Yo'-- Let's kick it. Ice Ice Baby

No big changes--

Snow and sleet develop north of 460 between 5 and 8 am tomorrow. 

Sleet, with maybe a few snow flakes, quickly changing to freezing rain develops southside Between 4am and 7AM.

460 north could see up to 2 inches of snow and sleet, mainly sleet. I suspect it's mostly freezing rain by mid afternoon, with a little sleet mixed in. For those wondering, sleet accumulates about a 3-1 ratio, so one inch of rain water  3 inches of sleet. I suspect that between .2 and .4 max falls as sleet. That's a half inch to about an inch and a quarter based on my best guess. 

Freezing Rain- southside will see a glaze to .25 at the most. 

460 corridor gets .15 to .40

Once you get NW Amherst County, Rockbridge, Fincastle north, .25 to maybe .60 could occur. The best moister wants to focus on that area JUST north of 460. Something to watch on radar tomorrow. 

Winter Storm Watches Hoisted-- Complicated forecast.

As is often the case, with our storm as some details clear up others become more murky.

It really seems like a mix of snow and sleet develops and begins a drift towards freezing rain, starting in areas to the SW and spreading north and northeast.

Drier air is a concern and where exactly the best lift sets up is a concern as well, because some areas that are expecting a decent snow and ice event COULD end up rather dry, with just freezing drizzle the bulk of the day. Anywhere from 460 south needs to be aware of this concern.

This will likely be a "winter storm warning" but will lack the total moisture to be a "big ticket event". The colder temps will make it a travel concern but major power outages, ect are not likely, especially from 460 south. North of there, snow and sleet should minimize ice build up.

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Yellow: Initial burst of sleet, maybe a little snow switching to Freezing Rain. up to a coating of sleet and snow, up to .15 ice build up.

Green:  Sleet and snow mix to start, Coating to 2 inches. Ice build up from .1 to .25 in hardest hit areas.

Pink;  Coating to 3 inches of snow/sleet. .15 to .40 ice build up. 

Yellow area includes: Martinsville, Danville and South Boston. 

Green area includes: Blacksburg, Lyncburg and Roanoke

Pink area includes: Northern Amherst, Northern Botetourt, Lexington, Staunton, Waynesboro. 

The devil is in the details.

No real changes-- AGAIN. Don't mean to bore you.

Let me "retract" my comments that sleet/snow chance have dropped. Model data has cooled and I think we can see a coating to 3 inches depending on location.

Southside- Danville, Martinsville could start as a quick burst of sleet and snow.

460 Blacksburg to Roanoke to Lynchburg= Coating to an inch or two of sleet and snow

North and west, more sleet snow and ice- Lexington, Fincastle, Staunton areas.


Key issue= from 460 south, including Roanoke and Lynchburg the once the sleet and snow flip to freezing rain some of the model data really slows down the precipitation. So, while it will be below freezing, we won't get a ton of ice in these areas. Southside is in the same boat, just less sleet and snow on the front side.

Second wave? So-- we flip to freezing rain and then it slows down. Some data suggest we will have a second wave of heavier stuff late evening as temps creep towards freezing.

Somewhere between late Sunday evening and Monday AM we should break freezing.

Lynchburg Christmas parade is in jeopardy .

Morning Update

No real major changes--

Big battle underway for this event between a HUGE SE Ridge (Ridge=heat) Between Thursday and Friday we should hit 70, with nearby cities like Raleigh hitting 80 possible. (that's record heat down there)

Ridiculous arctic front comes through and the exact details are a  bit mushy but we know it will precipitate and some layers of the atmosphere will be below freezing. The one change is my Coating to 3 inches may be generous for LYH and ROA, as it's trending more towards a more mostly if not all freezing rain event.

One model, the CMC or Canadian model is colder and has a longer period of sleet and a little snow. The rest are mostly freezing rain. The rest may and should have a burst of sleet. (Common when dry air is in place to moisten the atmosphere) and mostly freezing rain. I still think Lynchburg and Roanoke temps bottom out in the upper 20's and Danville to Richmond closer to 30 or maybe just 32.

Total precipitation will be between .5 and an inch.. and if it is just a slow, steady freezing rain-- that's the best way to get ice build up.

One thing to look for is as we get close, do the models trend colder from the arctic air density OR is it just because the cold air damming isn't established enough to really push the cold air down to our region. (West of the Mountains will warm nicely and have rain, it's east where the cold air is trapped because it's heavier and more dense)

Look at this dry air at 700 mb Sunday AM on the NAM-- that's 40 dewpoint. This model extrapolated our would have a decent sleet burst.

More updates on FB and twitter and full blog later.

Brief update on pending ice event.

Model data has trended as expected. For those of Facebook a lot, some "model" snow based maps were flying that showed 6-10 inches in our region. They were total bunk, not even correct because there was a warm layer above not shown. (AKA-- sleet more than snow)

So, don't expect a big snow-- at all. 

Will have a better update by tomorrow AM. 

Should get a nice bout of rain Friday and Saturday should be dry and cooler setting the stage. Temps COULD be at or slightly above freezing when it starts and quickly drop to the mid to upper 20's for a while Sunday. 

SOME data suggest a decent period of sleet mixing, while others are more beating the freezing rain drum. 

I still like my idea of coating to 3 inches of sleet and snow (especially north and west of Lynchburg)-- think more coating in LYNCHBURG, more as you hit Lexington and Staunton area.. then a decent ice event. If the model data comes in as I think it will, it should be our largest ice event in years. 

Many factors still up in the air, including:

Temps-- ice at 26 vs ice at 31-32 is a world of difference

Sleet/snow-- that tends to coat the group and make ice build up easier on roads, etc. 

Second wave MAYBE Tuesday? (after a warm up)

More late. 

Possible wintry event next weekend..

Well, November ended up 3-4 degrees colder than normal and December is continued the trend of frequent bouts of COLD air. 

We should have a respite for a few days with some seasonable days early in the week and then a few MILD days with temps reaching the 60's later this week. 

FROM THERE...

All week an arctic front will be slowing moving east, reaching our area sometime late Friday to sometime Saturday. This air as modeled is VERY cold. 

We have a unique set up with a strong -EPO ( blocking up west of Alaska that is currently pushed north near the Arctic Circle, pushing COLD air to our side of the globe) So, despite other things we need-- +PNA, -AO and -NAO the cold air keeps heading to our area. 

As the front passes our region, it slows down thanks to the SE ridge. Flow aloft turns to the SW and we get what's called "over running".  This will set the table for a possible major to significant snow and ice event. 

How much and When??

Hard to say EXACTLY at this point. 

Some key factors--

1. Strength of cold air both aloft (snow vs sleet and freezing rain) and surface (rain vs freezing rain) Cold air is often under modeled at the lowest levels in arctic outbreak, but sometimes overdone at the mid levels. 

2. Where does the cold front slow down-- Southern VA, Southern NC. SC?? This would tell the difference between more snow and less ice.

3. How much moisture transports into our region? AKA--how much stuff falls out the sky. 

First Thoughts:

I'm fairly confident we see some type of an event next weekend.  I'd guess a period of snow gives way to sleet and then eventually freezing rain. The big story will be figuring how much is sleet and how much is freezing rain. This won't be like that event last week with 3 day old stale and exiting cold air. This will be fresh cold air, maxing out during the event with MORE cold air pumping into the storm.  

Under this set up-- a typical event like this would be a Coating to maybe 2-3 inches of snow and sleet followed by some freezing rain with possible significant ice accumulation. We have a ton of factors in limbo that we don't know yet, but this is a "typical" outcome we'd see. More snow and sleet NW of Lynchburg and Roanoke, more freezing rain south and east of the area. 

Updates will be more frequent with this pending event. Lot's of Christmas events including my daughters FDA Christmas show next weekend AND the Lynchburg Christmas parade Sunday. 

November Rain

The big story SHOULD end up being the COLD November rain over a 36 hour period. Rain totals should be 1.5 to as much as 4 inches. Considering it's been dry, the rain is needed but is coming on worst travel week of the year.

Had we had blocking in the North Atlantic-- we'd be staring down a MAJOR snow and ice event-- instead the big story will be a Cold November Rain..

"It's hard to hold a candle, in a cold November Rain"

Did you know that Axl Rose started writing November Rain while in Jr High? 

The Bookend Problems. 

1. The storm should start as maybe a burst of sleet and then some freezing rain. Currently, the western regions of our area are under an advisory for the freezing rain, but it's predicted most areas for SOME ice. Cold air can be stubborn and despite that freezing rain without a cold air source is a self defeating process. (Freezing water actually releases heat, which sounds counter intuitive) And some pretty warm air will be riding over the top, (Surface temps will hold in the mid 30's but at 3-5k feet temps will approach 50)-- sometimes that last 200 feet are STUBBORN to warm up. So, while a trace to slight coating of ice is likely, we need to monitor for a longer period of ice tomorrow morning. Would not be surprised if most of the area ends up under an Advisory.

Chance of ice over .10 tomorrow.

Back Bookend: Ending as Snow-- If I had a dollar for every time a storm was supposed to end as snow...they are RARE.

However, this is a unique set up where we have a strong arctic front coming as the storm ends with some strung out vorticity riding along the front. Looking at the soundings, (vertical view of our atmosphere with temps and moisture) I think we do get a quick burst of snow. Most places will have 1-2 hours of gloppy snow flakes falling that melt on contact. I could see a line of snow developing that "coats" cars, trees--grass but it won't be a HUGE deal. 

WPC has our region under a 30-50% chance of seeing an inch-- depending on where you are located. The Mts to our west obviously do better. 

The Big Story will be "Cold November Rain"

Rain totals...

Nothing last forever, even cold November Rain...