the pattern all year  

[packbacker]

GGEM, day 8/9, getting closer

 

 

[packbacker]

Unbelievable, GGEM actually hooks it around the SE and MA and nails the NE, you just have to laugh....

 

 

[Cold Rain]

I was just getting ready to comment on this same thing.  There is a lot of energy coming down and digging far to the south.  If the trough axis was just a tad farther west we would of had a storm imo.

 

Yup...this is what I was talking about yesterday.  This is going to be the time for our storm.  I'll bet we start to see it in the next day or two.

[packbacker]

Just a parade of storms....

[superjames1992]

Just a fun feature in la la land, but the GGEM actually has some lee trough development from the hr ~192 storm, I believe.

 

If 2m temperatures were compliant, the OBX would be set.

 

[packbacker]

Beaches get pounded, I would chase this to the OBX.  Nice things is we won't have to worry about Kansas City getting another foot of snow, or an Apps runner.  It's either going to be wide right or a coastal hugger...or no storm at all.

 

 

Just a fun feature in la la land, but the GGEM actually has some lee trough development from the hr ~192 storm, I believe.

 

[WeatherNC]

The 0z Euro was similar, had a threat.

 

Despite the GFS having a much different H5 look compared to the 0z EC from days 6-10, it still manages to pop a low off the Carolina coast before truncation.  The Euro takes the cutoff over the north-east day 6-7 and lifts it out to the ene, whereas the GFS keeps it around over the OH Valley at day 8.  Just to further illustrate the differences, and Larry touched on it this morning, the 0z Euro is very very close to pulling off a big storm, at 204 it had a sub 540 cutoff centered over AR, it never really ejected the energy out of the Baha which the GFS is not even picking up on, and there is clearly a frontal boundary draped sw-ne through the SE US.  216 and 228 hrs were extremely impressive despite leaving some energy back over MX, almost a weak semblance of a cutoff over Central GA, and deep yet pos trough axis moving through the SE.

 

The period between 3/1-3/5 should be watched very closely, with a hypocenter right around 3/3, as the teleconnections, especially the sharp PNA spike peaking around 3/3, are supportive for a deep trough east of the MS.  Axis will likely depend on if we can get the cutoff over the OH Valley/NE to eject out prior to day 7, we need separation for anything to amplify.  I expect these fantasy range blips to become more frequent over the next several days, with the guidance starting to pickup on cyclogenesis off the SE coast ~3/4, which has a good potential of moving back to the northern Gulf as we move closer to the actual window.  

[WeatherNC]

Just a fun feature in la la land, but the GGEM actually has some lee trough development from the hr ~192 storm, I believe.

 

If 2m temperatures were compliant, the OBX would be set.

 

LOL, development starts in the FL Straits...

 

[pcbjr]

Not an IMBY question, but admittedly related to MBY -

 

How cold (surface) do you all think it will get into Fla? (12z GFS says 29º here) but with those 500 heights and 850 temps, I'm really wondering if a harder freeze is in the picture?

[GaWx]

I don't know if it will actually yield anything sig., but the 12Z Doc is clearly closer than the 0Z Doc imo. as of 168.

[packbacker]

I don't know if it will actually yield anything sig., but the 12Z Doc is clearly closer than the 0Z Doc imo. as of 168.

Agreed, and the last thing we want is a hit, we want an "almost" or a "looked closer"...

[GaWx]

Agreed, and the last thing we want is a hit, we want an "almost" or a "looked closer"...

 

This run may get very close to a sig. SE coastal snow...let's see.

[WeatherNC]

Not an IMBY question, but admittedly related to MBY -

 

How cold (surface) do you all think it will get into Fla? (12z GFS says 29º here) but with those 500 heights and 850 temps, I'm really wondering if a harder freeze is in the picture?

 

Hard to say 7-10 days out, but I would be preparing (those with Agri interests) for freeze warnings in Gainesville around the 3rd-4th of March, possibly in to the upper 20's which could trigger the hard type if this cold spell plays out as advertised.  12z Canadian 2m temps, 12z 3/4...

 

[WeatherNC]

I don't know if it will actually yield anything sig., but the 12Z Doc is clearly closer than the 0Z Doc imo. as of 168.

 

Money shot on the 0z was between 192 and 228, I hope we still keep that range minus 12hrs for some continuity, 3/3 event should be inside 192.

[WilkesboroDude]

12z EURO holds on to something frozen near hour 75 for WNC.

A few other frames of additional accumulations too...