Rain Totals

From the two rounds of rain this week, here are some of the totals (with most of the rain falling overnight last night):

Newland 3.0"

Coatesville 2.1"

Danville 1.8"

Richmond 1.7"

Lynchburg 1.7"

Charlottesville 1.6"

Farmville 1.5"

Reedville 1.4"

Fredericksburg 1.0"

Staunton 1.0"

Wakefield 0.7"

Petersburg 0.5"

South Hill 0.5"

Williamsburg 0.4"

Emporia 0.3"

Norfolk 0.2"

The upper-level disturbance and low responsible for our rain Tuesday and early Wednesday is rapidly exiting through the Northeast this morning. Our next storm system is currently overspreading snow through much of the Rockies and into the northern Plains. A foot or more of snow accumulation is possible by tomorrow.

Winter Storm Warnings and Watches have been expanded into the Dakotas as a result of this strong, early season snowstorm.

Widespread Rain Likely Tonight

Two systems are making weather headlines today, one in the East, and another in the West:

The first system in the East is the result of an upper-trough. As this system swings through the Eastern U.S. Tuesday and Wednesday, widespread rain will overspread the Commonwealth tonight into the first half of Wednesday after producing heavy rain in Texas and Louisiana Monday. The heaviest rain for us will likely fall around the Wednesday morning commute. Totals will be around an inch for many places in Central Virginia, with some higher totals possible. Here is the expected output from this upper system in the Eastern U.S.

The precipitation you see in the Plains and West is a result of the next upper system currently entering the Rockies. This storm system will bring more snow to the Mountain West, and another round of rain for the Plains. Check out the Winter Advisories/Watches/Warnings in Utah, Colorado, Wyoming, Idaho, Montana, and western Nebraska:

You can watch the snow as it falls in Colorado on their live traffic cams here. Also notice the Wind Advisories/Warnings from California to Arizona as this system brings gale-force winds. This potent storm will track northeast the rest of this week, passing through the Great Lakes Friday into Saturday. This is the storm that will sweep a cold front through Virginia Halloween and bring a slight chance for some rain. At this time, it appears any showers that do affect Virginia will exit the area Saturday evening. We'll be providing updates for the Trick-or-Treaters as we get closer to Saturday.

Hurricane Home Stretch

The World Series is upon us, and the match is now set (Yankees-Phillies, folks). With World Series time, I think about Halloween, cool-to-cold nights, and the end of the Atlantic Hurricane Season. We have about a month left of hurricane season (it officially ends November 30), and here's what typically happens during the last month of the season:

Not much activity, right? This map above shows the prevailing track of any storms that do form in November, and also indicates that the probability (compared to the height of the season) is less likely. Here's what September's climatology looks like, so you get the perspective:

So far this 2009 season, we've had eight named storms in the Atlantic Basin, two of which became hurricanes (Bill and Fred, both major hurricanes). An "average" season has about 10 named storms, with six becoming hurricanes, and 2-3 of those becoming major (Category 3 or stronger) hurricanes. So you can see by the math, that this season has been a little below average for total storms, but still produced two major hurricanes. There's still one month left before we close the book on this year's hurricane season, but this is typically when tropical activity starts winding down.

So why the below-average season? There is some research linking El Nino-La Nina with tropical activity. During a La Nina year, Atlantic cyclone development may be more likely, while during an El Nino year (like this year), less likely. The reverse happens for the Pacific Basin. So this year, often when it appeared that a system might organize in the Atlantic enough to strengthen to hurricane status, wind shear would disrupt the organization process. Could El Nino be to blame? It's certainly possible.