Tuesday, January 16, 2018

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.

Sunday, January 14, 2018

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..

Monday, December 25, 2017

Christmas week cold and storm threats! 2 or more "shots" at hand, yes I am serious, Clark.

If we could "flip" Christmas and New Years!

First, Merry Christmas to all!  Hope your holiday season is filled with love, joy and peace. My 9 year old is almost sure that Santa isn't real, but I just caught him red handed in my house..

I was snapping a pic of my tree..

Had a second pic that looked like "this".. 


So, the cold is a little later getting here or we could be talking about a little threat tonight. With that, Grandma's cabin up at 3k feet may see a litle snow up in West Virginia. 

We remain cold Christmas week. Model data has been insistent that we see some snow in the next 10-15 days but it can't figure out when/how much.  Breaking down the details. The ensemble numbers have been impressive with near double digit totals for the 15 day period.  

1. We will have plent of cold/air in place and a "pattern" that supports snow/ice.
2. 2 maybe 3 shots at hand.
3. Details are sketchy, The models have gone from a focus on the Friday event, to a focus on the New Years eve/day event. There is some hints at another event Jan 5/6 which could be the "breaking the cold" storm. 
4. Details are are hard with a faster jet, finding the right short wave to amplify is a challenge. Legit shot we get next to nothing and legit shot we score some snow on maybe all 3 events. This is more of an awareness post :)

Friday's event- At this point looks to be a southern slilder, with somewhat of a lack of moistuer. As modeled, if we "max" the potential a 2-4 incher is possible, and a total miss to our south is possible. Worth tracking- moving a storm 100 miles NW on the models in 5 days is not hard at all, but this is less than ideal and  very werid set up with cold in place but a second low in the Great lakes and at one point 4 areas of low pressure. 

New Years Eve-Day is on some models. The Euro model last run had the cold overwhelm the pattern. Some hints it could be a classic coastal low, (Nor Easter, Maybe  a Miller A)  Not a lock, but worth watching. 

Jan 5-6- Just looking at patterns and longer term ensemble members display a threat. No specifics. Often, as cold leaves and the pattern breaks down you get a  See ya! Storm. 

Will updated as needed. This evenings GFS/GGEM (American and Canadian) displayed a close call with Friday and more significant event Sunday.

Will blog when more details are needed. Look for updates on Facebook/Twitter and share with your family and friends. If you're bored.. click an ad :)


Friday, December 8, 2017

Full Snowstorm update 5 am , Friday Dec 8th.

I get that no one else is calling for a major storm yet. No model, NONE doens't give our area a big snow.  NWS has issues a Winter Weather Advisory for the NC/VA border states for 1-3 inches of snow. Our forecast is for a 50% chance of snow.

Last nights call:
1-3 West of 81.
2-4 LYH to ROA
3-6 Southside.

I'm going to hold those I see the noon data. If noon data shows the same information, I will double thouse totals (approx). We just need to train a little more.. :)



3-6  along 81  including Roanoke/Blackburg
4 to 8 Lynchburg to Danville Back west to Galax.

Crazy in that some areas may have some rain or snow falling by then.

The big issue is we have our low in the gulf, and it gets renergize by energy from the clipper energy aloft. This won't happen until late evening and overnight. I imagine our heaviest snows will be pre dawn tomorrow into late morning.  Restated - Our best snows fall towards Morning tomorrow and the bulk of the morning tomorrow. There could be some rain mixed in or even straight rain falling today. **If this pans out, our accumulating snow falls late tonight and tomorrow am**

Still a high risk bust event. Waiting on a storm to fire up overhead is RISKY! Things can go wrong.

Some maps!
This map is the short term Canadian. This is 10 am tomorrow morning. Heavy snow extends back to the blue ridge.

These two are from the latest run of the GFS. So the snow map could be a little overdone with some snow from today melts or falls as rain. But, shows the moisture. 

In summary, HOLDING with our calls but will double if the models hold..(Not doubling southside exactly) The short term models (Higher resolution) start around 9 am and the Euro at 1pm. Will tweet/post updates in run. 

When it's snowing heavy tomorrow morning and you hear a yell, It may be this guy!


Thursday, December 7, 2017

6pm fast update 12/7/17- What is going on..Snow expected

 Model data has trended to a more snowy look.

Why?

1.Low in the Gulf was progged to head NE to a spot off the NC coast but be weak. A Clipper system and it's upper air energy didn't look to interact much. The model runs that showed snow had some level of interaction

2. Last night ALL data trended away from a low being close enough for snow.

3. Noon data showed more interaction or phasing between the clipper system over The Great Lakes and our storm in the Gulf. The result is a slower system that is stronger ( Maybe sub 1000 mb east of Hattaras)

4, Snow may be in southside mid morning, up to 460 by mid afternoon, but that's just the teaser.

5. The bulk of our accumulating snows will come overnight into Saturday. There may even be a lull the bulk of Friday evening.

Best guess
East of 81 Roanoke to Lynchburg 2-4
Southside  3-6. (Martinsville, Danville
West of 8 1 1-3

If the trends continue, we could up those especially in the Roanoke and Lynchburg area.. and at some point mixing could be an issue in Southside areas.

Please share this with family and friends.


Rapidly changing data.. expect a ton of data tonight. 

Wednesday, November 29, 2017

It gets cold, then what??

Most of my friends and followers for my weather stuff likely follow other weather resources ( Yes, I consider that cheating :))  Haha, I should make a list of good people to follow (Kevin Myatt, Blue Ridge Weather, Wxrisk) and those to avoid (DooleyCaster)

So, this means that most knew the pattern change to cold was coming.  However, what it means in your backyard is much different.  Here are a few thoughts.

1. It will be cold by December 7th. Well below normal for a few days here and there and seasonable cold many other days.  Normal to above will be limited, but still happen.
2. The pattern looks more cold than not through December 20th, then make sink back colder after a lull or small break. Most data supports cold through the end of December and maybe even into the first 2 weeks of January. (The further out we get, the more risk is involved with that statement)
3. Most people care mostly about snow chances. Now, I do love a cold brisk day.. but reality is cold without snow kinda sucks. So, what do we know about snow changes.
A. No specific threats to really track. The models have flashed a couple of things starting December 7th, but nothing at all to "track".
B. It's not out of the relm that we don't see a decent snow, even though it will be cold.
C. With that, It's been snowless in December since 2010, and I think odds are greater than 50% that we break that streak.

Types of storms that impact our area (Central and Southwest VA, including Lynchburg, Danville, Roanoke and Blacksburg) that bring ice/snow to the region. 

1. Nor Easter, Coastal lows(Also called Miller A )- These are the classic big storms. They originate in the Gulf and head up the coast. These have the most potential for big events.

Risk of mix- high, especially east of the blue ridge.
These storms often deepen quickly, which creates for stronger winds.

2. West of the Mountains (Miller B)
These storms form in the south/west and end up west of the mountains. At some point, the jump to the coast, 99%of the time too far north to impact our area.

These often start as snow, change to ice and eventually rain. Snow amounts can be small to at times significant (each set up is different, and is dependent on the strength and depth of the cold air in place

3. Clipper systems (Alberta, not Los Angelos)
These systems originate over the Alberta Region of Canada and head south east. Most often, the pass to our north, but in times of strong blocking, will dip over our region. These systems are usually in the 1-3/2-4 inch amounts with the occasional amounts hitting the 3-6 inch range.

4. Overrunning-
No realy defined low pressure, but cold air in place and the flow aloft turns to the south and southwest pushing warm air our direction). These systems vary from ice events to decent snow events. Bigger overunning events can be in the 6-12 inch area, but more often are a few inches that changes to ice ( Think this way, if there is cold air in place and warm air pushes in, it would eventually change to ice/rain unless more cold pushes in

5. Souther slider- A coastal low like a nor easter that heads out to sea near the NC coast rather than up the coas.t

Less likely to mix, can be a big or biggest event

Now, these are labels we put on storms and not every storm falls into a box like I've described.  Once  we have a few storms to track, this is a handy glossery to use when I start talking about storm tracks.

Sunday, November 19, 2017

A winter outlook so to speak..

In the past I have done a more in depth write up and conveyed more "personal"ideas about what may happen in the upcoming winter. In General, long range at some levels is more of a "good guess" area rather than skill. Often I read many outlooks then do some local research and put out a forecast. This year,  I have some ideas

This year we have two schools of thought.

1. Normal "La nina" winters which would favor milder tems and less snow/dry. 

2. Other impacted "La Nina "winters which would feature more snow/maybe more snow. 
- Other impacts are the QBO, Hurricane season and global SST's. 

Analog years are harder in the context of weather or not you are a "believer" in some type of climate change, the globe is very warm and this does impact our sensible weather.  You could go above normal temps in an season at this point and be correct maybe 80% of the time. 

For our area (Lynchburg, Roanoke, Danville, Blacksburg) I'm to hedge colder, with below normal snow, but due to ice/mix and dryness. 

Temps- All Areas Normal to -1. I do think we see a couple of significant artic outbreaks. Let's be honest, if our lows are in the single digits with wind chills, kids are getting snow/Cold  days  from school. 

Snowfall- 
Danville 2-12 inches
Lynchburg 5 to 15 inches
Roanoke 7 to 17 inches
Blacksburg 11-21 inches. 

Upslope regions will be above normal (those places that just snow when it's cold)

Why the weird snowfall range?
La Nina winters tend to lack  the sub tropical Jet.  With that you tend to have system that are a smidge to north for our region. Storm track may feature systems going into eastern Kentucky then jump to the coast north of our region. Those are classic snow to mix or just mix events here. The risk for increase blocking could push those to our south under the block and increase our snowfall.

Snowfall is a guess at best, so take that for a grain of salt. I'd expect a little drier than normal winter. IF we over achieve on blocking (Blocking up north pushes cold air south) during an active storm pattern, we could easily over achieve on snowfall.

Be ready for frequent twitter, facebook and blog updates when pattern changes arive. We should remain seasonable chilly for the rest of the month. Good bet that we remain snow/ice free through mid December.