Saturday, March 7, 2015

Any cold left?

We are stepping out of what was one of the most intense 3 week winter periods in our area ever. The time period rivals any 3 week stretch combined cold/snow-- we had a few colder and few snowier, but combination of them both is top notch.

Finally, a break is on the way and we should begin to feel some seasonal temperatures. March is known for it's wild swing and it seems the next week or so should be normal to even ABOVE normal. Late next weekend/early the following week we will be be looking at the rebuilding of the west coast ridge that led to our continual dumps of cold air from the north pole. This could be another round of perhaps late March mischief.

Understanding the pattern, the PDO is a scale that measures temps in the pacific in certain locations. Positive numbers indicate a better change for a west coast ridge. Those who follow the weather know that Cali and nearby states were super warm and dry. I know I recall seeing countless reports of insane numbers in Seattle of 70-80 to the place that's the 49 and rain capital of the world. The PDO is a cyclical pattern.

As we start to wind down winter, I tend to fade out a bit in severe/hurricane season, especially when it's boring around here. It's probable PAST when I need, but I've been working on a blog that conveys some ideas about finding a good forecast in the digital era. In the next week or so, it will likely be a 2 part blog that may help you find out quicker what the weather will be like.

Thursday, March 5, 2015

No big changes

Map from Yesterday holds..

Sleet is going to be an issue where sleet develops between 8-10 in our area and doesn't change to snow till mid to late afternoon. Temps keep falling all day-- upper 20's by late day. We do get a few hours of snow late afternoon and evening.

Wednesday, March 4, 2015

Rain, Ice then snow-- Tricky forecast on the way. School days appear to be a 2fer-- Thursday and Friday off for most schools.

Tricky forecast on the way with ANOTHER winter event a virtual lock. The difference is we could escape with a minor inch or two of sleet and snow or could end up with 4-5 inches.

It's a simple set up, where an arctic cold front is pushing in the same time a HUGE slug of moisture is moving in. The exact time the the front gets in, and then the time it takes for the sleet to mix with snow will determine what happens.

Timing is Everything.

If anything the trend has been to nudge this more south, as all data yesterday moved that direction. There has been many systems where they nudge close enough to keep us in the game, and then as the event unfolds, the snow/sleet line ends up 50 miles north of modeled. This is HUGE because as modeled now-- The sleet line gets to Roanoke/Lynchburg before Sun up tomorrow, while it doesn't reach Danville until noon. So, sleet line moving about 10 miles an hour?? Further, after that we are waiting for the entire column of air to cool enough to flip it to all snow. What would be 6 inches of snow, could end up being just 1.5 inches of sleet. (Snow falls at a 10-1 ratio, while sleet is 3-1 at best)

Here is a map of my thoughts as of now-- In General, along 460 from Blacksburg to Roanoke to Lynchburg.  1-2 inches of sleet, 1-2 inches of snow 2-4 inches total. Change over rain to sleet 5-7 AM, Chang from sleet to snow 12-2 PM. It all ends by dinner time.

Southside- Martinsville to Danville 1-2 inches total sleet snow. Sleet mixes Late morning/early afternoon, ending as snow.

We have no wiggle room, meaning if this is off by 30 miles south, we only get an inch or two. Conversely, if the model data is off 30 miles to the north we could be looking at 6-7 inches. A fluid situation like will require some game time updates, so follow me on FB or Twitter for updates.

Monday, March 2, 2015

Wednesday Night- Thursday

Please follow me on Twitter--  @Lynchburgwx or follow me on FB personally or my Lynchburg Weather FB page. That's where I can convey some quick thoughts without the total blog post.

Big rain maker comes through and the snow should be melted and gone by Wednesday, and the very day another round of snow and ice is likely at this point.


Arctic front comes after the first round of rain and slowy sinks through our area. This is a key to the forecast because there is another ripple of energy riding along this cold front and depending on where this sets up, the ice and snow follows.

I about always play the north trend on the models and .. and as of now we are on the bottom rung of decent snows on some models while others go well to our north with about all of the frozen. This would mean that we may get little or no snow and ice.  Those north models are the same ones that pointed last week before the rest of the model date pushed the heavier snow into our area. I give pause a bit because when there is legit arctic air, that's a game changer at times on north trends (AKA, stops it-- reference blogs from last March 3)

I'm going to hedge in the middle now and suggest that the Heaviest snow (4+ inches) stays north but up to 4 is possible Wednesday night into Thursday. I also have a bit of concern that we have some sleet issues because arctic fronts VS subtropical jet is a breeding ground for COLD air undercutting the warm and a warm layer hangs on between 5-8k feet above the ground.

Extreme outcomes:

If we max our the snow potential, 6 or more inches is very possible. This will be a huge event over parts of KY, WV, TN and sw from there.

If we escape with a minor hit, literally nothing could fall.

Last week I felt very comfortable with my call all along  3-6 and it was very good. Here, I am much less certain and just trying to get the word out of the "possible" event. I'll FB/Tweet a few thoughts as the mid day models unfold as I have time during the work day and will have a full blog update IF needed to update where