Winter 2013-14 Pattern Discussion

[franklin NCwx]

Care to elaborate? TIA

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-epo -ao neutral to slightly -nao, split flow, brief positive pna. General trough in the east with arctic ait spilling in the plains/east.

[franklin NCwx]

6z ensembles look even better. Maybe this time next week we can track a storm.

[NCSNOW]

I'm feeling a January 7-8 1988 repeat. Remember this one very well. It's great reading material to help us snow addicts cope with the harsh weather heading our way over the next 4 days. Great thing about this storm is wasn't some big phased/ Super ULL, and did the unthinkable by putting down the white carpet across most of Dixie. Upstate guys I believe this is one of your biggest snowfalls. Enjoy!

 

http://www.erh.noaa.gov/gsp/localdat/TechAttachments/ta2001-02.pdf

 

The 7-8 January 1988 heavy snow event

across Georgia and the Carolinas is an

illustration of a record-setting snowfall that

resulted from a flow pattern significantly

different than a flow pattern associated with

the more heralded nor’easter. In the absence

of strong digging shortwaves, high amplitude

troughs, and a rapidly deepening surface

cyclone, heavy snow fell across a significant

portion of north Georgia and the Carolinas,

including the metropolitan areas of

Greenville-Spartanburg, Asheville, Charlotte,

Greensboro, Raleigh and Columbia. The

heavy snow, greater than 12 inches along and

north of the Interstate 85 corridor in the

western Carolinas shut down commerce and

closed schools for days. This case study

simply serves as a reminder that forecasters

should be just as aware of prolonged, strong

isentropic lift as they are of strong

cyclogenesis when anticipating significant

snowfall events in the southeastern United

States.

[mackerel_sky]

I'm feeling a January 7-8 1988 repeat. Remember this one very well. It's great reading material to help us snow addicts cope with the harsh weather heading our way over the next 4 days. Great thing about this storm is wasn't some big phased/ Super ULL, and did the unthinkable by putting down the white carpet across most of Dixie. Upstate guys I believe this is one of your biggest snowfalls. Enjoy!

http://www.erh.noaa.gov/gsp/localdat/TechAttachments/ta2001-02.pdf

The 7-8 January 1988 heavy snow event

across Georgia and the Carolinas is an

illustration of a record-setting snowfall that

resulted from a flow pattern significantly

different than a flow pattern associated with

the more heralded nor’easter. In the absence

of strong digging shortwaves, high amplitude

troughs, and a rapidly deepening surface

cyclone, heavy snow fell across a significant

portion of north Georgia and the Carolinas,

including the metropolitan areas of

Greenville-Spartanburg, Asheville, Charlotte,

Greensboro, Raleigh and Columbia. The

heavy snow, greater than 12 inches along and

north of the Interstate 85 corridor in the

western Carolinas shut down commerce and

closed schools for days. This case study

simply serves as a reminder that forecasters

should be just as aware of prolonged, strong

isentropic lift as they are of strong

cyclogenesis when anticipating significant

snowfall events in the southeastern United

States.

Yep! One of my favorite storms! It was very warm at Christmas time that year before the storm. Glad to see the pattern starting to look a little better

[franklin NCwx]

I remember that storm. I was living in highlands at the time think it was around 18" might have been more.

[DaculaWeather]

Not sure this is obs or discussion but...

 

This alert was generated by the National Weather Service
EMWIN (Emergency Managers Weather Information Network)
from messages received by DaculaWeather.com EMWIN server.
NOUS42 KWNO 191335
ADMNFD

SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE
NWS NCEP CENTRAL OPERATIONS COLLEGE PARK MD
1333Z THU DEC 19 2013


THE 12Z NAM HAS BEGUN ON SCHD WITH GOOD N AMER UPA DATA
COVERAGE INCL 72 CONUS 13 AK 31 CAN 8 MEX AND 8 CARIB RAOBS
AVBL.  12Z NAM RAOB RECAP...
72393/VBG - DELETED TEMPS 831-812 MB...SUPER-ADIABATIC.
72221/VPS - DELETED HGTS 200 MB AND UP...HYDROSTATIC ERRORS.
72572/SLC - LATE FOR NAM.
70414/SYA - LATE FOR NAM.


CRITICAL WEATHER DAY STATUS...
NCEP DOES NOT ANTICIPATE A CWD DURING THE NEXT 24 HOURS.
A CWD IS POSSIBLE AFTERWARD...A LOW CHANCE... DUE TO POSS
SEV WX OVER SE US DURING THIS WEEKEND.

[Cold Rain]

So the Posting Intensity Index remains in the negative phase today, thought not as strongly negative as yesterday (Grit, I've contacted CPC, but no response yet ).  The AO and NAO look to remain positive and the PNA is forecast to remain neutral before going strongly negative later in the period, according to the CPC page.  The CFS looks pretty horrible for both temps and precip for forever.

 

However, below is the 0z Op GFS at 312 hrs.  Way out in fantasy land, but perhaps we're finally starting to see some weakening in the persistent +NAO regime, as we're starting to see Greenland ridging/blocking being shown with more frequency.  Is this a trend that will continue and work into the T-10 day period?  Who knows, but it's good to finally start to see it show up more, instead of run after run after run of super +++++++NAO.  The 18z from last night also looked good in the LR, but I don't think it had quite as impressive a -NAO signature.  The closed contours show up on the 0z at about 300 hrs (with ridging prior to that) and basically remain through the end of the run.  The 6z didn't really look good in the LR and the Euro looked colder at 240, but overall, it was not a wintry look.

 

Expect more changes....hopefully to something better.  In the meantime, enjoy the nice warm-up and heavy rain.

[oconeexman]

I'm feeling a January 7-8 1988 repeat. Remember this one very well. It's great reading material to help us snow addicts cope with the harsh weather heading our way over the next 4 days. Great thing about this storm is wasn't some big phased/ Super ULL, and did the unthinkable by putting down the white carpet across most of Dixie. Upstate guys I believe this is one of your biggest snowfalls. Enjoy!

http://www.erh.noaa.gov/gsp/localdat/TechAttachments/ta2001-02.pdf

The 7-8 January 1988 heavy snow event

across Georgia and the Carolinas is an

illustration of a record-setting snowfall that

resulted from a flow pattern significantly

different than a flow pattern associated with

the more heralded nor’easter. In the absence

of strong digging shortwaves, high amplitude

troughs, and a rapidly deepening surface

cyclone, heavy snow fell across a significant

portion of north Georgia and the Carolinas,

including the metropolitan areas of

Greenville-Spartanburg, Asheville, Charlotte,

Greensboro, Raleigh and Columbia. The

heavy snow, greater than 12 inches along and

north of the Interstate 85 corridor in the

western Carolinas shut down commerce and

closed schools for days. This case study

simply serves as a reminder that forecasters

should be just as aware of prolonged, strong

isentropic lift as they are of strong

cyclogenesis when anticipating significant

snowfall events in the southeastern United

States.

Thanks for this! Greatest storm of my time...15-16". Fun to read how it all happened and somewhat understand it!

[Southern Track]

I'm feeling a January 7-8 1988 repeat. Remember this one very well. It's great reading material to help us snow addicts cope with the harsh weather heading our way over the next 4 days. Great thing about this storm is wasn't some big phased/ Super ULL, and did the unthinkable by putting down the white carpet across most of Dixie. Upstate guys I believe this is one of your biggest snowfalls. Enjoy!

 

http://www.erh.noaa.gov/gsp/localdat/TechAttachments/ta2001-02.pdf

 

The 7-8 January 1988 heavy snow event

across Georgia and the Carolinas is an

illustration of a record-setting snowfall that

resulted from a flow pattern significantly

different than a flow pattern associated with

the more heralded nor’easter. In the absence

of strong digging shortwaves, high amplitude

troughs, and a rapidly deepening surface

cyclone, heavy snow fell across a significant

portion of north Georgia and the Carolinas,

including the metropolitan areas of

Greenville-Spartanburg, Asheville, Charlotte,

Greensboro, Raleigh and Columbia. The

heavy snow, greater than 12 inches along and

north of the Interstate 85 corridor in the

western Carolinas shut down commerce and

closed schools for days. This case study

simply serves as a reminder that forecasters

should be just as aware of prolonged, strong

isentropic lift as they are of strong

cyclogenesis when anticipating significant

snowfall events in the southeastern United

States.

 

FWIW,  at the time of the storm,  we had a +PNA, but the NAO and AO were also positive. 

[Cold Rain]

FWIW,  at the time of the storm,  we had a +PNA, but the NAO and AO were also positive. 

 

But it did appear to have a very important feature -- a 50/50 low.  That helped to maintain excellent confluence in the NE and lock in high pressure across the northern tier.  If you don't have a +NAO to help suppress the PV, you need a 50/50 (and really, it's good to have both), to lock the confluence in place.  Otherwise, the tendency is for HP to slide out too quickly and WAA to take over.  It requires the most perfect of timing for the entire event to be frozen.  With good confluence, the timing window can be much longer.

[Southern Track]

But it did appear to have a very important feature -- a 50/50 low.  That helped to maintain excellent confluence in the NE and lock in high pressure across the northern tier.  If you don't have a +NAO to help suppress the PV, you need a 50/50 (and really, it's good to have both), to lock the confluence in place.  Otherwise, the tendency is for HP to slide out too quickly and WAA to take over.  It requires the most perfect of timing for the entire event to be frozen.  With good confluence, the timing window can be much longer.

Yes, did read that.  Without the 50/50 it probably would have had a changover, or just a Cold Rain.  

[dsaur]

^

 

This is what makes this forum special.

The main thing about the south is change.  You never get wall to wall anything.  The hottest winters have some cold nights, the coldest winters have warm ups...blah, blah, lol. If that ridge stays for 4 months, Burn will eat his hat!  I see cycles in it all, and we should see some cold highs and wet lows, coming back after Xmas day, if my figuremarations are correct.  Of course the ridge may come back too, but hey, all we want are windows....that's all get anyway   Tony

[Snowless in Carrollton]

God I hope we don't have another Jan 1988 repeat. Looks like a total screwjob for Birmingham and Atlanta. Kinda like the screwjob we had in the early 70s when areas further south and east had over a foot of snow.

[Snowless in Carrollton]

The main thing about the south is change. You never get wall to wall anything. The hottest winters have some cold nights, the coldest winters have warm ups...blah, blah, lol. If that ridge stays for 4 months, Burn will eat his hat! I see cycles in it all, and we should see some cold highs and wet lows, coming back after Xmas day, if my figuremarations are correct. Of course the ridge may come back too, but hey, all we want are windows....that's all get anyway Tony

except in summer of course, and then we usually get wall to wall heat. Last summer didn't seem too bad though.

[Cold Rain]

Yes, did read that. Without the 50/50 it probably would have had a changover, or just a Cold Rain.

Cold Rain isn't so bad. We're about to have some warm rain soon. And quite a bit of it.

[Southern Track]

Cold Rain isn't so bad. We're about to have some warm rain soon. And quite a bit of it.

Yes we are, but I guess the severe threat will stay west of us.

[Brick Tamland]

Yep. We're going to see a lot of this on all models due to the pattern changing and consequentially, favorable setups. Only a matter of time before we get a clown map and we get to really watch something! It's close.

 

I hope so. I think after Christmas we will start to have some fun. This winter has been frustrating to figure out so far. It's like trying to figure out Carolina's basketball team this season.

[Southern Track]

12z GFS has a colder look for the end of next week.

[Wow]

GFS finally does it toward the end of the run.  That is, pump the EPO ridge big time into the arctic circle AND building a modest -NAO block that is displaces the massive PV south as heights lift over the areas where it has been so cold recently (the Arctic and Greenland).

 

This is the makings of a major arctic outbreak for the entire US:

 

[franklin NCwx]

I see plenty of confluence on the gfs. Good to see the op following the ensembles. Now to time a wave.

[Wow]

Arctic front heading straight for us.  You get a boundary like that sitting on the gulf/SE coast, you'll have plenty of waves traveling up.  This is like 1899 type cold right here.

 

[SnowNiner]

GFS finally does it toward the end of the run.  That is, pump the EPO ridge big time into the arctic circle AND building a modest -NAO block that is displaces the massive PV south as heights lift over the areas where it has been so cold recently (the Arctic and Greenland).

 

This is the makings of a major arctic outbreak for the entire US:

 

 

Excellent....everything is proceeding as planned......maybe. 

 

This will be a nice test for the GFS.  It's had general hints of that happening for a few days.  Other models and ensembles have been hinting at it but I don't think that gung ho about the over the top ridging.  Be curious to see if it actually happens or gets within the 7-10 day window.  Would LOVE to see that look with an active STJ. 

[pcbjr]

This is the makings of a major arctic outbreak for the entire US:

 

 

 

Except Florida, it appears ...

[franklin NCwx]

You are correct sir. Would set up interior/upper south snow storms with waycross in the dryslot.

[franklin NCwx]

Cmc developes a coastal Christmas eve. Might have some snow showers here in the western nc mtns.

[Jon]

Arctic front heading straight for us.  You get a boundary like that sitting on the gulf/SE coast, you'll have plenty of waves traveling up.  This is like 1899 type cold right here.

 

 

-57 2m T in mountains of Montana...wow, but even more impressive -4 into Arkansas.

[buckeyefan1]

Cold Rain isn't so bad. We're about to have some warm rain soon. And quite a bit of it.

The models haven't lost the precip for mby so I still have hope  

 

Arctic front heading straight for us.  You get a boundary like that sitting on the gulf/SE coast, you'll have plenty of waves traveling up.  This is like 1899 type cold right here.

 

 

It just needs to sink about 200 miles to the southeast  

[NC_hailstorm]

Hmm...

We get a split at 30mb on the PV in la la land today,almost at 10mb.One piece comes right over Hudson Bay,PV looks to be under attack from both sides too.

 

Solar flux has been averaging around solar max and still into a +QBO for about 50 days,we'll see.

[franklin NCwx]

12z ggem has nice confluence like the gfs. Setting up for a big phase at day ten.

[DaculaWeather]

The friggin' Mother Load