TornadoVideos.net

Posted At: November 29, 2006 @ 11:30 AM

Posted By: Reed Timmer

An intense, textbook winter storm will impact the entire state of Oklahoma on Thursday, November 30, with a crippling snowfall possible over some locations.  As of Wednesday afternoon, a tornado watch and winter storm warning were in effect simultaneously for some central and southeast Oklahoma counties.  This could be the most severe winter storm we have seen in 5 years here in Oklahoma.  The National Weather Service held a live briefing on NOAA weather radio at 3:00 pm CST, emphasizing the potential severity of this winter storm.

    
The graphic below shows the massive area of winter storm advisories, warnings, and watches over the central and southern U.S., and the tornado watch in effect over southern OK and northern TX.  As of 4:30 pm CDT, the winter storm watches have been expanded to include much of the Great Lakes Region, where over a foot of snow could fall by Friday evening.

    
The OCS Mesonet map as of noon CST showed a STRONG cold front just south and east of Norman, with temperatures plunging to near and below freezing behind the front, with 70s ahead of the front.  The cold front blew through Norman at around 7:30 am, and as of 4:30 pm, temperatures were in the upper 20s in central OK!!!  setting the stage for frozen precipitation beginning in the early morning hours Thursday.

   
The WRF forecast for 12z Thursday shows a classic winter storm pattern for central OK, with a strong, closed vorticitiy maximum tracking just south of the Red River (upper left panel), a relatively intense surface low pressure center in Arkansas, and heavy precipitation falling in the deformation zone area over north TX, Oklahoma, and areas northeastward.  Cold temperatures will not be a problem, with high temperatures on Thursday struggling to surpass the low 20s!!

     

     
Displayed below is the public information statement issued by the NWS in Norman notifying the area of the special briefing that was held at 3:00 pm.  The NWS is forecasting 6-8 inches of snowfall over most of central and northern OK, with some locations receiving over a foot depending on the orientation of mesoscale convective bands.  Thundersnow is definitely not out of the question from this winter storm.  Stay tuned to TornadoVideos.net for continuous updates on this potentially dangerous winter weather situation, including video clips and pictures from the storm.

Posted At: November 27, 2006 @ 2:57 PM

Posted By: Reed Timmer

A strong cold front will plow across the nation this week behind a strong low pressure system, yielding the potential for heavy winter precipitation and the coldest temperatures of the season.  Temperatures ahead of the front will sore into the 70s and 80s, with low temperatures behind the front in the 20s as far south as Texas by Thursday.  A second area of low pressure will develop along the front in Texas Wednesday night ahead of a powerful vort max, and will move northeastward along the front into the Ohio River Valley.  This low pressure area will induce heavy precipitation behind the cold front in below-freezing temperatures, resulting in dangerous driving conditions and power outages.  Winter storm watches will likely be issued tonight and tomorrow from OK/KS into MO, where freezing rain and snow will be likely by mid-week.  Displayed below are the WRF forecast temperatures and 12-hr precipitation by Thursday morning.

Posted At: November 22, 2006 @ 5:44 PM

Posted By: Reed Timmer

The forecast models have been consistent in predicting a major upper trough to move into the western U.S. early next week.  As a result, moisture will be advected rapidly northward from the Gulf of Mexico, with dewpoints in the 60s forecast as far north as KS by Tuesday.  Impressive low-level shear will be in place across the central and southern Plains, with a 50 knot low-level jet persisting through the day on Tuesday.  A strong dryline will propagate across NE, KS, OK, and TX, with supercells likely in the warm sector.  Displayed below are the forecast 850 mb flow, 500 mb flow, and mslp, respectively, from the 12z GFS for Tuesday afternoon  If the models verify, we will definitely be chasing.  Stay tuned for more updates throughout the weekend.
     

Posted At: November 16, 2006 @ 11:02 AM

Posted By: Reed Timmer

A strong tornado touchded down at around 6:30 am EST in western Columbus County, NC, and cut a swath of damage right through the middle of a mobile home park.  Sadly, 9 people have been reported killed from this tornado, with a search still in progress.  This small town of Riegelwood is located west of WIlmington, NC.  A second tornado warning was issued at around noon for the same county, and a tornado watch is still in effect for the area.
         

Posted At: November 15, 2006 @ 1:14 AM

Posted By: Reed Timmer

Several supercells exploded in a confluence zone in southern LA and MS at around midnight local time, and rapidly became tornadic.  This prompted the issuance of a second tornado watch for this area until 6:00 am CST.  Given incredible low-level shear over this area as well, strong tornadoes appear likely.  The watch graphic is displayed below, along with some radar images of an incredible supercell likely producing a tornado in MS as of 1:00 am.
     

   
The velocity couplet of the supercell straddling the LA/MS border northwest of New Orleans is hown below.  This supercell is likely producing a tornado at the time of this image.  The location of the potential tornado would likely be just to the east of the purple triangle in the image, near the interface of the green (winds toward the radar) and red (winds away from the radar) colors.
    

Posted At: November 14, 2006 @ 11:29 PM

Posted By: Reed Timmer

The first tornado warning of this potentially massive nocturnal tornado outbreak was issued 10 minutes ago at 11:19 pm for northern Polk County in western AR.  This storm has a fairly large couplet on storm relative velocity, and could be producing a tornado.  This this would be nearly impossible to chase with dense forest at night and no roads. 
     

Posted At: November 14, 2006 @ 10:02 PM

Posted By: Reed Timmer

A "Particularly Dangerous Situation" Tornado Watch has been issued Wednesday night through Thursday morning for extreme southeast OK, northeast TX, southern AR, and northern LA from 9:15 to 6:00 am CST.   The strong trough is currently moving across the southern Plains as of 10:00 pm, with a strong surface low exploding in southern OK.  To the east of this rapidly intensifying low, a 40-60 kt low-level jet has developed over LA and AR yielding extreme low-level wind shear values.  Moderate instability with a weak cap in place in the warm sector will allow for surface-based convective development, and thus strong tornadoes will be possible.  The Storm Prediction Center mentions the liklihood of a "nocturnal tornado outbreak" in this region tonight.  Displayed below is the graphic for this PDS Tornado Watch, along with the wind profile from Shreveport, LA, and the radar image from Little Rock as fo 9:38 CST.
              
          
As seen in the VAD from Shreveport above, the wind at 2000 ft above the surface was 45 knots as of 9:38 pm, which is yielding 0-1 km helicity values of 500-600 m2/s2 (more than sufficient for large tornadoes).  Storms were beginning to develop over southern AR, which will likely become tornadic supercells in the very near future.  I'll be watching this situation closely throughout the night, and will post updates continuously.  Stay tuned!

Posted At: November 14, 2006 @ 11:23 AM

Posted By: Reed Timmer

A strong low-level jet is expected to develop tonight over the northwest Gulf Coast region into southern Arkansas, transporting deep moisture rapidly northward.  Dewpoints are expected to be near 70 deg F as far north as southern AR by late evening, resulting in an unstable and weakly capped environment through the night.  Given insanely strong low-level shear, strong tornadoes will be possible with any surfaced-based supercells over northern LA and southern AR tonight.  Realizing these forecast parameters, the SPC issued a moderate risk with a 15%/hatched area for tornadoes tonight (See below).  The strong upper system and 50 knot low-level jet by 06z tonight can be seen in the WRF forecast 500 and 850 mb maps below.  Stay tuned for continuous updates on this potentially dangerous situation.
             
       

Posted At: November 10, 2006 @ 11:22 AM

Posted By: Reed Timmer

Super-typhoon Chebi strengthened rapidly overnight into a powerful category 5 storm, and will track very close to Manilla, Philippines in 24 hours.  The Joint Typhoon Warning Center is estimating 125 knot sustained winds in the eyewall of Chebi, but this is likely an underestimate given the textbook 11 nm wide eye.  This typhoon reminds me of Hurricane Wilma from last year, which strengthened at a record-breaking rate into a strong category 5 hurricane with a 2 nm wide eye!
    
    

Posted At: November 9, 2006 @ 12:05 PM

Posted By: Reed Timmer

Severe weather is likely tomorrow in the densely forested areas of western AR and northeastern TX, as a strong trough sweeps through the southern Great Plains.  Storms will likely develop along a cold front late Friday afternoon in western AR, and later in the evening in northeast TX.  Tornadoes appear highly unlikely with this event, because most of the good low-level wind shear is well east of the instability axis.  However, if the models change, then we will likely be chasing this event.  Stay tuned!
    

Posted At: November 5, 2006 @ 1:13 AM

Posted By: Reed Timmer

Tornado Glory recently went on sale as a PBS Home Video, with details posted on Tornadoglory.com  Shown below is a scene from April 5, 2003, when a long-track supercell produced a tornado and morphed into a prolific hail producer.  Several storm chasers lost their wind shield on this day...luckily ours was only cracked.
Warning: Adult Language!!

Posted At: November 2, 2006 @ 4:11 PM

Posted By: Reed Timmer

1-2 feet of snow will fall in isolated locations near the Lake Superior and western Lake Michigan shorelines through tomorrow.  10-12 inches of snow has already been reported in many locations of the Upper Peninsula of Michigan.  Snowfall rates of 3+ inches per hour have been common in the heaviest lake effect snow bands, which form as cold wind flows over the relatively warm lake waters.  Lake temperatures are in the 50s, while 20-30 degree air temperatures are common over the northern Great Lakes.  The heavy lake effect snow bands are oriented parallet to the wind flow, and have been enhanced by upper-level disturbances.   Lightning and thunder are common in these early season lake effect snow storms.  Two radar images from northern MI from Thursday at ~4 pm are displayed below .