Friday, April 29, 2011

Virginia Tornado List From April 27-28

Tornado surveys are ongoing in Virginia after severe storms affected many parts of the state Wednesday and Thursday, from extreme southwest Virginia through the heart of the Commonwealth into northern Virginia. Here is the Enhanced Fujita Scale for your reference as we detail the completed survey results so far:

As of Noon Friday, here is the list of rated, confirmed, and suspected tornadoes in Virginia.

Prince Edward to Cumberland Co (4/27 6:55PM-7:05PM): EF 1 (estimated wind speeds 86 to 110 mph). 100 yards wide, 5.5 miles long from about 1.5 miles east of Farmville north-northeast into southeast Cumberland County. Several homes on River Road received mainly roof damage, and numerous trees were downed or snapped off.

Hanover Co (4/27 8:25PM): EF 1. Tornado reported from Noel at 8:25 PM. This tornado was 150 yards wide and on the ground for two miles across eastern Goochland and western Hanover Counties. A more detailed survey is being conducted Friday (4/29).

Halifax Co (4/27 8:45PM-9:08PM): EF 2. 350 yards wide, on the ground for 13.4 miles from near Chatham Road (7 miles NW of Halifax) to near the Roanoke/Staunton River. One person was killed with eight others injured, with most of the damage along Liberty Road.

Caroline Co (4/27 8:55PM-9:00PM): EF 1 (estimated wind speeds 86 to 110 mph). 100 yards wide, 1 mile path beginning about 2.5 miles west of the town of Carmel Church, crossing Jericho Road in the process. Numerous trees were downed or snapped off.

Goochland Co (4/27 7:25PM-7:30PM): EF 1 (estimated wind speeds 86 to 110 mph). 100 yards wide, 2 miles long from Bridgewater Bluff to Pony Farm Road, crossing I-64 in the process. Numerous trees were downed or snapped off.

Smyth Co (4/28 1:15AM-1:20AM): EF 2
. A tornado moved into Smyth County from Washington County at 1:15 AM, tracking for 2.8 miles creating a half-mile wide damage path, before lifting along Carlock Creek Road near Brushy Mountain. The EF 2 rating comes from damage assessed at five affected homes. Minor damage occurred to numerous other buildings and trees.

CONFIRMED (not yet rated):
Prince William Co (4/27): 6:14PM Report from two miles west of Triangle, where a Quantico-based observer saw a tornado on the ground.

Prince William Co (4/27): 10:57PM Report from three miles northeast of Nokesville, where a retail shopping center sustained structural damage.

Shenandoah Co (4/28): 2:21AM Report from two miles south-southeast of Orkney Springs, where structural damage occurred to a house and trees were downed.

Augusta Co (4/28): 2:31AM Report from one mile east of Christian with a 4 mile track, where numerous trees were snapped or uprooted. Several homes were damaged, including roofing removed from some of those houses. Several outbuildings were destroyed.

Washington Co (4/27)

Oilville (4/27)
Caroline Co (4/28): Funnel cloud spotted in Ladysmith and Doswell. Tree damage reported.

Stay with CBS 6, we'll keep you ahead of the storm. --CBS 6 Storm Team Meteorologists

Thursday, April 28, 2011

Tornado Watch Until 9 PM

New Tornado Watch Until 3PM

A new Tornado Watch has been issued for nearly all of central Virginia that will last until 3 PM Thursday.

Strong thunderstorms are developing in southwest Virginia as of 7:50AM Thursday, with frequent lightning, gusty winds, and heavy downpours. This line of storms is expected to intensify as it expands eastward into central Virginia the rest of this morning ahead of an advancing surface cold front. The threats from the strongest storms will include isolated tornadoes, damaging wind gusts in excess of 70 mph, large hail, and frequent lightning. Visit our Storm Room for the latest severe weather updates. Stay with CBS 6, we'll keep you ahead of the storm. --Meteorologist Carrie Rose (I'm providing updates on my Facebook page here.)

Tornado Watch Until 8AM: Parts of Central & Western VA

A Tornado Watch is in effect until 8 AM for part of central and all of western Virginia.

Strong to severe storms have been tracking along the I-81 area early this morning, with several tornado warnings issued for those counties and cities, including Staunton and Harrisonburg. This severe threat for isolated tornadoes, damaging wind gusts, and large hail will gradually shift east this morning ahead of an approaching cold front. We are monitoring the situation closely, and you can keep up with the latest warnings and live updates at our Storm Room by clicking here. Stay with CBS 6, we'll keep you ahead of the storm. --Meteorologist Carrie Rose (Click here to "Like" me on Facebook: I'm providing frequent updates on my page this morning)

Wednesday, April 27, 2011

Tornado Watch Until 8PM Wednesday

A Tornado Watch is in effect until 8PM for all of the counties highlighted in red, which includes much of central and western Virginia.

Isolated tornadoes, damaging winds to 70 mph, and large hail up to 2" in diameter (larger than golf balls) are all possible this afternoon and early evening with any thunderstorms that become severe.

Instability is rapidly increasing in the area as a result of ample moisture, wind shear aloft, and peak afternoon temperatures rising into the low to mid 80s. Scattered thunderstorms are developing across the area, producing heavy downpours, frequent lightning, and gusty winds. We'll be tracking the severe threat today. For the latest information, please go to the Storm Room here. Stay with CBS 6, we'll keep you ahead of the storm!

Severe Threat Again Today For Many States Including Virginia

Significant severe weather is likely again today through the Deep South and Ohio Valley region ahead of a potent storm system that has a history of producing tornadoes, hail and wind damage, and flooding through the Plains and Midwest. Here is today's Severe Weather Outlook for the eastern half of the U.S.:

In Virginia this afternoon, a few of our scattered heavy thunderstorms that should develop during the peak afternoon heating in a moist environment (just like on Tuesday afternoon) could be severe. Our primary threats in central Virginia include damaging wind gusts and hail, but southwest Virginia will have the additional threat for isolated tornadoes.

The cold front associated with this potent upper storm system will finally sweep through the East Coast Thursday, with a squall line likely advancing through central Virginia Thursday morning ahead of it. As a result, we'll have the slight risk for damaging wind gusts from that line Thursday:

Here's the time-line based on our data this morning for Thursday's squall line and cold frontal passage:

After sunrise Thursday, the squall line should be nearing I-95:

I expect strong wind gusts, heavy downpours, frequent lightning, and hail out of this line Thursday morning as it sweeps through our area:

It looks like the rain and storms will be forced out of the Commonwealth to the east by mid-afternoon as the cold front sweeps through, ushering in drier air.
This is great news for those of you with outdoor plans Thursday evening!

Rainfall accumulations look like they will range from half an inch to an inch in most of central Virginia from the squall line, with isolated higher totals possible from the embedded strongest storms. Stay with CBS 6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose ("Like" Carrie on Facebook by clicking here)

Monday, April 25, 2011

Rain & Storms Mid-Week, Nice Weekend Ahead

If you were outside Sunday for various Richmond activities, including Monument Avenue's traditional Easter on Parade, you probably thought it was Summer instead of Spring! Officially at Richmond International Airport Sunday the high temperature was 88 degrees. That's well above the average high for this time of year of about 72 degrees, but not quite to the record high for yesterday's date of 94 degrees in 1925.

Monday will be nearly identical to Sunday, perhaps a degree warmer up to 89 degrees! High pressure off the Carolinas coast is keeping us mostly sunny and allowing a steady south to southwest wind to bring in warmer, moist air. Today's record high is 96 degrees, also from 1925. So the beginning of this week feels like July's average highs (upper 80s), but we're still not breaking any records from this Summer preview. However, the morning temperatures today in central Virginia were close to being record-warm lows for today's date! This morning's low temperature was 66 degrees, just one degree shy of the record warm low for April 25th of 67 degrees from 1976!

With that steady stream of moisture gradually infiltrating the Commonwealth from the south, we should get scattered showers both Tuesday and Wednesday, especially in the afternoons when we are the warmest and can get scattered convection. But our best chance for heavy rainfall (which we need: current year-to-date deficit is about 2.5" below normal) will arrive Thursday ahead of a strong cold front. The exact timing of this front is still not set in stone, but it does appear that a squall line should advance into all of the Mid-Atlantic ahead of the front Thursday morning into early afternoon. Some of these storms could be severe with damaging wind gusts. As with any thunderstorm, threats will also include lightning, hail, and downpours. We'll be tracking the development of that system and its progression toward us over the next several days.

Once that cold front exits east Thursday, the end of the week looks dry with typical Spring weather settling into the region with afternoon highs in the 70s and comfortably cool mornings in the 40s and low 50s. This is great news for the big race events at Richmond International Raceway from Thursday night through Saturday! Click here for the RIR event schedule. Stay with CBS 6, we'll keep you ahead of the storm. --Meteorologist Carrie Rose

Wednesday, April 20, 2011

Slight Risk For Isolated Severe Storms Wednesday

We have the slight risk for a few isolated severe thunderstorms later this afternoon and early evening as a cold front approaches from the west and we warm this afternoon into the mid to upper 80s.

Good moisture (dew point temperatures in the low 60s) is moving into central and eastern Virginia, transported from the Atlantic and Southeast by our persistent southerly flow. High clouds (remnants from a squall line last night that tracked through Kentucky and Tennessee) are streaming over western Virginia before Noon, with full sunshine along and east of I-95. Here's the visible satellite image of our region, taken at 11:15 AM:

With plenty of sunshine in this area, we should reach peak afternoon heating that could lead to a few strong to severe thunderstorms developing in central and eastern Virginia. Any storms that do develop in this environment will be capable of damaging straight-line winds and potentially some large hail. The tornado threat appears low in our region.

The surface cold front associated with this low pressure system now tracking through the eastern Great Lakes will sweep through central Virginia tonight, bringing in a cooler air-mass to end the work week. It will also end any severe threat shortly after sunset this evening.

Sunday, April 17, 2011

Tornado Total Now Up To 8

As National Weather Service survey teams continue to assess Saturday's storm damage in Virginia, our official tornado tally rises. As of Tuesday morning, there are now eight confirmed tornadoes in Virginia from Saturday, April 16, with two more suspect areas in Lunenburg County (near Victoria and also around Rehoboth) that have yet to be surveyed. This graphics lists our six strongest tornadoes of the eight from Saturday:
The National Weather Service in Wakefield continued to survey the damage Tuesday in eastern Virginia from Surry through Mathews Counties and into Middlesex County from Saturday's tornadoes. They have now released an upgrade to EF3 (136-165 mph estimated wind speeds) for the tornado that tracked from just south of the Surry Nuclear Power Plant northeast into Mathews County. This tornado was initially surveyed as a strong EF2, pending further investigation, which was completed Tuesday. The NWS survey team estimates this EF3 tornado touched down just south of the Surry Nuclear Power Plant at 6:45 PM and caused a nearly continuous damage path all the way to Southwestern Mathews County at 7:20 PM. This puts the tornado on the ground for approximately 30 miles! The width of the tornado ranged from around 200 yards to as much as a half-mile wide in Gloucester County. More than 200 homes were damaged, with numerous trees either downed or sheared off. Two people were killed as a result of this tornado, with 24 others injured.

The damage farther northeast around Deltaville in Middlesex County was deemed to be from a newly formed tornado rated EF2 (111-135 mph estimated wind speeds) from that same supercell thunderstorm. Surveyors Tuesday estimate an EF2 tornado touched down at 7:25 PM at Fishing Bay in Southeastern Middlesex County, moved northeast through Deltaville, then dissipated at 7:40 PM over the Rappahannock River. This tornado was as wide as a quarter-mile and was on the ground for about 3 miles, damaging 95 homes (in Deltaville) and downing or shearing off numerous trees in the area. No injuries or deaths occurred from this tornado.

The National Weather Service in D.C. confirmed Monday evening an EF-0 tornado 2 miles west of Leesburg, VA in Loudon County at 7:14 PM Saturday. A few trees were uprooted and a street sign post was pulled from the ground and snapped. Several other snapped tree limbs occurred as a result of this tornado.

The National Weather Service in Blacksburg surveyed damage Sunday and confirmed two tornadoes from Saturday.

An EF-0 (85 mph winds) moved through Rockbridge County around 2:03 PM Saturday. The path length was 1.3 miles and the width was around 100 yards. It produced minor damage to a few homes and barns and knocked down several trees.

The other tornado was confirmed in Halifax County. An EF-2 (111-135 mph winds) moved through Virgilina and destroyed numerous homes. There were a few minor injuries, but no fatalities.

Here are some of the tornado touchdowns on our map from Saturday:Here is the Enhanced Fujita Scale for your reference:

Saturday, April 16, 2011

Update - At Least Four Confirmed Tornadoes In Virginia On Saturday

Severe thunderstorms raced across the area Saturday afternoon and produced widespread damage. At one point, storms were moving 55 to 70 mph. There are now at least four confirmed tornadoes in Virginia.

One tornado touched down in Augusta County (EF-1 with max winds 95 mph) and knocked down several trees and destroyed numerous barns.

A tornado is now confirmed in Dinwiddie County with a path around 8 miles long and 300 yards wide. Many homes were damaged along the path of this tornado.

Two more tornadoes were confirmed in Isle Of Wight and Gloucester counties. There was extensive damage in Gloucester with three fatalities. National Weather Service is going to survey the damage more today to see the strength of the tornado.

There was also wind damage in Halifax County where eight homes were destroyed with four minor injuries. National Weather Service will survey the damage today to see if this was from a tornado.

At one point, the Tri-Cities area was under a Tornado Warning, however, with the exception to a few toppled tress, there were no reports of major damage.

There were a few reports of hail in Crewe and Powhatan. We received pictures of quarter to golfball-sized hail.

Here are some maps which show all of the storm reports from today. The "W" represents wind damage, "H" is hail and "T" is tornado. North Carolina was hit hardest today, where there were nearly 100 tornado reports!

Thursday, April 14, 2011

Risk for Severe Storms Saturday

An intensifying low pressure storm system in the Four Corners region of the western U.S. this Thursday morning is going to track through the southern Plains today, then move northeast toward the Great Lakes at the end of this week. Along the way, it should produce rounds of severe weather. This storm system will impact the Commonwealth by Saturday with overcast skies in the morning with showers.

But as we get into our afternoon hours of peak heating, instability will be at its greatest as the surface cold front linked to that low pressure system in the Great Lakes begins its sweep through the state. Ahead of that front, there will be sufficient wind shear, lift, and instability for strong to severe (potentially rotating) thunderstorms to develop in the afternoon and continue through the evening until the cold front passes into the Bay by Midnight.
Here's a time-line of the storm system on Saturday:

We'll be overcast in the Commonwealth by Saturday morning, and showers should expand east into central Virginia from the west before Noon.

Saturday afternoon, as mentioned above, is when we'll have our enhanced threat for severe thunderstorms.

Isolated thunderstorms that develop in central Virginia (east ahead of the main line of storms along the cold front) will be the most likely to rotate and potentially produce a few tornadoes.

Once the cold front starts sweeping through central Virginia, storms should be in a long "squall" line with damaging straight-line winds being our primary threat into the evening.

The cold front will reach the Chesapeake Bay around Midnight, pushing storms to the east.

Although we'll have the downside of a severe weather threat, the good news out of this storm system is that it should bring heavy rain into the entire Commonwealth, which is something we still need in most of the area! Widespread accumulations of a half-inch to around an inch look likely. Here's the potential rainfall accumulation by late Saturday night:

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

Sunday, April 10, 2011

Things To Watch Heading Into Hurricane Season

Colorado State came out with their forecast for the upcoming hurricane season. They are calling for an above average season with 16 named storms, 9 hurricanes and 5 major hurricanes. Here are a few things we will be watching over the next couple months leading to the start of hurricane season.

La Nina

Hurricanes like warm ocean water and low wind shear. Wind shear is typically low during La Nina, which would lead to an active season. However, La Nina is rapidly weakening (see the map below), so the forecast isn't as clear-cut.

Atlantic Water Temperatures

As I stated above, hurricanes strive in warm ocean water. Sea surface temperatures (SST) have been above normal over the past few months, which points towards an active season.


The North Atlantic Oscillation (NAO) has an impact on the Trade Winds. We saw a dramatic shift to a positive NAO during January. This increased the Trade Winds and has consequently cooled the Atlantic waters slightly. If we remain in a positive phase, then ocean temperatures could continue to cool.


Colorado State has already decreased it's initial forecast for this upcoming hurricane season. If La Nina continues to weaken and NAO remains mostly positive, then we might see the number of named storms and hurricanes decrease. We will continue to track this and bring you more updates.

Friday, April 8, 2011

Spring Allergens Hitting Hard

It's that time of year...when the world falls in love. Oh, no wait; wrong season. It's actually (cough, sniffle, sneeze) Spring Allergen Season and it's hitting hard a little earlier than usual for those of you allergic to seasonal pollen and mold producing flora and fauna.

We've had some much-warmer than normal days in March and April and some much-needed rounds of rain during our Spring temperature roller coaster, and that gave the grass pollen an early start (typically we don't see pollinating grasses like timothy, Bermuda and orchard with higher counts until late Spring). The latest Virginia Adult & Pediatric Allergy & Asthma (VAPA) report has the following allergen update:
Pollen and Mold Counts
Last Updated: 4/7/2011

Tree Pollen
509 High (oak, birch, pine, sweet gum)

Grass Pollen

16 Moderate- EARLY!


1,200 Moderate
Weed Pollen- none

So not only are those of you allergic to the tree pollens listed above dealing with that, you're also having to contend with the grass pollen a little earlier than normal in central Virginia. Recent rains are also enhancing the mold spore production.

Although we'll be a little cooler the next two days, much-warmer-than-normal temperatures and sunshine are expected Sunday and Monday: 80 and 90 degree highs, respectively. Monday's high temperature will be very close to the record high for that date, 92 degrees (1930).

Here's some great FYI from VAPA:
  • Most pollens are emitted between 5-10 AM, so you may find it helpful to delay outdoor activities until late morning.
  • Beware of high mold spore counts after a heavy rain or in the evening.
  • Hot, dry, windy days are the worst for kicking up and spreading allergens! Stay indoors if you can.
  • Don't hang your laundry out to dry, as allergens will attach to your "fresh" laundry.
  • Wear a filter mask when you garden, mow the grass, or rake leaves.
  • As tempting as it is to open the windows and let in the fresh air, you're also letting in all those allergens into your home. Keep the windows closed during high pollen count days and run the AC if you can. And replace those air filters on time! Apply this same principle to your vehicles, as well.
Typical early Spring allergens include: oak, cedar, elm, maple, and hickory trees. Typical late Spring allergens include: pollinating grasses like timothy, Bermuda and orchard.

Tuesday, April 5, 2011

Tornado Watch Expiring Early

After a squall line of severe thunderstorms raced through central Virginia early Tuesday morning, the tornadic threat is exiting with the storms to our east. This means the Tornado Watch that covered all of central Virginia overnight is expiring early from west to east. The Watch remains in effect for these red counties, though, while the squall line moves into the Eastern Shore.

This line of severe storms has a history of producing wind gusts in excess of 70 mph earlier this Tuesday morning, knocking over trees and producing hail up to quarter size (1" in diameter). There was also frequent lightning at times (which caused power outages in central Virginia this morning) and heavy downpours (which made driving in the storm difficult and dangerous). You can check out the latest severe weather reports from overnight by clicking here. Stay with CBS 6, we'll keep you ahead of the storm. --Meteorologist Carrie Rose--

Severe Thunderstorm Watch in Effect Until 6 AM

A severe thunderstorm watch is in effect for parts of south-central VA until 6 AM. Wind gusts to 70 mph and hail up to 1" in diameter will be possible with the strongest storms. We'll be tracking these storms overnight in the weather center with updates online and on the air. Stay With CBS 6, We'll Keep You Ahead of the Storm.

Monday, April 4, 2011

Warm & Windy Monday Ahead of Strong Storm System Tuesday

Monday will be blustery as a strong low pressure system tracks eastward closer to us. This tightening of the pressure gradient between high pressure east of the Southeast U.S. Atlantic coast and the approaching low pressure from the west will create gusty southwest winds up to 40 mph in central Virginia, with gusts around 50 mph in the counties highlighted in tan on this map (Wind Advised counties).

This storm system has a strong cold front at the surface causing temperatures to drop about 20 degrees in its wake. It also has a history of producing severe weather, primarily in the form of damaging winds and hail. All of central Virginia will have a slight risk for severe thunderstorms early Tuesday morning as that cold front approaches:

Our primary threat will be damaging straight-line winds in excess of 65 mph, as these thunderstorms will likely occur in the form of a squall line with frequent lightning and heavy downpours. It looks like a mature squall line will track into western Virginia around Midnight tonight:

This squall line should sweep swiftly into central Virginia while most of you are asleep, so don't be surprised if you are awakened between 3-5 a.m. Tuesday in the Metro as these strong to severe thunderstorms track through.

The squall line should weaken as it tracks toward the Chesapeake Bay, reaching the Eastern Shore by 7 a.m. Rain will continue behind the squall line as the cold front begins moving through central Virginia after sunrise:

I expect the rain to taper off from west to east behind the cold front during the rest of Tuesday morning, with Tuesday afternoon likely being dry with rapidly decreasing clouds. Rainfall accumulations look like they'll range half an inch to an inch from Tuesday morning's storm system:

A seasonable air-mass will settle back into the Mid-Atlantic behind Tuesday morning's cold front with highs Tuesday and Wednesday in the mid-60s.