Wednesday, November 30, 2011

2011 Tropical Season Ends Today

The third most active tropical season on record ends today, November 30th. This 2011 season featured 19 tropical systems, which ties with three other seasons (1887, 1995, and 2010) for the number three spot. The most active tropical season on record is 2005. Records of tropical activity date back to 1851 for the Atlantic, Caribbean and Gulf basins.

Out of the 19 tropical systems, seven were hurricanes with at least 74 mph winds or stronger. Hurricane Irene was the first hurricane to make a direct U.S. landfall in three years (Hurricane Ike hit southeast Texas in 2008). Irene first made landfall in North Carolina, dashing the Outer Banks and eastern North Carolina before hugging eastern Virginia's coastline and producing widespread wind and flooding damage in the Commonwealth. Irene continued into New England, becoming the most significant tropical cyclone to affect the northeast since Hurricane Bob in 1991.

The best news out of this season was that no major hurricanes made U.S. landfall, which marks our sixth straight year without any landfalling major hurricanes in the country! Hurricane Wilma in 2005 was the last one.

Not all of the tropical systems received names. Highlighted in yellow are the names used this season:

There was also one system called Tropical Depression Ten, which never made it to Tropical Storm strength (which is when it would have received a name). That is how we get up to 19 tropical cyclones this year, even though only 18 names were used from the list. Tropical Storm Sean was our last named system to occur in early November.

This above-average tropical season may result in part because of better satellite technology available than in earlier years to better investigate systems in the open waters too far away from hurricane hunter aircraft or other reliable sampling techniques. This allowed tropical meteorologists to better asses systems and categorize them.

An average tropical season in the Atlantic Basin has approximately 11 tropical systems, 6 of which become hurricanes, 2-3 of which become major hurricanes. Here's a look at an average season's progression, peaking September 10th:

Stay with CBS 6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose

Wednesday, November 16, 2011

Severe storms possible Wednesday

Rounds of rain will continue to track northeast through central Virginia, producing heavy downpours at times. However the worst of this storm system is yet to come. Late this afternoon into this evening a cold front will move into central Virginia, producing a line of strong thunderstorms with heavy rain, gusty winds and lightning. The primary threat with any severe thunderstorms ahead of this cold front will be damaging straight line wind gusts of 60-70 mph. However, this is also a slim chance for isolated, brief tornadoes in the yellow highlighted area on this map.

Ample moisture is in place, as well as some modest instability to encourage storm intensification ahead of the cold front.

Aside from the severe threats, heavy rain could lead to ponding on the roads and flooding of poorly drained areas and low-lying spots. Rain totals could climb as high as an inch to two inches in a broad swath of central Virginia! Rain should taper off from west to east during the first half of Thursday as this storm system moves farther offshore. It will be much cooler behind the cold front, with highs Thursday and Friday in the 50s. Seasonably cold mornings and cool afternoons will persist through the weekend with surface high pressure in the region.

Stay with CBS 6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose

Wednesday, November 9, 2011

Dense fog descends Wednesday morning

Dense fog descended across much of central Virginia this morning, with the areal coverage and density even worse than in previous mornings this week. Skies were clear overnight with calm conditions, allowing the fog to redevelop. Visibilities are still being significantly reduced in spots as of 9 a.m., even down to near zero. As a result of this risk, there is a Dense Fog Advisory in effect until 10 AM for all of central and eastern Virginia. The counties and cities affected are highlighted in grey on this map:

Fog should begin to mix out and dissipate by late-morning. This fog is not only confined to low-lying, agricultural, or marine regions. It is widespread and can be suddenly very dense. Please allow extra distance between you and surrounding vehicles. Slow down. Reduce distractions (like the radio, using your cell phone, etc.) and turn on your headlights to their low-beam setting. Please also be aware that overnight construction is ongoing in some places where the thick fog is also occurring.

Stay with CBS 6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose

Tuesday, November 8, 2011

Look East after sunset for a Moon-Jupiter meeting

With clear skies this evening, go outside after sunset (it happens early at 5:05PM) and look East. The Full Moon will be bright in the sky a mere ten degrees apart from the brilliant planet Jupiter (it's the next brightest light in the sky; you can't mistake it). Here's a sky map to orient yourself on where to look (notice some of the surrounding constellations of interest):


Also worthy of noting is the Near Earth Asteroid "2005 YU55" that will safely pass by Earth this evening at 6:28 PM EST. The aircraft carrier-sized asteroid will be relatively close to the Earth at a mere 201,697 miles away, which is closer than the Moon's distance from Earth. However, astronomers are confident of the asteroid's track safely away from any Earth impact. Unfortunately for us, we won't be able to see the asteroid with the naked eye, or even with most standard backyard telescopes. The big research telescopes will be trained on the asteroid, though, collecting valuable scientific research for asteroid astronomers to analyze.

The last time an asteroid passed this close to earth was in 1976 when "2010 XC15" zoomed quietly by, unnoticed at the time by astronomers. Astronomers are currently monitoring approximately 1250 Near Earth Asteroids, including one that will be in our neighborhood December 26, 2011. That asteroid is a tiny 262 feet wide, and will be almost three times as far away from us as is the Moon.
--Meteorologist Carrie Rose

Subtropical Storm Sean developed early Tuesday morning

Our next named system of the 2011 Tropical Season developed early Tuesday morning east of the Bahamas in the Atlantic Ocean. Here's the latest color-infrared satellite image of the convection in Sean:

Subtropical Storm Sean will not impact the U.S., but it should track near Bermuda at the end of this week, bringing tropical storm force winds, rain, and rough waves. Here's the official forecast track for Sean from the National Hurricane Center:

So what does it mean to be a "subtropical" storm as opposed to a "tropical" storm? Sean possesses both characteristics of a tropical (warm-core low pressure system) and an extratropical (cold-core low pressure system) cyclone. The low that became Sean in the Atlantic is part of the remnants of a system that tracked through the eastern U.S. last week and stalled off-shore, spinning as a closed low for days. It's a pretty shallow low pressure system, not as deep as a tropical cyclone would be. As you could see in the satellite image above, it also doesn't "look" like a typical circulation associated with a tropical cyclone, being asymmetrical. But because of the convection and gale-force winds and rough waves, it behaves like a tropical cyclone. Therefore, it can only be classified as "subtropical."

Stay with CBS 6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose

Monday, November 7, 2011

Subtropical Storm Sean Developing?

A disturbance between the United States and Bermuda continues to produce very strong winds as it moves slowly westward. The system will eventually turn more northwesterly and then northerly, but will have enough time in a somewhat favorable environment to develop into a subtropical storm. If it does so, it would be called Sean, and the spaghetti plot above shows the collective model tracks over the next 5 days (120 hours). There will not be a threat of wind or rain to the Mid-Atlantic Coast, but rough surf and associated beach erosion will continue until this system moves north later in the week. Hurricane season officially runs until the end of November, so it's not that unusual to still have activity in the Atlantic Basin. -ZD

Thursday, November 3, 2011

Our engineers help keep you ahead of the storm, even if it means encountering the wildlife!

While performing maintenance on our CBS 6 Storm Team Metro Richmond Zoo Skytracker Camera this week, one of our engineers, Henry, encountered some of the wildlife at the camera site! Here is his tale, recounted in great pictures and his own words...

Richmond Zoo Tortoise "on the attack"

This one leaves to block the door so I can’t escape!

This one stands off and hisses in the corner:

I try to be nice to this one…

The hissing one comes closer...

Now the hissing one bites the ladder:

I can’t work on the PC until he is done with the ladder!

The hissing one sits by the ladder for 15 minutes. Finally, he leaves!
Now, I can work on the Skytracker Camera!

Thank you to our engineering staff whose work often goes unnoticed to our CBS 6 viewers. The live cameras that show current conditions in central Virgina are a tremendous asset to us as meteorologists and to you, our viewers. We have our engineers, like Henry, to thank for keeping them operational. Bravo, Henry, for your safe and successful visit to the Metro Richmond Zoo, despite a couple of tortoises who really liked you (or at least your ladder)!

Stay with CBS 6, we'll keep you ahead of the storm!
--Meteorologist Carrie Rose