CAD storms thread.

[mackerel_sky]

This thing is DOA, for everyone outside of Roxboro

[NCCatawba]

The Canadian(especially the RGEM) is actually an excellent CAD model.

 

It does I tend to take notice if and only if its in agreement with the euro/gfs.

 

[FallsLake]

Big difference on where the colder dew points are set between the NAM and GFS at hour 84. Click on the below site, change the tab to "Moisture", select dew Point temps, and then switch between GFS and NAM.

 

http://www.twisterdata.com

[dsaur]

Models are consistently showing a serious ice storm for Memphis, Jackson, Paris and points west in Tennessee for Friday. 

This thing was always on for parts of Tenn.  Now it just depends on whether the cold can make further in roads for other zrain destruction lovers, lol.  I got an email from a friend in Colo. and she said it was 55 in the morning yesterday, 15 when she wrote in the afternoon, and headed to 0 with 15 inches of snow on tap.  Now that, to me, is the way winter out to play out down here.  We so need some new glaciation, lol, to help push some cold in here.  It does point out the cold ooze does move, when it's on you, but getting it close is the key.  T

[Lookout]

The Canadian(especially the RGEM) is actually an excellent CAD model.

Speaking of the canadian. It has a pretty good looking winter storm days 7.5 and 8. Then something else brewing around day 10 with a good looking cad situation. although the 12z gfs lost it, the 06z run had something along the same lines around day 8. last night's euro also has a system moving through around that time frame with subfreezing temps or temps close to freezing. It has the day 10 system too but just too warm. Very long ways off of course so it's just for entertainment purposes but it  might be something to keep an eye on over the coming days.

 

 

 

day 10

 

 

[Suncat]

I don't plan on going shopping this week...no beer, bread and kitty litter run.  Maybe that will help the cold air mojo to come in further south. 

[Stovepipe]

NWS out of Memphis:

FRIDAY...THE BRUNT OF THE IMPENDING WINTER STORM WILL OCCUR
FRIDAY...WITH THE HEAVIEST AMOUNTS OF QPF AND CORRESPONDING ICE
ACCUMULATIONS. MODELS CONTINUE TO INDICATE THE SWATH OF ICE
AMOUNTS EXCEEDING A HALF OF AN INCH BOUNDED BETWEEN JONESBORO
ARKANSAS TO PARIS TENNESSEE TO THE NORTH AND I-40 TO THE SOUTH.
BUFF-KIT SOUNDINGS SHOW THE WARM LAYER DIPPING BELOW FREEZING BY
NOON FRIDAY OVER THE NORTHWEST COUNTIES SIGNALING A TRANSITION TO
MORE SLEET AND SNOW DURING THE LATE MORNING AND AFTERNOON HOURS.
ACCUMULATIONS OF ONE TWO INCHES ARE POSSIBLE...BEFORE THE
PRECIPITATION SLOWLY TAPERS OFF. FURTHER SOUTH LIGHTER AMOUNTS OF
SLEET AND SNOW ACCUMULATION ARE ANTICIPATED. PRECIPITATION WILL
COME TO END FRIDAY EVENING...WITH TEMPERATURES FALLING INTO THE
TEENS AND 20S. A WINTER STORM WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE MIDSOUTH.

[GaWx]

The 12Z Euro is slightly colder at 2 meters vs. the prior run in western NC with below 32/ZR being suggested for some areas.. Total QPF for this event is ~0.50-0.75". So, a significant icestorm on 12/8 for parts of NC is still quite possible. Keep in mind there tends to be a warm bias at 2 meters on the Euro when there is good evap. cooling.

[NCCatawba]

Lots of factors with the euro to consider. How much evap really cooling occurs with light precip or drizzle? How fast does the latent heat occur? Will 30-32 cut it for ice after 5 days of above freezing nights and 70 degree temps? Is the model right to the exact degree?

[GaWx]

Lots of factors with the euro to consider. How much evap really cooling occurs with light precip or drizzle? How fast does the latent heat occur? Will 30-32 cut it for ice after 5 days of above freezing nights and 70 degree temps? Are the models right to the exact degree?

 

Good Q's.

1) If the total QPF of ~0.5" in the heavier spots in W NC per the Euro were to verify and not be delayed, I'd think that should be enough for good evap. cooling. OTOH, if only drizzle or very light rain falls, that would obviously be different. We'll see what verifies and what are the wetbulbs.

2) My experience is that if the temp. gets down to 30-31 with steady rain falling, it will start to freeze on above ground objects pretty quickly in most cases regardless of warmth in prior days. The key, of course, would be how long it then stays below freezing. If it just dips for a couple of hours to 30-31 but then rises to above 32 quickly, then it likely wouldn't be a big deal all with regard to trees/power lines. With no really locked cold air source, that is quite possible in this case. However, if it stays below 32 for, say, 6+ hours, and 0.50" falls, it could be fairly significant though that still may not be enough for major power outages.

3) Are models right to exact degree? Who knows? That's a common concern in the SE US for winter storms.

[tazaroo]

I believe we are starting to see the cooling trend happen on the models.  The question is, is this the extent of it or will they continue to inch down by game time.  It only takes two or three more degrees to get many more of us involved.

[chapelhillwx]

Good Q's.

1) If the total QPF of ~0.5" in the heavier spots in W NC per the Euro were to verify and not be delayed, I'd think that should be enough for good evap. cooling. OTOH, if only drizzle or very light rain falls, that would obviously be different. We'll see what verifies and what are the wetbulbs.

2) My experience is that if the temp. gets down to 30-31 with steady rain falling, it will start to freeze on above ground objects pretty quickly in most cases regardless of warmth in prior days.

3) Are models right to exact degree? Who knows? That's a common concern in the SE US for winter storms.

 

I wonder if drizzle or light rain wouldn't freeze better at marginal temps of 30-31? It seems like the heavier ZR is, the more likely it is to just run off and not actually accumulate.

[GaWx]

I wonder if drizzle or light rain wouldn't freeze better at marginal temps of 30-31? It seems like the heavier ZR is, the more likely it is to just run off and not actually accumulate.

 

Yes, I'd think that whatever falls with those temp.'s would accumulate, but would there be enough evap. cooling to get it to 30-31 in the first place if only very light precip?

[Shawn]

Speaking of the canadian. It has a pretty good looking winter storm days 7.5 and 8. Then something else brewing around day 10 with a good looking cad situation. although the 12z gfs lost it, the 06z run had something along the same lines around day 8. last night's euro also has a system moving through around that time frame with subfreezing temps or temps close to freezing. It has the day 10 system too but just too warm. Very long ways off of course so it's just for entertainment purposes but it  might be something to keep an eye on over the coming days.

 

 

A few of the GFS ensembles have been showing some wintry deal around the 12th also.  I believe yesterday's 12z, 18, todays 00, 06, and 12.

 

looks more icy/sleet for kcae but.. yeah its there to an extent. just not the op yet.

[dsaur]

I am reminded today of how much I dislike hot weather It's right at 70 here right now in full sun, and it's killing me, after these cool, raining days.  But I'm also reminded of hot days like this that have preceded winter storms, so it's best to keep on ones toes, just in case   I don't think the blur is off the models. 

  And Shawn, it's coming buddy, lol.  It knows about you now   This thread will stay good for a while.  T

[Shawn]

I am reminded today of how much I dislike hot weather It's right at 70 here right now in full sun, and it's killing me, after these cool, raining days.  But I'm also reminded of hot days like this that have preceded winter storms, so it's best to keep on ones toes, just in case   I don't think the blur is off the models. 

  And Shawn, it's coming buddy, lol.  It knows about you now   This thread will stay good for a while.  T

 

One member went rogue and showed 2.60 inches of ice here last night.  Now that is something that nobody in the entire world would need to see even if they loved ice.   It's much calmer now and it's around 5-7 members showing anything wintry at a time.  If it gets more members on board within 192 then I will follow your advice and tell it to come.  This text is about the Dec 12th system, not the 9th.

[NCCatawba]

Severe weather chances increasing?

 

This is a classic setup for cad erosion (northwestern low west/ cold
front scenario per 2006 cstar study)...likely resulting in warming
temperatures throughout Sunday night. In fact...by 12z Sunday...at least
our southern areas will likely be in the warm sector. This is
significant...as the latest GFS depicts a tongue of Low Cape ahead
of the advancing cold front. This is aligned with about 40 kts of
low level shear. A GFS forecast the sherb parameter (a high shear/Low
Cape severe convective parameter originating from a recently
completed cstar project) exceeds the optimal value of 1.0 within the
warm sector during this time. Therefore...isolated severe convection
will be a concern Monday morning/afternoon...especially across the
Piedmont. 

[SN_Lover]

I definitly would not bet(anything valuable) on a major ice event; but I still think it could happen (maybe 20% chance). Lets see how the next model runs look.   

i agree. tis finals week, so im rooting for some type of delay XD 

[Disc]

Severe weather chances increasing?

 

This is a classic setup for cad erosion (northwestern low west/ cold

front scenario per 2006 cstar study)...likely resulting in warming

temperatures throughout Sunday night. In fact...by 12z Sunday...at least

our southern areas will likely be in the warm sector. This is

significant...as the latest GFS depicts a tongue of Low Cape ahead

of the advancing cold front. This is aligned with about 40 kts of

low level shear. A GFS forecast the sherb parameter (a high shear/Low

Cape severe convective parameter originating from a recently

completed cstar project) exceeds the optimal value of 1.0 within the

warm sector during this time. Therefore...isolated severe convection

will be a concern Monday morning/afternoon...especially across the

Piedmont. 

 

Haven't even paid much attention to this, but looking at the 12z GFS, shear is anywhere from 40-55kts throughout the piedmont and NE/E NC. DPs are also in the 60s with surface temps approaching the mid 70s in spots. CAPE isn't too impressive around 500 j/kg, but I wouldn't rule out a localized damaging wind threat.

[Stovepipe]

Despite this thread being primarily about NC/SC/GA and CAD focused, I'm going to use it for the upcoming potential crippling ice storm hitting west Tennessee Friday-Sunday.  I'm sure in addition to the 3 or 4 of active posters outside of those states there are more lurkers from the affected area that would find this relevant to their interests.

 

Anyways, I just talked to some family members from Paris and they said the Red Cross is working to have shelters ready for the storm.  They appear to be taking this one seriously.  Half inch of ice looks like a lock with bonus sleet and snow.  After Friday's ice, the NWS service is expecting the ZR monster to return Sunday for another 1/3rd of an inch or so.  This is looking to be a nasty one.

[WFFaithful]

Despite this thread being primarily about NC/SC/GA and CAD focused, I'm going to use it for the upcoming potential crippling ice storm hitting west Tennessee Friday-Sunday.  I'm sure in addition to the 3 or 4 of active posters outside of those states there are more lurkers from the affected area that would find this relevant to their interests.

 

Anyways, I just talked to some family members from Paris and they said the Red Cross is working to have shelters ready for the storm.  They appear to be taking this one seriously.  Half inch of ice looks like a lock with bonus sleet and snow.  After Friday's ice, the NWS service is expecting the ZR monster to return Sunday for another 1/3rd of an inch or so.  This is looking to be a nasty one.

 

2 inches of rain the day before the ice hits too

[Amos83]

Yeah there aren't a lot of peeps that post on here from Tennessee but Western part of the state is going to get hammered. I'm in Nashville for a while but appear to be just a tad to far east to get in on the major stuff.

[JoshM]

I love that most areas of West Tennessee are 70 degrees with a Winter Storm Watch/Warning!

[Stovepipe]

Question for Shawn, could you possibly render up one of those fancy p-type charts with the convective indicators for some coords in west TN?

 

36.3011° N, 88.3139° W

 

Much appreciated if you can, if not no worries.

 

*Internet Bro-Fist*

[dsaur]

Despite this thread being primarily about NC/SC/GA and CAD focused, I'm going to use it for the upcoming potential crippling ice storm hitting west Tennessee Friday-Sunday.  I'm sure in addition to the 3 or 4 of active posters outside of those states there are more lurkers from the affected area that would find this relevant to their interests.

 

Anyways, I just talked to some family members from Paris and they said the Red Cross is working to have shelters ready for the storm.  They appear to be taking this one seriously.  Half inch of ice looks like a lock with bonus sleet and snow.  After Friday's ice, the NWS service is expecting the ZR monster to return Sunday for another 1/3rd of an inch or so.  This is looking to be a nasty one.

You sir, are as a big a part of the SE as I am, or CR, or Shawn, or anyone...well, maybe MetalMan is questionable...but I digress.  I'm always interested in what goes up up there, as I'm sure are others!  I don't know them...but...well...

 Ok, in all seriousity...I've got good reason to hate ice storms, and I pity the folks who have to sit one out, even if it's minor, and I doubt Tenn. gets minor with this, especially if the precip maps remain north with the heavier precip.  So post away, I for one am always interested.  And get your car batteries all charged up, because it will come to them soon enough if you get a good one   Tony

[Buddy1987]

Burger, Shawn Widreman, Disc and everyone around good to see everyone's interest with the forum and continuing interest in weather! First time I've posted all year so it's been awhile. Anyhow I have seen a lot of posting and comments in regard to the Nam vs the GFS vs the euro and there superiority over one another for CAD events. From past experiences the Nam is by far a lot better in sniffing out low level cold and sensing overall or for that matter showing how the other models underestimate high pressure systems to our north. The nam model was specifically programmed to help forecast CAD events. I used to live in CT and this would always monitor NWS Taunton discussions for years and the writer which I wish I could remember who it was actually went into great detail on the Nam's superiority over these models. Granted I understand the nam is still out of its wheelhouse however if it is showing the low level cold air and subsequently having the 850 line farther south then the GFS for sure however not sure on the Euro then I would not bet against it in that aspect. It may have been horrid recently but it is usually the model to root for and pay attention to in these type of setups. Just a little food for thought and hopefully to get peoples spirits lifted somewhat we could all use some nice winter weather.

[buckeyefan1]

Despite this thread being primarily about NC/SC/GA and CAD focused, I'm going to use it for the upcoming potential crippling ice storm hitting west Tennessee Friday-Sunday.  I'm sure in addition to the 3 or 4 of active posters outside of those states there are more lurkers from the affected area that would find this relevant to their interests.

 

Anyways, I just talked to some family members from Paris and they said the Red Cross is working to have shelters ready for the storm.  They appear to be taking this one seriously.  Half inch of ice looks like a lock with bonus sleet and snow.  After Friday's ice, the NWS service is expecting the ZR monster to return Sunday for another 1/3rd of an inch or so.  This is looking to be a nasty one.

Yes it does    

[Shawn]

Question for Shawn, could you possibly render up one of those fancy p-type charts with the convective indicators for some coords in west TN?

 

36.3011° N, 88.3139° W

 

Much appreciated if you can, if not no worries.

 

*Internet Bro-Fist*

 

Short range:

 

 

 

Long range:

 

[WestTennWX]

Despite this thread being primarily about NC/SC/GA and CAD focused, I'm going to use it for the upcoming potential crippling ice storm hitting west Tennessee Friday-Sunday.  I'm sure in addition to the 3 or 4 of active posters outside of those states there are more lurkers from the affected area that would find this relevant to their interests.

 

Much appreciated....I am in NW Tennessee (Union City area) and I am anxiously awaiting this one. Local forecasters are all over the board as far as totals/precip types. It will be interesting to say the least to watch this unfold. Memories are still fresh from 2009, the days without power (weeks in some cases) and people are on edge. Definitely weird to have a 71 degree day today and a Winter Storm Warning in effect.

 

I never post, I just try to read and learn from the knowledgeable guys on the board. Threads like this one really help to keep me informed. However if anyone is interested, I could post some Observations and/or photos later on.....at least while I still have electricity.

[Shawn]

For the TN folk especially in the West.. this is about to turn catastrophic for you guys.  Looking at around 1" of modeled ZR.. prob less.. prob more.. who knows?  So close to the event it can only trend worse imo... especially due to the models underdoing the cold and all that stuff.. along with precip sometimes.  There are some areas that will be out of power for at least a week if not more.. if the models come to fruition.  If you have big trees around your home, you may want to stay with someone who doesn't.  If there was  ever a need for a bread + milk run.. this is it.

 

It's causing NOAA to upload videos to youtube... over the event.. its serious.

 

Be careful. <3