Winter "Pre" Previews are trickling out.. If you like cold and snow you will LOVE..

Winter outlooks done by mets/ weather hobbyists are more fun than accurate at times but they do make fodder to read and post. I've noted a few notable mets with early previews and others tossing hints.

I have some early thoughts for the areas including Lynchburg, Roanoke,Danville and Blacksburg.

Most guess are predicated upon:

1. We will most likely have a low to moderate Modoki El Nino. This means the Pacific, especially in the mid pacific known as Regions 3/4 will be in an El Nino phase. 

2. The PDO should be positive- Warmer water closer to the north pacific coast from Alaska down towards the US will be warmer. 

3. The Atlantic MAY be more favorable for high lattitude blocking in the NAO and AO regions.

If you have every kept up with my blogs, those are all really good things if you like cold and snow. We always blog from the perspective that snow is a good thing,.

A modoki El nino is the closest winter  to a consistent theme.  Most end up remebered for being fairly cold and rather snowy.  Winters with similiar patterns were 86/87, 02/03 09/10 with other years having lesser levels of commonalities. 

86/87 is remember for have back to back 10-14 inch snowstorms in our area from Jan 22 to 26. Region had 30 to 60 inches of snowfall.

02-03 had MANY storms in the 3 to 6 range and a BIG storm ended up being sleet here (in the 3-6 inch range of sleet). The region had 20-50 inches of snowfall for the winter. 

09/10 had 2 storms over a foot and another get really close. Snowmaggedon dumped close to 15 to 30 inches region wide over a few days but DC north had 40 or more inches in a 10 day stretch.  Seasonal totals were 25 to 50 inches region wide. 

With that,  nothing is every a lock-- especially before we have an offical El Nino and a few other variables. 

If we get to October 15, we know the Modoki El Nino is happening and the other factors are in place, my winter outlook would be:

Temps regions wide-- Seasonal 1-3 below normal for the winter. 

Snowfall, by city. 

Danville region/southside- 10 to 20, but a lot wiggle room for more. 

Lynchburg Area 18 to 28 inches, with higher end potential. 

Roanoke Valley region- 21-31 inches, potential for more. 

Blacksburg, NRV and Highlands Region- 25-35, even more in Lake Effect areas. Also, potential for much higher totals. 

Each city's top 10 snowfall winters has 2-3 modoki winters in those totals. 

Modoki El Nino's are known for having 2 or more LARGE events of over 10 inches.. once snow gets into double digits around here, it's a memorable event. 

There is also a "hot" period from around January 20th until February 10th or so that has a historical precedent these large events with other events being more scattered thoughout the winter season. 

That time period is often easily identifed  in advance by-- Modeling showing strong blocking in the Artic/Greenland region (Negative A0/NAO cuplet) positive PNA(Ridge on the west coast) and the SOI (Southern oscillation index) dropping  7-10 days in advance. (This is tied into the sub tropical jet becoming active)If that happens we could pop 2-3 winter events in a 7-10 day period. 

A couple runs of the seasonal runs from the Canadian Model and European model showed literally perfect 500 mb maps if you wanted a cold and snow winter for December to March. These maps displayed blocking on the west coast and artic/NAO regions with clear evidence of a strong sub tropical jet. Sub tropical jet is very important for our region because we do sit far enough south that we need a pretty unusual pattern to have the northern jet suppressed for snow in our region. 

With that, we are only on August 18th and a lot can and will change.  It is completely possible that we have all the pieces I cited in perfect alignment and we end up with a rather tame winter. This outlook previews where I am likely heading, but will updated my thoughts hopefully by late October. 

In Lynchburg, 1/10 of one inch of snow in April is more rare than a 10 inch snowfall any other time of year.

I've been light on blogs this winter for many reasons. One main reason is the many storm events AFTER daylight savings time.  Model data runs late and it's just easter to tweet out thoughts then an entire blog.

I've had several messages about WILL it snow this weekend.  Model data has been all over the place and knowing the lateness of the year I was certain the risk of snow was good, but models that showed 6+ inches were easy to discount. In 120 years of record, our largest April snowfall is 3.9 inches in 1907, our last inch was in 1992 and last tenth of an inch was recent, in 2013.

Since 2009 alone, we've had 5 storms above 10 inches measure here in town. So, any accumulation Saturday (Heck and Maybe Monday) is a big deal climatology wise, but not a huge impact compared to rain. (Rain or snow on April 7th will ruin your day but travel should be FINE, except maybe if it snows hard a few hours)

So, what will happen??

Data has gone from heavy snow well into NC and us being on the north fringe, to the best snows being north of DC, to now showing the best snow maybe to our south and east. Now, models don't control weather, they display what we MAY see happen.  There are a lot of moving parts, crazy cold air pushing in fast but pretty warm air in place before the storm approaches.

Rain pushes in Friday overnight and flips to sleet and snow before ending. Some data is pushing for another enhanced wave of snow for parts of the region after the chance to ice/snow.  Another storm pushes in late Sunday that could give ANOTHER coating or more of snow to parts of our region.

Rather than clutter the blog with pics, I'm going to post various maps from resources about the storm. Remember, anything that is a .1 of an inch is a VERY rare event. (Roanoke/Blacksburg see a little more and had over an inch in 2013, Danville Likely a bit less)  Some people are bullish on an inch or two in part due to the strong push of cold air with warm temps to the south could feed bands a little better than modeled. I'm not sold either way yet, and honestly because it's april I'm not overly concerned other than the "historic" nature rather than impact on the day. Sports would be cancelled with rain. If we see snow, it may impact your day a few hours but I don't expect long term dangerous roads.

So, make sure you have me on Twitter or Facebook under LynchburgWx/VirginiaWx.

Well, That esculated quickly..snow totals going UP!!

OK, Party people in the house! Who wants more snow??
Look at the bright side-- even if we get 8 inches, You will be driving tomorrow afternoon. March Sun is burtal, same angle as Late September.

I am going to beef up totals a bit, and even say- some places, Lynchburg especially I would not be shocked if we had 2 inches total or even 8 or 9.

Why? We have a strong contrast between warm and cold. Look at these dewpoint temps 8 over southern PA and 65 in North Carolina.

In simple terms, the cold air push is a bit stronger and the low is being forced further south. This should keep us in heavier snow longer and timed well. The snow last week- if you noted we hit 4.5-5 and stopped getting deeper when the snow slowed down. The best snows should fall overnight into mid morning but snows may linger a bit longer. If we were in January, We'd be talking about MAYBE  a foot or more. 

The snow will start in impressive fashion: all the models show some type of heavy band that fires up over NW North Carolina and explodes north and northeast. Any rain will quickly change to sleet and snow, then snow. After that first crushing band of snow, we should see 5-6- more hours of moderate accumulating snow.  By midmorning, it will keep snowing but hard to make snow depths greater.

What go wrong?

1. The band misses your house. Very possible, greatest changes east regions (Danville, LYH area.

2. Storm ends not not as far south (less of a band, less moderate snow after)

3. Sleet- greatest risk eastern regions. 

4. It may "snow" 8 inches, but only accumulate 4. March-- it will lay, but not the usual ratios. 

My map has ranges. I may be underdone southside.

Lynchburg: I have this theory about West to east moving upper air lows vs Southwest to north east. We usually do better than Roanoke in East west, and they do better in Southwes to north east. Last week, Southwest to north east- we had .15 more liquid and an inch more snow. (Feb 12, March 13 Jan 10 as other examples) We will put this to the test. Model data has slowly moved  heavier snow into Lynchburg. 

Why? My theory is the low level jet comes in better with the east locations and the "bands" I often mention are more mature  on West East moving upper air lows vs SW to NE bands tend to dry slot Lynchburg in a relative sense. This is another test of that theory. 

My map: I really just forecast the Roanoke/Lynchburg DMA-- If you are just outside, I did not review your area. :)

Share me with your friends and follow me on Twitter/Facebook at VirginiaWx. Will Tweet/post current obs, radar shots and other forecasting ideas about this event. 

Get this: MAYBE more snow Saturday!! 

Details on Late Season Winter Storm for Lynchurg, Roanoke, Danville and Blacksburg Areas..

Late blogging, simply put-- I was a doubter of this storm.  In my interchat and responses, a later storm was better. First, night time was better for snow and more importantly We'd get a stronger coastal low. Well, we have a storm that is 12 hours later than thought and a decently strong coastal low.

Currently:
Winter Storm Waches Roanoke Valley south down 81.

Expect: Watches and Warnings All of 81 and likely 460 to Appomattox.

Expect: Advisories, maybe watches and warnings along southside from Martinsville to South Boston.

Amounts :
Everyone along 81, except the actual Roanoke Valley (Orange Ave, Peters Creek, ect) 4 to 8, with some 10-12 inch totals possible in Floyd, Bent Mountain, ect.

Roanoke City, valley level only east on 460 to Bedford, Forest, Lynchburg to Appomattox 3-6, possible 8 spots here and there.

Southside:  2-4, possible 6.

Small issues:
1. May start as a mix or rain, but will change to snow.
2. Start time: 10pm Sunday far west, 2 am far east.
3. End time noon Far west Monday, 3pm far east.
4. More accumulations on colder surfaces and grass.
5. Low ratio snow- normal is 11-1 or so, this will be as low as 6-1 to maybe 9-1 in mountain west.

Bust issues:

We go under totals if:
Low is weaker, further away.
Quicker mositure jump to coastal could rob central areas like Lynchburg.

We go over if:
A bit colder, a bit faster a bit stronger.

Will post map outside of this post for easy sharing :)

I love it when my readers share pics, amounts and start/stop times.

Moving forward :To quote GNR-- Where do we go now??

We are slowly shifting back towards a colder pattern. Some areas saw a dusting of snow, or even more in the higher elevations of Amherst County. 

We all know I don't blog about cold, so where are the snow chances??

1. Friday- Rain may end as snow. Places west of the Blue Ridge, especially higher elevations have a shot a some accumulations. 

2. Superbowl Sunday into Monday- Another storm approaches from the south. We have limited cold air but maybe enough. Current thoughts think the Western Areas catch up on some snowfall while the south and east regions snow to mix or mix to rain events. 

3. Feb 8-9-- maybe, but that's 10 days out. Just watching. 

After this event, we could have a brief 3-4 day warm up then we get a colder look, maybe not that different from the colder pattern we had after Christmas into the first week of January.  We had serious issues getting moisture so we missed any real shots at snow. Some signals look more wet and stormy, but I say that with caution because I remember model runs around Dec 22 showing a crazy storm pattern that never materialized. 

For the year, Danville is above normal snowfall while the rest of the region has some catching up to do.  With enough cold air lurking around, I think we have a punchers chance to reach our "normal' snowfall.. give or take a little.  We are not moving towards a "big" storm (12 plus for much of the area) but more like a shot a 1-3 moderate events. 

Someone may see half a foot of snow!

OK,  hard, low confidence event for what will be a 1-3 event most places. Someone may very easily report 5 ot 6 inches, but where?

Complicated set up. We really had 4 events from this thing.. starting yesterday over a large chunch of the nation. We will get involved in the final act of this storm system.

So, most places up in the 40's today. One last arctic shot comes through and little wave forms behind it. There is snow behind the front and it forms or reforms as it gets close to our region. Where it reforms/forms decides who gets how much snow.

I wait to blog until the Euro came out. Other than the NAM model, all data had pushed the 3 inch snow line to Lynchburg. The euro last night had 2 inches and today has backed off a bit, down to an inch. Some of that is noise, but it does match more of what the NAM displays.

So, with that-- The best guesses at this point

Roanoke, NRV
Coating to 2 inches:

NC border counties, west of Martinsville: 1-3

East of Blue Ridge including Lynchburg/Danville Think Route 29: 1-3, someone may pop 4 inches on in this area.

East of here to include South Boston, Keysville, Charlotte Court House, Appomattox Farmville, Clarksville, Bug Island: 3-6.

Risk Factors:
I'd be shocked if most places dont get at least a coating. But, when you have a band form, rising air in point A means sinking air in point B.. which means you dry out.
I'm most concerned the areas from Moneta to Bedford to near Lynchburg may get caught in a relative minimum.

The flip side is: Some data has pushed a little closer to Lynchburg where 3-4 is very doable in Lynchburg.

This could be an event where Wildwood out on 460 west near the 7/11 has a half inch and the Burger King on Campbell has 3.  Pretty tight gradient.

Share this blog and your updated on my weather page/twitter feed. Especially want to find reports from those in the highest risk areas for 5-6 inches.

Tuesday Night and Wednesday Snowstorm ideas.

First- Always remember if I saw or show what a model does, it doesn't mean it will happen. It also doesn't mean that is my forecast.  Maybe I was careless with my words about the Euro run Friday and it seemed some people may have ran with this as my forecast. I don't run with one model, I blend some model runs with added knowledge about our local climate and past events. When I make a forecast, it will be clearly marked. I share model data to raise awareness of future events.

This event: As stated, Friday looked like a nice step towards a decent event, we had a backing off  late Friday into Saturday and then last night a step back towards a decent event.

The floor of this event seems to be a coating to an inch for most places.

The ceiling seems to be a 3 to 6 inch snowfall.

Right now,  the best bet is a 1 to 3 inch snowfall for most of my readers (Blacksburg, Danville, Roanoke and Lynchburg. 

Somewhere, right now it seems to be favored east could end up more in that 3 to 6 range.

The basic set up. 

There is a clipper system that has a cold front attached to it. The front slows down and a wave develops on it, enhanced by a strong jet aloft. So, there isn't really a "strong low: or really even any low at this point. If we do get a low developing faster, like the Euro showed on Friday we could end up with a decent event again.

The Euro last night was a little more bullish on the wave..


3 AM

6 AM

9AM

12pm

This is the total precipitation from the last run of the euro. The best enhancement is just east of Lynchburg, but about .25 falls in Lynchburg.  This could move  either way before Wednesday.

That is the progression of the snow as it moves through. It strengthens over our area due to a strong jet over head. Basically, when the air aloft is moving that fast, our air rises to replace what is moving away. Lift = wrings out our moisture into cold arctic air.

Not in this mapthe strong winds from the Jet stream (Lets say from 15k to 30k feet, flow is out of the southwest.

Summary:

At this point, Most areas are on target to see a 1-3 inch snow fall.
Some places, as show on that map, could see a bit more like 3 to 6. As of now, best locations may be east of Lynchburg but that will likely change a bit as get closer.

I will tweet out updates throughout the day and likley have a blog updated in the morning. Share this write up with your friends..