Extreme Tornado Tour begins

I met up with the Extreme Tornado Tour group at the Sleep Inn KCI (near the Kansas City, MO, airport KCI) this afternoon. Dave Holder will be our driver/guide for most of the trip, though Chris Chittick will be filling in tomorrow afternoon and Wednesday. Two other weather fanatics are joining me on this tour: Blake from West Chester, PA, and Casey from Bay City, MI.

The original forecast when we first met had some possibility of severe storms in OK tomorrow; but when we got back together at 2030 to go to supper, that possibility had nearly vanished. However, the prospects remained strong for a moderate risk (nearly 50% chance) on Wednesday in an area from south central MO through just southeast of the Chicago area (see map below). So the plan is to hang around KC until Chris gets here to drive us to the St. Louis area to be in position for Wednesday.

awc 2009-05-12 00:05:15

UPDATE

Excerpt from Tuesday morning's forecast from the Storm Prediction Center

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 AM CDT TUE MAY 12 2009

   VALID 131200Z - 141200Z

   …THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ILLINOIS AND
   MISSOURI…

   …THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID TO
   UPPER MS VALLEY…OZARKS…CNTRL PLAINS AND SRN PLAINS…

   …SEVERE WEATHER OUTBREAK WITH TORNADOES POSSIBLE WEDNESDAY
   AFTERNOON AND EVENING ACROSS THE MID TO UPPER MS VALLEY…

   …MID TO UPPER MS VALLEY…
   A PROGRESSIVE UPPER-LEVEL TROUGH AND WELL-DEFINED 75 TO 90 KT
   MID-LEVEL JET WILL MOVE EWD ACROSS THE NRN PLAINS WEDNESDAY. AHEAD
   OF THE SYSTEM…A BROAD LOW-LEVEL JET WILL BE IN PLACE WITH A LARGE
   WARM SECTOR FROM THE SRN PLAINS NEWD ACROSS THE OZARKS INTO THE MID
   TO UPPER MS VALLEY. A DEEPLY MOIST BOUNDARY LAYER…MODERATE
   INSTABILITY…STRONG VERTICAL SHEAR AND IMPRESSIVE LOW-LEVEL SHEAR
   PROFILES SHOULD RESULT A SIGNIFICANT SEVERE WEATHER EPISODE ACROSS
   PARTS OF THE MID TO UPPER MS VALLEY. AN OUTBREAK OF SEVERE WEATHER
   AND TORNADOES WILL BE POSSIBLE WEDNESDAY AFTERNOON AND EVENING.

   THE LATEST CONSENSUS OF THE MODELS WEDNESDAY MORNING MOVE A CLUSTER
   OF ELEVATED THUNDERSTORMS ASSOCIATED WITH THE LOW-LEVEL JET EWD
   ACROSS THE OH VALLEY WEDNESDAY MORNING. THE TRACK OF THIS STORM
   CLUSTER SHOULD BE IMPORTANT WITH THE MOST SUBSTANTIAL
   DESTABILIZATION OCCURRING TO THE SOUTHWEST. BY THE TIME OF
   INITIATION…IT APPEARS MODERATE INSTABILITY WILL BE IN PLACE FOR A
   WIDESPREAD SEVERE WEATHER EVENT FROM CNTRL MO NEWD INTO WRN AND
   CNTRL IL. NAMKF FORECAST SOUNDINGS OVER THIS AREA LATE WEDNESDAY
   AFTERNOON SHOW 45 TO 50 KT OF VERTICAL SHEAR WITH 0-3 KM SRH VALUES
   IN THE 250 TO 350 M2/S2 RANGE. THIS COMBINED WITH LOW LCL HEIGHTS
   SHOULD BE FAVORABLE FOR SUPERCELLS WITH TORNADOES. FORECAST
   HODOGRAPHS SUPPORT THE POTENTIAL FOR A FEW STRONG TORNADOES WITH THE
   GREATEST POTENTIAL FROM CNTRL AND ERN IL SWWD ACROSS CNTRL AND ERN
   MO IN THE LATE AFTERNOON OR EARLY EVENING. IN ADDITION…FORECAST
   SOUNDINGS ACROSS THE MODERATE RISK AREA SHOW STEEP MID-LEVEL LAPSE
   RATES WHICH SHOULD ALSO SUPPORT A THREAT FOR LARGE HAIL. DURING THE
   EVENING…INCREASING LOW-LEVEL CONVERGENCE ALONG THE COLD FRONT MAY
   RESULT IN A TRANSITION TO A LINEAR MODE. HOW QUICKLY THIS TRANSITION
   OCCURS IS STILL IN QUESTION. IF A WELL-DEVELOPED LINEAR MCS OR
   BOWING LINE SEGMENT CAN ORGANIZE…A SUBSTANTIAL WIND DAMAGE THREAT
   WILL BE POSSIBLE AS WELL.

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awc 2009-05-12 09:47:28