Winter 2013-14 Pattern Discussion II

[metalicwx366]

There's a NEW ecmwf?

Probably talking about the most recent run and comparing it to the 0z run.

[Brick Tamland]

Robert is probably on to somwthing with the models being confused again. I would bet this system trends colder and further south, and the southern ridge will not be as storng. That hasbeen the pattern most if the time this winter. Looks like next week is going to be interesting, and I think folks should prepare and keep a close watch on this.

[superjames1992]

The 06z DGEX hammered the western half of NC. As you know, in order to get a Southeastern winter storm, we must have a weenie DGEX run, haha.

[BIG FROSTY]

The 06z DGEX hammered the western half of NC. As you know, in order to get a Southeastern winter storm, we must have a weenie DGEX run, haha.

I'll take and call it a good run!!!

[Tacoma]

Hmmm... (GSP Disco)

 

LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/  

 

AS OF 225 PM EST SAT...GOOD MODEL AGREEMENT IS HAD IN THE FIRST  

PORTION OF THE FCST. THE NW FLOW SN SHOULD BE TAPERING OFF RATHER  

QUICKLY WED NIGHT AS DRYING OCCURS IN THE H92/H85 LAYER ON THE FRONT  

END OF A DRY AND COLD ARCTIC AIRMASS. THERE SHOULDN/T BE TOO MUCH OF  

A SE/RN PUSH WITH THE ARCTIC FRONT OUTSIDE THE MTNS THU AS THE MEAN  

MLVL FLOW REMAINS SW/LY. THIS SHOULD CREATE A DISPARATE MAX  

TEMPERATURE REGIME ACROSS THE FA WITH THE MTN VALLEYS WARMING ABOUT  

5-8 DEGREES LESS THAN THE NON/MTNS. OVERALL...MAX TEMPS SHOULD BE  

HELD ABOUT 8-12 DEGREES BELOW NORMAL IN GOOD INSOLATION YET COLD  

N/LY SFC FLOW.  

 

UNCERTAINTY INCREASES IN THE FCST BEGINNING THU EVENING THROUGH THE  

PERIOD. THE 00Z GFS IS STILL A COLDER AND MORE DYNAMIC OUTLIER THAN  

THE CWM/ECMWF SOLNS AND THE MODEL HAS A VERY DIFFERENT ULVL  

CONFLUENT PATTERN OVER THE NE CONUS. THE GFS IS PRODUCING A MUCH  

STRONGER AND COLDER SFC HIGH THAN THE OTHER OP MODELS AS IT/S  

UPPER PATTERN INCLUDES AN UPSTREAM RIDGE BEHIND THE CONFLUENT ZONE.  

THE OTHER MODELS HAVE CYCLONIC FLOW IN THIS AREA...THUS THE GFS IS  

ABLE TO SUSTAIN STRONGER LLVL SUPPORT.  

 

A QUICK LOOK AT THE INCOMING 12Z ECMWF SHOWS THIS MODEL IS TRENDING  

TOWARD THE UPPER PATTERN OF THE GFS...BUT IT STILL HAS A WEAKER SFC  

LOW...ALBEIT IN A BETTER CAD POSITION BY 12Z FRI. SOUNDINGS ON THE  

GFS ARE SO COLD WITH THE CAD ONSET THAT THEY SHOW ALL SNOW FOR THE  

FIRST PART OF FRI CHANGING OVER THE -FZRA IN THE AFTERNOON ACROSS  

THE NRN ZONES. THE OLD ECMWF HAD ALL RAIN...WHILE THE NEW ECMWF  

SOUNDINGS ARE MUCH COLDER THROUGH H7. WITH SO MUCH CHANGE OCCURRING  

IN THE MODELS AND VARYING AVAILABLE MOISTURE DIFFERENCES ASSOCIATED  

WITH SFC CYCLOGENESIS...POPS HAVE BEEN LEFT IN THE CHANCE RANGE  

WITH A PUSH TOWARD THE HIGHER END. WILL STILL COUNT ON A STRONG WARM  

NOSE BUILDING IN FRI AND MAKING THE CASE FOR -FZRA AS THE STRONGER  

CAD SCENARIO LOOKS TO BE FAVORED ATTM. IT/S TOO EARLY TO SPECULATE ON  

QPF/ICE AMOUNTS AS THE LLVL MASS FIELDS/FLUXES HAVE LOW CONFIDENCE  

AND NEED TO BE FIGURED OUT...BUT THIS WILL BE A SYSTEM TO KEEP AN  

EYE ON FRI INTO SAT. 

please no warm nose.......what do we need to not have a ---------- warm nose,  this ruins our snow chances everytime.  but sometimes a warm nose is predicted but never gets that far north.  there has been times when the snow was to change to rain but never did.  it stayed snow the whole event and instead of 2 or 3 inches we had 9 or 10 inches. 

[SN_Lover]

The euro ensembles continue to reduce winter precip for the charlotte area and the 18z  GFS is a winter weather p-type to rain event for all NC.SC,GA. Don't bank on a miracle, because the warm nose WILL erode whatever CAD sets up.  

[mackerel_sky]

It's 7 days away, don't bank on anything at this point!

[SN_Lover]

It's 7 days away, don't bank on anything at this point!

The models are not pointing towards a system cutting from CO to NC anymore. It's a apps runner now. 

[CaryWx]

The models are not pointing towards a system cutting from CO to NC anymore. It's a apps runner now.

Really? "The models"? All of them?

[BullCityWx]

Really? "The models"? All of them?

I'm glad he figured it out almost a week out. Saves us all time!

[SN_Lover]

I'm glad he figured it out almost a week out. Saves us all time!

hey, if yall wanna wishcast. then go ahead. lol more power to you.  

[Tacoma]

The euro ensembles continue to reduce winter precip for the charlotte area and the 18z  GFS is a winter weather p-type to rain event for all NC.SC,GA. Don't bank on a miracle, because the warm nose WILL erode whatever CAD sets up.  

hey all we need are better trends which has happened numerous times.  I bank a lot on Robert and he is saying the storm track at this time of year is at its lowest or southern most dip and with whats going on in Canada should keep the storms on the southern route.     I HOPE HE'S RIGHT!

[SN_Lover]

hey all we need are better trends which has happened numerous times.  I bank a lot on Robert and he is saying the storm track at this time of year is at its lowest or southern most dip and with whats going on in Canada should keep the storms on the southern route.     I HOPE HE'S RIGHT!

These "storm tracks" are very arbitrary. If a longhorn low or Colorado low forms the low will go towards areas of PVA and WAA. Nothing to do with "storm tracks" or whatever that is. The models fall inline with that idea. 

[burgertime]

hey, if yall wanna wishcast. then go ahead. lol more power to you.  

 

You would have accused people of wishcasting 3 days ago when this looked like a Lakes Cutter if they said it was going to the Apps. 

On a serious note though 18z looked awfully bad for CAD regions. 1036 high floating around never really letting cold air lock in but if there is a strong high floating around someone is going to get some serious ZR with all that moisture. 

[SN_Lover]

You would have accused people of wishcasting 3 days ago when this looked like a Lakes Cutter if they said it was going to the Apps. 

On a serious note though 18z looked awfully bad for CAD regions. 1036 high floating around never really letting cold air lock in but if there is a strong high floating around someone is going to get some serious ZR with all that moisture. 

it's still going to the lakes? 

[burgertime]

it's still going to the lakes? 

 

I have no clue what this question means. 

[burrel2]

The euro ensembles continue to reduce winter precip for the charlotte area and the 18z  GFS is a winter weather p-type to rain event for all NC.SC,GA. Don't bank on a miracle, because the warm nose WILL erode whatever CAD sets up.  

 

 

You’re right.  CAD is always easily eroded by warm air aloft..... 

 

I bet I can guess our next lecture from you, “Model’s always over estimate trapped low level cold air in CAD events. Especially in the long range."

 

 

I don’t know who pissed in your cheerio’s, but you need to take a break from posting for a while.  It’s one thing to give reasoning why you think this event may end up as predominately rain. It’s another thing to declare it as fact 7 days in advance and mock anyone else who believes there is a possibility of a wintry outcome.

[CAD_Wedge_NC]

it's still going to the lakes? 

I don't know if you're asking us or telling us with that statement....... One thing that all of should have learned by now is that a 7 day forecast will change from what is being modeled. Sometimes it changes for the better and sometimes it changes for the worse. the thing we should take away from today's runs is that strong signal is being seen by the models for a storm in that time frame. As for the thermal profiles, it's anyone's guess. I for one will be watching the trends.

[GaffneyPeach]

You’re right. CAD is always easily eroded by warm air aloft.....

I bet I can guess our next lecture from you, “Model’s always over estimate trapped low level cold air in CAD events. Especially in the long range."

I don’t know who pissed in your cheerio’s, but you need to take a break from posting for a while. It’s one thing to give reasoning why you think this event may end up as predominately rain. It’s another thing to declare it as fact 7 days in advance and mock anyone else who believes there is a possibility of a wintry outcome.

Please...

[BullCityWx]

CAD events never trend colder, either.

[DixieBlizzard]

CAD events never trend colder, either.

 

Just ask Larry Cosgrove!

[SN_Lover]

You’re right.  CAD is always easily eroded by warm air aloft..... 

 

I bet I can guess our next lecture from you, “Model’s always over estimate trapped low level cold air in CAD events. Especially in the long range."

 

 

I don’t know who pissed in your cheerio’s, but you need to take a break from posting for a while.  It’s one thing to give reasoning why you think this event may end up as predominately rain. It’s another thing to declare it as fact 7 days in advance and mock anyone else who believes there is a possibility of a wintry outcome.

no doubt someone will see winter type precip, but the low's path currently modeled suggests that all winter precip will transition to a rain event for NC,SC,and GA. We will see if models trend the low to the coast like they did a few days ago. 

[burgertime]

Update on Friday 12z ECMWF

Our analysis of the last few days model runs concerning the flexing of the ridge in the SE, is that todays 12z ECMWF is on the right path indicating that the winter frozen precipitation activity will indeed be focused well north and west of North Carolina.

Let's watch the pattern together and have some fun seeing how February plays out and if it has a winter storm surprise in store for us.

 

 

When an event is imminent or in progress, the judgement of NWS GSP and RNK is highly valued and respected as they have superb skills in local guidance on winter events in Western North Carolina. You better have a sound reason to go against their guidance.

 

 

Hmm.....interesting! I know which one I am rooting for. Here is part of GSP's long term from the overnight:

 

MODELS DIVERGE CONSIDERABLY IN REGARDS TO P-TYPE...TIMING OF THE

ONSET OF PRECIP...AND THE MAGNITUDE OF CAD FRIDAY. THE GFS

INDICATES THAT A STRONG 1045+ MB HIGH WILL BUILD INTO THE NE STATES

BY FRI NIGHT AND UPGLIDE MOISTURE WILL OVERSPREAD THE REGION FRI

AFTERNOON IN RESPONSE TO SECONDARY SOUTHERN STREAM WAVE APPROACHING

FROM THE SW. MEANWHILE...THE ECMWF SUGGESTS THAT RELATIVELY WEAKER

1030 MB HIGH PRESSURE WILL BUILD INTO THE NE ON FRI WITH

ISENTROPIC INDUCED PRECIP SPREADING OVER THE AREA BY MIDDAY ON FRI.

THE COLDER GFS SCENARIO HINTS WINERY MIX WILL OCCUR (POSSIBLY A MIX

OF SNOW AND SLEET) ACROSS ENTIRE CWA FRI NIGHT INTO SAT MORNING. THE

WARMER ECMWF SUGGESTS SOLID LIQUID PRECIP WILL PERSIST THROUGHOUT

THE EVENT. GIVEN THE HIGH UNCERTAINTY...HAVE INHERITED LOW END

CHANCE OF RAIN ACROSS THE REGION WITH FREEZING RAIN HIGHLIGHTING

NORTH OF I-40 CORRIDOR EARLY FRI MORNING AND FRI NIGHT. IF MODELS

TREND COLDER ON FRI/SAT...WE MAY ENCOUNTER A SIGNIFICANT WINTER

STORM DURING THIS PERIOD.

 

 

Good read on next week's potential from  from Wright-Weather (Mike Dross)

 

http://blog.wright-weather.com/?p=762

 

 

Thanks for posting.

.

 

 

 

So you... *cough* I mean your "team". Was sure the SE ridge was going to flex and all winter precip would be north of NC. Yet GSP and a supposed met you really respect is saying winter precip in NC. Now that you have all those weighted do you still think the SE ridge flexes? 

[GaWx]

 Winter pretty much over mid-Feb. per Larry Cosgrove's hot off of the press weekly newletter:

 

"As stated in the previous section, it would appear that worst part of this winter season is behind us. When you compare the previous winters with a strong resemblance to the 2013-2014 DJF period, you will see a shift in the upper atmosphere away from the vigorous -EPO/-AO/-NAO ridge complexes seen in recent months. Semizonal flow and no high-latitude blocking always favor few cold deviations in the U.S., and the GGEM/ECMWF solution strongly implies much milder readings for most of the lower 48 states for the middle of February into March.

This is not to say that someone in the Intermountain Region or Upper Midwest could experience an Arctic intrusion (maybe a rogue snow/ice event)or two. But it is my belief that we are headed toward a fairly warm late February and March. The position of the cAk vortex in the 11 - 5 day period computer forecast is telling: retreat to the farthest reaches of Canada into Alaska. That is a warm teleconnection for those of you living below the Canadian border."

 

 Do others here agree or disagree with this forecast? To Larry's credit, he has been mainly cold up til now.

[Isopycnic]

Thanks for posting.

 

Mile Dross? LOL

[FoothillsNC]

This looks like the first good split in the flow this season really and the models are having a bad time getting the flow right past 72 hours. Already I see the 18z NAM has picked up on a very strong Polar S/w that drops across the Alaska ridge and drops across the NP and toward Hudson's Bay quickly. The latest NAM continues that idea and the 18z GFS started to look like NAM at 84, but then suddenly lost the strength of the wave once it gets east of Hudson Bay. Still at that time range, the difference between GFS and ECMWF are pretty strong. Euro wants no part of an eastern Canada Vortex, but GFS is heading that way strongly, probably because of how the models handle that Polar or Arctic Wave. It will be critical as to the formation of a central Canada closed high, and downstream eastern Canada vortex. That is a recipe for a damming high. The European also looks funny by moving a 1050 high from Montana to New York City in about 24 hours.  The 18z GFS tried to hold on to more surface high ridging in the Northeast on Saturday, but ends up breaking the main high out to sea, and a residual weaker high ridging from CAnada holding northeast winds in, but not as strong as true Classic CAD.  The models could be making a very big mistake at the surface, and since this is still so far out, I won't be surprised or really blame them if they do, but I think the models will soon start to trend more inland with more surface ridging for Friday Night and Saturday. Not to mention, they may be too late in the beginning stages of moisture return for east TX, LA, MS, AL, TN and GA ...by the tune of 12 to 18 hours.  As for snow, not much. The 850 will be borderline, some to start on the northern edge, say part of Ark, and TN, but quickly to something else late Friday. For the east of the mountains region, the CAD areas, this overall setup is a classic ICY one early Saturday, but I won't go full bore on it yet since we don't know if there truly will be a closed Canada Ridge and a 50/50 vortex. Right now, I think there will be one in place and I think there will be some ice to start even in northeast GA, but with time the heavy rain axis moves in and the ice line edges its way inland to the escarpment regions and into western Virginia. But if that high holds just a wee bit more and gets more enforced than even what I am thinking, then the damming will be even stronger than I think it could be. I'm a bit conservative this far out, but the potential on this event is pretty high. The progressive nature has been the saving grace for so long now, but a split type flow out west and middle Canada may create the right conditions to build that high in the Northeast and keep it inland, more than any models show right now. And if that does, and considering just how much snow cover will be on the ground about everywhere to our north by then, the cold air will be strong on northeast winds. By Thursday, much of the mid section and northeast will be snowcovered by the (then recent) snow storms.  Very little modification. It's been a while since a classic CAD occurred in VA, NC ,SC GA regions and this one definitely could be offering up that, atleast the first half of the event. I think eventually, the rains come in hard and 33 degrees for many, but that could be after a heck of a lot of ice damage. GFS has been showing a classic southwest to northeast QPF axis that is hard hitting and could reinforce the northeast winds at the surface. As always, models get rid of low level cold too quickly. Too early to guess that as far as micro climate forecasting goes, but that would be reserved for extreme western NC, VA next to the chain. Hopefully the main high does pull out just in time...who wants 1.50" qpf under 32 degrees with strong northeast winds?

Anyway , we'll soon see if the globals follow the NAM on that ridging in mid Canada and what the shape of the western cutoff will become over the weekend. I think the verdict is still out on the track of that cutoff. BTW, we're entering the time of year where cutoffs take the low road. sagging jet and the models won't capture that well yet. What a cold Winter this has been overall since late October.  And  now we enter February, which is always a climo time for the Southeast snow and ice threats best chances. Dont' trust the models beyond 7 days when they show long period of zonal flow across the US...they keep on reverting back to eastern troughing. Odds are still very high for one or more significant Winter type storms somewhere in the Southeast, regardless how the models look beyond 7 days. Very volatile. The cold just keeps on keeping on. For the record, I'm going with an above normal (warmer) March though.

 

 

[sparkync]

Great read Foothills, thank you sir.

[buckeyefan1]

This looks like the first good split in the flow this season really and the models are having a bad time getting the flow right past 72 hours. Already I see the 18z NAM has picked up on a very strong Polar S/w that drops across the Alaska ridge and drops across the NP and toward Hudson's Bay quickly. The latest NAM continues that idea and the 18z GFS started to look like NAM at 84, but then suddenly lost the strength of the wave once it gets east of Hudson Bay. Still at that time range, the difference between GFS and ECMWF are pretty strong. Euro wants no part of an eastern Canada Vortex, but GFS is heading that way strongly, probably because of how the models handle that Polar or Arctic Wave. It will be critical as to the formation of a central Canada closed high, and downstream eastern Canada vortex. That is a recipe for a damming high. The European also looks funny by moving a 1050 high from Montana to New York City in about 24 hours.  The 18z GFS tried to hold on to more surface high ridging in the Northeast on Saturday, but ends up breaking the main high out to sea, and a residual weaker high ridging from CAnada holding northeast winds in, but not as strong as true Classic CAD.  The models could be making a very big mistake at the surface, and since this is still so far out, I won't be surprised or really blame them if they do, but I think the models will soon start to trend more inland with more surface ridging for Friday Night and Saturday. Not to mention, they may be too late in the beginning stages of moisture return for east TX, LA, MS, AL, TN and GA ...by the tune of 12 to 18 hours.  As for snow, not much. The 850 will be borderline, some to start on the northern edge, say part of Ark, and TN, but quickly to something else late Friday. For the east of the mountains region, the CAD areas, this overall setup is a classic ICY one early Saturday, but I won't go full bore on it yet since we don't know if there truly will be a closed Canada Ridge and a 50/50 vortex. Right now, I think there will be one in place and I think there will be some ice to start even in northeast GA, but with time the heavy rain axis moves in and the ice line edges its way inland to the escarpment regions and into western Virginia. But if that high holds just a wee bit more and gets more enforced than even what I am thinking, then the damming will be even stronger than I think it could be. I'm a bit conservative this far out, but the potential on this event is pretty high. The progressive nature has been the saving grace for so long now, but a split type flow out west and middle Canada may create the right conditions to build that high in the Northeast and keep it inland, more than any models show right now. And if that does, and considering just how much snow cover will be on the ground about everywhere to our north by then, the cold air will be strong on northeast winds. By Thursday, much of the mid section and northeast will be snowcovered by the (then recent) snow storms.  Very little modification. It's been a while since a classic CAD occurred in VA, NC ,SC GA regions and this one definitely could be offering up that, atleast the first half of the event. I think eventually, the rains come in hard and 33 degrees for many, but that could be after a heck of a lot of ice damage. GFS has been showing a classic southwest to northeast QPF axis that is hard hitting and could reinforce the northeast winds at the surface. As always, models get rid of low level cold too quickly. Too early to guess that as far as micro climate forecasting goes, but that would be reserved for extreme western NC, VA next to the chain. Hopefully the main high does pull out just in time...who wants 1.50" qpf under 32 degrees with strong northeast winds?

Anyway , we'll soon see if the globals follow the NAM on that ridging in mid Canada and what the shape of the western cutoff will become over the weekend. I think the verdict is still out on the track of that cutoff. BTW, we're entering the time of year where cutoffs take the low road. sagging jet and the models won't capture that well yet. What a cold Winter this has been overall since late October.  And  now we enter February, which is always a climo time for the Southeast snow and ice threats best chances. Dont' trust the models beyond 7 days when they show long period of zonal flow across the US...they keep on reverting back to eastern troughing. Odds are still very high for one or more significant Winter type storms somewhere in the Southeast, regardless how the models look beyond 7 days. Very volatile. The cold just keeps on keeping on. For the record, I'm going with an above normal (warmer) March though.

GFSsaturdayMiddayconfluence.gif

GFSmishandledHighSaturday.gif

EuroDay7No50_50.gif

This post brought a smile to my face     Thanks for stopping by Robert    

[burgertime]

Out to 120 it looks like the GFS is going to have a different solution for next weekend compared to 18z. 

[FoothillsNC]

This post brought a smile to my face     Thanks for stopping by Robert  

The warm March lured you in   By the way, the incoming GFS sure is screaming that Arctic wave across the Pole. The NAM was onto something I guess. At 96 hours that vortex is really charging due south. That is bound to do something for the vortex in eastern Canada, which would have a big impact on the surface high eventually. We'll see.  The Arctic Highs this year have been something. This one is big again at 1050 or even bigger. Little nervous for NC, SC, VA next Fri/Sat.