Forecasting ...

Means to predict or estimate.

Remember that when your weather guy gets one wrong. :)

True story last weekend while watching that Seahawks - Pack game that I put on facebook-- Famous last words, this feels over. Pack had dominated most of the game, Seahawks had no time and again could not move the ball. We know how that ended up for my call-- NOT TOO GOOD!

This storm has been up and down-- the best thing I said was when it was suppressed (Best snows over eastern NC per the models) is that I am more concerned it will be too warm than not wet enough.

This map shows where our LOW is tomorrow early evening and shows you where the is a LOW over CANADA where we need a high. That low is what costs us a decent snow event. Had it been a decent High that pushed JUST cold enough air, we'd be looking at a 12 inch snow fall.

Note the L near FL coast and the SECOND L in Canada. That is killing our cold air supply. 

Forecasting this has been tough. There are no exact flow charts to show you what should go where for temps and this is very marginal everywhere. 

1. Danville should be mainly rain. Maybe a quick burst of sleet and or snow start then a cold rain. 

2. Roanoke and Lynchburg won't see a ton of snow, but an inch or two of sleet and snow is possible, especially west of LYH towards Roanoke. 

3.  Lynchburg will start as a burst of snow and sleet and move to sleety rain and maybe a period of freezing rain. The data shows cold air JUST above the surface so literally SNOWFLEX could have ice forming while timberlake road is just wet. (It's happened before)

4. Roanoke Will start as sleet and snow, hang on to sleet longer and end as rain. 

5. Would be remiss to not mention Blue Ridge Weather has idea of a second wave of snow saturday AM. Would be rare, but possible 

6. Fast mover- best stuff should actually be gone by midnight or shortly there after. 

We do have some other chances for snow in the next 2 weeks. Superbowl weekend LATE has an interesting set up where there is a strong pulse on the Sub tropical Jet and some decent cold shots coming from the arctic regions. Both seem legit.

1. The SOI (Southern Oscillation Index) bottomed WAY out which means the get will be more amped with moisture and energy. 

2. The EPO is forecasted to go negative. That is what kept us cold most of last winter. 

This will be a now cast event-- I like a quick coating in LYH and some freezing rain. I like more sleet in Roanoke, ending as rain. The further up 81 you get, the more snow and sleet you get. Decent event Hagerstown, Lancaster..etc. 

Dusting off the blog..Friday- Monday

It's been a while since a blog and honestly, I'm leaning towards event one (Friday Night and Saturday)NOT being a big deal for us. It's the classic case of so close, yet so far away. I think we get from between .75 to 1.25 inches of rain/junk falling out the sky saturday and 50% it's mainly rain, 25% we get enough snow to cover the ground and WAY at the bottom, 10% chance of 4+ inches of snow. (Not the WPC 10% chance either, for my weather enthusiasts)

Without getting to technical, where we need a HP to supply cold air, we have a low pressure. parts of NW Virginia and MAYBE the Mts to our west could survive this, but for Roaonke, Lynchburg and Danville LIKELY means MOSTLY rain. We've got 3 days to play this out, but I often say-- when is the last time in a storm we ended up colder than progged. Answer is--..A LONG WHILE.

Will update as needed, but strongly in the mainly rain for the Roanoke, Lynchburg and Danville areas. Areas above 2k feet and well to the north and west like Harrisonburg, etc may do well.

Event 2- Clipper type system is going to dig VERY deep Monday time frame. (Dig- how far south it goes with the upper air energy) In general, I like to see the energy at least at the VA/NC state line, if not down to -40 in Carolina. This vortmax is possible heading into GEORGIA. Funny, because it's not far off from making a heck of a low and there is a way we miss the storm as it moves south and then north up the coast.  As of now, this may be our first chance to get decent snow of like 1-4 inches over much of the region.

Will update with some maps later for those who like more data.

582 & Florida..

Looks like the American model, the GFS will win a round of the model wars.  Maybe??

The Euro was gung ho on a strong low, with plenty of wintery precipitation this weekend before Christmas.

The GFS never really bought in and ALL the data is trending towards a very minor event, or maybe just some clouds and drizzle.

With all the reading I do on weather, I recall once reading the 582 height line needs to be in south Florida, or even off shore towards Cuba. I commented in my " chats" with my weather people/meteorologist that it was north of Orlando. To me, it's not a forecasting tool, but like an easy cheat that may give you some insight.

With that, the low will be much weaker and drier and the with that the temps end up warmer for many reasons. Some light snow, sleet and rain still possible but not a big deal.

I've attached a picture of what I mean.. DT from Wxrisk showed what was wrong with the BIG pattern, and I just circled my little clue over Florida. When the 582 height line is that far north, the flow aloft can be hostile for storm development.  DT made this map, but note where I circled Florida.. the orange is the 582 line. When the storm looks good, its just about SE of Miami and when sheared out, it's almost north of Orlando.

Quick update..

If forecasting was easy-- anyone could do it. I mean, what job lets you get it wrong HALF the time and still have a job?

:) Of course, .350 is a great baseball average and .500 is a good shooting percentage for the NBA. I'm a big fan of Will Ferrell and I'd say like a third of his movies are actually good.

Where we stand--

Models are not in agreement but we know this:

1. Cold air works in Friday..
2. Low forms in Gulf of Mexico

What we don't know:

1. Does cold air get locked in? I've mentioned a feature called a 50/50 low-- it sits at 50 latitude, 50 longitude. (New Foundland area) This feature keeps the cold air locked in by keeping the high pressure from scooting out to sea. Times like this I need to make video blogs. :)

2. Where does the low pressure go? Some data has kept it WELL south where we get fringed with light stuff, some take a pretty aggressive track up to Wilmington, NC and then up the coast and others take the first low into Kentucky and then reform it in NC.

A. WELL south is a fringe job-- it may be mainly snow, but not a ton.. like 2-4 inches at best.

B. The aggressive southern route brings us more moisture, but with moisture comes warmth. This would allow some mixing, especially along and east of the Blue Ridge. I could see this being a 6-12 inch event along 81, with more of a 2-4, 1-3 event east of there.

C. Primary low goes into Kentucky and reforms somewhere. This would be mix to maybe even plain rain many areas, ending as some mix or snow. Mts areas may get 2-5 inches while the sleet and snow MAY cover the ground east of the blue ridge. This has variables because there is a big difference between the low reforming of the South Carolina Coast vs lets say 50 miles east of Raleigh.


Any guesses?

Model data didn't really clarify much today. For everyone that looks like it moves towards the Euro, the Euro moved away from it's last 2-3 days of runs and it's ensembles moved towards the solution from last night.

Best guess as now:

NRV and MT Empire-- 2-5 inches of snow and sleet.
Roanoke Valley- `2-3 inches of snow and sleet, with some glazing of freezing rain.
 Bedford, Lynchburg down to Altavista- Coating to 2 inches of sleet, decent amount of freezing rain.
Martinsville to Danville- Sleety rain, ends as some snow maybe a coating and slight glaze of ice.

This is NOT locked in stone and still very fluid. I tend to warm up the models based on what usually happens on southern stream events in the mid levels, cool the surface at this point out.

Best snows at this point still look to be on 81, north of Exit 220-- Stuanton area north into PA on 81..

Dub stepping to Christmas..

Storms and rumors of storms will abound.

We are in a slow change pattern time and as we move towards Christmas week we will have SOME cold air around and some storms. 

What does this mean? 

Those of you who are on social media have likely already noted some posts discussing possible storms on Dec 20-21 and a follow up December 25 or so. 

Dec 20-21

The Euro has been consistent with showing an event that stays to our south, times just enough cold air and holds it JUST barely and we get a pretty nice pre Christmas storm. Now, if the euro is exactly right we'd have a NICE mix to snow event with accumulations north of 460 north of 6 inches, with 2-3 inches down to the NC state line. If the Euro is exactly right.

The biggest thing that always happens is UNLESS the confluence (Air moving quickly behind a low that parks near 50/50) there will be a north trend. Models always tend to start too far south and trend north) Outside of a couple events.. FEb 2012 and Jan 2013, the north adjustment is real. If I had to target an area that is in the highest risk, I'd take the 81 corridor NORTH of Staunton as the highest risk, but extend the risk down the NC state line all the way east to the piedmont. 

We are stepping slowly towards a colder pattern, but the real cold is still 3-4 weeks away. Just cold enough works in a perfect set up, but I'd not be too excited at this point. Everything would have to go swimmingly for us to see a nice storm. 

Follow up possible Dec 25 or so-- 

The signs are there for a colder pattern early January but I'm always nervous at this point. DT from Wxrisk-- and many of you follow him has a good eye for these type events and he's updating a lot. He's a great follow for big ideas and patterns but when events get close, always stay with your local guys. Sean Sublette from WSET is fantastic. I say this often, but we are blessed with a skilled met who takes his job very seriously. For my people in Roanoke, Kevin Myatt is as good of an "semi professional" as I am (if not better) and if you know people in the NRV down to the Mt Empire, Zach from Blue Ridge Weather is a great resource. What skills that Kevin, Zach and I have are just great feels for the local climate and how storms would impact our specific region. I'd trust Kevin in about any event if I was unable to access model data. As we move forward, Wxrisk.com, Kevin from the Roanoke Times, Zach from Blue Ridge weather and let me throw in WxSouth with Robert Gamble are great resources for 411. Of course, stay with me for your local and precise winter weather updates.  Even if the 21st and Christmas Day event don't pan out, things look to be picking up.

Like a Suicide Pool-- I'm not burning my Vanilla Ice yearly usage for the..

Little ice event coming Tuesday. I need a "To the Extreme" event for that reference.

Strong cold front pushes through tomorrow and some energy starts some overrunning precipitation overnight Monday into Tuesday. Should start as a rain and end up mixed with sleet. Above 1500 feet or so, some ice build up will be a problem as temps are decently cold for about 4000 feet or so and will get to NEAR freezing.

The moisture looks to be concentrated in a narrow area, so maybe as near as south of Altavista won't actually get much than a drizzle. IF this ends up a tad north than modeled-- (ever hear me say that before) the worst of the event will be from Staunton north.

I think places along and north of 460.. Blacksburg, Roanoke and Lynchburg COULD end up with a low end advisory.

You all know I love my soundings-- everything to the RIGHT of the blue line is above freezing, so we have a solid layer of above freezing temps from about 8000 feet to 4000 feet-- so this isn't a snow threat. BUT, below that temps of -3 or so are just deep enough to indicate some sleet for a while. Surface temps look to be around 33-34 so a degree makes all the difference. Not a huge deal, but the ground could be coated a while and this will be near the AM rush on Tuesday. The cold air and storm book out and we warm up back into the 50's Tuesday and Wednesday.

Pre snow update

I wanted to put a quick update out this morning before the rain changes over to snow. I've said this already but had this been December 25 and the 26 we would be looking at a 6 to 12 inches snow fall across the region. Snow is already mixing then and places to our west above 2500 feet or so. This should drop as we continue throughout the morning. I'm not going to attach them map or picture as they often like to show the actual soundings of Lynchburg and/or Roanoke. However, based on the information I gather from those I think that we change over to snow between as early as eight and parts of Roanoke to as late as 930 or 10 o'clock in the Lynchburg area. We should get several hours of moderate to even heavy Snow falling and like I said according to up to 2 inches is definitely possible.  That should fall mostly on the grassy areas with at the height of the heavy snow some of the roads may get some slush on it. Once this thing pulled out here, the Suns going to pop back out and I expect it all to be melted by 5 PM. There will be another wave of snow overnight that could coat the ground before you wake up on Thanksgiving morning.

Share your observations with me on Facebook and Twitter. Should be a festive morning with some nice fat flakes falling out of the sky as people wrap up their work week before the Thanksgiving holiday. Everybody be safe out there who is traveling and I wish you all and your family the happiest of Thanksgiving.