TornadoVideos.net

Posted At: March 30, 2008 @ 10:39 AM

Posted By: Reed Timmer

There are significant differences between this morning's NAM and RUC model runs, especially in terms of the location of the primary surface boundaries (dryline, cold/then-warm front), and timing of convective initiation this evening.  The NAM is forecasting the cold front to sag south to near I-40 by 00z this evening, with ~2000-2500 J/kg and little CIN prevailing to the south, but delays convective initiation until after 00z.  The 13z RUC on the other hand, maintains a more SSW to NNE orientation of the cold front stretching from Woodward, OK to just north of Childress, TX.  The RUC also is predicting much higher CAPE values by 00z approaching the 4000 J/kg range, with convective initiation throughout western OK between 21 and 00z!  This solution is believable considering the quality of moisture over the Southern Plains this morning, and the fact that the front is surging southward primarily in the Texas Panhandle, but not further east.  We'll definitely be chasing this event...our target is western OK near 00z -- the brand new tracker will be up and running in an hour or so...we've fixed our data connection problems and the tracker updates every few seconds.  Stay tuned for updates, and check out the forum for Nowcasting and Reports over the next few days (Monday looks like the apocalypse).

Posted At: March 29, 2008 @ 2:03 AM

Posted By: Reed Timmer

The WRF and GFS now agree on a classic dryline tornado outbreak on both Sunday and Monday across the Southern Plains.  A massive uncapped warm-sector with 1500-3000 J/kg CAPEs will prevail east of the dryline forecast to exist along the eastern TX Panhandle Border by 00z Monday, with a warm front extending ENE through southeast KS.  A 40-50 knot low-level jet will develop near or shortly after 00z Sunday evening, thus any discrete supercells will have a high likelihood of producing strong tornadoes from Northwest Texas across western OK into southeast KS on Sunday evening.  There is a high possibility of an outbreak of strong tornadoes overnight Sunday as a jet streak ejects from the Mexican Plateau and storms increase in coverage.  The dryline will progress slowly eastward overnight Sunday into central OK by Monday afternoon.   The warm sector will easily recover and become sufficiently unstable for supercells along and east of the dryline across North Texas, Central OK, into Southeast KS and MO from Monday afternoon through overnight.  The WRF forecast CAPE for 00z Monday and 00z Tuesday are shown below:
The timing of LLJ intensification tomorrow evening near or shortly after 00z will be a huge factor determining the extent of the tornado outbreak tomorrow evening.  However, low-level shear will certainly not be a problem on Monday, and a widespread tornado outbreak seems inevitable based on these models runs.  The WRF forecast 850 mb flow for 00z Monday and 00z Tuesday are below.  Note the classic dryline setup for both days!:


The SPC has issued a slight risk in their Day 2 outlook, but this will likely be upgraded to a moderate risk by tomorrow.  We will definitely be chasing this event, and may try out our new and improved tracker on both days.  Stay tuned for updates!

Posted At: March 27, 2008 @ 7:12 PM

Posted By: Reed Timmer

Supercells have initiated along the cold front in OK, AR, and MO this afternoon and propagated southward ahead of the surging boundary.  Looking at the recent RUC analysis, 0-1 km helicity values are approaching 150 m2/s2 with a 20 knot southwesterly low-level jet.  Given southward storm motions, the storm-relative low-level shear is even higher.  I wish I would have looked at this earlier!!!!!!!   The loop of the Muskogee Co, OK storm including the time it had the tornado on the ground is shown below:

Posted At: March 27, 2008 @ 5:40 PM

Posted By: Reed Timmer

A very strong cold front roared through central Oklahoma today, with temperatures reaching the 90F mark immediately south of the front due to compressional warming.  The temperature in Norman fell from around 90 degrees to the low 70s in about 30 minutes!  Severe thunderstorms have been developing along the cold front from central MO southwestward to eastern OK.  Given very weak low-level shear and marginal moisture, the tornado threat is almost zero in the watch area below.  Still though, isolated reports of damaging winds and large hail are definitely possible.


Shown below is the Oklahoma Mesonet map from around 5:30 CDT, showing the front surging southeast through eastern OK, with temperatures falling into the upper 40s in the northwest part of the state!  As daytime mixing has ceased, dewpoints have also been nearing the 60F mark at several stations in southeast OK, so the storms along the front will likely intensify through the evening as moisture increases.  Hopefully next week we'll have some chase opportunities!

Posted At: March 26, 2008 @ 9:05 PM

Posted By: Reed Timmer

A very interesting feature is apparent in this evening's radar loop from Key West, FL, with several curved bands of higher reflectivity values over the Gulf of Mexico to the west and south of the radar site.  They appear to be some kind of mesoscale convergence zones, but also could be a non-meteorological phenomenon like chaff plumes, which are clouds of aluminum-coated glass fibers released by the military to confuse enemy aircraft -- but usually for test purposes in the U.S. of course.  Any thoughts on what this might be??

Posted At: March 25, 2008 @ 9:47 AM

Posted By: Reed Timmer

Glancing at last night's GFS, it looks like the strong zonal flow across the northern U.S. will continue through late March, with the hint of a pattern change around the first of next month.  There will be a sheared-out shortwave that will move through the zonal flow by 72 hours, but moisture will be limited and the LLJ will be way too veered for any substantial tornado threat with this system.  By ~168-180 hours, recent GFS runs have been hinting at the development of a more substantial western U.S. trough as the zonal flow breaks down into higher amplitude Rossby Waves.  As is often the case with La Nina years, I wouldn't be surprised if we have a late start to the Great Plains severe weather season...which is better than never.

Posted At: March 22, 2008 @ 12:25 AM

Posted By: Reed Timmer

Check out this incredible video of a house floating down the flooded White River in Izard Co, AR, and slamming into a bridge!  Thanks to Heidi for providing the link. The flooding has been catastrophic in this region, especially in the states of Arkansas, Missouri, and Ohio, where over a foot of rain fell from this recent storm system.  Most of the flooding has been associate with smaller rivers from AR northeast to OH, but the major rivers such as the Mississippi and Ohio River have had only minor flooding, likely because they originate in areas that did not receive heavy rain. 

http://www.cnn.com/2008/US/weather/03/21/severe.weather.ap/index.html

Meanwhile, a record-breaking snowstorm struck parts of the Northern MS River Valley through the southern Great Lakes Region today, dumping over a foot of snow in areas.  An Alberta Clipper was responsible for this snowfall, as is often the case this time of year.  Two years ago during late winter/early spring, an Alberta Clipper with a similar track, but much more compact and intense of a system, dumped 12 inches of snow in about 4 hours in Grand Rapids with thunder and lightning!  Milwaukee, WI received 14 inches of snow from this event, and Grand Rapids, MI has received ~8 inches and counting.  INCREDIBLE winter weather event!!!!

Posted At: March 20, 2008 @ 12:22 AM

Posted By: Reed Timmer

Here are pictures of the camera probe we'll be dropping in the paths of tornadoes this year.  The camera below shoots HDV quality, and is housed in a "bullet-proof" bubble, which will hopefully protext it from flying debris.  Inside the orange frame is a steel re-enforced 300 pound block of cement -- hopefully heavy enough to keep the probe from going airborne!

Posted At: March 19, 2008 @ 7:32 PM

Posted By: Reed Timmer

REMINDER!!!  Please vote for the Ellis County, OK tornado video for the 2007 Youtube Awards at the following link:

http://www.youtube.com/ytawards07

The video can be found under the "Eyewitness Video" section.  Thank you!!

The voting ends tonight!

Check out these pictures of major flash flooding in the Ozark Mountains of Sharp Co, AR, courtesy of Heidi Farrar.   The  Spring and White Rivers are setting record water levels today, with the Spring river reaching 22 feet this morning, shattering the old record of 16 feet on 9-23-06.  This flooding resulted from 8 inches of rain that fall during this recent storm system.  Thanks to heidi for providing this info and pictures.

Posted At: March 19, 2008 @ 11:50 AM

Posted By: Reed Timmer

REMINDER!!!  Please vote for the Ellis County, OK tornado video for the 2007 Youtube Awards at the following link:

http://www.youtube.com/ytawards07

The video can be found under the "Eyewitness Video" section.  Thank you!!

Here is the video of supercells we intercepted on March 17, 2008 in the Texas Hill Country.  The first supercell shown in the video was shot just south of Abilene, and was a short-lived LP that exhibited mid-level rotation but "split" to death shortly thereafter.  Note the mid-level funnel between the storm splits featured near the beginning of the video.

The second supercell we intercepted further south just west of Coleman, TX.  This storm was tornado warned near and just after sunset, and produced a ground-scraping wall cloud and a few "funnels".  We thought this storm was going to produce, but the good low-level shear never made it back west in time.


The pictures below show the intense flash flooding that occurred in Sulphur National Park in Southeast Oklahoma, shot by storm chaser Jason Young.  Given that the shear failed to materialize on Monday or Tuesday, flash flooding was the main threat to life and property during both severe weather outbreaks.

Posted At: March 18, 2008 @ 9:55 AM

Posted By: Reed Timmer

The warm sector east of the cold front today will be characterized by very high wind shear but marginal instability due to modified lapse rates and cloud cover.  It appears that a vast majority of the convection today will be disorganized and "junky" in nature, but the extreme low-level shear values could result in a few significant tornadoes over the Piney Woods of Texas into the jungles of Louisiana.  More will be posted about this event as it unfolds, as well as pictures from the beautiful supercell from yesterday intercepted near sunset west of Coleman, TX.

Posted At: March 17, 2008 @ 8:42 AM

Posted By: Reed Timmer

While the tornado threat today is very conditional, the potential exists for large, long-track tornadoes this evening over central Texas if storms can remain discrete until the low-level jet intensifies this evening.  A large uncapped warm sector with CAPEs exceeding 1500 J/kg is forecast to develop by this afternoon from extreme southwest OK southward into central TX (see 00z WRF forecast below left).  The only complicating factor today is a lead shortwave that ejected last night to the Northern Plains, which will cause the low-level flow to temporarily weaken and veer this afternoon over the Southern Plains.  However, as the main vort max ejects this afternoon, the low-level jet will intensify to 40+ knots east of the dryline near or shortly after 00z.  The timing of this LLJ evolution is key for tornadoes today.


The SPC has issued a slight risk for the Southern Plains for this afternoon and overnight, with a 10% area for tornadoes from about Aspermont, TX southwestward to the Mexican Border.  Our target will initially be the Abilene area, and we'll either adjust south or stay put as things evolve.  Stay tuned for updates, and also to the forum for nowcasting/discussion/reports!

Posted At: March 15, 2008 @ 2:48 PM

Posted By: Reed Timmer

A high risk has now been issued for eastern GA into central SC for the threat of long-track supercells and damaging tornadoes.  Several cyclic supercells have already developed across northern GA into western SC, with additional explosive development anticipated along and east of the SW to NE convective line.  8 tornadoes have already been reported across northern GA, with several homes damaged.  However, that number will likely triple before the day is over.  Stay tuned for updates!

Posted At: March 15, 2008 @ 2:10 PM

Posted By: Reed Timmer

The 18z RUC analysis maps below for CAPE and 0-1 km helicity tell the entire story!  A MAJOR tornado outbreak is likely this afternoon and evening across northern GA and SC, as a strong, compact vort max moves through the region.  A massive, uncapped and unstable warm sector is in place across the Southeast, which is a major ingredient for most significant tornado outbreaks.  As seen in the map below, CAPEs are surpassing 2000 J/kg across eastern GA!



A tornado watch has already been in effect for several hours from eastern AL into western SC, with one particularly strong supercell moving across northern GA through 19z.  This cell has exhibited very strong, persistent couplets, and has even had reported tornadoes.  I would not be surprised at all if these tornadoes were large and damaging given the insane shear values in place.  Additional storms have been developing to the southwest of this parent storm, and these cells will likely become tornadic very soon.  Stay tuned for updates, and check out the Nowcasting thread in the blog for near real-time updates!

Posted At: March 14, 2008 @ 11:28 PM

Posted By: Reed Timmer

Shortly before 10 pm, a possible tornado roared through Downtown Atlanta causing damage to Philips Arena, the Georgia Dome, and even CNN center.  The overtime battle between Alabama and Mississippi State in the SEC tournament had to be halted as the tornado struck, and small debris was raining down from the roof onto the basketball court!  Minor damage occurred to the CNN center building, including shattered windows in the newsroom! 

http://www.cnn.com/2008/US/03/14/storm.atlanta/index.html

Here is the radar loop around the time of the tornado -- showing a textbook, right-moving supercell with a classic hook echo.  These storms in the Southeast resulted from the same subtle shortwave that produced the storms last night in Eastern OK...

Posted At: March 13, 2008 @ 8:32 PM

Posted By: Reed Timmer

We have just been informed that the Ellis County, OK tornado video, shot on May 4, 2007, has been nominated for the best "Eyewitness Video" for the 2007 Youtube Awards!!  In order to win, we need as many votes as possible!!!  Please go the link below, and vote for our video stat!  If you think it's deserving of course!

You'll see the video under the "Eyewitness Video" category.

http://youtube.com/ytawards07

We'll keep you updated on the status of the footage as we hear.  The winning video will be flown out to NYC for the awards show.

Posted At: March 13, 2008 @ 10:57 AM

Posted By: Reed Timmer

A shortwave trough will eject from the Southern Rockies this afternoon, bringing the upper-support necessary for severe storms today east of the dryline in Central OK.  An upper jet streak, and the sufficient moisture will arrive relatively late (21-23z) in southeast OK, so it looks like convective initiation will hold off until at least 5:00 pm, but a strong cap may delay things until after that time.  The RUC initiates convection in eastern OK after 6:00 pm, but between 6 and 7 pm explosive, isolated convection is forecast.  A low-level jet of 30-40 knots will intensify ahead of the advancing shortwave (see 850 mb RUC forecast below), with CAPE values of 1500-2000 ahead of the dryline (see RUC cape forecast below).


While the cap will be a concern today, as well as the late arrival of the upper support and deep moisture (tied in with the strong cap), supercells will still be possible by very late afternoon and overnight across eastern OK into western OK - but these storms may quickly become elevated shortly after sunset, so the window for tornadoes will likely be rather narrow.  The SPC has issued a 5% area for tornadoes, as well as a hatched area for very large hail.  We'll be keeping a close eye on this event, and will likely head out and chase if convective initiation becomes imminent....but tomorrow (Friday) looks like the big event!  Stay tuned for updates.

Posted At: March 11, 2008 @ 10:22 AM

Posted By: Reed Timmer

A strong vorticity maximum is forecast to amplify over the Rocky Mountain Region and eject east across the Plains on Monday, March 17.  Model runs over the past few days have been very consistent with the timing and strength of this feature, so confidence is high that severe weather will develop somewhere across the Southern Plains east to the MS River Valley early next week.  A strong low-level jet will develop ahead of this vort max, which will transport Gulf moisture northward and generate favorable low-level shear for tornadoes in the warm sector.  The only possible limiting factor for severe weather with this system is the quality of the moisture return, especially for the Southern Plains, with dewpoints struggling to make the 50F mark.   Stay tuned for updates...

Posted At: March 10, 2008 @ 11:41 AM

Posted By: Reed Timmer

Check out this comprehensive video production of this weekend's blizzard in Montreal, Quebec, as shot by local resident, "Caro".  12-24 inches of total storm accumulation occurred in this area, with drifts approaching 5 feet! 

Posted At: March 9, 2008 @ 12:11 PM

Posted By: Reed Timmer

This weekend's snowstorm from the Ozark Mountains through the Ohio River Valley resulted in record-breaking snow accumulations for many areas.  20.4 inches of snow fell in Columbus, OH, which shattered the previous record of 15.3" set in February of 1910!  Over a foot of snow was commonplace across parts of the central MS River Valley into the Northeast, with IN, KY, OH, southernOntario and Quebec, Canada being the hardest hit.  3-5 foot drifts and blizzard conditions shut down roads and knocked out power to tens of thousands of people!  Up to 30 inches of snow is on the ground in northern OH, where lake effect and lake enhanced snow added to the storm totals.  Here is a list of the snowfall totals from the hardest hit areas in northern OH:


CNN story:
http://www.cnn.com/2008/US/weather/03/08/march.snowstorm.ap/index.html


STORM TOTAL REPORTS:

Southwest OH:
http://kamala.cod.edu/oh/latest.nous41.KILN.html

Northern OH:
http://kamala.cod.edu/oh/latest.nous41.KCLE.html

Southeast IN:
http://kamala.cod.edu/in/latest.nous41.KILN.html

Northern KY:
http://kamala.cod.edu/ky/latest.nous43.KLMK.html

Posted At: March 7, 2008 @ 5:11 PM

Posted By: Reed Timmer

Winter storm warnings are currently in effect from Arkansas to Ontario, where up to foot of snow has already accumulated in many locations.  A massive area of deformation zone snow extends from the Lower MS River Valley through upstate NY, with warm advection precip from there eastward. 

This morning and early afternoon, 13 tornadoes touched down in southern GA and northern FL, with several homes damaged and 2 fatalities reported in Columbia Co, FL.  These tornadic supercells occurred within a strong mesoscale convective system (MCS) ahead of a strong cold front moving slowly southeastward across the southeast US. 


The unofficial SPC storm reports map for today is displayed below.  The tornadoes producing significant damage were in north-central FL to the west of Jacksonville.  While a tornado watch is still in effect across the central/southern FL Peninsula, it appears that the core of the LLJ has translated well north and east of the area, so only weak/brief tornadoes are anticipated tonight, if any at all.


Below are pictures from the winter storm in northern AR, that dumped up to 8 inches across the region.  These pictures were taken by Heidi Farrar early this afternoon - she reported 7 inches of storm total snowfall in her area.  If anyone else has pictures of this winter storm, please share them in the forum!

Posted At: March 5, 2008 @ 3:26 PM

Posted By: Reed Timmer

A potentially record-breaking snow storm is forecast to hammer parts of central and southern Oklahoma into the Ozark Mountain region tomorrow through Friday, with up to a foot of snow likely, especially over southern OK into northern AR/southern MO.  The 12z WRF from this morning is predicting .75-1 inch of water equivalent precip from southern OK into northern AR, but higher amounts will likely fall within persistent mesoscale bands.  The 12 hr precip forecast valid 00z tomorrow is shown below:


This is definitely a classic, TEXTBOOK winter storm pattern for southern/central OK into the ozarks, with a nice, nearly cut-off upper trough pivoting across the Southern Plains, with the track of the 500 mb vorticity maximum just south of the Red River.  A tight baroclinic zone will also be in place across OK, with bigtime warm advection ahead of this system before the deformation zone snow arrives.  The WRF forecast surface and 500 mb patterns valid tomorrow evening are shown below:


Of course, winter storm warnings are now in effect across central OK for this system tomorrow, including the OKC Metro area, with winter storm watches further northeast.  These watches will likely be upgraded to warnings by tonight.  We'll be covering this system extensively from Norman, OK, so stay tuned for continuous video/news updates throughout the event!

Posted At: March 4, 2008 @ 10:12 AM

Posted By: Reed Timmer

As a strong, nearly cut-off vorticity maximum moves across the Ohio River Valley today, a strong low-level jet and a large uncapped warm sector will prevail across the Southeast U.S. by this afternoon through evening.  500-1000 J/kg CAPE (left image below), and a 50-80 knot low-level jet (right image below) is forecast to exist from northern FL across the Carolinas into southern VA by 00z this evening.  The 12 hr WRF forecast CAPE and 850 mb for 00z is displayed below:

Posted At: March 2, 2008 @ 11:42 PM

Posted By: Reed Timmer

Here is great video of the Blaine Co, OK tornado, as shot by Don G and co.  The tornado touched down at around 2245 UTC, and was on the ground for at least 10 minutes, severely damaging at least one small home.  The southward surging cold front was within 10 miles or so of this storm as it was producing the tornado!

Posted At: March 1, 2008 @ 10:01 PM

Posted By: Reed Timmer

The WRF model continues to slow-down the upper trough for tomorrow, and accordingly, the surface cyclone is forecast to be stronger and further north than in previous model runs.  The WRF is showing a classic dryline bulge across Southwest Oklahoma by 00z just south of a triple point in the eastern Texas Panhandle, and the best low-level shear is forecast to be just east of this feature with 150+ 0-1 km helicity values over a large part of western OK.   The triple point and attendant dryline bulge can be seen in the WRF forecast CAPE and 0-1 km helicity for 00z tomorrow:


Given this slower solution, the low-level jet is forecast to back to a more southerly if not SSE-ly direction by 00z tomorrow in response to the stronger low-level cyclone.  This backing of the LLJ will make the hodographs more favorable for tornadoes given a northeasterly storm motion. 

The only potential limiting factor for a widespread tornado outbreak over the Southern Plains tomorrow is a rather strong capping inversion, which is forecast to limit surface-based convection south of dryline bulge.  The WRF also fires a strong line of convection well east of the dryline in northeast TX into southeast OK by 00z, which may be due to the lead shortwave forecast to eject ahead of the main "energy", but is still hard to believe given the lack of any well-defined surface convergence boundary.  We'll likely be playing southwest OK/northwest TX near the bulging dryline but far enough south of the triple point such that any storms will not be undercut.

Meanwhile, as this system moves east towards the central Mississippi River Valley overnight Monday, heavy snow and near blizzard conditions are likely in eastern OK into southwest MO, with up to a foot of snow accumulation possible.  If the severe weather setup does not look as favorable on Monday, we may document this snowstorm after the severe weather event in the Southern Plains tomorrow.  Stay tuned as this insane weather situation unfolds!

Posted At: March 1, 2008 @ 1:54 AM

Posted By: Reed Timmer

The Friday evening WRF and GFS runs are trending slower and slower with each consecutive run with the progression of the strong vort max that will eject from the Southern Rockies on Sunday.   Given this slower solution, surface cyclogenesis is forecast to occur further west, allowing for a strong low-level jet to counter the southward surge of the cold front.  Therefore, a dryline will likely form across West Texas on Sunday extending south of a surface low forecast to track rapidly eastward through the afternoon and evening, generally along I-20.  WRF forecast loops for 850 mb and the surface are shown below:


Given the massive uncapped and unstable warm sector forecast to develop across Central Texas on Sunday, with a LLJ of 40+ knots just above the surface by afternoon, tornadic supercells will likely develop in the vicinity of the triple point and southward along the dryline.  However, as is always the case with early season setups in the Southern Plains, there is still a high probability the cold front will surge southward faster than predicted by the models, undercutting any surface-based convection that initiates.  But...the models could verify for this event!  Stay tuned for updates as this severe weather event unfolds!