Wednesday, September 30, 2015

Rain, Rainier and Rainiest..

Sure has been dry?

Rainfall this month..

Blacksburg 8.61 inches
Roanoke 8.48 inches
Lynchburg 7.13 inches
Danville 7.7 inches

Some higher elevations have in excess of 10 inches. All these places run into the James and or Roanoke River.

90% of more has fallen since Monday 9/21

Time crunched and sparring you the synoptic details...
2 options from here.

Either way, I believe we get 2 more "waves" of rain between now and Sunday.

Option 1.. Wave one is dominant, The Hurricane stays far east and we still end up with an additional 2-7 inches of rain. Will have wide spread flooding. Some trees fall as well due to weakened soil.

Option 2- Hurricane gets captured by upper air low and ends up over NC/VA as landfall. Rainfall is still 2 waves, additional rainfall is more in line of 6-15 inches region wide, flooding goes from really bad to about historic. Winds are much stronger. Trees will fall with option one simply because the ground is so wet, with option 2 the winds are much stronger maybe 20-30 sustained with gusts to 50 and trees and power outages will be much more wide spread.

I'm leaning option one as of now with a 70/30 probability.

Wednesday, September 9, 2015

What does the Godzilla El Nino mean for Winter in Lynchburg, Roanoke, Danville and Blacksburg?

There is no simple answer for this question. Some of our snowiest winters have been tied to moderate to strong El Nino's. Conversely, some very boring and benign winters have been strong El Nino's.  What can we learn from them?

When the water is warmest towards South America, the winter is usually not severe. When the water is warmest towards the Central Pacific, closer to the international dateline, the winters tend to be more severe.


Boring Examples

1997-1998- SUPER El NINO, our are of Central/Western VA had 1 significant event, 4-10 inches, 1 Elevation dependent event (12 -24 inches above 2000 feet) and a near miss.

1972-1973- 6-12 inches total for the winter with a near miss to our south. February ran -3 for the month, but wasn't very snowy.


09-10- VERY Cold and snow, snowfall was 30-50 inches for the winter region wide with 2 to 3 events above 10 inches.

86-87- 3 big events region wide, 2 smaller events, 30-50 inches region wide. 2 12 inche snowstorms within 4 days of each other. Crippling 2 weeks.

65-66  Incredible winter, jammed into 3 weeks where 40-60 inches of snow fell region wide during those 3 weeks. Storm after storm pounded our region from Mid January to Mid February. Crippling 3 weeks.

Sidebar: Chatting with a lady up in Covington, my weather hobby came up. She mentioned that her son was born during the horrible stretch of winter weather as her husband was actually visiting Lynchburg. Snow removal/ Snow Travel was harder back then and it took him days to get home including the last 10 miles by horse.

Above Normal

57-58- Colder winter, 25-35 inches total, one BIG storm in February, 8-15 inches region wide.
82-83 Winter was non existent much of winter, early December storm of 3-6 inches, early Feb storm of  3-6 inches. BIG Mid February storm of 12-20 inches region wide. (Historic Storm for the East coast)

Currently, the El Nino is MORE east based (leans boring winter) but the warmth has been moving west. Much data has the central area becoming warmest which hedges towards cold and snow. I'm not quite willing to jump on that yet. However, a few thoughts:

1. Winter may resemble last winter in that most of the events fall in a 2-3 week period.
2. The risk for a "Big one" will be at the highest level.
3. Much of December and January may be boring and warm.
4. My current hedge for winter would be the "above normal" but not Severe group.  I'm going to let September play out, review some more data and have a complete Winter Outlook by Mid October.

In essence, December and January will average above normal temp wise with a small event or two possible. A time or two where a storm takes a perfect track, but has no cold air to work is very likely. Winter will be consolidated into 2-3 weeks from Late January to Mid Feb with a BIG event possible.