2012.02.11
Coldest morning of winter so far likely across much of Southwest Virginia; Tuesday precipitation looking doubtful
Northwest winds will keep howling for several more hours, gusting over 50 mph at times, gradually easing during Sunday morning, and that will keep some snow showers going mainly along the Virginia-North Carolina border/I-77 corridor and points west overnight. The wind trajectory is gaining a bit more of a northerly component, so that’s turning the snow squalls on more of a bit more of a south-southeast heading, which tends to keep them more to the west. Overnight lows may be the coldest of the season in lots of places, with widespread teens and some single digits. Keep in mind that Roanoke hasn’t had an official low below 20 all winter – appears Sunday morning will be the first, with temperatures already in the low 20s at mid-evening on the Saturday. Blacksburg’s coldest low so far this season was 13 back on Jan. 4 — that also appears likely to be beaten.
An “overrunning” situation with Gulf of Mexico moisture being thrown on top of a cold dome of Arctic air is an excellent way to trigger a winter storm in this pattern of alternating cold and mild periods. West of us, in the south-central U.S. headed east toward some of the Tennesee and Ohio valleys, this scenario is going to occur to at least a medium degree on Monday, with many locatoins getting a snow changing to mix changing to rain scenario. But it’s becoming more apparent that this situation won’t have the juice for much, if any, wintry precipitation for Southwest Virginia. The surface low is likely to be too weak and too far south, with the upper-level energy shearing out as it heads eastbound. It is unlikely to get a sizeable boost of moisture into the cold, dry air that will still be hanging near and around us, pooled a bit east of the mountains, by Tuesday. The Hydrometeorological Prediction Center, following models’ trends, has painted a big white dry zone right over most of Virginia extending into North Carolina for the Monday night to Tuesday night period. I’ll keep an eye out for any changes in this, but for now, I’m not putting much stock in the Monday-Tuesday winter weather threat that seemed quite plausible a couple of days ago.
Long term, most of the broad climatic indicators we watch for signals of whether it’s likely to lean colder or milder are headed away from any wintry turn … the Arctic Oscillation projected to move toward its positive phase (cold air held in close to North Pole), the Pacific-North America pattern slipping toward neutral or negative (less high pressure ridging near West Coast to drive cold air south over East), and the North Atlantic Oscillation, after a brief negative dip, returning to positive, as it has most of the winter (no Greenland blocking high to hold in Arctic air). But there is a split jet stream flow, with northern and southern branches, over the U.S. now. When that exists, there is always potential for the two branches to link up and create a storm system that will pull cold air southward while throwing moisture inland. We’re likely to see a sizeable storm in the central U.S. by late week, and at least some models have been showing some possibility for a storm over the Southeast next weekend or early the following week. We’ll shee how the various pieces of energy interact between the two jet stream branches to determine if there is a threat of a larger storm system affecting us in the next several days, be it heavy rain or a winter storm.
RSS feed 
Temp down on my thermometer to 12.3º and peak wind gust @ KHLX still 51 mph.
Comment by Johnny — February 11, 2012 @ 9:49 pm
Checking in from up on the ridge here at Dopplerville. Going to call it a night soon so wanted to let Doug Griggs know it was now down to 12 F and the windchill is down to “-3.6″F at about 9:50 Sat. evening.
Doug G – sorry to hear you have been “under the weather” the last 24 hours or so. Hope you are feeling better soon.
Will check back in tomorrow morning and let you know how we survived the night up here on the ridge.
Comment by Doppler Carol — February 11, 2012 @ 9:50 pm
Getting quite a few trees/power lines down reports tonight around the area:
http://www.nws.noaa.gov/view/prodsByState.php?state=VA&prodtype=public#LSRRNK
Comment by Kevin Myatt — February 11, 2012 @ 10:02 pm
Link for checking power outages. Over 1,000 without power in Giles county.
http://www.aepcustomer.com/customer/StormsAndOutages.aspx
Comment by Johnny — February 11, 2012 @ 10:07 pm
Brrr…
gone to curl up in front of the fire place for the night. Down to 22 here with winds gusting to 34 mph. I don’t even want to know what the wind chill is…
Come to think of it, this winter has been pretty nice up until now! Still a Snow Lover, but a cold disliker…lol!
Stay warm!
Comment by Captain Glen Quagmire — February 11, 2012 @ 10:58 pm
Thanks D. Carol, Johnny of Hillsville, Mike in Marshall, OJ, and of course Captain for the updates. I have 16.5 degrees at 11:30. For any newcomers here, I live about a mile south (uphill) from Allstate, and have 1420 feet elevation. I live just off Sugar Loaf Mountain Road. I just watched Jay Webb announce that this is the coldest air (at least in Roanoke) in exactly 12 months, when it was 16 on 2-11-11. And I come here and KM says this is the first time RRA has been (“will be”) below 20 this winter.
Comment by Doug Griggs of SW Roanoke County — February 11, 2012 @ 11:45 pm
Through Friday, Roanoke has been 5.9 degrees warmer than normal month-to-date, and Blacksburg is at +4.7. Are those ever going to take a big tumble after today and Sunday get mixed in!!
Comment by Doug Griggs of SW Roanoke County — February 11, 2012 @ 11:49 pm
It is too late and I am way too tired to do the major comment I have in mind, but I can at least describe what I have done. I stumbled upon a link under the NAO page on the CPC website that gives a list of what the monthly NAO numbers were DATING BACK TO JANUARY 1950! I guess they took the average of the daily NAO readings and averaged them to get the monthly numbers. Anyway, after printing out the pages and analyzing them, I made a list of the most negative and the most positive. First I grouped together the 4-month period FOR EACH WINTER of December through March. Rather than average those numbers, I came up with an overall total for the 4-month period, which often included both positive and negative numbers. I made a roughly Top Ten list for most negative and most positive, out of the 62 winters’ worth of data. Then I also made a Top Ten list of the most positive and most negative individual months. Some expected findings and a few shockers, too. More tomorrow.
If some of you have a dog in your bedroom for the first time or the first time in a long time, ask the pooch in the morning if he/she snored more or one of the humans snored more. LOL I know what the correct answer is for our bedroom …. and it ain’t the dog.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 12:00 am
On Bent Mtn, elevation 2,950, it is 10.2 degrees and windy at a few minutes past midnight. Moon glows bright.
Comment by Jeff — February 12, 2012 @ 12:08 am
As you can see from the above map, my Moisture Forcefield has been powered up and is working to the full desired effect.
Definitely not digging the cold! Don’t think I’m going to get out of bed tomorrow! : )
Comment by scott — February 12, 2012 @ 4:13 am
40 gallons of sap per 1 gallon of syrup.
Comment by wdbrand — February 12, 2012 @ 6:06 am
Brush mtn roared the loudest in our 15 years here…
Comment by Capt. Hop — February 12, 2012 @ 6:30 am
47.9 mph at 6 AM. 15.6*
Comment by wdbrand — February 12, 2012 @ 6:41 am
Durn, what a night! The mercury at my home in the Windsor Hills section of Roanoke City dropped like a rock all afternoon and evening, then stopped on a dime at 19.1. I thought for sure it would be lower when I woke up at 6 AM, but it’s still hanging at 19.1. Needless to say, that wind was downright violent all night long.
Comment by Sam Oakey — February 12, 2012 @ 7:24 am
My unofficial low was 9.5º at 6:30 and the wind is still blowing at a pretty good clip.
Comment by Johnny — February 12, 2012 @ 8:34 am
Good Sunday morning greetings from up here on the ridge- 2546 feet. It was 9 F this morning. Howling wind all night long. Will need to do a shingle check to see if any blew off. Wind had died down (some) earlier but now sounds like it is picking up again. Brrrr!
Comment by Doppler Carol — February 12, 2012 @ 8:40 am
The persistent winds kept radiational cooling from setting in, so the temperatures stalled after the cold air advection carried on the winds reached its max.
Still, Roanoke had its lowest of the season so far at 19. My thermometer across town from the airport at about 300 feet higher elevation dropped to 16.
Comment by Kevin Myatt — February 12, 2012 @ 9:24 am
Kevin, I looked at over a dozen PWS’s around our area from B-Burg to Check and they all held within a degree or two from midnight til after daylight. Not the same temps at each one but all were stable from midnight on. The wind put the damper on the temps bottoming out, just like you said, area wide. All the way back to Bristol.
Comment by wdbrand — February 12, 2012 @ 9:42 am
Hello everybody. I slept a bit late (much later than my work mornings, by almost 3 hours) and temp was “up” to 17.5 at 8:15 A.M. Had a first …. about 4 very small branches (really oversized twigs) were right in front of our garage. I often find them in the back yard …. I guess that proves that the wind was more out of the north than NW overnight. Thanks for the kind wish last night, Doppler Carol. I wonder how cold Hot Springs and Highlander got …. Kevin, please send Highlander an e-mail and tell him how eagerly some of us would like to hear from him again. But you are probably forbidden from doing that. Incredibly fabulous visibility now.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 11:45 am
Oh, and Wd, that is the same ratio for the sap to maple syrup that my brother-in-law told me years ago. I remember how stunned I was when I first learned that. Thank God somebody is willing to go to that much trouble to create one of the very best food products I have ever tasted. Comparing pure maple syrup to the “table syrup” sold in grocery stores is like … um …. comparing the Salem Red Sox to a major league baseball team. No offense to our local Red Sox …. I try to go see them about 5 times per season.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 11:50 am
OK, here goes: NAO research. Before I get into the details, one of the most important things to keep in mind is what I believe Kevin mentioned once recently. That one of the most historic snowstorms in the history of US weather happened throughout the eastern seaboard with a slightly POSITIVE NAO!!! The “Superstorm” of mid-March 1993. So even though the “Naughty, Evil, Wicked” NAO of this winter has been a major reason (IMO) for a practically snowless winter so far (snowless for lots of us, that is), it doesn’t rule out snow for the last 6 weeks of snow season. The NAO level for March 1993 was a +0.30. In fact, all four winter months (which I define as December-March) that winter were positive, with January 1993′s NAO of +1.35 being the 12th highest NAO reading for a winter month since 1/1950.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 12:15 pm
OK, here is the final comment on this subject that I would recommend everyone read. As I described in my midnight comment (comment #8) above, I looked at monthly NAO levels since January 1950. Then I arrived at an overall net total for each winter season, including March along with the meteorological months of Dec. thru Feb. ***Wanna guess which 4-month winter season had the most negative overall level of the previous 62 winters? *****
While you are thinking, I will repeat what Kevin has said many times here, that most of the coldest, snowiest winters during this 62-year period were in the 1960s. Indeed, 6 of the most negative NAO levels were during the 60s, and 1958 and 1971 were two more winters that made the top 12. BUT THE WINTER THAT HAD THE MOST NEGATIVE OVERALL NAO LEVEL WAS MY NIGHTMARE, THE WINTER OF 2009-2010, AND BY A DECENT MARGIN. The overall NAO total was -7.70 and 2nd most negative was -7.21 in 1964 and 3rd most neg was -7.11 in 1969.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 12:24 pm
More details about the NAO, and please skip this if not interested. The top 12 most negative, with the year first and then the overall NAO reading;
1st place: 2010 -7.71
2nd place: 1964 -7.21
3rd place: 1969 -7.11
4th: 1963 -6.67
5th: 1977 -5.54
6th: 1958 -5.21
7th: 1960 -5.21
8th: 1965 -5.07
9th: 1955 -4.77
10th:1971 -4.47
11th:1979 -4.45
12th:1962 -4.07
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 12:30 pm
My low here in Hardy was 18.2. We were without power from about 11 last night to 9:30 this morning. Winds HOWLED all night.
Comment by Betsy — February 12, 2012 @ 12:34 pm
I can relate some of the following months with either very big snowstorms or extremely cold weather, or both. Here is a list of the Top Nine months with the most negative NAO levels:
1st place: January 1963 -2.98!!!
2nd place: February 1978 -2.94!!! BOSTON BLIZZARD OF ’78
3rd place: February 2010 -2.69!! REMEMBER??? -6.0 Degrees for ROANOKE
4th: January 1955 -2.65
5th: February 1960 -2.59 MASSIVE SNOWS IN FEB AND MARCH
6th: January 1966 -2.54
7th: March 1958 -2.46
8th: January 1985 -2.38 INAUGURATION CANCELLED BY BRUTAL ICE, WIND
9th: March 2005 -2.32
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 12:42 pm
The wind collapsed the grocery cart return canopy at the Krogers in Bonsack. Also my neighbor’s trampoline ended up in their front yard…about 80 feet from original position and 20 feet higher!!
Comment by Paul — February 12, 2012 @ 12:45 pm
The top nine winters that had the most positive NAO readings.
1st place: 1989 +4.69
2nd place: 2000 +3.47
3rd: 1995 +3.11
4th: 1994 +3.06
5th: 1983 +2.45
6th: 1993 +2.12
7th: 1990 +1.84
8th: 1984 +1.18
9th: 2007 +1.03
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 12:46 pm
Thanks Doug for brining up the “Storm of the Century”. I love reading about it. I only regret that I was still living in Nebraska, and missed it. Here’s the link for all those that want to “relive it”.
http://en.wikipedia.org/wiki/1993_Storm_of_the_Century
Comment by Rick in Wytheville — February 12, 2012 @ 12:52 pm
The top ten individual months that had the most positive NAO levels.
Want to know why both December and January of this winter were so very warm locally? HERE IS ONE BIG REASON!!! The month that had the very highest NAO reading since January 1950, and by a big margin, ….. DECEMBER 2011 +2.25!!!
2nd place: February 1989 +1.82
3rd place: December 1994 +1.78
4th: December 1982 +1.56
5th: March 1989 +1.54
6th (tie): February 1997 +1.48
February 2000 +1.48
8th: January 1984 +1.42
9th: December 1999 +1.40
10th: March 1986 +1.39
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 12:55 pm
One thing I will add to what Doug mentioned about the Superstorm — it occurred during a NAO+ period, but the NAO had just flipped from negative to positive on March 11, with the storm developing in the Gulf on March 12. There is a good bit of meteorological opinion that the wild flip from moderately negative to strongly positive that occurred in early to mid March helped create such an intense storm. The PNA had also flipped from positive to negative a few days before. Recall that we typically look for NAO-, PNA+ for wintry periods to develop in the East, but at the time of formation of the Superstorm, those factors were in the opposite modes, though only for just a short time.
Just from observational experience, late February and March often seem to “bend the rules” on developing winter storms, with some unusual setups producing that fall flat earlier in the season. So that’s why it’s important to keep watching the atmosphere even if the winter has been a “dud” in the snow department.
Comment by Kevin Myatt — February 12, 2012 @ 1:06 pm
Here is another tidbit about the NAO that relates to the three most recent winters, including this one. The NAO had 4 deeply negative NAOs in the winter of 2009-10 (I define “deeply” as a monthly NAO more negative than -1.3). Incredibly they were -1.88, -1.80, -2.69 (the 3rd most neg number) and -1.33. The combination of -4.47 for January and February 2010 only would qualify for 9th place on the alltime list (because 2009-10 was 1st place). But if one also includes December 2010 and January 2011 to string together 6 consecutive winter months, the combined NAO level was a truly awesome -11.04!!! No wonder a certain letter carrier who was completely fed up with very cold winter months was spurred to re-word the Battle Hymn of the Republic here roughly one year ago. “Mine eyes have seen the glory of the coming of the warmth, He is trampling out the vintage where the Grapes of Cold are stored …… etc.”
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 1:10 pm
On Doug’s 12:44 comment — January 1966 that ranks 6th on that list is the snowiest single month on record for Roanoke, with 41.2 inches. March 2005, ranking 9th, started with the Feb. 28 snowstorm (6-12 inches across the area) and remained relatively cold with 3 other light snows through about March 20 or so.
On Doug’s 12:46 comment about positive NAO winters — while that list reads like a who’s who of mild, snow-challenged winters, 1983 varied from the list in one way, with a major February snowstorm and 2 feet for the month.
Comment by Kevin Myatt — February 12, 2012 @ 1:12 pm
Now we are on a streak of four straight winter months (Feb. & March of 2011, and Dec. 2011 and last month) with positive NAOs. Respectively, +0.35, +0.24, the almost unbelievable +2.25, and +0.86 last month. I think that this month is continuing NAO positive, but at very low levels so far.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 1:13 pm
When I began looking through the first 20+ years of data, I was beginning to wonder if I would ever find a winter when the NAO was positive for all 4 months, but later I found quite a few. The first winter that had an overall NAO that was positive (I started back with 1950 and worked “forward”) wasn’t until 1961, and that was a tiny +0.18. The next one wasn’t until 1971, but that was still only a +0.55, and two of the months were negative. The first winter that I came to in which it was “completely positive” was 1989, which had the highest overall NAO of +4.69, by far the most positive winter of the 62 winters researched. Could this winter get there? We are at +3.11 through January. My WAG is that this winter will end up in 2nd place, between +3.5 and 4.0. Which would mean that my out-on-limb forecast for an extremely cold March will be way off.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 1:22 pm
Overall, there were 5 winters that were completely positive like the winter of 1989, and 3 of them were in the 1990s. 1993, 1994, 1995, and 2000. The 6th, 4th, 3rd, and 2nd most positive winters on the list above. 1983 was the 5th most positive winter, but had a -1.04 in February that kept it from being the 2nd most positive. This winter has a decent chance of joining that group.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 1:29 pm
Doug, Kevin, from what I understand of your research, the more positive NAO seems to correlate with warmer months, and the more negative with colder months. But cold, or lack of it, is only part of the equation, the rest is moisture. With the superstorm speculated as a result from a change, would the snowier months also correlate more with changes, i.e how many times it flips from positive to negative? Does that change correlate more with the movement of storm systems? It seems this may make sense as the fundemental driving force behind most weather is the movement or transfer of energy.
Comment by Trevar — February 12, 2012 @ 1:29 pm
Wow, Kevin’s comment at 1:12 and mine a couple of minutes ago dove-tailed perfectly about Feb. 1983. I made my comment without having seen his.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 1:31 pm
Kevin and Rick, just read your comments about the March 1993 monster. I was hoping that someone else would pick up on that event. Rick posted a great link, and Kevin provided incredibly valuable information about what was happening with the oscillations just before and during the event. I will add my two cents about why I would theorize that some big storms (both snow and otherwise) form in late February and March. The days are getting longer, and the potential for a massive difference in temps between the relatively warm Gulf states (and maybe even the southern half of the mid-Atlantic) versus a very cold region in the eastern Rockies and plains …. that potential becomes much bigger in the upcoming weeks. KM and others who are experts on tornadoes and severe storms have explained here many times that is a key factor in causing late winter and spring to be active for tornadoes.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 1:42 pm
Woke up to Snowmageddon II here in DC this morning. Snow squalls overnight tripled our seasonal snowfall total. 1/4 inch to 3/4 inches!!
Comment by I'm in DC — February 12, 2012 @ 1:44 pm
Trevar: At our latitude, the general manner in which we have snowy periods is that it gets cold, stays cold and moisture runs into it. To get cold and stay cold, it generally needs to be NAO-negative, so the high over Greenland can block the cold air and force it south. Then you have to have a favorable storm track to drive moisture into that cold air without overwhelming the pattern and making it warm. El Nino provided that in 2009-10 (it sometimes did overwhelm the pattern, even as strongly NAO-/AO- as it was, seeing how much rain we got in addition to all the snow). Another reason the PNA+ pattern sometimes favors winter storms is that the big high on the West Coast gets undercut by a southern branch of the jet stream, which can supply wet storms.
So, in general, NAO- is by far the best case for snow in our region if there is a source of moisture. There are specific storms however that can arise from extreme changes in these patterns and occur during periods that seem opposite of what we typically expect.
Comment by Kevin Myatt — February 12, 2012 @ 1:49 pm
I would also theorixe that this spring is going to be a normal or perhaps even a relatively tame one for tornado activity across the USA. That could be just another in an ever-growing list of poor Griggs predictions. But this winter has been a warm one, at least here in the east. And although the middle of winter was roughest in the CONUS in the Rocky Mountain States, I don’t think it has been that cold in the past few weeks. I could be wrong about that. Instead of making a statement that could be way off, wasn’t last winter particularly cold in January and even continuing into some of February in COLO, WYOM, NEB, SD, KANSAS, etc.? If so, that may have contributed to why last spring was the worst for tornadoes in many decades.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 1:49 pm
A recent example of a fairly large snow event that occurred in a NAO+ period was March 1, 2009. That storm dumped 4-10 inches across most of the region (a little less than 4 officially at Roanoke, but most of the metro area with any slightly higher elevation had significantly more). We did have the big high on the West Coast, PNA+, and it pushed a vigorous upper-level disturbance deep to the south, scraping the Gulf Coast, before lifting north in the Eastern US trough. But that also occurred on the lip of a radical pattern shift, as the PNA ridge moved east over the next several days. Roanoke was 13 degrees with snow cover on Tuesday AM and 83 by Friday afternoon.
In following these various oscillations, we’re always looking for what stacks the deck most in favor of a particular weather pattern. But none of them are 100 percent necessary for whatever pattern we’re watching out for. We can have milder weather in an NAO- period if the high is closer to Iceland or England than to Greenland. We can have snow in an NAO+ period if a disturbance is far enough south and happens to time right with a cold air mass.
Comment by Kevin Myatt — February 12, 2012 @ 1:59 pm
Trevar, I am glad that Kevin replied to you and explained. From what I can discern and remember of individual months and winters, I would generalize that the primary thing that a negative NAO does is maximize the chances of it being cold in the eastern U.S. That is not a guarantee, however. Whether a cold month or winter translates into it being snowy depends on the moisture and also the very short-run timing of the moisture. There was a winter or couple of months almost ten years ago when we had very cold weather, but the few days that had moisture happened on the warmest days during that month. Very little snow. And of course there was last winter. The NAO was very negative for both December and January, and both months were cold (December was something like a -6 here in ROA, and I think KM said it was the 6th coldest ever), but nearly the entire moisture of the month happened in the wee hours of the Dec. 1st, when the temp was 60 at 12:01 AM. From Dec. 2, 2010 through Feb. 23rd 2011, Roanoke only got a bit over 2 inches of precip. Therefore it was cold but mostly quite dry (and I was unbelievably lucky!!), and therefore little snow locally. The winter of a lot of what others called “busts.” Especially in ROA.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 2:00 pm
Does anyone remember the ice storms of 1994? We had 3 or 4 that winter. The big one was just about this time in February, 1994. Power was out for 3 days at my house (which is ALL electric) and for a week or more in some places. The water pumping station lost power so no water pressure at all and then any you got you needed to boil for safety. I remember cooking Spaghetti-Os over a sterno stove for my boys. There were no batteries to be had in town. That year the kids missed something like 17 days of school and the school system got special dispensation from the state on making some of those days up or else they would be going until July. In my book, I’d rather have a 3′snow than an ice storm.
Comment by HokieTrax — February 12, 2012 @ 2:05 pm
Thanks Mr. Griggs for researching and posting the info. Most informative.
Comment by wdbrand — February 12, 2012 @ 2:50 pm
HokieTrax – I was in Christiansburg in ’94 and remember something of that. What I remember is the big electrical towers that cross Floyd County buckled from the ice and they had to use helicopters to fix them. Yes, I agree – I would rather have a 3″ snow than the ice storm.
Comment by Doppler Carol — February 12, 2012 @ 2:54 pm
Wow! It’s all I have to say about Doug’s analysis of the NAO. Excellent! Brvao!
Comment by Captain Glen Quagmire — February 12, 2012 @ 3:17 pm
12Z models for Sunday are confusing to look at with a first glance.
GFS crushes the President’s Day event then wipes it clean off the map.
Euro still shows it and is slowly beginning to put the puzzle pieces together.
Now where did I put that fork?
Comment by Captain Glen Quagmire — February 12, 2012 @ 3:22 pm
Yes, HokieTrax gal, I do remember that 1994 winter. I was still in northern Virginia, close to DC. The number of accidents on the Washington (or “DC”) Beltway was very high. It sounds like you may have had it worse in Hokieburg, at least in Feb. As I remember it, they started in the 2nd half of January in the DC area, and it seems like they had a total of about 6 of them (ice storms, that is). The area that really got hit hard by ice storms was the province of Quebec and northern Vermont to a slightly lesser degree, but that may have been winter 1998, not 1994. The local and TWC meteorologists (The Weather Channel was a lot “younger” then) blamed it primarily on a layer of warm air aloft that refused to be budged out. Precip would fall as snow, melt into rain in the warmer layer, then refreeze near (sleet) or AT the surface (ICE!!!). I think that the meteorologists said that either one of two things were needed, but it was a long time before either one did. A real warm-up so that the surface layer got well above freezing, or a major cold snap, that would at least move out the persistent layer of warm air. I think that eventually the former happened, but not really until (well into?) March.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 3:55 pm
Betsy, sorry that you were one of the unlucky ones to lose electricity. And the other reports of wind damage were impressive, too. Thanks for posting them, folks. It is events like this one that make me glad that we live here ….. like I said earlier, well protected from most strong winds. Even folks in the floor of the Roanoke valley (like the fabulous Sam Oakey) with an elevation much lower than me got much stronger wind gusts than I did. I wonder how the folks on Moorman Avenue, NW fared. I was the regular carrier delivering that street for 6 and 1/2 years, and the damage in the 1900s thru 2100s of Moorman Ave. after that mid-February 2008 monster windstorm was really incredible.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 4:03 pm
Oh, one more thing about the NAO for now. One thing I was able to identify was trends. And one of them was that there were plenty of examples of winters (using my definition of “winters”) in which the NAO was most negative in March. Even a couple of winters in which the only negative NAO month was March (1981 was almost one …. Jan. was only a -0.08, while March was a big -1.65); 1984 was another one) So there is still time for the NAO to turn around and go “NEG.” But it better start showing up in the GFS NAO outlooks page fairly soon.
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 4:55 pm
Two other trends stick out like sore thumbs about the NAO. The period from roughly 1955 through 1981 (and one can add 1985, too) were loaded with lots and lots of negative NAO months and winters, especially from 1958 through 1971. Conversely, the period from about 1986 (but especially starting in 1989) through the year 2000 were loaded with lots of positive readings. Surprisingly, the 9 years from 2001 through 2009 (not including 12/09) were pretty tame as far as the NAO were concerned, despite the fact that I expected the overall +NAO trend from the 1990s to continue and despite the fact that there was a regional snow drought here. However, then December 2009 arrived and all HE– broke loose. The most negative NAO winter of the entire database, followed up by two more very neg NAO months in Dec. 10 and Jan. 11, but then a big switch and the last four winter months (Feb. & March & especially Dec. 2011 and Jan. 2012) have all been positive, including the single most positive NAO reading of +2.25 for a single month in 12/11. What does the rest of this decade hold? I have absolutely no idea. Will we return to the tameness of 2001-2009? Or continue with the mostly positive readings of very recent history, and thus a return to the 1990s conditions? Or will the winter of 2009-10 be the “engine” that leads the “train” of a very negative decade, if not like the 1960s, at least similar to the 1970s?
Comment by Doug Griggs of SW Roanoke County — February 12, 2012 @ 5:16 pm
Doug,
Hope you’re feelin’ better. I’m a longtime reader of this blog but don’t post much. I’ve learned over the years that you learn more sometimes from listening than by talking. I’m fascinated by KM’s, Quag’s, and your prowess with model forecasts and NAO research. You guys have taken my weather enthusiam to a whole new realm. Thanks.
Doppler Carol,
I’ve noticed your appreciation for our “feathered friends”. I used to have the feeders here when we built in ’88 but couldn’t believe the damage the squirrels would do to empty them so I quit putting them out. Since I’m only here on weekends I’ve noticed recently how fat the bluebirds and snowbirds are when they’re feeding in my yard. Are they that healthy where you are?
Comment by Merle Spencer — February 12, 2012 @ 5:30 pm
Thanks Kevin and Doug. Kind of what I suspected, the more you have the cold air in place, the better the chances of moisture coming through. This has been quite a lackluster winter, no just because of no snow, but the lack of any real chances. Most winters I enjoy watching and following the blogs as storms show up on the models and progress over time. Usually a storm shows up, and eventually it comes to fruition, the tough part 10 days out is where does it end up, and is the cold air in place. This year, the storms simply do not show up, or if they do they already look too iffy 10 days out for any real chance.
Comment by Trevar — February 12, 2012 @ 5:48 pm
We’ve also missed some minor events, some which might have been moderate/major, this winter due to several degrees. Think lack of snow cover anywhere in the east.
Comment by wdbrand — February 12, 2012 @ 6:14 pm
Kevin, Per Quags #48 comments why is there such a difference in the Euro and GFS even a week out. Is there a tendency for one to be more reliable than the other at this range? Or, should both be taken with a grain of salt past a certain time frame?
Comment by Mark in Pulaski — February 12, 2012 @ 6:29 pm
Thanks for the informative research, Mr. Griggs. Much appreciated. I do have a question that I do not think was talked about above that hopefully you or Kevin (or others) can answer. This is my first year (started back in the fall) following the weather closely, so I have not been on the blog much for the other seasons.
My question is; how does the NAO influence spring and summer weather? I assume with a negative NAO in the spring, we have less chance of severe weather and more chance of a late freeze? And positive NAO boosts severe weather threats? Or does it have little effect on severe WX? And in summer, I assume that the difference between a NAO- and NAO+ is even less pronounced, with only slight cooling with the former. Is this the correct thinking? Please correct me all you need to. Fascinating research.
Comment by Roa10 — February 12, 2012 @ 6:31 pm
A certain model has caught the attention of the Weather Blogs. The JMA or Japan Meteorological Administration medium range model has become the talk of the web. JMA now shows a whopper of a Gulf Coast Miller “A” type storm at 144 hours which is next Saturday for the Gulf Mex. Problem is that the JMA has been batting 1 for 4 this season like all the other models. This particular Gulf Low per the JMA will move ENE out of the Gulf to off the NC/VA Coast Late Sunday which is close to the sweet spot for coastal lows to bring snow our way. If the track were a bit more NE, then chances are much greater for a Major snow event for the Mid-Atlantic. Problem is the other models are under performing this scenario. Euro is placing a huge bet that there will be a 50/50 Low to provide blocking for this potential event but is way too progressive with the northern jet, which has been the norm this winter. GFS is on another planet & has no clue and places next weekend’s event on Mars. Again, way too far out to say what happens.
Here’s the link to the JMA courtesy of Ray’s:
http://grib2.com/jma/CONUS_JMA_1000-500_SLPTHKPRP_144HR.gif
As Mr. Griggs eludes to above with his NAO dissertation, this ties in sort of to what he was saying. I made reference some days ago about the historical significance of President’s Day and snow storms. FWIW, the NAO during the 2 largest President’s Day storms back in 1979 (aka PD1) & 2003 (aka PD2) were slightly positive. Fast forward to today. NAO is slightly + but may go slightly – in the coming days as the holiday approaches. And now, the JMA shows a threat. Karma or PD3?
Comment by Captain Glen Quagmire — February 12, 2012 @ 6:53 pm
It is 23 F with a windchill of 14.5 F out in the backyard. Another 4 dog night here on the ridge. The wind does not seem as bad as last night.
Merle – yes, I know about the squirrels. When I lived in NoVa during the early 2000′s I had loads of squirrels in the back yard. I finally moved my feeders around and then put one up just for the squirrels. That helped some. Here out in the country, we only have a “mountain boomer” show up every now and then. The birds seem pretty healthy here too. I think that with the lack of snow cover and the warm days we have from time to time, they are probably supplementing their diet with bugs etc. I saw my first red wing blackbird yesterday – not sure if the other black birds were the same or were starlings. I always seem to have a large flock of male red wing blackbirds come through and they stay here till spring and the females show up. Have not seen the first robin here.
Comment by Doppler Carol — February 12, 2012 @ 7:09 pm
This has to be one of the coldest days of winter so far,only hit 27 here for a high today.Low this morning was 17.Down to 23 now.Had some light snow last night for about 2 hours just covered the ground a little.Doug Griggs glad to here your feeling better,and Captain Glen good to here your a snow lover,Doppler Carol we have not been in the single digits for lows all winter up here in the morning,that had to be brutal down your way this morning.Everyone have a great weekend whats left of it.
Comment by Mike in Marshall — February 12, 2012 @ 7:26 pm
Mark,
All major global forecast models use different programs & different data input (Model output Statistics, Parameterization, etc.). The GFS is the most stand-alone model as it uses no other model data except its own. All the other models are inter-connected and share data. Remember that the models take a snapshot of the atmosphere at a precise time then take that data and extrapolate it to predict what may happen later. The nature with statistical data is the farther in time you go, the less the accuracy.
The GFS runs 4 times a day but updates the data only 2 times. The GFS’s advantage is in the short term as it updates more frequently. The Euro has an advantage over a longer time period as it can absorb all data and provide better results.
A better way to say this is weather is always changing and the models can only see but so much data when it takes that snapshot. Ensembles are a different story. I’ll explain more on that another day.
Long story short…In the medium range, Euro is much more reliable 6-10 days out than the GFS. GFS is not very reliable beyond 4 days. CMC, UKMET, NOGAPS, JMA are somewhere in between. On some occasions models tend to agree on some runs. Like for instance tonight’s 18Z GFS operational run compares more to the 12Z Euro Op. run than with the 12Z GFS. 12Z Euro & 18Z GFS both show a 50/50 Low over the Canadian Maritimes to possibly provide a blocking mechanism for next weekend which is what you need for a coastal event to bring that snow. Come back Monday PM and see what the models show then. It’s never the same.
18Z GFS for Sunday
http://www.meteo.psu.edu/~gadomski/AVN_18z/avnloop.html
12Z Euro for Sunday
http://www.meteo.psu.edu/~gadomski/ECMWF0.5_12z/ecmwfloop.html
Comment by Captain Glen Quagmire — February 12, 2012 @ 7:28 pm
Roa10:
You’re thinking in the right direction with your assumption but NAO is more of winter teleconnection.
The NAO doesn’t affect summer patterns as much as winter patterns. In the summer months, the jetstream is positioned farther north closer to the North Pole which moves the upper air patterns as well which is what the NAO is based upon. But on occasion, you may get a -NAO to influence the spring & summer patterns if it is strong enough. For the most part, the NAO has little affect on severe weather on the US during the spring and summer. Late Spring Freezes are affected by other parameters as well. You can have a late freeze but no NAO.
Comment by Captain Glen Quagmire — February 12, 2012 @ 7:39 pm
Cap’t, do most major terminals have certified mets or do you do your own. If you do and are flying out Monday morning at 7 AM, when do you look at what weather you’ll be running into and do you discuss this with the mets?
Comment by wdbrand — February 12, 2012 @ 8:04 pm
Good discussion today without much input from me.
Quagmire’s answer at 7:39 p.m. regarding the NAO in other seasons was similar to what I would have answered. I do know, however, that there is one particular NAO- pattern that triggers Hudson Bay vortex that can scour out the moisture and shut down severe weather in May. It has shown up 6 years out of 7 running our Virginia Tech storm chase trip. We have waited it out most years.
Comment by Kevin Myatt — February 12, 2012 @ 8:12 pm
D. Carol, with the fire I had going last night, it would have been only a one dog night. However, the daughter got back for Pitts-B and took her dog home. Needless to say, I’ve got it chunkin tonight. A no-dog night.
Comment by wdbrand — February 12, 2012 @ 8:13 pm
What is the major difference with the president’s day storm chance and all the other chances that have come and gone? DT is really posting a lot about this one, and he had basically written off an east coast storm this winter due to the positive NAO. There has to be something out of the ordinary catching his eye this time around.
Comment by Bedford snowman — February 12, 2012 @ 8:34 pm
There is a split jet stream flow, which always provides the possibility of linking northern and southern stream energy. Also some indication of a 50-50 low near Newfoundland developing — this is a feature that helps slow the progressive pattern down just enough to drive a low down near the Gulf and up the East Coast rather than speeding out to sea. The NAO may only be slightly positive or even near neutral. So there are a couple of pieces on the board, but it will have to work out just so with little margin for error to happen.
Comment by Kevin Myatt — February 12, 2012 @ 8:39 pm
wd…
It’s all automated now. rarely talk to a met these days with internet.
I’m planning a flight for Monday now.
I’ll get back to ya shortly. Joe may be able to help too.
be right back….
Comment by Captain Glen Quagmire — February 12, 2012 @ 9:03 pm
bedford snowman…
+1 to Kevin’s #67 comment. DT is all over this due to fact of a possible jetstream phasing, 50/50 Low & southern energy getting the Gulf of Mexico going. None of which have really happened together yet this winter.
If they all come together, then next weekend’s event could be real for the first time this winter. Real as in over 4″.
Comment by Captain Glen Quagmire — February 12, 2012 @ 9:07 pm
wdbrand…
Back to what you asked me earlier about aviation weather. In today’s modern world of technology, 99% of all aviation weather resources are automated with a few places that have certified Mets or FAA Air Traffic Controllers doing the hourly observations manually, but it’s mostly now automated with the ASOS/AWOS/METARS observations. NOAA is the official source aviation weather source in the US & likewise for other countries that have the gov’t run weather agencies. The Blacksburg NWS Office is responsible for the terminal area forecasts (TAF) for Roanoke, Lynchburg, Bluefield, Blacksburg & Lewisburg.
Now the internet is your weather briefer. Back in the day, the FAA had Flight Service Specialists that gave Pilots weather briefings. The FSS (Flight Service Stations) are still operational today, but modern technology will soon make them extinct. There are many websites available for aviation weather. There are Professional sites that you have to pay for access for the good stuff. My company (A private Business that owns its own aircraft) utilizes 2 private aviation firms on contract to provide international weather, flight planning & handling services. But here are some widely used by pilots today.
http://www.jeppesen.com/aviation/personal/aviation-weather.jsp
http://www.stratosjets.com/weather_reports.php
http://www.duats.com
http://www.pilotweatherbriefing.com
http://www.fltplan.com – Professional Full Service Flight Planning and Flight Tracking-Quags personal fave
http://www.aviationweather.gov
http://www.avnwx.com
I usually start looking at weather the day before if on a domestic North American trip & 3 days before an international trip with multiple briefings all the way up to takeoff. I can call the FAA or NWS if I so choose, but with my experience, I’d probably know more than they would.
For instance, I prepped for tomorrow’s flight starting this evening. There will be a final crew briefing before wheels up in the morning. What’s even cooler now is you can access all your aviation weather resources from the flight deck instantaneously onto either your I-Pad or via the aircraft’s internal Flight Management System or electronic flight bag. I usually download all the info I need for the flight from the I-Pad to the FMS & have the wi-fi access to pull up whatever I need from both including radar & satellite. Modern technology…cool toys!
Comment by Captain Glen Quagmire — February 12, 2012 @ 9:48 pm
I’m driving students to a conference this week, down to Auburn. Looks like Thursday, our long driving day there, will have ‘weather’- possible snow showers here, rain there. Long as we can get through Fancy Gap. Will we be coming back to snow on Sunday?
Comment by HokieTrax — February 12, 2012 @ 9:55 pm
HokieTrax…
There is a possibility…yes but not definite. Check back later in the week.
Comment by Captain Glen Quagmire — February 12, 2012 @ 10:10 pm