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Wednesday, November 4, 2015

Official 2015-2016 Winter Outlook

I'll give you the quick outline of how I think this winter turns out and then do some "splaining" about why and how I got there.

Winter snow totals: Lynchburg 20-25 inches.  Roanoke 25-30 inches, Blacksburg 30-40 inches, Danville 10-20 inches. 

Month Temps:  December Normal to +1, January +2  February -2 to -4
Seasonal Average 0 to +1

Summary :Winter temps slightly above normal, snowfall above normal. 

If I use a term and you don't know what it is, GOOGLE it.

The "Godzilla El Nino" as labeled has behaved as expected and it makes for somewhat of challenging forecast. There are honestly quite a few good reasons why going warmer and less snow is not a bad call including the QBO and some calculated risks about what the El Nino will do.

Remember.. Western Based El Nino's are usually colder with more snow, while eastern based tend to be much warmer with less snow. Basin wide events are less frequent and have mixed results. We currently have a basin wide el nino, stronger in the west but not much stronger. The overall belief seems to be that it will trend more west based and then weaken, but not sure exactly when. This is a key factor to a later winter surge of cold and snow.

As a result, hedging on things that we are not certain about is always a risk and needs to be treated that way.

The QBO is measurement of winds in the tropical stratosphere and a negative reading favors high latitude blocking while positive is usually more associated with less blocking. The number is strongly positive currently. On the flip side, certain snap shots of the AO from the summer reflect a likely hood of a negative AO in the winter.

I've mentioned the topic before of Snow cover in Eurasia and it grew quickly in October-- the second best advance on record. This DOES support high latitude blocking. High latitude blocking is associated with longer lasting cold snaps AKA, ways to get cold and keep it cold so we can snow. (-EPO, -AO and or -WPO)

The General feel for winter :
December starts off warm but trends colder later in the month. A week either side of Christmas has a shot at a snow/ice event.  The El Nino of 09-10 had a big event December 18th. 02-03 had a Dec 5th event PLUS a big Nor Easter on Christmas Eve/Day (That was north of here, but close enough to consider) 97-98 had a small event on Dec 27 and then 4-8 incher on December 30. 86-87 had a 4-8 inch snow ending as rain in early January.

Early January trends warmer and this will last most of the month. By mid to late month we see the pattern change clearly and we know it's on the way. By late month, we are back in a colder regime and should get 1-2 small to moderate events and ONE big event that helps us reach above normal snow during February.

March - some Data supports some risks for additional snow/cold but I'm going to punt that off and avoid it as of now predicting a benign weather month.

I'm not to jazzed about basing my forecast on the hopes that we get ONE big snowfall to push us above normal. Talking with Kevin Myatt from the Roanoke Times, he cited that El Nino's winters push our likely hood for a 12 + event snowfall from 20% to 40% . I'd like to add that we could end in a near perfect pattern, storm track is a little off or cold air isn't deep enough and we end up with ice rather than snow.

Another factor is that often if we get ONE 10+ event, we see another. 09-10, 86-87 and 65-66 are prime examples of this. So, I could be too low too..

Some clunker winters with El Nino's are : 06-07 but it was east based little snow, one ice event. 91-92, least snowiest winter on record, the Eruption of Mt Pinatubo has been offered as a reason why.  72-73 in many areas to our north had NO snow, but we managed 10 inches down here so not  horrible winter here. 41-42 winter had only 5 inches, but if you look at the bigger pattern you'd think we had a snowy winter. 97-98 wasn't horrible here with a few snows east of the appalachians and 2 near misses, one that crushed those west of the Blue Ridge.

Some snow el nino winters: 09-10, big snow in December then a pretty brutal stretch from late January till Mid February. We missed the worst with 20-30 inches in a 10 day stretch but places up from DC to Philly had 40-60 inches in 10 days. 02-03 Pretty cold and snowy all winter, with the BIG event being a sleet storm. 86-87- One snow to rain just after new years then back to back events Late January, a few more events in February. 65-66- one of my favorite winters where from Mid January till  early Febryary 40-60 inches fell in a 3 week period.

So, outside of a cold snap and possible snow/ice  near Christmas- We wait for the pattern to develop in the second half of winter and should have some decent snow to enjoy. If you recall last winter, we had literally nothing then for 2 weeks it snowed 3 times, including a 6-10 inch snowfall and schools were out the most past of 2 weeks. This winter may reflect that in our "sensible" weather.

If you want my confidence level:
50% we end up within a reasonable range of this forecast.
30% we end up warmer/less snow
20% we wend up colder/ more snow and ice.

I'm using 82-83 as my top analog. We had a December snow, but a warmer month. January was warm and basically snowless, February flipped colder and had a decent event on 6 of 3-6 inches then a NICE storm of 15-20 inches region wide on February 10-11.

Wednesday, September 30, 2015

Rain, Rainier and Rainiest..

Sure has been dry?

Rainfall this month..

Blacksburg 8.61 inches
Roanoke 8.48 inches
Lynchburg 7.13 inches
Danville 7.7 inches

Some higher elevations have in excess of 10 inches. All these places run into the James and or Roanoke River.

90% of more has fallen since Monday 9/21

Time crunched and sparring you the synoptic details...
2 options from here.

Either way, I believe we get 2 more "waves" of rain between now and Sunday.

Option 1.. Wave one is dominant, The Hurricane stays far east and we still end up with an additional 2-7 inches of rain. Will have wide spread flooding. Some trees fall as well due to weakened soil.

Option 2- Hurricane gets captured by upper air low and ends up over NC/VA as landfall. Rainfall is still 2 waves, additional rainfall is more in line of 6-15 inches region wide, flooding goes from really bad to about historic. Winds are much stronger. Trees will fall with option one simply because the ground is so wet, with option 2 the winds are much stronger maybe 20-30 sustained with gusts to 50 and trees and power outages will be much more wide spread.

I'm leaning option one as of now with a 70/30 probability.

Wednesday, September 9, 2015

What does the Godzilla El Nino mean for Winter in Lynchburg, Roanoke, Danville and Blacksburg?

There is no simple answer for this question. Some of our snowiest winters have been tied to moderate to strong El Nino's. Conversely, some very boring and benign winters have been strong El Nino's.  What can we learn from them?

When the water is warmest towards South America, the winter is usually not severe. When the water is warmest towards the Central Pacific, closer to the international dateline, the winters tend to be more severe.


Boring Examples

1997-1998- SUPER El NINO, our are of Central/Western VA had 1 significant event, 4-10 inches, 1 Elevation dependent event (12 -24 inches above 2000 feet) and a near miss.

1972-1973- 6-12 inches total for the winter with a near miss to our south. February ran -3 for the month, but wasn't very snowy.


09-10- VERY Cold and snow, snowfall was 30-50 inches for the winter region wide with 2 to 3 events above 10 inches.

86-87- 3 big events region wide, 2 smaller events, 30-50 inches region wide. 2 12 inche snowstorms within 4 days of each other. Crippling 2 weeks.

65-66  Incredible winter, jammed into 3 weeks where 40-60 inches of snow fell region wide during those 3 weeks. Storm after storm pounded our region from Mid January to Mid February. Crippling 3 weeks.

Sidebar: Chatting with a lady up in Covington, my weather hobby came up. She mentioned that her son was born during the horrible stretch of winter weather as her husband was actually visiting Lynchburg. Snow removal/ Snow Travel was harder back then and it took him days to get home including the last 10 miles by horse.

Above Normal

57-58- Colder winter, 25-35 inches total, one BIG storm in February, 8-15 inches region wide.
82-83 Winter was non existent much of winter, early December storm of 3-6 inches, early Feb storm of  3-6 inches. BIG Mid February storm of 12-20 inches region wide. (Historic Storm for the East coast)

Currently, the El Nino is MORE east based (leans boring winter) but the warmth has been moving west. Much data has the central area becoming warmest which hedges towards cold and snow. I'm not quite willing to jump on that yet. However, a few thoughts:

1. Winter may resemble last winter in that most of the events fall in a 2-3 week period.
2. The risk for a "Big one" will be at the highest level.
3. Much of December and January may be boring and warm.
4. My current hedge for winter would be the "above normal" but not Severe group.  I'm going to let September play out, review some more data and have a complete Winter Outlook by Mid October.

In essence, December and January will average above normal temp wise with a small event or two possible. A time or two where a storm takes a perfect track, but has no cold air to work is very likely. Winter will be consolidated into 2-3 weeks from Late January to Mid Feb with a BIG event possible.

Thursday, May 21, 2015

Severe Weather Tips and Guidance

Severe Weather is fun and exciting but can also be very dangerous.. here are a few thoughts about ways to protect yourself and raise your personal awareness.

1. Have a good radar app--  Android- Rainy Days,  iPhone- My Radar.  Have them in motion so you see if the storm is moving towards you..etc.

As a corollary- if you're not good at geography, learn a little. Often a warning cites a location and tells you where the storm is heading. Example : Storm is near Forest and heading NE towards Lynchburg and Madison Heights. That's an easy example. Know the counties near you so you get an idea where these things are headed.

2. Beware of OLD 411 on Facebook. Often a warning gets issued for a region and the next AM it's cycled up on Facebook again. Once again, if anyone has Zuckerberg's email, let him know to write some code so we can expire weather data, which has become a great medium to get important information to the masses.

3. TWC-  TWC is a nice resource, but in severe weather times, I strongly recommend watching your local stations. Why? TWC covers the entire nation and your local guy does your area specifically and only. Yeah, TWC scrolls your data non stop, but they will also have tons of 411 on wherever else in the nation is having severe storms. This is NOT a knock on TWC, but advising you to find more specific information to your area.

4. Lighting and outside play, sporting games. If you hear thunder, end the game, Get your kid off the field, out the pool, etc Lighting can be 10 miles away from a storm. Many places have adapted policies to reflect this but don't allow parents, coaches or even you kids (please let us swim longer, it's far away) The pool will be there when the storm passes, the game can be rescheduled but lives can't be resurrected nor do all injuries heal as we want.

5. Know the difference between Watch and Warning.
Watch- storms are possible with *hail, strong winds, tornadoes
Warning storms are happening with hail, strong winds, tornadoes

With that, learning geography helps because a Tornado warning for Henry County for a storm heading Due East shouldn't scare you if you live in Evington. :)

Thursday, April 2, 2015

Winter review..

Now that we are into April and any shot of snow/ice is really gone-- let's go back and see how I graded out.

Winter outlook 14-15

Overall, we grade out pretty well.
December was the warmest month and in Lynchburg we ended up right in the range of snowfall, with Roanoke and Blacksburg being just a smidge low. I called for temps to be 1-2 degrees below normal, and we ended up in the -3 to -4 range region wide because of the ridiculous -9 to -10 departure in February.

One of the best quotes is:

1-2 degrees isn't much I'd not be shocked if that 30 day stretch I mentioned is a -4 to 5. I think the we get a stretch where 2-3 storms beat us up pretty good in a 10 day period and snow falls on top of a snow pack during that stretch. 

Now, my timing was slow by about two weeks and that was because the trough axis was a bit east and pulled back west into mid February. We had some colder temps before that but it was basically dry. 

It started out on Valentines day with a decent Saturday that ended with a STRONG cold Front passage, where we had a about a quarter inch of snow. That lead us up to the Presidents Day storm where 6-9 inches of snow was common over all of our area. The following Saturday we had Snow to ice where parts of Amherst county had 10-12 inches, while Rustburg south only had 1-2 inches. The official number on the Climo report for Lynchburg is 6 inches, but I think that was a mistake that I talked to Sean Sublette about before he left and it was never corrected at the NWS. That would actually knock Feb 15 out of the snowiest February ever, but this is science and exact figures matter. 

Next we had the Huffman special on Feb 25-26 where 3-4 days out many outlets bought the storm well to the south and I held on my 3-6 inch call and it worked out very well for our region. 

Lastly, the snow to ice in early March topped of our winter season. My forecast was on par with everyone else as we all had to guess at where the sleet line ended up. 

Best Call: 3-6 inch event Feb 25-26

Proud of: Hitting the sleet on the Presidents day storm. It cost us about an inch and a half of snow here, but not I did pull the sleet into Lynchburg if you check my map Here

Needed work: The Saturday event I played the north trend and it drifted a bit south last second. I could have hit the ice a bit harder too-- it wasn't a HUGE ice storm but it was significant.

Summer Outlook? Working on it-- El Nino summers tend to be warmer than normal.

I grade that a Solid A-- not bad compared to my TOTAL F for my outlook last winter.  We've hit our average snowfall the past 2 winters and 12-13 was only off by 1-2 inches. We've also hit a trend of bigger events. From The 96-97 winter until 07-08 winter we only had 3-4 snow events over 6 inches in that 13 year stretch. Since 08-09 we've had 9. 

Saturday, March 7, 2015

Any cold left?

We are stepping out of what was one of the most intense 3 week winter periods in our area ever. The time period rivals any 3 week stretch combined cold/snow-- we had a few colder and few snowier, but combination of them both is top notch.

Finally, a break is on the way and we should begin to feel some seasonal temperatures. March is known for it's wild swing and it seems the next week or so should be normal to even ABOVE normal. Late next weekend/early the following week we will be be looking at the rebuilding of the west coast ridge that led to our continual dumps of cold air from the north pole. This could be another round of perhaps late March mischief.

Understanding the pattern, the PDO is a scale that measures temps in the pacific in certain locations. Positive numbers indicate a better change for a west coast ridge. Those who follow the weather know that Cali and nearby states were super warm and dry. I know I recall seeing countless reports of insane numbers in Seattle of 70-80 to the place that's the 49 and rain capital of the world. The PDO is a cyclical pattern.

As we start to wind down winter, I tend to fade out a bit in severe/hurricane season, especially when it's boring around here. It's probable PAST when I need, but I've been working on a blog that conveys some ideas about finding a good forecast in the digital era. In the next week or so, it will likely be a 2 part blog that may help you find out quicker what the weather will be like.

Thursday, March 5, 2015

No big changes

Map from Yesterday holds..

Sleet is going to be an issue where sleet develops between 8-10 in our area and doesn't change to snow till mid to late afternoon. Temps keep falling all day-- upper 20's by late day. We do get a few hours of snow late afternoon and evening.