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Dry, Cool Fall...But What's Next


FoothillsNC

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Overall, for most of the Southeast it has been a cool Fall, following a HOT year overall, so nothing will change the fact this will probably be one of the warmest years on record nationwide (although Southeast has seemed to mostly lean toward "less warm" relative to the rest of the country, especially Summer and Fall when you average out the numbers. Here's a look at October rankings, and I think November will come in either at or slightly below normal for many in the Southeast as well. There have been quite a few cold fronts as the trough has been in the East a while now, especially following Sandy.

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Next up, the precip. All the northwest flow and lack of Gulf taps has made for a dry Georgia and Carolinas especially, but Sandy brought substantial to heavy rains to eastern NC and much of VA. But mostly, what's been going on , has been going on all year long, that is wetter on the West side of the Apps than east. This last front was just another example of the moisture completely drying up in eastern GA to most of the Carolinas, but did have enough lift and dynamics west of the Apps in Tennessee Valley. Less than 8" fell in most of Carolinas, southern VA, Georgia for the 3 month period.

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Here's a look at 90 day departures. As you can see, most have been below normal, except parts of TN Valley (Ky, Tn, Al)

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The yearly departures all paint a dry picture for most of the South and East. Here's a breakdown of various cities: (strong departures in Red or Green--Notice Tropical systems helped some areas)

Georgia

Atlanta -14.41"

Athens -10.83"

Columbus -12.17"

Macon -13.82"

Savannah -6.54"

Augusta -2.43"

Valdosta -7.20"

South Carolina

Columbia -1.93"

Florence -2.20"

Charleston -7.34"

Greeville-Spa -9.74"

North Carolina

Fayettevile -4.95"

Greensboro -4.95"

Raleigh -2.21"

Elizabeth City .08"

New Bern -1.44"

Wilmington -7.89"

Asheville -1.42"

Charlotte -8.30"

Virginia

Norfolk .82"

Richmond -6.42"

Wallops Isl. 7.97"

Blacksburg -3.62"

Roanoke -7.75"

Charlottesville -5.56"

West Virginia

Bluefield 3.85"

Elkins -0.29"

Charleston -3.89"

Parkersburg -1.31"

Tennessee

Memphis -5.31"

Jackson -9.91"

Nashville -1.56"

Chattanooga -1.98"

Knoxville 4.42"

Tri-Cities 4.75"

Mississippi

Tupelo -5.65"

Greenwood -8.85"

Jackson 12.20"

Meridian 2.96"

Alabama

Mobile 4.15"

Huntsville -2.72"

Birmingham -6.03"

Montgomery -11.43"

Kentucky

Lexington -4.91"

Frankfort -6.75"

Louisville -2.74"

Jackson 1.59"

Paducah -18.02"

Louisiana

New Orleans 6.25"

Baton Rouge 0.96"

Lake Charles 14.67"

Alexandria -1.29"

Shreveport -0.30"

Monroe 3.49"

Arkansas

Little Rock -7.74"

Pine Bluff -4.85"

Texas

Dallas-Ft Worth -4.13"

Waco -0.23"

Victoria -12.05"

Laredo -9.92"

Corpus Christi -11.05"

Houston -6.26"

Florida

Miami 26.49"

Naples -14.16"

Melbourne -11.69"

Orlando -8.17"

Jacksonville 1.67"

Tallahassee 0.98"

Key West 8.88"

What's up next, with Winter Approaching?

A warm start will begin Meteorological Winter, with a western trough and ridging beginning in the East. Temps could reach 70s in Texas to central Ga to eastern NC by Sunday and Monday, and maybe Tuesday if high clouds aren't too thick. So some 10 to 15 degree above average air is coming, but no rain. Already the next front looks to do exactly like the last few, which is drop some rain in the Tenn. Valley but probably not much east of the Apps, atleast for NC, SC, GA and FL regions...dynamics peter out. Meanwhile out west, they will be slammed on the northern and central coast of California and points north, with high mountain snow of FEET, with flooding at the PAC NW coast.

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On my website, I noted that the models were probably too fast in cooling the East with severe cold, and as you know they've all backed down from the super strong NAO pattern. This is a result of a warring regime of -PDO and -NAO fighting each other. This also helps keep the Southeast from being "too warm" for too long. Those indices produce enough troughing out west, yet also allow no ridging in the Southeast, so this isn't a case of what happened last year. Have you noticed so far the warm ups in November never really amounted to much in the Southeast? Thats because troughs had a tendency to dig more along the Northeast coast, which brought northwest flow, so that helped squelch any warm ups.

Now we are truly about to get into a hard core western trough, so that will allow the next mid week front to bring up warmer air, much more than seen recently, hence the warmup the next few days.

But I also noted on my website that we are approaching a stepping down or retrograding pattern, and I still see that. The GFS has over the last week been showing this in general, with this next front, then another, then another front. Each one dropping a little more south than the preceeding one. And at this point, the cold air will be tremendous in Canada and Alaska, so as the main trough (Gulf of Alaska low) retrogrades over the next 7 to 10 days, this will bring shortwaves into the Rockies, then the Plains. And within 7 to 10 days now, there will be some serious Arctic Air coming into the northern Rockies and northern Plains and all over western and central Canada.

Look how snowpacked Canada is to become (GFS) as there will be system after system laying down snowpack. With the shortening days, cold air is going to lock in, and there's not exactly zonal flow in Canada, thanks to some weak -NAO, so the cold is going to build. (snow cover day 1, day 10, day 15)

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The CPC has recently released a Winter Outlook that highlights Tenn. Valley with above normal precip, and I'm not surprised. That area has been a max zone (until recently) and I think it returns this Winter. This also lines up with what I have been thinking for most of last Summer and this Fall for an area for above normal snowfall and probably below normal temps...roughly the Tenn. Valley to Apps to MidAtlantic region.

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The first real round of True Arctic air is probably less than 10 days away for the northern tier of states, with both the ECMWF ensembles and operational showing a weak PNA+ pattern and downstream trough digging into the Rockies. Slight neg NAO as well, so this will combat Southeast ridging (unlike what we saw last year--when there was no -NAO)

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The next question is "how do you know the trough doesn't unload totally out West"? Already GFS and ECMWF tried to do just that 2 weeks ago, and it never happened. But it is about to happen, esp. Northwest. This goes back to the warring factions of -NAO and -PDO, but now we're seeing the westerlies drop more southward, as they should since we're entering that time frame. It could mostly out west and some runs have done just that, but they seem to always correct themselves the next run. Same thing for the runs that show extreme Eastern Trough and western Ridge....they correct themselves soon.

This probably argues for generally speaking, a supressed flow, instead of one regime dominating the other. Very cold Canada, stepping down to moderately cold northern tier and bouts of below and above normal in the Southeast next 2 weeks. But there is one strong possibility that could occur, that I'm a little nervous of, and that's a strong Arctic Outbreak in the Plains.

Tropical Storm/Typhoon Bopha in the Pacific may add energy to the retrograding Gulf of Alaska low, which ***could** help pump up more ridging than shown by models around day 10 out west. If that happens, which is a totally risky *IF*, that would dislodge a giant chunk of Arctic air (abetted by 1050mb HIGH) and bring it down into the US. I don't know if that will happen around day 10 or beyond but it's a possibility.

Regardless, I do see a general pick up in storminess (which is normal for December) across the nation and colder and colder for the northern half, and there's the chance that with these dueling indices, the Arctic Front lays down in the South somewhere by mid month of so. And if that happens, we'll atleast get rains. North of the front will deal with Wintry precip patterns. I also think the NAO and AO goes toward more negative as time goes along in December, so with some lag time effects, those effects will be felt in the TN Valley (and Southeast) with cold air and increasing moisture. Some of the models like CFSv2 and Beijing Model like the idea of high latitude blocking ruling this Winter (CFS is back and forth)...so this could just be a volatile Winter with no ruling pattern. I've noticed 9 or so major blocking regimes in Canada and Greenland since late last Spring and into the current timeframe, whereas NONE or nearly none last Winter. So obviously if that continues to repeat, I'm absolutely positive Wintry Precip is coming to parts of the Southeast, but just because some Decembers were good in the past doesn't mean bank on this one. Overall, with neutral conditions most likely, and a tendency for Greenland blocking to repeat, I think odds are good that a Winter storm or 3 is likely this Winter, unlike last Winter where there was practically no blocking.

NAO next 2 weeks:

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AO Forecast:

post-38-0-57347900-1354242737_thumb.gif

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Great write up Robert, There's no way this winter can be as bad as last! (Is it?) lol

Says the guy who actually saw some snow last Winter, LOL. Well I don't see a long lived Bermuda ridge this season , or all those cutoffs from last year that messed up the pattern (or the Alaskan vortex). That thing is showing signs of moving by about day ten now.....GFS and ECMWF both agree. I'll re-evaluate in 2 weeks. With all the damming that occurred this Fall, it raises concerns for icing where you are. I'm also about positive you'll be atleast normal in snow amounts, if not above.

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Thanks so much, sir, for sharing some great research and data with us all. You do such a fantastic job explaining the weather and teaching the novices, such as I. Thanks for stopping by your ol' stomping grounds and hanging out for a bit. You obviously devoted quite a bit of your time to put that synopsis together with all the images and data. Many thanks...

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Says the guy who actually saw some snow last Winter, LOL. Well I don't see a long lived Bermuda ridge this season , or all those cutoffs from last year that messed up the pattern (or the Alaskan vortex). That thing is showing signs of moving by about day ten now.....GFS and ECMWF both agree. I'll re-evaluate in 2 weeks. With all the damming that occurred this Fall, it raises concerns for icing where you are. I'm also about positive you'll be atleast normal in snow amounts, if not above.

Let there be hope!

I am surprised places like Asheville and the southern mountains way higher in elevation received less snow than places like Mount Airy and North Wilkesboro. Seems like the snow was very north-south oriented regardless of elevation...don't always see that.

Normal snow amounts may be a shocker compared to last winter...esp. for the new people and businesses who recently located in the northern foothills.

Can a mod pin this thread?

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Robert, thanks for the detailed discussion and the time you took to prepare it.

If you have a few moments, would you address why the GOA low is not likely to be a mainstay this year as opposed to last year when it burned us up? There seems to be a lot of worry that that feature will continue to reappear and keep us from locking in a cold/stormy pattern ever.

To me it appears that feature is going to break down and move out soon.

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Hey, Robert! Between you and Dr. Feelgood Larry, it's hard to get nervous about a winter that hasn't started yet, lol. YOu do bring a sense of calm and common sense to a forum that goes crazy when our betters abandon us from time to time. I think you need to let Facebook go, and use the extra time to come hang out with us...to sooth the fevered brow :)

We could have a ticker tape parade thru Shelby, if it would help :) T

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