| Storm 03 - April 18, 2002 to April 19, 2002 Archive produced by WISCWX lead forecaster Alex Lamers with assistance from lead technician Jordan Gerth |
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| WISCWX ARCHIVE - STORM EVENT 03 WITH INFO AND GRAPHICS BY SPC AND NIDS PRODUCED AND PUBLISHED APRIL 19, 2002 THIS STORM EVENT WAS CREDITED TO A SLOW MOVING LOW WHICH ALLOWED SOUTHWESTERLY FLOW AND A BUILDUP OF HEAT OVER 4 DAYS IN A ROW STARTING ON APRIL 15, 2002. HIGHS IN THE REGION EXCEEDED 80 ALL DAYS AND SEVERAL DAYS PRODUCED 90 DEGREE APRIL TEMPS...EXTREMELY UNSEASONABLE. THE SLOW MOVING LOW SPED UP THE AFTERNOON OF THE 18TH DUE TO A STRENGTHENING JET AND EXTREME CONVERGENCE WAS CREATED. SEVERAL HUNDRED MILES AHEAD OF THE ADVANCING COLD FRONT ONE ROUND OF SEVERE WEATHER OCCURED. THIS WAS MAINLY SUPERCELLS AND SEVERE CLUSTERS AS SHEAR WAS SIGNIFICANT AND THE ROTATION CAUSED TORNADOES TO FORM RAPIDLY, ESPECIALLY IN NORTH CENTRAL WISCONSIN. THE SECOND ROUND WAS CAUSED BY THE COLD FRONT WHICH PROVIDED ISENTROPIC LIFT AND PRODUCED A SQUALL LINE. REPORT RECEIVED FROM LAKE COUNTY, IL BY WISCWX AT ABOUT 7:30pm CDT: GREG MANARIK REPORTED 1/2" DIAMETER HAIL...GUSTS OF 40 MPH...AND A ROTATING WALL CLOUD. HE REPORTED IT TO THE NWS CHICAGO AND IT WAS CONFIRMED BY RADAR. THIS WALL CLOUD EVENTUALLY DID PRODUCE A TORNADO. REPORT RECIEVED FROM OSHKOSH, WI AREA BY WISCWX AT ABOUT 9:00PM CDT: PETE REPORTED DIME SIZED HAIL...GUSTS IN THE LOW 50S...AND A "TORNADIC ROAR". TO MY KNOWLEDGE THIS TORNADO WAS UNCONFIRMED BY SPOTTERS AND NWS RADAR. RAIN APPARENTLY REDUCED VISISBILITIES DOWN TO 100 FEET AT TIMES, SO CONFIRMING IT ON THE GROUND WOULD BE DIFFICULT. NO WARNING WAS ISSUED FOR TORNADIC ACTIVITY BUT IT IS POSSIBLE THAT ONE MAY HAVE OCCURED. WILL LOOK FOR FURTHER SPC STORM REPORTS TO SEE IF TORNADO GETS CONFIRMED. NOTE: DO NOT ALWAYS ASSUME A ROAR IS TORNADIC...IT COULD BE DOWNBURSTS OR FLASH FLOODS. HOWEVER, ON THE 18TH MANY TORNADIC SUPERCELLS DEVELOPED AND SO TORNADOES WERE POSSIBLE. REPORT RECEIVED FROM EAU CLAIRE, WI BY WISCWX AT AN UNKNOWN TIME: 3 INCH DIAMETER HAILSTONES REPORTED...FORWARDED BY PETE. THANKS TO ALL FOR THESE REPORTS. IT APPEARS MANY MORE HAIL AND TORNADO REPORTS OCCURED THAN WIND EVENTS. OVERALL CONDITIONS WERE VERY FAVORABLE FOR A WIDE SEVERE WEATHER OUTBREAK. CAPE LEVELS CAME CLOSE TO 4000 J/KG, HELICITY CLOSE TO 400, AND LIFTED INDEX CLOSE TO -9. THE EXTREME NUMBERS LOOKED GOOD ON PAPER AND PROVED TO COME THROUGH IN REAL FORECASTS. LINKS BELOW WILL HELP YOU GET THE FULL SCOPE OF THE NIGHT FROM UPPER AIR DATA TO STORM DAMAGE REPORTS. THANKS FOR VISITING THIS ARCHIVE. TO RADAR ARCHIVE PAGE OF IMAGES FROM 18TH. TORNADO WATCH # 110 BY SPC TORNADO WATCH # 111 BY SPC TORNADO WATCH # 113 BY SPC TORNADO WATCH # 114 BY SPC SEVERE THUNDERSTORM WATCH # 117 BY SPC SEVERE THUNDERSTORM WATCH # 118 BY SPC SPC UPPER AIR MAPS FOR 700PM APRIL 18TH SPC UPPER AIR MAPS FOR 700AM APRIL 18TH SPC DAMAGE REPORTS FOR APRIL 18TH-AM OF 19TH MORE LINKS TO COME SOON! ALEX LAMERS LEAD FORECASTER |