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Day 10 - Discussion


Paul Sherman

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Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    Currently Sat in Abilene on th I20 With a Chase Target of Gainesville

    ETD :- 930am

    ETA :- 1230pm

    post-24-1210166819_thumb.png

    DAY 1 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0757 AM CDT WED MAY 07 2008

    VALID 071300Z - 081200Z

    ...THERE IS A SLGT RISK OF SVR TSTMS TODAY THROUGH TONIGHT FOR PARTS

    OF THE SRN PLAINS TO THE LOWER MS VALLEY...

    ...SRN PLAINS TO PARTS OF THE LOWER MS VALLEY THROUGH TONIGHT...

    A STRONG MID LEVEL SHORTWAVE TROUGH OVER SE NM/W TX THIS MORNING

    WILL EJECT ENEWD TO THE RED RIVER VALLEY BY LATE AFTERNOON...AND

    THEN CONTINUE OVER AR TONIGHT. THIS MID LEVEL TROUGH WILL BE

    ACCOMPANIED BY A SURFACE CYCLONE WHICH WILL DEVELOP ENEWD FROM NW TX

    TO NW AR BY THE END OF THE PERIOD. A 70-80 KT SSWLY MID LEVEL JET

    AND ASSOCIATED 50 KT LLJ WILL PRECEDE THE MID LEVEL WAVE TODAY INTO

    TONIGHT ACROSS TX/OK/LA/AR.

    WIDESPREAD OVERNIGHT CONVECTION HAS MUDDLED THE SURFACE PATTERN THIS

    MORNING AND APPEARS TO HAVE REDUCED THE POTENTIAL FOR SEVERE STORMS

    ACROSS NW TX AND WRN/NRN OK. INSTEAD...THE GREATER SEVERE STORM

    THREAT WILL SHIFT EWD TO NEAR AND E OF I-35/I-44 IN S CENTRAL/SE OK

    AND N CENTRAL/NE TX THIS AFTERNOON...IMMEDIATELY IN ADVANCE OF THE

    SURFACE CYCLONE AND OUTSIDE THE AREAS OVERTURNED BY WIDESPREAD

    CONVECTION THIS MORNING. IT APPEARS THERE WILL BE A NARROW CORRIDOR

    ACROSS N/NE TX INTO SE OK THIS AFTERNOON WHERE THE STEEPER MID LEVEL

    LAPSE RATES OVERLAP THE LOW-LEVEL MOISTURE AXIS...ON THE W SIDE OF

    THE STRONGER LOW-LEVEL SHEAR. CONVECTIVE INITIATION SHOULD BE

    FOCUSED NEAR AND JUST E OF THE SURFACE LOW NEAR THE RED RIVER

    TODAY...AND ALONG THE TRAILING DRYLINE THIS AFTERNOON INTO N/NE TX.

    FORECAST SOUNDINGS IN THIS AREA ARE SUPPORTIVE OF SUPERCELLS CAPABLE

    OF PRODUCING LARGE HAIL...DAMAGING WINDS...AND A FEW TORNADOES. A

    POTENTIAL LIMITING FACTOR TODAY WILL BE CLOUDS REDUCING SURFACE

    HEATING ACROSS THE RED RIVER VALLEY.

    STRONG LOW-LEVEL FLOW AND SHEAR ARE EXPECTED THIS AFTERNOON FROM NRN

    LA INTO AR. HOWEVER...SATELLITE DERIVED PRECIPITABLE WATER

    ESTIMATES AND OBSERVED SOUNDINGS HAVE SHOWN SUBSTANTIAL DRYING ABOVE

    THE SURFACE ACROSS THE NW GULF REGION. SOME OF THE DRY AIR WILL

    LIKELY MIX DOWN INTO THE BOUNDARY LAYER THIS AFTERNOON AND REDUCE

    DEWPOINTS/SURFACE-BASED INSTABILITY ACROSS LA/AR...LEAVING A NARROW

    INSTABILITY CORRIDOR ALONG THE DRYLINE ACROSS OK/TX. LOW-LEVEL

    MOISTURE WILL BE MORE SHELTERED FROM MIXING ACROSS SRN/SERN

    MO...THOUGH CLOUDS/COOLER SURFACE TEMPERATURES WILL TEND TO LIMIT

    DESTABILIZATION SOMEWHAT. FINALLY...LOW-LEVEL MOISTURE MAY RECOVER

    SOME OVERNIGHT INTO THE LA/AR AREA AS THE SYNOPTIC SYSTEM MOVES EWD

    INTO AR AND VERTICAL SHEAR REMAINS STRONG. THERE WILL BE SOME

    THREAT FOR DAMAGING WINDS AND AN ISOLATED TORNADO OR TWO...THOUGH

    CONVECTIVE COVERAGE/MODE ARE IN QUESTION LATE TONIGHT AND RELATIVELY

    LOWER PROBABILITIES ARE WARRANTED COMPARED TO AREAS FARTHER W THIS

    AFTERNOON/EVENING.

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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    Teams destination for todays chase.

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    Posted
  • Location: SE London
  • Location: SE London

    current Radar for the area http://radar.weather.gov/radar.php?rid=fws...111&loop=no

    hi Guys, looks like you may get some decent Thunderstorms on the route you have chosen. just checking out the Hazardous Weather Outlook on SPC and it says

    DAY ONE...THROUGH TONIGHT.

    THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS ALL OF NORTH

    TEXAS TODAY AS A DRYLINE AND A POWER LEVEL LEVEL DISTURBANCE MOVE

    ACROSS THE REGION. THE SEVERE WEATHER THREAT WILL END FROM WEST TO

    EAST LATE THIS AFTERNOON AND EVENING AS THE DRY LINE MOVES TO OUR

    EAST. LARGE HAIL...DAMAGING WINDS AS WELL AS HEAVY RAIN AND CLOUD TO

    GROUND LIGHTNING ARE POSSIBLE. ONE OR TWO TORNADOES MAY ALSO OCCUR.

    good luck and keep safe. hope the winscreens are up to any more batterings :rolleyes:
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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    The team left Abilene about a 45mins ago, slight change to their target area from

    Gainesville TX to Sherman TX, a 30 mile jaunt further east.

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    Posted
  • Location: SE London
  • Location: SE London

    Sherman looking better then Gainesville

    current reports from NOAA

    Today: Showers and thunderstorms, mainly before 1pm. Some of the storms could be severe. High near 76. South wind between 15 and 20 mph, with gusts as high as 25 mph. Chance of precipitation is 80%.

    Tonight: Showers and thunderstorms likely, mainly before 7pm. Some of the storms could be severe. Mostly cloudy, with a low around 59. South wind around 15 mph becoming west northwest. Winds could gust as high as 20 mph. Chance of precipitation is 60%.

    THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

    .DAY ONE...THROUGH TONIGHT.

    THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS ALL OF NORTH

    TEXAS TODAY AS A DRYLINE AND A POWER LEVEL LEVEL DISTURBANCE MOVE

    ACROSS THE REGION. THE SEVERE WEATHER THREAT WILL END FROM WEST TO

    EAST LATE THIS AFTERNOON AND EVENING AS THE DRY LINE MOVES TO OUR

    EAST. LARGE HAIL...DAMAGING WINDS AS WELL AS HEAVY RAIN AND CLOUD TO

    GROUND LIGHTNING ARE POSSIBLE. ONE OR TWO TORNADOES MAY ALSO OCCUR.

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    Posted
  • Location: Seattle, WA
  • Location: Seattle, WA

    Upgraded to a moderate risk for NE TX / SE OK with an enhanced tornado threat. Will be leaving Norman for somewhere in an Ardmore-Durant-Sherman-Gainsville area by 12.

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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    Good luck Hilton and stay safe..! lookin like some higher end EF,s this late afternoon/ evening.

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    Posted
  • Location: Leicestershire, England
  • Location: Leicestershire, England

    Blasting East towards NE TX (GainesVille) to set up for the Mod risk area - current thinking is that there will be a 2 -3 hour opportunity before it all lines out. Web Cam Stream will be up today.

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    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    Plans sound good, teams may run into developing tornadic cells even before they reach Sherman, I can see rapid development past half hour around Mineral Wells which is about where the travelling teams would be now.

    The 12z obs came in pretty much on track from the earlier models and so the timing and degree of forcing is about the same as expected, should really blow up fast today with the ongoing height and thickness crash.

    I'm expecting tornado risk to peak 18z to 20z ... well within the comfort zone for the UK readers today.

    Radar link for you:

    www.radar.weather.gov/radar.php?product=NCR&rid=FDR&loop=yes

    (make sure you enable Autorefresh lower right)

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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    Watched quite a bit of your stream yesterday Stu, hoping the stream is a bit more continuous

    today than it was yesterday.... better WiFi coverage over NE Texas SW Oklahoma..? Good luck and i'll be

    tuning in.

    Latest Visible and IR images.

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    Posted
  • Location: SE London
  • Location: SE London

    update for the Meoscale discussion

    MESOSCALE DISCUSSION 0810

    NWS STORM PREDICTION CENTER NORMAN OK

    1159 AM CDT WED MAY 07 2008

    AREAS AFFECTED...SRN TX PNHDL INTO PARTS OF NW TX

    CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

    VALID 071659Z - 071830Z

    TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT AND THE

    POSSIBILITY OF A WW.

    AN INCREASE IN CONVECTIVE DEVELOPMENT IS ONGOING WEST OF LUBBOCK.

    THIS APPEARS TO BE IN RESPONSE TO FORCING NEAR A MID-LEVEL CYCLONIC

    VORTICITY...WITHIN BROADER SCALE CIRCULATION SHIFTING OUT OF THE

    SOUTHERN ROCKIES INTO THE SOUTHERN HIGH PLAINS. THE LOW-LEVEL

    ENVIRONMENT ALONG/AHEAD OF THE SURFACE COLD FRONT NOW SLOWLY NOSING

    THROUGH THE SOUTHERN TEXAS PANHANDLE HAS BECOME WEAKLY UNSTABLE WITH

    NEGLIGIBLE CAP...AND IT IS POSSIBLE STORMS COULD CONTINUE TO

    INCREASE ACROSS AND EAST/SOUTHEAST OF LUBBOCK THROUGH 19-20Z. IF

    THIS OCCURS...LAPSE RATES BENEATH MID-LEVEL COLD POCKET ARE BECOMING

    VERY STEEP...CONTRIBUTING TO A RISK FOR DAMAGING DOWNBURSTS AND SOME

    MARGINALLY SEVERE HAIL IN STRONGER CELLS.

    HOWEVER...MUCH OF MODEL GUIDANCE IS SUGGESTIVE THAT THE MAIN

    MID-LEVEL VORTICITY CENTER WILL RAPIDLY DEVELOP EAST SOUTHEASTWARD

    TOWARD THE TRIPLE POINT LOW BETWEEN ABILENE AND WICHITA FALLS BY

    EARLY AFTERNOON...WHERE DESTABILIZATION AND DEEP LAYER SHEAR

    PROBABLY WILL BE MUCH MORE SUPPORTIVE OF SUPERCELLS. AND... THOUGH

    THE MAIN SOUTHERLY LOW-LEVEL JET IS WELL TO THE EAST...

    SOUTHEASTERLY BOUNDARY LAYER WINDS MAY CONTRIBUTE TO SUFFICIENTLY

    LARGE LOW-LEVEL HODOGRAPHS FOR A TORNADO THREAT...PARTICULARLY GIVEN

    THE PRESENCE OF FAVORABLE AMBIENT VERTICAL VORTICITY.

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    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    UPDATE _ May 7/08 _ 1830z (1330 CDT)

    The cells most likely to become tornadic are presently developing south of Wichita Falls TX. Another area of strong activity further west is likely to develop into a secondary squall line feature and represents the wrap-around moisture interacting with the dry air mass that has reached a line just west of Wichita Falls to just east of Abilene.

    With the dry air feeding into the high risk zone north of DFW ahead of these two prime severe weather producers, the stage is now set for tornadic development as strong low level southerly winds shear rapidly to westerly along the remnants of the dry line. Dry line features usually become P front features by the longitude of MWL to DFW due to long transport of the desert-origin air over moist surfaces, therefore you can look for the "dry line" to be led by dew points 40-50 F rather than 20-30 F as is the case further west in Texas.

    The team may have halted their eastward progress with this set-up becoming apparent, but if they have reached Sherman I think the tornadic activity will come fairly rapidly towards them, so backtracking would not be a major issue, although at the moment I would like to be around Valley View to Decatur slightly WSW of Sherman. This is about where I think the tornado risk should max out.

    I also believe that the secondary squall line feature could develop severe weather and even a tornado or two, with a dry slot of about 1-2 hours between the two lines as they develop further this afternoon.

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    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    We're sat at Denny's Restaurant at Denton (north of DFW on the I-35), just had a bite to eat, and we are contemplating heading north to Gainesville then east to Sherman and wait in that general area for the cold front to the west (through Witchita falls) to move east and engage the very warm moist air currently here, should trigger severe storms in the MODERATE risk area which we are in. Hopefully a few tornadoes will form too! Quite a few other chasers on stormtrack seem to be targeting this general area too.

    Currently partly cloudy with altocumulus, warm and humid (dew points heading towards 70F!), some good breaks apppearing with sunshine, cold front should arrive in this area in next 2-3 hrs, storm motions quite fast today though!

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    Posted
  • Location: Ashford, Kent
  • Weather Preferences: Anything
  • Location: Ashford, Kent

    Good luck Nick, great potential for you guys today, if you can keep up! Looking forward to the footage already. Keep up the good work!

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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    Teams current location.

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    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    In the 19z Texas obs, notice there's a NW 30G45 at a mesonet station west of Graham while Graham itself reports SW 20 or so. This is to the south of the radar echoes near Wichita Falls. Looks like the front is about to activate. The echoes developing near Guthrie show the potential of the second line of storms that I mentioned.

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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    Something brewing in Parker County 45 mile SW of Denton

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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    The storms around south/ central Oklahoma are shifting along at over 50 Knots..!! ;)

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    Posted
  • Location: south east London
  • Location: south east London

    Update From Paul S on Ian's account

    We are sitting tight in Gainsville and have elected not to Chase the stupid fast moving Supercell about 60 miles North of here, our attention is drawn to a new storm that is going to track near to Sherman, we will move east on 82 and watch it come to us.

    Paul Sherman

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    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.

    New Tornado watch issued for east central texas.

    TornadoWatch - 0200Z

    WWUS20 KWNS 072042

    SEL4

    SPC WW 072042

    TXZ000-080200-

    URGENT - IMMEDIATE BROADCAST REQUESTED

    TORNADO WATCH NUMBER 274

    NWS STORM PREDICTION CENTER NORMAN OK

    345 PM CDT WED MAY 7 2008

    THE NWS STORM PREDICTION CENTER HAS ISSUED A

    TORNADO WATCH FOR PORTIONS OF

    EAST CENTRAL TEXAS

    EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

    900 PM CDT.

    TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

    GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

    AREAS.

    THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE

    MILES EAST AND WEST OF A LINE FROM 45 MILES SOUTHEAST OF TEMPLE

    TEXAS TO 50 MILES NORTH NORTHEAST OF CORSICANA TEXAS. FOR A

    COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

    UPDATE (WOUS64 KWNS WOU4).

    REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

    TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

    AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

    THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

    AND POSSIBLE WARNINGS.

    OTHER WATCH INFORMATION...CONTINUE...WW 273...

    DISCUSSION...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG

    SURFACE DRYLINE FROM WEST OF TPL TO NEAR DAL. THESE STORMS WILL

    THEN TRACK EASTWARD ACROSS THE WATCH AREA DURING THE EVENING.

    SUPERCELLS CAPABLE OF TORNADOES...LARGE HAIL...AND DAMAGING WINDS

    ARE POSSIBLE.

    AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

    SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE

    WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

    500. MEAN STORM MOTION VECTOR 25035.

    ...HART

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