Wintery Weekend on Tap..Sloppy Saturday and Soaking Sunday.

But first-- Today. 

Similar to Saturday, Strong cold front approaches the air and because it's such an extreme cold blast, there is a good bit of energy tied into it so we should see a line of snow squalls rocket through with 15 to 45 minute blasts of snow.  Could be a coating and in an extreme case an inch or two is possible. Timing will stink because it will be mid to late afternoon.

The Cold...

Tomorrow morning will be brutal with temps down around 5 degrees and windchills -5 to -20. UGLY and the kids won't have school. Friday AM will have CALM winds, but literal temps will be 0 to -10.

The Snow.

The details are slowly coming into focus, but this weekend won't be good. We'll have that cold air sitting in place and a very wet system approaching our area. Due to the lack of blocking (Famed -NAO) I've mentioned, this storm again will eventually be able to dislodge the cold air and we may hit for the precipitation cycle when all is said and done.

Highlights as of now--

By noon Saturday most of our area is snow.
By late afternoon most of the area is NOT snowing, but the temperature is still below freezing and stuff is falling from the sky.
By Sunday AM-- the temp is above freezing and it COULD still be raining.

Often, as you get close to these events the models catch on that it's harder to dislodge the cold air. As an example in this last storm-- sleet fell in areas where freezing rain was expected. This happened because the cold air depth was greater than modeled. (Lower levels of atmosphere)

This is NOT my prediction, but a general idea of what these events do:

Mountains 3-6 inches, ROA- LYH 2-4, Southside 1-3 inches with a good bit of ice on top.

So, we have 3-6 inches of snow left, add a few inches, add some rain and start the melting. Both Saturday and Sunday will be pretty ugly days.

A winter storm with no big surprises..Wicked cold and Weekend Snow!

Yesterday's snowy event ended up close to what I thought. A few short term issues where I didn't think much sleet was going to make it in and we actually had a good bit of sleet after midnight. I think the official number will be close to 8 inches. I measured 8.5 inches and now have 8 but I crashed around midnight and missed the sleet show. I'm putting my total at 9 inches. There's about an in inch or so of sleet and snow on top so I'm going to put my final as 9. My 6-10 was a good call and that 8-14 zone area did well with some Mountain regions hitting over a foot, but some locals had a tad less..

Even with small short term error, I did beat the sleet drum louder than most and once again I was right. I thought it was OVER, and that snow ended earlier than thought rather than the sleet didn't make it up here.

Pretty impressive event with temps in the lower teens with snow falling. I've been down here with temps 17 or so with sleet and or snow falling, but 13 is unreal.

THE COLD!

If we don't get above freezing today, we will NOT get above freezing till this weekend.  I'd say 50/50 shot we get above freezing today. Another arctic front comes tomorrow and we could get another snow shower like we did Saturday with a quick coating to a half inch.

20% shot we get below zero Wednesday AM.

50% Shot we get below zero Thursday AM

80 % shot we get below zero Friday AM.  Extreme arctic high parks right over us and we could see some record setting cold of 0 to 5 BELOW zero.
For the record, I'm going conservative on the cold, and legit shot that both days are below zero and Friday is CRAZY cold.

MORE SNOW??

Over the weekend, another storm not THAT far off from this one will take place where a storm takes aim at our strong arctic air. The arctic air will be a bit more stale and I think the ice line makes it in sooner and likely ends as rain. No initial thoughts yet, but it could be advisory or warning level event.

Some during storm tid bits

Based on observations-- storm seems to be taking southern route. I feel a little less nervous for sleet working into Lynchburg, Danville and South Boston should mix later on as anticipated.

Based on trends now-- and model data-- 460 from Blacksburg to Richmond is the bullseye for this event. Totals of 8-14 inches will be common in this area.

I think we need 12.5 inches to get a top 10 snowfall in Lynchburg. Outside shot we get it., under 10% but still a shot.

Great ratio's have NOT developed here yet-- . As the low gets close to the mts and a low level jet interacts, we could see larger flakes and more fluff. So, the cold temps made it stick fast but we are NOT getting 15-1 ratio yet. Same report out of Roanoke.

Let's get ready to RUMBLE!!!

We are all systems go for what will end up being a significant storm across all of our region. Note on this quick radar shot that we already have snow falling ALOFT, but it's drying as it falls. (Called VIRGA)

S

Snow should overspread most of the area by noon. The heavier stuff should hold off till late 

afternoon.  The worst of the storm will be between 5 pm and Midnight and things will taper down quickly after that, flurries wrapped up well before sunrise. 

Updated Map

Easy to understand. The dotted black line is as far north as the sleet COULD make it, In
the places north of the 3-6 zone, don't expect sleet to be a big issue, some cold fall LATE in the event.

Do you promise it's going to snow? 

YES!

Can anything go wrong and we don't get as much?

The atmosphere is fluid so once you get data it's already changed. Unless your in the 3-6 zone, the floor for any one location is 4 inches if EVERYTHING went wrong. Conversely, I can see that 8-14 zone pushing a tad east is everything goes well. 

What about school days?

Most area schools closed today- good call in that these east west moving storms tend to start faster. With anything over 4 inches, we usually get back to back snow days, so I imagine most people are out Wednesday.

Where this gets bad is- Another SEVERE arctic oubreak passes our area Wednesday. AM temps could go below zero. I've never noted a model runs where MULTIPLE runs have MOST of VA below 0. Thursday and Friday will be a delay, if not closed as well and another system starts to bear down on our region Saturday. 

With the holiday week,  we could hit the grand slam of snow days-- the Entire week off. It's like a rain shortened no hitter for any school that was already closed today, but still rather impressive. 

This should the last blog on this event. Will be doing live tweets and FB updates as the storm starts and continues.

Winter Storm Watch over our ENTIRE area... SIGNIFICANT snow likely now.

Certainly had a feeling that would be the right course of action after watching evening model runs.

First, in my "weather hobbyist" ever running chat-- I noted that I failed to mention the bitter cold this AM and snow showers yesterday. It wasn't a shock and played out as I expected. That was an exciting 20 minutes of snow.  I need to do a better job of conveying messages about cold and windchill. It's the big story today with temps at 7 or so this AM and windchills well below zero.

The wave 1- wave 2 issue has been resolved. For the last few days, resolving if wave 1 or wave 2 would be dominant was causing model chaos, which in turn lead to forecasting challenges. The traditional thinking was slow this down, let the jets phase as I mentioned and we'd get a bigger event.

1 is the polar Jet, 2 is the Subtropical Jet. 

Where this ended up was, the phase was NOT needed and Polar Jet is riding solo on this event. 

1. Time issues- When the thought that the phase was needed, it was almost a full 24 hours slower. As a result, our storm time is now Monday afternoon until Tuesday morning.

2. Mixing issues? Here goes my north trend talk. We are literally in the bullzeye at this point and 100% snow on most of the models. These things tend to nudge north with time. I'd put odds at 50/50 that some mixing occurs late in the storm up to the Blue Ridge including Danville, Lynchburg and Martinsville. 

3. Snow amounts.  I held to my thoughts of 2-4 and I'm glad I kept snow options on the table. Looks like DOUBLING that amount nice place to start most places. Even if we mix, 4 inches should occur most places. Very possible places exceed 8 inches and I've noted that in my map.

4. VERY cold during this event and even colder after. Reasonable shot many places get close to 0 Wednesday and Thursday AM. 

5. School closings-- Be ready for some serious closing issues. Tuesday is about a lock to be closed. 

Wednesday at best will be a delay, but with cold temps MAYBE slightly above freezing Tuesday afternoon I doubt the back roads are clear enough to have school Wednesday. Thursday AM will be COLDEST of the days with lows near 0, slightly below 0 possible. That screams 2 hour delay unless we get the 8-10 inch amounts possible. That gets us to Friday. (I heard some schools did not close for Presidents Day too-- which somewhat bothers me and I got an email from Abe Lincoln and he's really upset about it) So, as of now-- 1 day closed and 2 days delayed is about a lock.  2 days closed and 1 day delayed is likely. 3 days closed 1 day delayed is still an option and man, for you teachers out there-- would not rule out  the entire week being gone if your specific region gets 10 inches. 

6. Another storm on the map next weekend. Has the potential to be a decent event, good changes it's a mixed bag and another big cold shot behind that one. 

Region wide 4-8 is likely. ON the west side of the red, up to 10 inches possible.
These numbers may need to be massaged a little either way as we get closer
to the event. 

Not going to change anything...

I had hoped to gain a little more clarity yesterday for this event, and while we did get some my confidence level has not climbed a ton. Once we established that the low would not cut to our west, but move to our south I moved the region snow total to a general 2-4 inches. That isn't going to change at this time. 

Key Factor:

I've used the term phasing, which is when energy aloft from 2 jet streams work together. I used the term "bundled" energy and this is in that realm as well. The model runs that show a decent event 

have decent phasing and those who don't have a smaller or a NON event. If that energy from the Baha area ejects and phases (interacts) quick enough, we should have a decent, if not significant event. 

Best locations: 

At this point in time places along the VA/NC border are at higher risks to see more significant snowfalls. 

Model trends

If you want a snow storm-- Yesterday started as a great day and ended on the downslope. 

The trend yesterday was to slow down the system, keep the cold air in place and kept us on any models to an all snow event. Some of the mid day model runs had stripes of 9 to 15 inches across much of our regions. 

A late afternoon model run pulled the low more south and then ALL the late evening model runs went south and most kept the snow out of our region. However, the ensemble runs kept snowfall region. As a refresher, ensemble forecasting is taking a specific model (GFS, ECMWF, GEM- American, European and Canadian) and running a set amount of times with changes in run to weed out a bias of a model. 

IS IT GOING TO SNOW?

Great question and I'll do my best to answer. 

In general, this type event trends north as we get closer. So that's one in the in our favor. We have some subtropical jet interaction and those are famous for last day north adjustments even just in where the heaviest precipitation lines up. 

A concern is that the drastic trend on ALL the models could indicate something. 2 of those issues are:

1. The energy aloft is split, and as a result the storm is sheared out and weak, not throwing back moisture into the cold section. Just like bundling your TV and internet services, bundled energy is good for bigger storms. 

2. COLD air. The track has been adjusted in part because the cold air coming down is harder to forecast and the models adjusted in part because of the cold air in place AND the cold air coming in. 

AND YOUR ANSWER IS?

Yesterday I went 2-4 east regions. (Meaning east of the Blue Ridge) and west 4-8. This was based on the idea that we'd have a mix at certain points. Remember that forecasting is FLUID and information changes. Not much data shows the storm cutting to our west-- so the mix idea has dropped greatly. 

I'm going to blend the ensembles and operational models and hold to an idea that a 2-4 inch snowfall is the most likely outcome at this time. Usually, I'd love a low that is 150 miles too far SE at this time based on the ever present north trend, but with the drastic change yesterday (AKA disturbance in the force) I'm not positive we have a really good grasp on this yet. 

Model runs today between 9 and 1:30-- I'll toss a few ideas from those on FB and Twitter. But, as of now-- the best guess is 2-4 inches region wide, maybe more SE regions.