January Pattern and Storm Discussion

[valkhorn]

There is a potential for major flooding in the SE in the next 5-10 days:

 

 

 

 

HYDROLOGIC OUTLOOKNATIONAL WEATHER SERVICE NASHVILLE TN330 PM CST TUE JAN 8 2013...WET PATTERN DEVELOPING FOR MIDDLE TENNESSEE...LOW PRESSURE OVER NORTHERN MEXICO WILL TRACK NORTHEAST TO THELOWER GREAT LAKES BY FRIDAY MORNING...LEAVING BEHIND IT A LARGEAREA OF HEAVY RAINFALL ACROSS THE LOWER MISSISSIPPI RIVER VALLEY.FOR MIDDLE TENNESSEE...ROUGHLY 1 TO 2 INCHES OF RAIN CAN BEEXPECTED FOR MOST AREAS...WITH THE HIGHEST AMOUNTS FALLING NEARTHE TENNESSEE RIVER. FLOODING IS NOT ANTICIPATED WITH THISPASSING LOW PRESSURE SYSTEM...BUT RUNOFF IS EXPECTED TO CAUSERISES IN AREA CREEKS AND STREAMS AND LEAVE THE GROUND NEARLYSATURATED FOR ADDITIONAL RAINFALL EXPECTED THROUGH NEXT WEEK.A DEEPENING TROUGH OVER THE WESTERN U.S. WILL ALLOW A SERIES OFSHORTWAVES TO TRACK ACROSS THE LOWER MISSISSIPPI RIVER AND OHIORIVER VALLEYS THROUGH TUESDAY. EACH OF THESE SYSTEMS HAS THEPOTENTIAL TO BRING A FEW INCHES OF RAIN TO THE MID-SOUTH...AND MAYLEAD TO FLOODING OF THE LARGER CREEKS AND RIVERS IN MIDDLETENNESSEE. THOSE WITH INTERESTS ALONG AREA WATERWAYS SHOULDMONITOR UPCOMING FORECASTS AND STATEMENTS FROM THE NATIONALWEATHER SERVICE THROUGH THIS WEEKEND.

 

 

Flash flood watches already popping up for a large part of the SE:

 

 

 

Frankly, this is a much more pressing issue than whether or not we get cold/snow at the end of January.

[valkhorn]

I'm not.  It is what it is, but we have a dearth of posters from TN, AL, and MS.  The map you posted does not demonstrate flooding rains for NC, SC, or GA (where ~85% of our active posters in this sub-forum reside).  Ergo, you don't see much activity regarding this particular flooding phenomenon.

 

I'm not discouraging talk of this subject.  I'm just offering an explanation which you seemed to desire.  In fact, to further the discussion, here's the 7-day precip forecast just released from HPC.  Their map seems to favor the heaviest rains (not quite as heavy as the 18Z GFS) staying to the western side of MS and centered in LA, but the eastern extent of the rainfall seems to mirror your 18Z GFS posting quite closely.

 

 

True. Point taken. This slug of moisture will eventually get into the Apps and East TN after day 7.

 

This is a general discussion thread so talk of the major flooding potential is warranted. Plus, I wouldn't trust the GFS much until all of this rain moves through after day 10. I'm surprised not many people who want a cold snowy pattern realize that the models will have a hard time until after this event takes place.

[metalicwx366]

I'm surprised there isn't a whole lot of discussion about the potential for flooding rains across much of the Southeast over the next 10 days:

Its because no one lives in those areas. Move that further east and Bam 20 pages!

[Mr Bob]

True. Point taken. This slug of moisture will eventually get into the Apps and East TN after day 7.

 

This is a general discussion thread so talk of the major flooding potential is warranted. Plus, I wouldn't trust the GFS much until all of this rain moves through after day 10. I'm surprised not many people who want a cold snowy pattern realize that the models will have a hard time until after this event takes place.

 

True but the Euro is not in agreement with as much rain as far east....Euro suggests the heaviest QPF is more in the South Central states...3-5" is not necessarily a huge deal in our neck of the woods this time of the year. The threat of a significant icing event and Arctic discharge is no less important.

[Jonesing for a chase]

Don't forget the fact that we have a major SSWE that is ALREADY underway...

 

Edit:  Is that something you or someone could check out for us using climate datasets (i.e. the % of winters where a major SSWE in the middle of winter led to significant pattern change across the eastern US)?  I think that would be very interesting to say the least.

 

Typhoon Tip has an interesting read on the SSWE on the New England forum.   The most interesting statement he makes is how the AO is forecast to go back significantly negative before the actual SSWE has ANY effect on the actual tropopause.  Should we interesting to watch unfold in the coming weeks.

[BullCityWx]

Another GFS run where the cold is here for 36 hours then hightails it out

[DixieBlizzard]

This winter reminds me a lot of Larry's analog of '93, particularly for January. I doubt there we be a blockbuster March like that year but it does go to show that there may be possibilities even later into the winter. I haven't given up hope but I sure wish there would be a taming of the Pacific and this SE ridge really needs to scoot over.

[valkhorn]

Another GFS run where the cold is here for 36 hours then hightails it out

 

It'll be hard to tell until this huge slug of rain moves out. The 00z GFS is changing the heavy rain to snow right as the cold air arrives and the moisture exits across TN though. Accumulation, if any, is very light.

[GaWx]

This winter reminds me a lot of Larry's analog of '93, particularly for January. I doubt there we be a blockbuster March like that year but it does go to show that there may be possibilities even later into the winter. I haven't given up hope but I sure wish there would be a taming of the Pacific and this SE ridge really needs to scoot over.

 

KATL:

 

2012-3: lowest winter to date (and probably at least through 1/20) 30 F

 

1992-3: Lowest temp. winter to date through 2/17: 29 F; 19F on 2/19;  no measurable snow til blizzard/4"+ snow on 3/13; 18 F (coldest of winter) on 3/14

 

 Per six analogs (coldest winter to date 26F+ through 1/20), this kind of thing is very believable except there being an actual blizzard/Storm of Century.

[GaWx]

The 0Z Euro is quite disappointing vs. the 12Z Euro. The wait til 1/20 at the very least for any chance for strong cold or wintry precip. for most is suggested . No ZR storm (or snowstorm ) is even close on this run. Of course, that was totally expected

[FallsLake]

The 6z GFS is really bad. It would indicate that we do cool down at about day 8 or 9 (slighty below or even just normal) but quickly go back to a warm pattern. Actually could be as warm or warmer than the one we're going into now. It shows no hope in the LR. Is it right... I don't know. This is a case where the indicies were looking great and it still might not work out.   

[Mr Bob]

The 0Z Euro is quite disappointing vs. the 12Z Euro. The wait til 1/20 at the very least for any chance for strong cold or wintry precip. for most is suggested . No ZR storm (or snowstorm ) is even close on this run. Of course, that was totally expected

 

Yup...12Z giveth...00Z taketh away....thus the folly of Day 10 operational model forecasting...

[Tacoma]

Another GFS run where the cold is here for 36 hours then hightails it out

this is the story of our winter, gets cold but doesn't stick around much then we'll have a snowstorm 300 hrs. out and then the next couple of runs the storm is gone and it warms up.  I sure hope this winter changes or it will be as bad as last winter.

[Cold Rain]

Just from intermittent observation over the last couple of years, the MJO forecasts seem to lose skill in the LR. Of course, it's no surprise that a model forecast plot loses skill in the LR, but it seems like the MJO forecasts can be really bad. I've also observed the models killing waves too quickly, especially if it a stronger one. It's all anecdotal, so it's not going to carry any weight in sort of scientific discussion. But that's why I'm not too pessimistic about what the models are showing.

Also, the MJO is only one factor...granted, it's one you'd like to have on your side, but it's just one of many factors that can get us cold.

As I suspected, there seems to be a little more support today for the MJO making it farther into phase 7 than we saw yesterday. Doesn't mean it will get there, but it looks a little better than yesterday's progs.

[BristowWx]

Remember, the only thing that verifies 100 percent of the time is a map of what happened...the day after. 

that's true...12Z runs could be epic...but most of us are so jaded that it won't matter much...the only thing to consider is how often to we have a much above normal DJF...can't imagine the we are wall to wall warm until spring

[Jon]

Looks like another 240 hour fail. Why do we even bother looking at the models more than 5 days out? They never get anything right in regards to winter weather here when it is more than a couple of days away.

 

It's about trends. Whenever in a warm spell when we want the cold to come back, I don't look at images of particular models. I look at the comparison teleconnections on Allan's site of the ensembles and operationals and other medium range forecasting tools. Looking at images 240 hours out will only disappoint.

 

MJO moving into phase 7 for a number of days is shown on many models. It looks as if it's going to stay either in phase 6, on the 6/7 border or into 7 or into 8, no one knows for sure, but it doesn't look all too bad considering we are in phase 5 right now. I can see us stalling in phase 7 or maybe making it to 8 by Feb. Keep in mind these MJO images are only progged til Jan 22nd...we are still early and these should still trend for the better, assuming the pattern is changing, toward the 20th.

 

GFS Ensemble

 

Euro OP

 

UKMET OP

 

CMC Ensemble

 

JMA Ens

 

You get the point. Just because it's spinning around in 6/7 or 7 doesn't mean that will really happen. I hope that goes without saying for most.

[packbacker]

There is still huge spread in the AO/NAO ensembles, which is why we will see run to run flip flopping for several more days. The mean is negative which is good.

[tnweathernut]

"Brutal Coldwave Headed for the US" is an article by accuweather today.  They could easily be overplaying it, but the potential is there.  I have thought for several days that Jan 20th, give or take a day or two is when we begin a much colder regime.........

 

Joe Lundberg is one I really pay attention to as he is normally very conservative.  Here is a quote in that article

 

 

Expert Senior Meteorologist Joe Lundberg added, "While a zone of high pressure off the southern Atlantic coast will offer some resistance to the cold initially in the East, most of the time in situations like this, cold air finishes the job and reaches the Atlantic Seaboard."

 

and a link to the article itself:  http://www.accuweather.com/en/weather-news/brutal-cold-waves-could-reach-us/3586088

[burgertime]

12z GFS is just "blah" so far. It looked like it might have potential just after truncation but it craps the bed. That SE ridge is just killer.  Oh well on to the next run. 

[Bevo]

There is still huge spread in the AO/NAO ensembles, which is why we will see run to run flip flopping for several more days. The mean is negative which is good.

 

pack - I've come to enjoy your posts more and more...

 

Now to Brick - as has been explained to you more times than the number of your posts that state the same thing, you cannot live and die in 4-6 hour increments or by each model run.  It is only by recognizing trends in the pattern that you have a shot at understanding the direction of the pattern.

 

We are always in a weather pattern.  There is never a time when we are not.  The reason I look at models runs is an attempt to decipher what features are common denominators within the pattern.  If they show up in some form or fashion over a number of runs without departing too far from one another, they become trends.  There is a reason that different run times tend to produce odd balls and different solutions, but overall you are looking for the similarities.  Therefore, at medium to longer ranges it is necessary to examine the individual runs - not forecast by them. 

 

If you remember back about two weeks ago, a 12Z (I believe) GFS run suddenly threw a big, glossy High out there.  It was very pretty, and sparked a little excitement.  However, it was a new feature to the established trends running up to that moment.  Therefore, I nudged it aside as potential - it had to prove itself worthy of becoming a trend by showing up consistently (in some fashion) throughout subsequent runs.  In this example, the trends were obviously correct.  That High walked on stage for a couple of acts, then disappeared back to being an understudy. 

 

With our current pattern, the only thing we can do is look for those trends in the LR to determine if they remain viable or if they dissipate.  In my meager opinion, the most dominate trend of winter has been the inability for the long and medium range guidance to overcome the runaway train PAC and produce solid conclusions beyond 5 days (and that is pushing it).

[wxgeek]

According to the models now, the only way I am going to get any cold air is if I leave the freezer door open too long.  The 12Z seems to really be

backing out of the artic plunge.

[GaWx]

 12Z GFS, taken literally fwiw, says KATL's Jan.2013 would have a shot at a 50+ F month and that the SE in general would have a shot at a top ten warmest Jan. The good news is that IF that were to verify, March would be looking more promising for the SE...that's no joke. The warm Dec/Jan. analogs are emphatic about this.

[wxgeek]

The GFS 12Z is so radically different from 24 hours ago.  It will be interesting to see if the 12 Euro shows such

a swing.

[GaStorm]

The MJO will be crucial as others alluded to for driving the pattern. If we can get to phase 8 and then phase 1 and 2 by February I would expect good things.

[Snowless in Carrollton]

 12Z GFS, taken literally fwiw, says KATL's Jan.2013 would have a shot at a 50+ F month and that the SE in general would have a shot at a top ten warmest Jan. The good news is that IF that were to verify, March would be looking more promising for the SE...that's no joke. The warm Dec/Jan. analogs are emphatic about this.

 

That would be unfortunate if things don't look promising until March. By then, the sun angle is about the same as it is in October and it becomes extremely difficult for snow to stick if it does snow. There's nothing worse than daytime snow in March.

[GaWx]

That would be unfortunate if things don't look promising until March. By then, the sun angle is about the same as it is in October and it becomes extremely difficult for snow to stick if it does snow. There's nothing worse than daytime snow in March.

 

1) It would be better than a warm March (assuming you like cold) and would definitely be more exciting for the BB.

 

2) I think that worry is way overdone. 7.9" of it stuck in 3/1983 and 8-10"+ stuck on the northside on 3/13/1993. ~3" stuck on 3/2/1980, ~4" in 3/1960 and 3/1924, etc..

 

3) Who cares if it melts more rapidly? Let's see if we can get some first.

[jmundie]

The biggest difference in the GFS is the handling of the s/w in the southwest. That cut off low allows the northern stream to rush by.

All of us need that thing to get underneath the trough and phase, which should ramp up the nao block and will dump the real cold down into the southeast.

If the energy cuts of in the southwest, new england will get the brunt of the cold, and maybe only the upper south has a chance at winter event... but more likely kentucky and the ohio valley.

[burrel2]

That would be unfortunate if things don't look promising until March. By then, the sun angle is about the same as it is in October and it becomes extremely difficult for snow to stick if it does snow. There's nothing worse than daytime snow in March.

I'll take daytime snow in march vs no snow all winter.

[burgertime]

Well on a positive note the GFS ENS Mean is colder out in the LR at least out to 192. 

[packfan98]

Well on a positive note the GFS ENS Mean is colder out in the LR at least out to 192. 

 

http://raleighwx.americanwx.com/models/gfsensemble/12zgfsensemblep12240.gif

 

I'll take this look from hr 240