Imagine a 6 by 6 oak post, sunk three feet into the earth as a support for an outbuilding. Now imagine wind strong enough to suck it up out of the ground like a golf tee and toss it the length of four football fields. That's what the NWS surveyors found in Virginia where one of Sunday's three tornadoes struck. And that was only an EF-0 twister. Here's more on the Enhanced Fujita scale of tornado intensity.

The initial reports from the NWS Sterling forecast office are now available online. Click here. For the specifics on the Maryland damage, click here. For the Virginia details, click here.

There's also this nifty map of rainfall reports from the precip on Sunday and Monday.  It's a bit disorienting, covering just the Sterling office's forecast area. That's the Western Shore of the bay on the right, with Harford County at upper right, St. Mary's at lower right. The Pennsylvania line runs across the top, as far as Allegany County. (Garrett is covered by the Pittsburgh office.) The bulk of the map covers Northern Virginia.

Posted by Frank Roylance at 5:39 PM | Permalink | Comments (0)
                    

There are some amazing online videos of the Atlanta tornado. Here is a sampler:

Here's one from CNN: http://www.cnn.com/2008/US/weather/03/17/atlanta.tornado/index.html#cnnSTCVideo 

Here's some local TV footage, from an airport webcam: http://www.youtube.com/watch?v=rxfa1AVQlS8

More local TV video, from a helicopter: http://www.youtube.com/watch?v=EPdJah-P0F8&feature=related

A walking tour of downtown Atlanta: http://www.youtube.com/watch?v=JRxOCFh_mm4&feature=related

Here's video of the hailstorm as the tornado approached: http://www.youtube.com/watch?v=IxhTY7o-4dM&feature=related 

Another walking tour, with MalaniKai: http://www.youtube.com/watch?v=Qr0OUzkrmo8&feature=related

Posted by Frank Roylance at 12:23 PM | Permalink | Comments (0)
                    

The National Weather Service has rated Monday evening's Harford County tornado an EF-1 on the "Enhanced Fujita Scale."  That suggests maximum winds between 86 and 110 mph.

Here's the statement this afternoon from the Sterling forecast office:

"A TORNADO TOUCHED DOWN NEAR FALLSTON MONDAY AFTERNOON. NWS DAMAGE SURVEY SUGGESTS THIS TORNADO WAS AN EF1 INTENSITY ON THE ENHANCED FUJITA SCALE. MAXIMUM PATH WIDTH WAS 150 YARDS AND THE LENGTH APPROXIMATELY 4 MILES LONG.

"EXTENSIVE DAMAGE TO TREES INCLUDING SOME SOFTWOOD TREES SNAPPED AND MANY HARDWOODS TOPPLED. STRUCTURAL DAMAGE OBSERVED WAS LIMITED TO TREES AND LIMBS FALLING ONTO STRUCTURES. MANY POWERLINES WERE ALSO DOWNED.

"NO INJURIES WERE REPORTED. EVENT TIME APPROXIMATELY 6:15-6:27 PM."

For a detailed list of damage reports from Monday's storms, click here.

The June 13 tornado that ripped up woodlands north of Butler, in Baltimore County, was rated an EF-0, with top winds between 65 and 85 mph, the lowest rating on the scale.

Posted by Frank Roylance at 4:10 PM | Permalink | Comments (0)
                    

An inspection team from the National Weather Service is on its way back to Sterling, Va. this morning after inspecting damage from last evening's storm in Harford County. The preliminary word from their three-hour tour of the Fallston area is that the damage was caused by a small twister.

"The damage we saw suggests that, yes, it was a tornado," said David R. Manning, warning coordination meteorologist for the National Weather Service's Baltimore-Washington Forecast office in Sterling.

There was no immediate estimate of the storm's intensity on the Enhanced Fujita Scale. "I didn't see damage that would suggest a strong tornado, but there was some fairly significant damage to trees and a lot of power lines were taken down."

"At this point it looks like it was on the ground for a few miles - less than 10 but more than 3," Manning said. ""We have not mapped out all the locations yet completely."  The twister's path of destruction stretched from near Fallston, southeastward to very close to Abingdon. Its width varied from 100 to 150 yards.

A Fujita rating and a better estimate of the length of the tornado's path of destruction across Harford County is expected later today in a public information statement to be published on the Sterling forecast office Web site. 

Manning was also part of the team that inspected damage from the F-0 tornado that ripped through woodlands north of Butler in northern Baltimore County on June 13. The Fallston damage suggests yesterday's storm was bigger - "a little wider and a little longer," he said.

The fast-developing thunderstorm boiled up over northern Baltimore County around 5:30 p.m., knocking down trees near Old York Road and Troyer Road in Monkton, and near Corbett Road in Phoenix. 

The weather service issued a severe thunderstorm warning at 5:35 p.m., Manning said, followed by a tornado warning for Harford County at 6:12 p.m.

The storm crossed into Harford County, snapping and toppling large trees in the Fallston area. Many of the trees took power lines and poles down with them. Utility and highway crews were still clearing and repairing the damage this morning.

Here's the story in this morning's Sun. 

Manning said he saw trees as large as 3 feet in diameter at the trunk that had been felled by the storm. "Some trees were topped, with either parts or most of them snapped off. Most of them were pushed over."

The key to distinguishing tornado damage from straight-line wind damage is the orientation of the downed trees and debris.

"If they diverge, it's straight-line wind," he said. He compared the effect to that of pouring a bucket of water onto the floor. The water moves out and away from the center. In a tornado, the debris is drawn in toward the center of the storm's track.

Fortunately, he said, yesterday's damage was almost entirely to trees and power lines. "A lot of the trees that fell, even though they were near homes, didn't fall on homes," Manning said. "I did see a few locations where limbs or trees did fall on homes, but I didn't see any major structural damage where I looked."

Accompanying Manning on the inspection tour this morning was another meteorologist from the Sterling forecast office, and a representative of Maryland Emergency Management.

Posted by Frank Roylance at 10:21 AM | Permalink | Comments (0)
                    

It's official. Those thunderstorms Wednesday evening included a small tornado that touched down briefly in Baltimore County. A National Weather Service team yesterday inspected the tree falls and other forest damage north of Butler and concluded it was consistent with a small tornado - an F-0 on the "enhanced" Fujita scale. Here is the statement from Sterling. 

Here's The Sun story. And here is the link to video, shot Wednesday in Silver Spring, of a funnel cloud that was part of the same storm system. We're told the cloud never touched the ground in Montgomery County, and therefore was not officially a tornado (which, by definition, must touch down). But it sure looks like it did.

Posted by Frank Roylance at 8:03 AM | Permalink | Comments (0)
                    

Posted by Frank Roylance at 4:04 PM | Permalink | Comments (0)
                    

The National Weather Service has issued a tornado watch for all of Maryland east of Washington County. The same stormy cold front that brought flooding to Florida and deadly tornadoes to the Deep South overnight is on our doorstep this morning.

So far, the rain has been spotty, but there's more to come. The National Weather Service is still warning of 1 to 2 inches of rain in places, all falling in a relatively short period. That can lead to street flooding where drainage is poor. Wet leaves can make the streets slippery in spots, too. 

Winds are already gusting as high as 18 mph here at Calvert and Centre streets. There's been little rain - barely two hundredths of an inch here. But that will change. Here's the radar loop. And here's the forecast for BWI-Marshall.

Strong south and southeast winds are holding water in the bay today, and high tides are running well above predicted levels. Coastal flood warnings are up along the west shore of the Chesapeake. Here are the links to the real-time tide gauges. Just click on "MD" and then the gauge of your choice.

Posted by Frank Roylance at 11:07 AM | Permalink | Comments (0)
                    

The National Weather Service has determined that the wind storm that caused significant damage yesterday in Anne Arundel County was, indeed, a tornado - an F1 on the Fujita scale, meaning its winds fell into the range of 73 to 112 mph. The Fujita Scale runs from F0 to a never-yet-observed F5.

Here is a link to a rather incomplete and disorganized, but interesting NWS page with links to reports on past Maryland tornadoes.

Here's the full text of today's report:

"...A TORNADO TOUCHED DOWN IN CENTRAL MARYLAND THURSDAY EVENING...

"THE NATIONAL WEATHER SERVICE CONDUCTED A STORM SURVEY IN SEVERNA
PARK AND PASADENA MARYLAND TODAY. FROM THIS SURVEY... INTERVIEWS
WITH EYEWITNESSES... NATIONAL WEATHER SERVICE SKYWARN SPOTTERS...
AND DOPPLER RADAR IMAGERY... IT WAS DETERMINED THAT A TORNADO
TOUCHED DOWN AROUND 6:30 PM IN CENTRAL MARYLAND IN THE AREA OF
SEVERNA PARK... AND TRAVELED TWO MILES BEFORE LIFTING IN PASADENA
MARYLAND AROUND 6:40 PM. AT ITS MAXIMUM THE STORM WAS 250 YARDS WIDE
WITH WINDS OF 90 MPH WITH A RANKING OF F1 ON THE FUJITA SCALE WHICH
RUNS FROM F0 TO F5. 33 HOMES WERE SEVERELY DAMAGED BY FALLING TREES
WITH 13 OF THOSE HOMES RENDERED UNINHABITABLE.

"INITIAL MINOR DAMAGE WAS LOCATED NEAR THE INTERSECTION OF RITCHIE
HIGHWAY ROUTE 2 AND MCKINSEY AVENUE. A HARDWARE STORE HAD ITS SIGN
BLOWN DOWN AND A SMALL TREE WAS DOWNED NEAR THE SEVERNA PARK
MARKETPLACE SHOPPING CENTER. A FEW TREES WERE ALSO DOWNED
IMMEDIATELY BEHIND THE SHOPPING CENTER ALONG LEELYNN ROAD.

"THE TORNADO GATHERED STRENGTH AS IT PROGRESSED THROUGH WEST RIDGE
AND TOWARDS CATTAIL CREEK OFF OF THE MAGOTHY RIVER. FIVE LARGE
HARDWOOD TREES OF ONE TO TWO FEET IN DIAMETER WERE UPROOTED... AND
SEVERAL OTHERS WERE SNAPPED OFF ALONG WHITTIER PARKWAY. TWO OF THE
LARGE TREES HAD FALLEN THROUGH HOUSES. THESE TREES... AS MOST OF THE
TREES WERE IN THE SURVEY... WERE BLOWN DOWN NEARLY PERPENDICULAR TO
THE PATH OF THE TORNADO... KNOCKED DOWN TOWARDS THE WEST.

"THE TORNADO THEN PASSED OVER A NORTHWEST EXTENSION OF THE MAGOTHY
RIVER CALLED CATTAIL CREEK... AND REACHED ITS MOST INTENSE AND
WIDEST EXTENT AS IT PASSED THROUGH THE COMMUNITY OF LOWER MAGOTHY
BEACH. IN THIS AREA WINDS WERE ESTIMATED TO HAVE REACHED 90 MPH. AT
ITS MAXIMUM THE STORM PASSED THROUGH A VACANT LOT BETWEEN NORTH
DRIVE AND SOUTH DRIVE. IN THAT AREA NEARLY EVERY TREE WAS UPROOTED
OR SNAPPED OFF AND BLOWN DOWN TO THE WEST. MANY OF THESE TREES WERE
LARGE TWO FOOT DIAMETER HARDWOOD TREES THAT WERE 60 TO 80 FEET TALL.
IT WAS EVEN NOTED THAT A SMALL SHRUB OF THREE FEET TALL WAS
UPROOTED... AN INDICATION THAT THE CIRCULATION REACHED ALL THE WAY
TO THE SURFACE. LEAF SPATTER WAS NOTED ON THE SIDES OF HOMES AND
VEHICLES. SLIGHT SIDING DAMAGE WAS NOTED ON ONE HOME. SEVERAL HOMES
HAD DAMAGE FROM TREES OR LARGE TREE BRANCHES FALLING INTO THEM. MANY
WIRES AND TELEPHONE POLES WERE KNOCKED DOWN IN THIS AREA. THE WIDTH
OF THE TORNADO AT THIS POINT WAS 250 YARDS.

"THE TORNADO THEN BEGAN TO WEAKEN AS IT PASSED JUST WEST OF HAMILTON
HARBOR MARINA AND CROSSED OVER THE COMMUNITY OF STEWARTS LANDING
BEFORE CROSSING OLD MAN CREEK INTO RIVERDALE. DURING THIS TIME MORE
TREES WERE BEING SNAPPED OFF THEN UPROOTED AS THE TORNADO WAS
BEGINNING TO LIFT OFF THE GROUND.

"IN THE RIVERDALE AREA... A FEW TREES AND SEVERAL LARGE BRANCHES WERE
DOWN. A SMALL GARAGE WAS DESTROYED BY A TREE. DAMAGE BECAME MUCH
MORE LIMITED AS THE TORNADO CONTINUED NORTH ACROSS NORWITCH ROAD AND
INVERNESS ROAD IN RIVERDALE. BY THE TIME THE STORM CROSSED THE
MAGOTHY FOR THE FINAL TIME AND TRAVELED OVER THE COMMUNITY OF
BEACHWOOD PARK... ONLY LEAF LITTER AND SMALL DOWNED BRANCHES WERE
NOTED."

Posted by Frank Roylance at 5:07 PM | Permalink | Comments (2)
                    

Update: The weather service has canceled the tornado watch posted earlier today, at least on the western shore of the bay, as the band of storms moved through without affecting our area. But there was more excitement to our south, as this radar loop shows.

Earlier: The National Weather Service has issued a tornado watch for Baltimore and the surrounding counties in north-central Maryland and parts of southeastern Pennsylvania - the yellow region on this map - in effect until 8 p.m. tonight.

We don't usually think of this area as tornado country, but twisters - almost always small ones - are not really uncommon in Maryland. For an interesting, albeit incomplete accounting of past Maryland tornadoes, click here.  The biggest tornado in recent memory was the F4 La Plata twister that struck Charles County in April 2002. For a detailed tour of the damage, click here.

Posted by Frank Roylance at 2:35 PM | Permalink | Comments (0)
                    

Want to see the weirdest, skinniest tornado ever? Click here for a link to the video. The twister was taped by a homeowner in Colorado, who provides a running commentary as she calls family members to describe it. She probably didn't expect her narration, or her baby's whining, to be carried worldwide via the Web. "It is really cool. I'm videotapin' it," she says. Her 5 minutes of fame.

Posted by Frank Roylance at 2:35 PM | Permalink | Comments (0)
                    

How often do the Orioles open their season under a tornado watch?  Most of Maryland and Virginia (and parts of the Carolinas, Georgia and Pennsylvania) were placed under a tornado watch at 4:15 this afternoon as a cold front approached with a threat of severe thunderstorms. A station near Hancock reported three-quarter-inch hail this afternoon. Here's a radar image showing the storm front.

Here's how the tornado watch reads for counties in the Sterling, Va., forecast area:

THE NATIONAL WEATHER SERVICE HAS ISSUED TORNADO WATCH 148 IN
EFFECT UNTIL MIDNIGHT EDT TONIGHT FOR THE FOLLOWING AREAS

THE DISTRICT OF COLUMBIA

IN MARYLAND THIS WATCH INCLUDES 13 COUNTIES

IN CENTRAL MARYLAND

ANNE ARUNDEL          HOWARD                MONTGOMERY
PRINCE GEORGES

IN NORTH CENTRAL MARYLAND

CARROLL               FREDERICK             WASHINGTON

IN NORTHERN MARYLAND

BALTIMORE             HARFORD

IN SOUTHERN MARYLAND

CALVERT               CHARLES               ST. MARYS

IN WESTERN MARYLAND

ALLEGANY

Here's a definition: 

Tornado Watch (SEL):  This is issued by the National Weather Service when conditions are favorable for the development of tornadoes in and close to the watch area.  Their size can vary depending on the weather situation.  They are usually issued for a duration of 4 to 8 hours.  They normally are issued well in advance of the actual occurrence of severe weather.  During the watch, people should review tornado safety rules and be prepared to move a place of safety if threatening weather approaches.

Posted by Frank Roylance at 5:20 PM | Permalink | Comments (0)
                    

Who says this isn't "tornado country"? The Sterling Forecast Office (National Weather Service) has posted its initial survey of the tornado damage Sept. 17 in Virginia, Maryland and West Virginia. The storms were spawned by the remnants of Hurricane Ivan. They chewed up trees, homes and businesses in 11 Virginia counties, three in Maryland (Frederick, Montgomery and Washington) and one in West Virginia. The strongest, which struck western Fauquier County, Va., was rated at F3 (158-206 mph) on the Fujita scale. It tracked 22 miles across the county and tossed a pickup truck 75 yards, over trees and power lines and dropped it in a field. To see the report,click here.

Posted by at 4:45 PM | Permalink | Comments (0)