NWS Open House on Saturday; weekend warmth portends generally milder pattern ahead after chilly start to November
Remember the National Weather Service Open House is Saturday at Blacksburg, from 10 a.m. to 3 p.m. If you’re there 11 a.m. to 2 p.m. or so, holler at me at the Virginia Tech Storm Chasers display.
Once we had the second-warmest winter on record, and the hottest March on record, and the hottest spring on record, and the hottest July on record, I presumed that 2012 was just about a lock to be Roanoke’s hottest year on record. But, locally, the year has fallen off that hot pace significantly. June, August and September were each within two-tenths of a degree of normal, and October was more than half a degree below normal. That leaves the last two months of 2012 needing to average 1.7 degrees above normal for 2012 to tie the record annual average temperature of 59.6, set in 1931. Now that November has started nearly 8 degrees below normal through the first 8 days , that seems to be an unlikely prospect. (Friday’s temperature averaged normal at Roanoke — 67 high, 33 low averaged to 50 — breaking an 11-day streak of below-normal temperatures, the longest since 20 in December 2010.) Still, if November and 
December are merely normal, or even just a little below normal, 2012 will become only the fifth year in Roanoke’s 101-year recorded weather history to average at least 59 degrees (1931 at 59.6 degrees, 1921 and 2007 at 59.4 degrees and 1991 at 59.1 degrees are the others.) The first 60-degree year, which seemed likely at midsummer, is just about out of reach now, barring an extreme blowtorch in the remaining 7 1/2 weeks of the year.
No “blowtorch” warmth appears to be in the offing, but it does look as if we are switching into a much milder pattern for at least the next couple of weeks, maybe beyond. The climatic indicators of PNA (Pacific-North America pattern) negative (signaling low pressure in West, high pressure in East, funneling milder air into our region), NAO (North Atlantic Oscillation) positive (no Greenland blocking high, so no forcing of jet stream southward to deliver Arctic air into East) and Arctic Oscillation positive (low-pressure over North Pole, keeping Arctic air pulled in tighter rather than expanding southward) all line up well for the expected period of milder weather ahead. Weekend highs may top 70 degrees from Roanoke south and east — Roanoke wasn’t far off that pace at 67 on Friday — but a cold front arriving Tuesday will temporarily pull temperatures back to near or below normal for a two or three days (50s highs, 30s lows, mostly). There may also be some showers and even a few thunderstorms with the front’s arrival, perhaps as early as Monday. Temperatures will slowly moderate upward after the front, but probably not into extreme warmth. There are many questions and mixed signals lingering for Thanksgiving week, including the European model already backing off considerably from a potential strong southern-stream storm crossing the nation during the preceding weekend that I mentioned in my last blog post. We’ll see if any of these details become clearer next week when Kathryn Prociv fills in for me Monday to Wednesday.
November 9, 2012 - 6:33 PM
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Suits me jest fine. I got by on less than 100 gallons of oil last year and could stand another dose of that.
The Ohio State and Marquette basketball game is delayed in Charleston SC on the flight deck of the USS Yorktown because of dew on the court. Air temp is around 50 and dew point at 46…. Going to be a losing battle
Good, lets keep it mild until mid December like it was back in 09-10! Then the bottom can fall out and snowmagedden can be unleashed again!
Has anyone noticed how dry its gotten? Haven’t seen a drop of rain in these parts since Sandy. Kevin, any decent rain chances down the road?
That’s an unusual weather delay.
Now a weather cancellation for the aircraft carrier basketball game.
Charlotte TV meteorologist and Ohio State alum Brad Panovich had a great comment on Twitter:
“Tuned into watch the #Buckeyes play a basketball game & a dewpoint explanation broke out, SWEET! #CarrierClassic”
Jared: Showery stuff Mon-Tues. Don’t see a real solid areawide rain on the horizon, unless the pre-Thanksgiving storm materializes.
WD!! Your wish is my command. You asked about the snowy winters. The winter of 1995-96 is one of the ones covered by my ‘vestigation. Comment 27 on the previous thread, at 5:26 PM, last sentence. December was a -1.67, but January was only a -0.12 overall. I will resume this comment in a second, while I go look up the daily levels in early January 1996. Enormous snowstorm hit about the 6th or so. I had only been a letter carrier for not quite 12 months, and Falls Church got something like 22 inches. Dulles Airport got close to 30, and I am sure that ROA and especially Blacksburg got buried.
Sure enough, the NAO tanked to -1.126 on Dec. 29th, and went all the way to -1.6 twice, -1.7 on JAN 2nd of ’96, and -1.5 on the 3rd. Given that when NAO levels are most steeply neg, their effect is maximized about 3-5 days later here in the eastern USA, that perfectly explains the timing of the monster snowfall.
Kevin may butt in here with exceptions, and one I am fairly sure of is the March 1993 Superstorm. I am pretty sure that the NAO was not even negative before that one.
Sure enough, the March 1993 Mega storm hit about the 13th, I am pretty sure. The NAO was very close to neutral for the entire first two weeks of 3-93. Levels did fall a tiny bit from March 9-11 to -0.1, -0.2 (almost) on the 10th, and back to -0.1 on the 11th, but those levels are piddling. Other factors caused that epic event.
OK, the NAO levels during the enormous “DG nightmare” winter of 2009-10 were very revealing. November 2009 started out with plus NAOs for most of the first 11 days, then switched briefly to negative (nothing severe, only to -0.8 and -0.9 on the 14th-15th) through the 18th, then plus again through the 24th, then previews of the upcoming winter for the end of November. NOV 2009 ended up almost right at neutral, -0.02. The monthly index levels for the next 4 months were stunning. -1.93 for DEC 2009, then -1.11, -1.98 (!!!!) for FEB 2010 which was one of the coldest Februarys ever here in SW Virginia, then still -0.88 for MARCH 2010.
November was tame, then the hammer was lowered. That’s why snow-lovin’ Jared wants the NAO to go positive for 4 weeks or so. I bet it doesn’t happen, dear fellow golfing fan! I bet we get another nosedive starting just before Tgiving. Might not be as steep as the one for late October, but still will go negative. The NAO outlooks pages are now showing the start of one.
This is something …. the snow hater (me) is rooting big negative NAO to return in late November, while the snow lover El Senor French is rooting for a positive NAO ….
I remember the winter of 1986-87 up in Alexandria VA / Wash DC. DC area got hit with two big 10+-inch snowstorms within 3 days of each other in late January, then got one more in late February, the first time in Washington DC recorded history that the city got 3 snowfalls of at least 10 inches in the same winter. The NAO? Monthly readings for JAN were -1.15 and -0.73 for FEB. And sure enough, the NOV 1986 reading (in fact, all three of the OCT-DEC 1986 NAO levels) was a big positive, +2.29!!
More evidence? The winter of 1959-60. The grand-daddy. Sure enough, the NOV 1959 NAO was positive, +0.41. Remained plus in DEC ’59, at +0.44. Table got set with the cold air in JAN 1960 at -1.29, then the true Snowmageddon in these parts was FEB with -1.89 and March with -0.50, but March was positive from the 20th until just about the end of the month, meaning that for the first 19 days the NAO was also quite Neg.
wd, you also asked about 1985-86. Judging from the monthly NAO levels, I would not guess that was a rough winter, with possible exception of FEB. The numbers: A negative NAO for NOV. 1985 of -0.67, usually (we now know) a bad sign for a big snowy winter. DEC was +0.22, then +1.11, -1.00 for FEB, then big plus of +1.71 for March. Definitely a strange winter for the NAO. Three flips. To positive for DEC-JAN, back to neg for FEB, and back to huge plus for March.
Hey, I found an exception to the “rule” about a negative NAO in NOV leading to a not very cold winter. Trouble is, it was almost 50 years ago. 1965-66. NAO was -1.66 for NOV ’65, but then flipped to +1.37 for DEC. Then flipped big time again for JAN 1966 (when at least MASS was buried with 4 consecutive snowy Saturdays) of -1.74 and -1.39 for Feb.
Another enormous winter was 1968-69, especially for FEB and MARCH. Let’s see. WOW!! Another exception year. Big time. NAO went to negative in JULY 1968 and stayed there all the way through MARCH 1969!! From September onward it never got closer to neutral than January’s -0.83.
Regarding 1993 Superstorm — NAO had just flipped from negative to positive. It occurred during NAO+.
Locally, it’s difficult to get the right pattern without the blocking high at Greenland (NAO-) to crank up the really really big snowstorms — the twice-a-decade on average foot-plus events (just 1 that was areawide in past 16 years, but made up for by 3 in 4 years 1993-96). Can’t get the jet stream buckled far enough south to get the storm to blow up on the Gulf Coast instead of on the East Coast, can’t park the cold air long enough. But we do get snow during NAO+ and can even get the 4-12 inch type events, like Feb. 19 of this past winter.
Another factor for the winter that DT talks about quite a bit is the snow cover in Siberia. He stated just last week or so that the snow cover in Siberia is building much like it did for the winter of 09-10! Not saying that is going to cause the same type of winter but bodes well for snow lovers at least in DT’s mind.
DT is also bullish on his predictions for Noreasters in the January-February 2013 time frame. Gotta admit sometimes DT misses a storm, but last year he wasnt going along with the rough winter outlook like Accuweather and Bastardi did.
50.2* here on da Knob.
The Siberian snow cover bit is impressive, Jared. DT, NWS-Blacksburg both have picked up on that … and I mentioned it in my winter predictions, though it mainly analyzed similar El Nino patterns and our winter specifically in Roanoke.
http://www.roanoke.com/weather/wb/316354
And I’m gonna mention it again in Wednesday’s Weather Journal column.
Thanks Mr. Griggs. Just wondered what a neutral reading in Nov. showed for the later months of those years you listed plus some you didn’t list. Great research.
Low this morning was 33 went out for a walk with my wife at the park in Marshall,this morning it was already getting nice out.Now up to 56 here.Hey Doug Griggs i remember the 1987 snowstorms up here,I had only been in Marshall for about 2 years after moving out from Manassas!Recorded the storms on my Weather Channel calender along with the high and low temp each day.Saved all the old calenders,will have to break them out and see how much snow we has in Marshall.Have a great day all? Mike!
Kevin, I never noticed that the Great Salt Lake in Utah can create lake effect snow. Do you know how significant that can be?
http://www.wrh.noaa.gov/slc/
And now I see we have lake effect snow from Pyramid Lake in Nevada.
http://forecast.weather.gov/showsigwx.php?warnzone=NVZ004&warncounty=NVC027&firewxzone=NVZ453&local_place1=&product1=Lake+Effect+Snow+Warning
Rick: I remember once in the 1990s when the Mississippi River created “lake effect” — er, river effect — snow. Also aware of lake effect snow off reservoirs similar in size to Smith Mountain Lake (not sure about it specifically — but theoretically possible) Anywhere the wind can carry over a fetch of water for a period of time in the same direction with the right temperatures.
And then … there is this from Oklahoma — “power plant effect snow”
https://www.youtube.com/watch?v=pj2O7TXMuwA
Kevin and at least 3 of us who comment regularly were at the Blacksburg NWS event this afternoon. It was great meeting Doppler Carol and her husband, as well as HokieTrax. We got to see one of the storm chase vans up close and personal, too. DC and hubby took a tour a bit before 2 PM, and I took it at 2:20. I waited until the tour was over, then asked one of the NWS employees who was one of the sort-of greeters if he had been at the Blacksburg Office since the beginning of 2011. Alas, no. I had planned on asking him if he remembered the “Bust” snowstorm of Jan. 26th, 2011, and if he could provide any explanation why the NWS issued a Winter Storm Warning during that episode, which caused a lot of us to be puzzled, misled, you-name-it.
Remember that?
Dave Tolleris and I may have a big disagreement about what conditions will be like in JAN-FEB, depending on what happens to the NAO in upcoming weeks. If someone is willing to give me odds (only 19-1, that’s all I ask!!), I might be willing to bet on it …. LOL.
The graph for the 14-day GFS NAO outlook shows another nosedive for the NAO starting on the 21st, the day before Thanksgiving. 3 straight days at -1, then a 4th day that abates a bit to about -0.75. Assuming it verifies, which is still a very sizable if this far out (more than 10 days from now), the tiny increase in temp on the 24th does not necessarily signal an end to the downturn. We should know more by tomorrow’s run, and especially by Monday’s.
Link time: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao_index_mrf.shtml Bottom-most graph is the one to which I am referring.
The NAO and AO daily levels for October 2012 have now been posted by the ncep/cpc. WOW!! What a “NEGATIVE” month! NAO got to more than -2 a couple of times in late OCT, and the AO almost reached -3!! Speak up if any of you want to see the link. No wonder I was wearing wool pants, a stocking cap, and a very warm dickey in late October, and why it only reached 41* here in ROA on this past Monday.
Yes, it was the highlight of my day to finally meet Griggs, Hokie Trax and Kevin today at the Open House. I did learn a lot on the tour and had a great time. I wish I had been able to meet KP and to have spent more time chatting with you folks.
Got home and have been outside taking care of the animals and noticed a smokey smell in the air and a haze developing. Saw that the wind/breeze was out of the southeast so I am guessing that I am smelling the fire that is on Pilot Mt. down in NC. I don’t think there is another fire around.
Kevin, I still can’t get over how tall you are! Doug and Hokie Trax you both looked like I had imagined.
Kathryn was not feeling well today and did not make it to the Open House. As far as I know now, she’s still going to be on Weather Journal Monday-Wednesday. I’ll post something fresh later tonight and leave it for Sunday.
I “re-tweeted” this on Twitter on Friday, a pic of the Pilot Mountain wildfire that Doppler Carol refers to.
https://www.facebook.com/photo.php?pid=1094054&l=934ebe84bc&id=162655917140206