Winter 2013-14 Pattern Discussion

[Jon]

I don't like the pattern we are about to find ourselves in. We have had good enough cold for winter weather thus far and plenty of moisture. WNC dodged a few ice storms already by a degree. Now it looks like dry cold for Jan. CPC has the entire Gulf coast from Texas to Florida with a +40% chance of below normal precip for the month of January. But......I have seen a lot of cases where the arctic air begins to leave we can sometimes squeeze in a winter weather event before its gone and out near the tail end of things.

 

 

EXTENDED FORECAST DISCUSSION

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1046 AM EST WED DEC 25 2013

BEFORE THE ARCTIC ONSLAUGHT, ONE MORE JUICY WAVE SHOULD SPREAD

RAIN THROUGH THE GULF STATES, SOUTHEAST, AND COASTAL ATLANTIC

DURING THE FIRST HALF OF THE FORECAST. BY DAYS 6 AND 7, THE WEST

SHOULD SEE BUILDING HEIGHTS WHILE CONTINENTAL AIR FLOODS THE

EAST--SHUTTING DOWN OCEAN-FUELED PRECIPITATION FOR A WHILE.

CISCO

No, it doesn't look like "dry cold air for Jan"  and the CPC made that forecast on the 19th, I doubt they had much confidence.

 

"THERE ARE CONFLICTING INDICATIONS FOR CLIMATIC ANOMALIES OVER THE UNITED STATES

FOR THE JANUARY OUTLOOK. THIS OUTLOOK IS BASED IN LARGE PART ON ENSO-NEUTRAL

CONDITIONS, PROBABILISTIC FORECASTS FROM THE CFS, NMME, IMME, AND LONG TERM

TRENDS. THE MJO HAS BEEN GENERALLY WEAK AND THERE IS HIGH UNCERTAINTY IN ITS

FUTURE EVOLUTION."

 

Also it's not going to be an ICE BOX the entire month, it will retreat, come back, etc...it will be fluid. There will be plenty of chances for some moisture from the gulf if we get into some of the setups the models have been showing.

 

Second, you do realize what you bolded is only valid for 5 days and more specifically, only until January 1st? Most of what we're talking about is occurring after the period noted by that AFD.

 

EXTENDED FORECAST DISCUSSION

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1046 AM EST WED DEC 25 2013

VALID 12Z SAT DEC 28 2013 - 12Z WED JAN 01 2014

[Cold Rain]

Agreed, although it's not a great pattern for a 6"+ event I think we can get a 1-2" type of event, we have seen the models the past few days (Euro/GFS) give something close to that, I just want something that will whiten the ground, I haven't seen that here at my house since 3 years ago tonight.

Yep, it'll be much easier to squeak out a sloppy inch or two than get a blockbuster in this pattern. But like Jon said, we can always route for the underdog!

[bobbitt]

am shocked no one showed the fantasy gfs 18 today for jan2? it showed nc snow, the threat is still there .

[SnowGoose69]

True, the past 20 years here in RDU we are at our lowest 20 year average in the past 120 years, which means it must start ticking up, eventually.  For all the griping we do (RDU folks), in the past 15 years ( since 99/2000) we have had 6"+ events in 6 of those years, on average we typically average a 6"+ event every 2-3 years, which is right on average, it's the skunk years that have killed our averages.

 

Not surprising, the snowfall in the SE U.S. tends to dip during highly active Atlantic hurricane periods, this is not necessarily a largely known fact but its generally true, why that occurs I don't know, but you look back at some of the snow events in the SE U.S. from 1970-1994 or so when the Atlantic was largely in an inactive quiet phase and compare it to 1995-2013 and 1940-1965 you'll see that the latter two periods were markedly less snowy in the region for many locales vs. that 1970-1994 period and the funny thing is that period was perhaps one of the biggest snow drought 25 year periods ever up in the Northeast U.S.

[HKY18]

Eventually we are going to have to pay up for our wet year. Just like how we paid up for our snowy season a few years back.

The atmosphere doesn't remember ****! In the long term averages usually do work themselves out, but not because we are "paying" for anything. It's simply because the atmospheric variables at the time allow for wet, dry, cold, or warm.

[CAD_Wedge_NC]

am shocked no one showed the fantasy gfs 18 today for jan2? it showed nc snow, the threat is still there .

 

We've been talking about it all evening.

[Shawn]

The atmosphere doesn't remember ****! In the long term averages usually do work themselves out, but not because we are "paying" for anything. It's simply because the atmospheric variables at the time allow for wet, dry, cold, or warm.

 

Reading into analogs and other's mets opinions such as SnowGoose69 above; I really think that a pattern in one part of a season or set of years can ultimately help make an accurate longer range forecast.  Nothing seems to ever be perfect in long range forecasting due to so many variables, but the indicators are sometimes too accurate to just discount.

 

Now, your point about "paying" for a previous month, year, or last couple of years storms is right.  Weather does what it wants to, although It's still much easier to forecast in the longer range based on previous events in recent history.

 

Now, I'm not a long range forecaster or anything.  Just read lots of blog and forums.

[CAD_Wedge_NC]

Eventually we are going to have to pay up for our wet year. Just like how we paid up for our snowy season a few years back. Let's hope this cycle does not start in the heart of winter going into Spring. That would suck for the new year and we would probably end up with a drought in the summer. Which is predicted by the way for most here save central and western NC...based on the CPC.

The atmosphere doesn't work like that. However, Climo has a way of balancing things out when the abnormal occurs.

[HKY18]

Reading into analogs and other's mets opinions such as SnowGoose69 above; I really think that a pattern in one part of a season or set of years can ultimately help make an accurate longer range forecast.  Nothing seems to ever be perfect in long range forecasting due to so many variables, but the indicators are sometimes too accurate to just discount.

 

Now, your point about "paying" for a previous month, year, or last couple of years storms is right.  Weather does what it wants to, although It's still much easier to forecast in the longer range based on previous events in recent history.

 

Now, I'm not a long range forecaster or anything.  Just read lots of blog and forums.

Oh yes I totally agree. The atmosphere obviously never repeats the exact same event, but certain tendency's can be recognized. And using analog years is an important part of forecasting at greater lead times.

[WidreMann]

The atmosphere doesn't work like that. However, Climo has a way of balancing things out when the abnormal occurs.

Climo doesn't work that way either. Climo is a statistical snapshot over a short period of time of the underlying probabilities inherent in the multitude of meteorological mechanisms that produce sensible weather. The weather doesn't tend towards average because of some law of averages, it tends that way because the range results produced by these mechanisms mostly fall around what we call average. Or rather, we call it average because that's what these mechanisms tend to produce.

[POWERSTROKE]

Eventually we are going to have to pay up for our wet year. Just like how we paid up for our snowy season a few years back. Let's hope this cycle does not start in the heart of winter going into Spring. That would suck for the new year and we would probably end up with a drought in the summer. Which is predicted by the way for most here save central and western NC...based on the CPC.

It was suppose to be a hot dry summer this year too and that didn't happen. I agree if its raining a lot now it will be dry in summer most of the time but not always

[Bevo]

You don't pay for snow with no snow. The debt for rain is not no rain. That's silly.

 

In fact, if any actual relationship exists, it would be like compounding interest. Rain begets rain. Drought begets drought. There is no opposite/equal reaction here.

 

There is no debt anyway. Fat years and lean years happen all the time, and long-term trends skew the averages meaning that even in the long-haul, we may never get "repaid".

 

This.

[packbacker]

Not surprising, the snowfall in the SE U.S. tends to dip during highly active Atlantic hurricane periods, this is not necessarily a largely known fact but its generally true, why that occurs I don't know, but you look back at some of the snow events in the SE U.S. from 1970-1994 or so when the Atlantic was largely in an inactive quiet phase and compare it to 1995-2013 and 1940-1965 you'll see that the latter two periods were markedly less snowy in the region for many locales vs. that 1970-1994 period and the funny thing is that period was perhaps one of the biggest snow drought 25 year periods ever up in the Northeast U.S.

Thanks for the insight! I have never heard of that correlation, which isn't saying much though. I haven't looked at the numbers in a while but I want to say the during the late 80's was when RDU had its highest 20 year average which goes with exactly what your saying. This is good news for us as this past hurricane season was very quiet :-)

[Shawn]

Well on this aspect of climo and patterns...  We have words like "El Nino" and "La Nina" for a reason.  Whichever pattern we are in based on those two words has proven to produce or not produce many times here in the SE (not just winter weather).  More words/names can be added later on as weather knowledge evolves and past weather events/averages can be proven indicators, etc.

[griteater]

A case can be made that the upcoming pattern is better for snow than the one we've been in. But it's not really a great winter storm pattern for us yet. Perfect timing can occur, and we can get a good storm, but it's not a perfect pattern. Still, there are a few windows over the next couple of weeks worth watching, and that's about all you can say at this point. And that's not really saying all that much.

Agreed, although it's not a great pattern for a 6"+ event I think we can get a 1-2" type of event, we have seen the models the past few days (Euro/GFS) give something close to that, I just want something that will whiten the ground, I haven't seen that here at my house since 3 years ago tonight.

 

These are a good summation of where we are.  The 18z GFS is the type of system that bests fits the pattern if one were to work out...a weakish northern stream wave diving out of the Pacific Northwest into an eastern U.S. trough.  

 

A similar analog example is Jan 16-17, 2003:

http://www.meteo.psu.edu/~fxg1/NARR/2003/us0115.php

http://www.meteo.psu.edu/~fxg1/NARR/2003/us0116.php

http://www.meteo.psu.edu/~fxg1/NARR/2003/us0117.php

 

You'd like to see sharper ridging out west than what is currently showing up.

[dsaur]

Yep, and what happens when Iceland erupts with a major, or Krakatoa goes off again?  Or the rock from the Ort cloud visits? Who pays for that weatherwise?  When it's been super warm for a decade, and suddenly we've got year round winter.  About the only thing the weather owes humans is a swift kick in the butt, if they don't pay attention T

[SN_Lover]

I don't like the pattern we are about to find ourselves in. We have had good enough cold for winter weather thus far and plenty of moisture. WNC dodged a few ice storms already by a degree. Now it looks like dry cold for Jan. CPC has the entire Gulf coast from Texas to Florida with a +40% chance of below normal precip for the month of January. But......I have seen a lot of cases where the arctic air begins to leave we can sometimes squeeze in a winter weather event before its gone and out near the tail end of things.

 

 

EXTENDED FORECAST DISCUSSION

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1046 AM EST WED DEC 25 2013

BEFORE THE ARCTIC ONSLAUGHT, ONE MORE JUICY WAVE SHOULD SPREAD

RAIN THROUGH THE GULF STATES, SOUTHEAST, AND COASTAL ATLANTIC

DURING THE FIRST HALF OF THE FORECAST. BY DAYS 6 AND 7, THE WEST

SHOULD SEE BUILDING HEIGHTS WHILE CONTINENTAL AIR FLOODS THE

EAST--SHUTTING DOWN OCEAN-FUELED PRECIPITATION FOR A WHILE.

CISCO

As I said before. Troughs have nasty consequences. haha

[Shawn]

I think some of us are getting a tad bit off topic.  I am a culprit and I apologize for my part in it.

 

With that said, back to more of a meteo deal.. the 00z NAM finally removed most of the moisture for many in the ice prone areas for the morning.  Looks like coastal sc does alright with some light rain though.

 

Longer in the period, I am definitely a fan of many GFS runs that have come out over the last little bit.  While we are still looking at an overall timing regime, I am definitely happy that cold is close by along with an active storm pattern at the same time even showing up.  Many of us will end up rain, especially in the deep South.. but someone can squeak at least a nice 2-4 inch snow event out before the pattern gets bad again.  Feb is the best month for the deep south like my back yard, and while I feel like we could possibly be cold, I'm still not too amped up on much working out for us this far South.

 

I went back to the old board and searched for the old Feb 12-13th 2010 threat that turned into an actual storm for SC.  The coolest part about that thread is how it started off slow showing no precip for many and ended up getting most of GA,SC, and a good chunk of NC when everything finally verified.  It's always good to go back and read how the forum postings go on during bigger events like that (at least for mby) and watch how much the models really do shift around in or out of favor for us.

[griteater]

I don't like the pattern we are about to find ourselves in. We have had good enough cold for winter weather thus far and plenty of moisture. WNC dodged a few ice storms already by a degree. Now it looks like dry cold for Jan.

 

Today was the first day in Nov or Dec in which Charlotte's high temperature was less than 40 degrees.  Hard to have wintry precip with those kind of temperatures.

[BullCityWx]

Today was the first day in which Charlotte's high temperature was less than 40 degrees. Hard to have wintry precip with those kind of temperatures.

Yep.

[Shawn]

Today was the first day in Nov or Dec in which Charlotte's high temperature was less than 40 degrees.  Hard to have wintry precip with those kind of temperatures.

 

Aren't we looking forward to Jan already though?  Pretty much throwing everything else out and seeing the colder temps fall into the area around a week - week 1/2 out?  December died a while back I thought, although the 30-31st has shown up quite a few times on the GFS especially as having a Wintry possibility for some.

 

I think QueenCityWX had a good thread going on with areas being above normal possibly, and I agree with that for December surely for almost everyone especially as those 80F+ 2 days came through to bump temps up a bit down my way.

[metalicwx366]

u keep saying there no pattern change coming ? when u wrong what will be your excuse?

You said no SE ridge this winter.

[Berlin1926]

Thanks for the insight! I have never heard of that correlation, which isn't saying much though. I haven't looked at the numbers in a while but I want to say the during the late 80's was when RDU had its highest 20 year average which goes with exactly what your saying. This is good news for us as this past hurricane season was very quiet :-)

Two of the snowiest winters were 1996 and 2000?

[NCCatawba]

Not surprising, the snowfall in the SE U.S. tends to dip during highly active Atlantic hurricane periods, this is not necessarily a largely known fact but its generally true, why that occurs I don't know

 

It would make sense if we have an active season in the Gulf of Mexico or off the East Coast we would see a reduction in "fuel" or water temps for our storm systems resulting in a deduction in the amount of precip.

 

Maybe the low action in the Gulf of Mexico is to blame for our wet spells this year....or at least enhances the Subtropical Jet Stream with even more moisture?

 

Maybe it's not always true because of how we define active seasons. This year had 14 named storms which I believe is above average. But strength and location is more important to defining an "active season" by most...and obviously more important for seeking out this correlation to the US... if any.

[griteater]

Aren't we looking forward to Jan already though?  Pretty much throwing everything else out and seeing the colder temps fall into the area around a week - week 1/2 out?  December died a while back I thought, although the 30-31st has shown up quite a few times on the GFS especially as having a Wintry Possibility.

 

I think QueenCityWX had a good thread going on with areas being above normal possibly, and I agree with that for December surely for almost everyone especially as those 80F+ 2 days came through to bump temps up a bit down my way.

 

A lot of things are being discussed from volcanoes to hurricanes..  The point was made that it's been cold enough for winter weather thus far...by in large that hasn't been then case in most areas.

[packbacker]

Two of the snowiest winters were 1996 and 2000?

Yep, and 2004. In 2002 we had a 10"+ event, it's the years in between where we get an inch or less that brings our averages down. Also, it's been since 2004 since we had over 10" in a season, which is our longest stretch ever I believe. We typically average 3 10"+ seasons every 10 years.

[Cold Rain]

The Posting Intensity Index has ticked up to slightly into positive territory, so that's a good sign.

[Marion_NC_WX]

The Posting Intensity Index has ticked up to slightly into positive territory, so that's a good sign.

 

 

I'm sure Bastardi will have that in his video tomorrow...

[Cold Rain]

I'm sure Bastardi will have that in his video tomorrow...

Ha! It'll probably be about as useful as his stratosphere maps.

[burgertime]

00z GFS continues with the weak disturbance coming through NC. Drops roughly around .20 or so with cold enough air aloft for snow. SFC temps aren't really there but that can be worried about sooner. Timing is sure to change on this system.