Wednesday, December 17, 2014

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.


Monday, December 15, 2014

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..


Saturday, December 13, 2014

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.

Sunday, November 30, 2014

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.






Wednesday, November 26, 2014

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.

Monday, November 24, 2014

Fine line between heavy rain and heavy snow

Sometimes the tragedy is in that a perfect scenario presents itself and is not realized to minor, yet significant details. Had this storm been knocking on our door in EXACTLY one month, meaning Christmas eve, the area would be filled with glee that a post Christmas storm was on the way with what would be likely a 6-12 inch snowfall region wide. That would be simply awesome.

Remember weather is fluid and this has time to adjust...with that, I'm just not seeing the mechanism to cool the lowest 3000 feet of the atmosphere.


That blue line shows the freeze line- which this is at 10am, when the heaviest stuff is in our region.  3000 ft of 34-35 degrees just isn't accumulating snow.

Here is the text data in that range--




In this frame, the temp from 1800 feet down the ground is 34-35. could be snow falling, but not snow that will accumulate.

With that, the calender says November 24th and we have to deal with JUST warmer temps based where the calender is. With the models reading JUST too warm-- I mean, 3-4k feet down to the surface at 34-36 degrees during the height of the storm is just to warm to overcome.

Unless there are drastic changes--

Most places start as rain and end as snow. Most places see between .75 and an inch of liquid falling. Heaviest stuff clears our area by noon or so actually.

Places above 1500 feet see 2-4 inches, with up to 6 in highest elevations

Roanoke-- an inch or two of slush at best.

Lynchburg - Coating to an inch.

Danville- ends as snow/mix

It's going to rain hard for a while and at some point there is going to big fat flakes mixing in, but simply not enough cold air to accumulate.. at the lowest level of the atmosphere

I think Staunton north along 81 has a big event... I don't have time to break details for the rest of the world, but in our area I think we get a couple hours of scenic snow falling that coats the ground. Should feel festive.. North of 64, along 81 should have a nice 4-8 inch event.

Near miss, but still a miss.

My home internet SHOULD be fixed tomorrow...or Wednesday at the latest. If late evening model REALLY convinces me otherwise, I'll update. 

I get with the travel day this is a huge call for our region.. will blurb on FB and Tweet as needed.

Sunday, November 23, 2014

Thanksgiving Eve Snow..

I was 16 years old, my first year driving and we had a DECENT 6 inch snowfall Thanksgiving eve into the early hours of Thanksgiving. The first flakes started to fall as I walked to corner sub shop to grab the family cheesesteaks as we prepared the pies and other foodie stuff for Thanksgiving. I was living in Wilmington DE. Down in this area, daytime temps were just a bit warm and some rain ended as a little light snow and a coating to an inch fell.

If you refer to my blog from November 11th, I stated that the best shot of snow was going to be Thanksgiving week, and dangit if I wasn't right. On what is the busiest travel day of the year, if this thing reaches potential it's going to be a miserable travel day and I'd suggest anyone with family travelling from NC north to New England start to have alternative plans with leaving early or later than planned. This won't be a BLIZZARD but Wednesday may be a bad travel day with many cancelled flights, etc. I'm supposed to be driving to my mom's in Rehobeth DE, and think as of now we won't hit the road till Thursday AM.

The personal torture for me is that my home internet is acting up and I can't get the maps to load..I get a drip of net service that gives me SOME FB updates and chat. I'm currently at McDonalds eating pancakes and using their net service. (And I live in the ONE and only bad cell data spot in the city of Lynchburg so my ipad and cell are useless too)Cable service will be out tomorrow to fix it, but it is taking my competitive advantage away compared to other forecasting outlets. I'll be somewhere late afternoon where I can hop back on line and comb through the data.

I always write from the perspective that snow is a good thing, and despite the holiday we are NOT changing our format.

Basics- Storm moves in after midnight, towards morning-- 3-5 AM time frame and will be rain or rain and snow mix. At some point it flips to all snow and accumulates nicely. IF we can slow this thing down a few hours our snow totals go up. if it speeds up, the cold air doesn't have enough time to get in place and we get more rain.

Initial thoughts are we see 3-5 inches, with maybe 4-8 higher elevations especially west of BR above 1500 feet elevations. I think most places see .75 to an inch of liquid, but the start as rain with temps near 40 most areas and we bottom around at 32-33 most of the day. So, wet past snow all over everything. Get those christmas lights up early.

Can we get more?? Yes-- if the system slows down and the models are a tad warm as shown now. This is a rapidly developing storm and that's a very real possibility that we are at 40 degrees and an an hour we are at 33 with moderate snow falling. Think of March 16th this year-- we went from 48 and drizzle to snow in 2-3 hours.

Can we get less?? Yes-- the set up isn't ideal but the pieces work just well enough to give this threat. Any minor subtle changes would change the path and strength of the storm/cold will be huge.

You'll likely see some crazy snow maps on facebook and please don't feed the trolls, especially one out from the Euro. It's based on a 10-1 snow ratio and it simply won't be that good. Take those maps and multiply the total by .7 or so to get a legit number, and that is likely your upside. So, the EURO shows us getting about 10 inches, I'd take that as a 4-7 inch total for us. But, that's assuming we get an inch of liquid.

The Euro is leading the way,and it does usually on southern stream events (thanks almost el nino). The GFS has moved towards the EURO now, we are just waiting on the Canadian model and a newer version of the GFS (better resolution).With that, here is my first outlook. I'm way west of guidance because these southern stream events are ALWAYS way west. Feb 13th I was west of ANYONE else with guidance and I was still too east.

Here is a first stab at this-- COULD be way off and I'm running of some HUGE assumptions, mainly being this will be a strong system and the best bands will set up further west than modeled. That's a safe bet VERY often. If this was NOT a major travel day, we'd be in discussion mode, not making my lovely maps. :)


First Guess.. use with Caution. 

I'll throw out some tweets and FB updates before I get full access with info as passed along to me.

If we max out, I can see LYH getting 6-8 inches and maybe 10+ on higher elevations of the Blue Ridge. Not a forecast but just a Worst Case.. with some lingering leaves, some power outages could start to creep in.

Lastly, big shout out to Nick-- LU football star and blog reader and the entire team on the exciting win yesterday. I moved here 20 years ago to attend LU and what a thrilling season. What a way to get the first FCS playoff appearance in school history. Proud of the team!!