1/28 - 1/30 Storm Thread II

[burgertime]

Sounds like me and skip were having the classic case of just looking at SFC maps and not thinking about all the other factors. 

[Lindsaywx]

The trends are better but no blockbuster bomb.

Hour 78 moisture is in retreat and moving off the coast for ATL,GSP,RDU.

We are running out of time for a bomb

[Lookout]

Very strange. SV maps are showing that 850 line well west of CHS. Looking at the region map 2m line does appear to be good but thickness and 850's are not there. 

I was referring to the surface temps. 850s are just slightly above freezing in charleston which could mean sleet..or it's freezing rain along the immediate coast and a lot of sleet just inland.  It certainly isn't plain old rain.

[SnowGoose69]

I don't buy such a sharp cutoff. If we are dealing with a storm strong enough to drop that kind of liquii don't see how more doesn't get thrown north. Maybe I'm clouded by the fact I'm so close to something good yet so far....

 

The NAM has long had a bias of overly sharp cutoffs on northern edge of precipitation shields with storms, even since its "ETA" days...sometimes its correct but that is usually when you are running a S-N system into a monster high/dry airmass, in this case you're sort of half doing that and half not...the concern I'd have in this event is that way more precipitation breaks out earlier than forecast and more north because of the pure overrunning potential which models tend to miss frequently.  Myself and another meteorologist noticed a few years ago that in these sort of systems, your 700mb RH over 90% can sometimes be indicative and when precipitation will actually start forming in the overrunning more than the actual QPF fields.

[BullCityWx]

I'd bet on ZR at the coast and IP probably starting somewhere just north of 526.

[a5ehren]

I don't buy such a sharp cutoff. If we are dealing with a storm strong enough to drop that kind of liquii don't see how more doesn't get thrown north. Maybe I'm clouded by the fact I'm so close to something good yet so far....

At this point I'd have to wager on this run having a bit too much moisture unless the other models follow it later today. 

[Lookout]

sounding for near charleston at hour 69, for example. Looks an awful like sleet with the above ground warm layer just barely above freezing while it's very cold below 925mb.

NAM Text Sounding | 09 UTC Wed 29 Jan 2014 | Latitude: 32.9634 | Longitude: -79.5262
PRES	HGHT	TEMP	DWPT	RELH	MIXR	DRCT	SKNT	TWTB	TVRT	THTA	THTE	THTV
1023.7	0	-2.2	-2.7	96	3.1	356	17	-2.4	-1.7	269.1	277.5	269.6
1000.0	183	-5.2	-5.7	96	2.5	359	23	-5.3	-4.8	268.0	274.9	268.4
975.0	383	-6.7	-7.2	96	2.3	7	29	-6.8	-6.3	268.4	274.8	268.8
950.0	587	-1.5	-2.2	95	3.4	18	28	-1.8	-1.0	275.6	285.2	276.2
925.0	801	0.9	0.6	98	4.3	357	13	0.7	1.6	280.2	292.3	280.9
900.0	1021	1.0	0.7	98	4.5	340	11	0.9	1.7	282.5	295.3	283.3
875.0	1247	0.4	0.3	99	4.5	26	6	0.3	1.1	284.2	297.0	284.9
850.0	1480	-0.2	-0.6	97	4.3	84	12	-0.4	0.5	285.9	298.4	286.7
825.0	1719	0.4	0.4	100	4.8	140	13	0.4	1.2	289.0	303.0	289.8
800.0	1966	1.5	1.5	100	5.4	186	22	1.5	2.4	292.7	308.5	293.7
775.0	2223	1.9	1.9	100	5.7	206	33	1.9	2.8	295.8	312

[beanskip]

Yeah, I was looking at 850s -- plus, also noticed that some of the really cold air over the midsouth retreats with 12z run -- but it seems like that doesn't have too much impact further south.

I was referring to the surface temps. 850s are just slightly above freezing in charleston which could mean sleet..or it's freezing rain along the immediate coast and a lot of sleet just inland.  It certainly isn't plain old rain.

[deltadog03]

Agreed Lookout.  Burger you are right, that the 850 0 line is mostly to there NW, but at 2m its def. at or below freezing.  I would say southern GA to CHS is going to have a helluva sleet/freezing rain issue.  **IF** that run is right.

[BullCityWx]

One thing about that CHS sounding is CHS is on the far northern part of that area. I'd be worried about 33 and rain S of there.

[Jaguars]

I don't buy such a sharp cutoff. If we are dealing with a storm strong enough to drop that kind of liquii don't see how more doesn't get thrown north. Maybe I'm clouded by the fact I'm so close to something good yet so far....

Not trying to be a Debby Downer but I've seen storms in the northeast

do it before. 09 or 10 I believe parts of central New Jersey got pummeled

with close to a foot and a half. The city got 4-5 inches and just north of the city

practically nothing. I agree, seems unbelievable on the maps but it can happen.

[burgertime]

Yeah, I was looking at 850s -- plus, also noticed that some of the really cold air over the midsouth retreats with 12z run -- but it seems like that doesn't have too much impact further south.

 

Don't know if you were looking at the regional views but I know on the big SFC map on SV the 2m temps looked like they were well west. It wasn't until I looked at the regional view that it looked to be something frozen. 

 

Agreed Lookout.  Burger you are right, that the 850 0 line is mostly to there NW, but at 2m its def. at or below freezing.  I would say southern GA to CHS is going to have a helluva sleet/freezing rain issue.  **IF** that run is right.

 

Yea I think it was mainly because the map I was looking at had the 2m line blending in so it just looked like it was west of CHS. Either way that is a monster for them. I would not want to be in that bullseye if it indeed turns up ice. 

[BullCityWx]

Hopefully the ZR for whoever gets it can be a self limiting process.

[burgertime]

Hopefully the ZR for whoever gets it can be a self limiting process.

 

Just a heads up check out the Hi-Res NAM @60 it's very close to something good for us. 

[Lookout]

I don't buy such a sharp cutoff. If we are dealing with a storm strong enough to drop that kind of liquii don't see how more doesn't get thrown north. Maybe I'm clouded by the fact I'm so close to something good yet so far....

I think it's a fair bet there will be. There is pretty much universal agreement on such a cutoff. Some are slightly less extreme than others but overall they all show it.

 

this run shifted north with the precip about 25 or 30 miles and puts me in the 0.25 range or somewhere between 0.10 and 0.50. but another shift of 30 miles and I'm in the 0.50 amounts which would be great given the higher than normal ratios.

 

I'm actually a bit surprised it's wetter since the northern stream was further east which would normally mean less sw flow aloft. But the nam actually does back the flow more, assuming it has more to do with the southwest system being a bit faster. quite often the models  will under perform in over running situations.

[LithiaWx]

GFS did drop 1" of snow on Hartsfield with temps down in the 20's, starting around sunset on Tuesday.  Even that small amount imo would cause some major travel headaches for all travelers.

[Wild Weather Monger]

Looking at many of the surface temps where zr/ip will be the predominate precipitation type, folks need to pray for ip.  zr with temps below 30 with as much qpf as modeled will deal a devastating hit to those areas.  Bread, milk, and beer run is in order.

 

Following this system with extreme interest.  Have a daughter down in Houma, La. and I am east of Atlanta.  Both areas are at the extreme edges as modeled.  The former in for SE Louisiana may have temp issues, and MBY lies along the northern fringe.   

[dg12x]

One thing about that CHS sounding is CHS is on the far northern part of that area. I'd be worried about 33 and rain S of there.

Exactly. If you want a sampling further south, use JZI. That's the executive airport located a few miles south of most of the population. A blend of those two results will give anyone looking for it a good idea of the NAM's idea for most of Charleston's residents.

[beanskip]

U-G-L-Y

 

 

Date: 60 hour Eta valid 0Z WED 29 JAN 14
Station: VPS
Latitude:   30.48
Longitude: -86.53
-------------------------------------------------------------------------------
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
-------------------------------------------------------------------------------
SFC 1021    21  -0.5  -1.1  95  0.6  -0.7  11  16 271.1 271.6 271.3 280.3  3.45
  1 1000   187  -2.9  -3.2  98  0.3  -3.0  12  20 270.2 270.7 270.1 278.3  3.01
  2  950   592  -2.2  -3.0  94  0.8  -2.5  38  29 275.0 275.5 273.3 283.8  3.23
  3  900  1027   2.3   2.2  99  0.1   2.2  34  13 283.9 284.7 280.4 297.8  4.97
  4  850  1491   3.8   3.8 100  0.0   3.8 284  14 290.1 291.2 284.2 307.0  5.92
  5  800  1984   3.3   3.3 100  0.0   3.2 258  25 294.6 295.7 286.1 312.2  6.05
  6  750  2508   3.2   2.6  96  0.6   2.9 236  37 300.0 301.1 288.2 318.3  6.16
  7  700  3064  -0.6  -0.6  99  0.1  -0.6 227  45 301.9 302.8 287.9 317.6  5.22
  8  650  3653  -3.6  -3.8  99  0.2  -3.7 230  57 304.8 305.7 288.2 318.4  4.43
  9  600  4282  -7.0  -7.6  95  0.6  -7.2 236  62 308.1 308.7 288.5 319.3  3.60
10  550  4957  -9.7 -10.6  93  0.9 -10.0 237  70 312.6 313.2 289.5 322.6  3.11
11  500  5687 -14.3 -15.7  90  1.3 -14.7 243  78 315.6 316.0 289.7 323.0  2.26
12  450  6478 -19.4 -21.3  86  1.8 -19.9 245  81 318.8 319.1 290.0 324.1  1.56
13  400  7343 -25.6 -27.7  82  2.1 -26.0 246  75 321.8 321.9 290.3 325.2  0.98
14  350  8293 -33.9 -36.8  75  2.9 -34.2 245  78 323.0 323.1 290.2 324.7  0.47
15  300  9362 -39.0 -42.2  71  3.2 -39.3 242 106 330.4 330.4 292.2 331.5  0.31
16  250 10588 -48.1 -51.4  68  3.3 -48.3 244 116 334.5 334.5 293.0 335.0  0.13
17  200 12026 -57.3 -60.1  70  2.8 -57.3 246 140 342.1 342.1 294.9 342.3  0.06
18  150 13814 -63.1 -77.3  13 14.2 -63.2 247 131 361.4 361.4 299.0 361.4  0.01
19  100 16270 -70.0 -84.3  11 14.3 -70.1 249  87 392.5 392.5 304.2 392.5  0.00

[NEGa]

I am right at the sharpest part of the gradient. gfs gives me between 0.10 to 0.25. N. 30 miles northwest is almost nothing, while 30 miles southeast there could be 0.50 to 0.75. Nam is even sharper (and i'm right on the edge of accumulation. And that's the case all along the back edge. Literally the smallest of shifts either way will make or break it. . And that really goes for all of us right on the line from ga to nc. There will be some very heart broken folks no matter where it sets up while others are going to be jumping for joy just a few miles away. For those on the back edge, the good news is if we see a shift northwest comparable to what the 0z and 06z did, we/us will be in business. 

 

edit to say 09z sref looks like between 0.25 to 0.50 here.

 

Ugh I am so nervous. I haven't been this nervous in a long time. I feel like I'm 8 years old lol

lol join the crowd.  this is looking to be a nail biter big time - nothing worse than watching radar show snow, moderate to heavy, 25-30 miles away and watching and hoping and yet never seeing it move west just that little bit haha.

 

i guess maybe time to get ready for a quick road trip haha.  historically things shift and being in the bulls eye days out is horribly disappointing at the end.  but i am just not confident in the shift this time like a couple of years ago when that would happen.

 

wpc could either be a genius or a disaster with some of their maps showing decent snow where the models are dry lol. it was nice to see the other thread locked and a new one this morning - hopefully all our mojo will help us bring a good storm to almost everyone

[SnowGoose69]

The RGEM not joining the nam yet at 48 hours it has way less precip breaking out over TX and the WRN Gulf

[LithiaWx]

ATL is in for a huge surprise, imo.

There is room for that to happen but I don't think the odds are that good for it. At least we still have a chance at a surprise with this one.

[burgertime]

Also be cautious of NAM totals, it has been known to totally overblow QPF. I remember during the Christmas storm it had 2 inches of QPF in MBY at one point. I finished with about 3 inches of snow. Different setup but just keep it in mind. 

[sctvman]

JZI is John's Island, while CHS is actually in North Charleston. Keep that in mind when you're talking about Charleston.

[burgertime]

The RGEM not joining the nam yet at 48 hours it has way less precip breaking out over TX and the WRN Gulf

 

I'm guessing it's mainly how it handles the southern energy? My bigger fear is that that energy gets shunted south with the western energy moving east ever so slightly. 12z was reassuring but I guess we'll see what the GFS and Euro have to say. 

[deltadog03]

I broke down the 12z NAM run in bufkit for KMCN....  0.06" qpf of rain basically on Monday.  Tue am to Tue pm about .12" of sleet fell, and then around 3-4pm on Tue we switch over to snow and about 0.97" QPF falls as snow...  I still think overdone, but either way...a .25" of qpf of snow would lay down 2-3"

[tramadoc]

I'm not buying the amounts of precip that the NAM is showing. I've always heard that the NAM model is usually way overdone on QPF amounts. Any truth to that?

[burgertime]

I broke down the 12z NAM run in bufkit for KMCN....  0.06" qpf of rain basically on Monday.  Tue am to Tue pm about .12" of sleet fell, and then around 3-4pm on Tue we switch over to snow and about 0.97" QPF falls as snow...  I still think overdone, but either way...a .25" of qpf of snow would lay down 2-3"

 

That would be some fun sledding snow due to the blanket of sleet underneath. 

[beanskip]

I'm sorry, but I need some acknowledgement of the historical significance of this meteorogram. It is entirely possible that, if this happened (yes, yes, I know the disclaimers) that it would be the first time something like this occurred since the New World was discovered -- perhaps longer. This shows about 1.75 inches of liquid falls with subfreezing surface temperatures for the entire event and subfreezing 850s for the last half at the Ft. Walton Beach airport.

 

[DaculaWeather]

Atlanta