Gradual trend toward somewhat warmer than normal temperatures for latter half of October
We’re back to the classic October weather we’ve been having, with mild to warm days (60s/70s) and cool to chilly nights (30s/40s) and remaining dry through at least Thursday. There are some major questions about how much moisture the next front late Thursday or Friday will be able to lift northward and squeeze out. We’ll wait for some later details on how that pans out. Part of the issue is that the series of lows moving through the central U.S. are steadily pulling farther northwest on their tracks (Thursday’s weather map linked here), and that means less direct influence in lifting moisture. It also illustrates a broader development with the weather pattern, and that is the tendency over the next two weeks for temperatures to gradually warm, at least relative to normal. While we will have periodic cold fronts moving through, the air is become less of Arctic origin and more of Pacific origin. This is the because of the negative Pacific-North America pattern (PNA), which indicates a jet stream dip in the Pacific northwest, rising 
northeastward into Canada. The “icicles” hanging below the line on the far right side of the graf at the left are indicative of projected negative values in the PNA over the next 10 days, which show an expected continuation of this pattern. This will likely lead to continued low-pressure tracks well to our northwest, periodic frontal passages that merely reinforce the mild to cool weather rather than introduce intense cold from the Arctic, and warmups in between the fronts that could take temperatures above normal into the 70s at times. Keep in mind that normal highs and lows are continuing to decline rather rapidly this time of year through the 60s for highs and 40s for lows, so even a similar temperature pattern as we’ve seen that has been near or somewhat below normal in early October could be above normal in late October. Don’t expect a blazing summerlike heat wave, but at least some warm weather relative to normal as we move through the latter half of October.
October 16, 2012 - 12:08 AM
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As long as it is nice for the Virginia is for Racing Lovers 300 in Martinsville this weekend. Right now it looks great!!
Wow, Griggs was (apparently) right for a change the other day. I mentioned that the AO and NAO are going negative this week, which usually means cooler/colder than normal temps for us a few days later, but that the PNA was also negative. Kevin has just sermoned that the PNA will cause us to likely be warmer than normal all through next week. I don’t mind that at all for the very short run (next 2-3 weeks) …. more chances to “goof.”
However, I want the PNA to go positive and have the AO/NAO remain mostly negative for most of November. I want a cold November. If I was a snow/cold lover, I would want a warm November. Reason? November 2009 in ROA? 4.2 degrees warmer than normal. November 2010? 3.2 degrees warmer than normal for the period November 9-26. Blacksburg in Nov. 2009? 3.0 degrees warmer than normal. We all remember the winter of 2009-10. Well, the winter of 2010-11 was even colder, especially from December 1 through Feb. 11th. But the 2011 winter was incredibly dry.
In my 10:16 PM comment yesterday evening I yakked about how this winter is shaping up to be the first ENSO-neutral winter since 2008-09. Later on I looked more closely at the monthly 3.4 levels during very late autumn 2008 and winter 2009, and really that winter was another La Nina, coming up shy by 0.1 degree for the Oct-Nov-Dec 2008 level (-0.4 instead of -0.5) of being ruled an official La Nina.
My point? The most recent winter that was truly neutral for the ENSO values? 2003-04. None of those values were more than 0.4 degrees either way. Another similarity to now? All the values were slightly positive. You snow lovers would love another winter like that one. Blacksburg’s monthly snow totals for Dec. through February were 10+-12+-10+. The biggest snowfalls in Hokieburg were 7.0 inches on 1-25, 6.8 inches on Dec. 4th, and 5.5 inches on Feb. 15th.
John Ruskin said, “Sunshine is delicious, rain is refreshing, wind braces up, snow is exhilarating. There is really no such thing as bad weather, only different kinds of good weather.”
Hokie Trax – what time do the fireworks go off?
But before any of us assume that this will be a snowier than normal winter just because it is ENSO-neutral and 2003-04 was snowy, the winter before that one that was also neutral was 2001-02, and it was a snow drought year. If the numbers on the Daily Climate Data page are correct, Bburg got a trace in Dec. 2001 and only 3+ in JAN and 2+ in Feb. However, Blacksburg had a very “wet” day on 12-10-01 with 1.33 inches of precip, with a high of only 38 and a low of 28, yet the snow total column for that date shows “M”. Can you provide further details on that date, KM?
Wind started whippin from about 4 AM to 6 AM. Higest was 23.5 MPH but at first light it had laid some and the leaves had held on pretty good. They never really got soaked and the wind yesterday dried them some. And the color hear still ain’t no watch winder. Don’t see a memorable color season here this fall.
Had some fair wind gusts[23.5mph] here before daylight, but the leaves hung on perty good. Color ain’t what I’ve seen before and ain’t no watch winder. Don’t think it’s going to be one of those memorable leaf peeping years.
Drove my mother and son to Mabry Mill and back, on the parkway today. Color was a kind of a random patchwork … brilliant in spots, kinda dull in some places, not quite peak in others, past peak in some others. Elevation seemed to play little role. Would agree it’s not one of our better color years, but not the worst, either. Some nice spots.
I golfed at Blue Hills today in eastern Roanoke County (or is it inside city limits?). The hillsides NE of the course (Read Mountain area, I think) had a bit more color than the trees close to where I live. But I agree with both wd and KM …. not looking like a particularly good year for the colors.
The air was very dry today. Sure enough I got home and turned on “7″ and the dew point in Buchanan at 5 PM was 33*. Dew point at Bedford Middle School was 35*. I hope that we get at least 1/3rd of an inch from the Thurs-Friday event, and that the weekend is not too windy. If the opposite occurs, I bet the chances of wildfires go up.
Frost advisory for Wednesday morning generally I-81 and north/west as far north as Roanoke, then U.S. 460 corridor and north to east.
http://www.erh.noaa.gov/rnk/emer/emer.php
Frost will be patchy.
Doug: Don’t know about that particular date, but 2001-02 was probably, all in all, the weakest snow winter we’ve had since I moved to Roanoke in 1999. Only 1 almost-moderate snow event here — changed to sleet after about 3 inches — and some very minor ones. As I recall, it was not a La Nina or El Nino but some of the circulation patterns remained similar to the two consecutive La Nina winters that preceded it, so it was almost like a third straight La Nina. Blacksburg had only a little more. Missing statistics are a problem at both sites, but I can assure you they weren’t missing much.
To confirm Doug’s accurate summation of the latest ENSO Report, here’s the October 15, 2012 CPC ENSO Report Summary
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
Expect Neutral to just barely very weak (if that at all) El Nino conditions to continue.
Lesson 4 Winter Storms will be up on Wednesday.
Breaking news! 4.6 magnitude earthquake in Maine felt as far south a PA.
USGS earthquake map. Quake occurred at 7:12 PM Tuesday.
http://neic.usgs.gov/neis/bulletin/neic_b000d75b_l.html
Rats, GQ beat me to the punch. About the earthquake in SW Maine, practically in New Hampshire, in town of Hollis Center according to one website (NBC NEWS) I looked at, 20 miles west of Portland. Guess who was practically there in early July?
Talk about funny. The NBC article claims it was a shallow quake, only 3 miles deep. Another website claims it was a deep one, 17 miles deep.
I think I’ll do some more research about the winters of 2001 and 2003. Could prove enlightening, helping all of us understand what made one winter well above average for snow (very snowy in Blacksburg, I think), and the other a 2012-like non-winter, so to speak. I bet the NAO and also possibly AO levels were very different for those two winters ….
Correction. Winters of 2002 and 2004. Surprisingly I have already found a 4-week streak of days from Dec. 10, 2001 through Jan 4, 2002 when the NAO was quite negative. Must have been something else that caused it to be non-snowy then (like a negative PNA, or a dry spell).
Sure enough, the remainder of winter 2002 was almost exclusively positive NAO, which is what 2012 was.
I just looked at the NAO for Dec. 2003 and early months of 2004, and it is a “head-scratcher.” Dec. 2003 had a few days that were negative NAO, but none more than -0.5. Only 13 of the 31 days had negative NAO. From January 15th through January and into early Feb. there was a multi-week streak of negative NAO, with the last 5 days of JAN all being a -1.0 or lower (more minus). But the rest of Feb. was mostly + NAO until the 21st, when we had an 8-day streak of neg. NAO. Not all that impressively negative NAO that winter, but certainly more than 2002.
AO might have been at least as big a “culprit/hero” in 2004. Early Dec. it was positive, but then it went quite NEG for the 15th though the 22nd.
The huge news was in January 2004. The AO took a bit of a Journey to the Bottom of the Sea that month, with such values as -2.97, -3.85, -4.39, -3.89,-3.38 on 5 consec days in mid-January. Still another big nosedive from Jan. 24th through Feb. 3rd, and yet another one from Feb. 11th through March 2nd!!
Wow. These teleconnection levels are eye-opening. So like Kevin says, what happens with the NAO and the AO are MUCH more important in determining whether a winter is cold or not compared to the ENSO stages, and thus whether the chances for snow go way up. And sometimes PNA can have a fairly big influence.
Sure enough, the PNA was mostly positive that winter, especially in early DEC 2003 and for most of winter after JAN. 9 2004.
Went to Bristol this am and on the way back had to take an alternate road since the Rich Valley Road was detoured. Came back through Poor Valley and Brumely Gap. The leaves on Clinch Mountain were spectacular. As this year has proven, just drive around awhile and you will see some beautiful sights and go a little further and there will be dull spots. Enjoy the beauty while it lasts and I expect it will be over here by the first of next week.
Already down to 38 here in Woodlawn..some great and not so great colors on the way to work in Mt Airy today…down 52 some trees will reach out and grab you with colors while others you barely notice…
Blah!!! DT is talking 80s over the next few weeks! I’m done with that crap, bring on old man winter! Guess this is a good sign, perhaps it will stay warm through Thanksgiving and then turn cold and snowy!
32 and light frost from up here on Doppler Ridge on this Hump Day. Beautiful red skies at pre-dawn. “Red skies in the morning – sailors take warning.”
The leaves have really changed up here since Sunday. I agree with Clarkdocvet – some of the trees will reach out and grab you while the others are unnoticeable.
We dipped to 34 in New River this morning, and had a pretty decent frost on the cars, and grassy surfaces for the first time. It wasn’t thick on the grass, but it was on the car, had to let it warm up a tad so I could thaw the windshield to drive.
Snowfall contest was announced in today’s Roanoke Times. Online version has some missing information. As soon as that is corrected, I’ll post it here — and will draw much more attention to it with my next blog post tonight.
Here is the link for the Weather Journal column announcing the annual snowfall prediction contest, the entry details at the bottom. I’ll post it again on my next blog post.
http://www.roanoke.com/weather/wb/315450
Hey guys. If you are a fan of learning and want to read up on basically any winter storm in the past 20 years – check this out. One problem – it’s a North Carolina database. But the compreshiveness and the ammount of info here is unreal. I HIGHLY reccomend it. A great learning tool.
http://www.nc-climate.ncsu.edu/climate/winter_wx/database.php?location_county=&StartMonth=01&StartDay=1&StartYear=1959&EndMonth=10&EndDay=17&EndYear=2012&Submit=Submit