July 20th, 2011 Severe Thunderstorms

Monitoring Tsunami Impacts Across the Pacific; Air Quality Concerns; Dangerous Heat; Critical Fire Weather for the West

Tsunami impacts continue for portions of the Pacific basin. Wildfire smoke causes unhealthy air in Midwest to Great Lakes. Heat dome spans Mississippi Valley to Mid-Atlantic with excessive heat warnings and advisories. Critical fire weather in Great Basin to Pacific Northwest (dry thunderstorms). Cold front spawns severe storms/heavy rain in Central U.S. today, shifts to East Coast Thursday. Read More >

PUBLIC INFORMATION STATEMENT...UPDATED NATIONAL WEATHER SERVICE WILMINGTON OH 325 PM EDT FRI JUL 22 2011 ...MICROBURST /STRAIGHT LINE WIND DAMAGE/ CONFIRMED 4 SE OF UNION CITY IN DARKE COUNTY OHIO... LOCATION...4 SE OF UNION CITY IN DARKE COUNTY OHIO DATE...JULY 20 2011 ESTIMATED TIME...622 PM EDT ESTIMATED MAXIMUM WIND SPEED...90 MPH MAXIMUM PATH WIDTH...0.8 MILES PATH LENGTH...1.5 MILES BEGINNING LAT/LON...40.1801N/84.7543W ENDING LAT/LON...40.1656N/84.7323W * FATALITIES...0 * INJURIES...0 * THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO CHANGE PENDING FINAL REVIEW OF THE EVENT(S) AND PUBLICATION IN NWS STORM DATA. ...SUMMARY... THE NATIONAL WEATHER SERVICE IN WILMINGTON OH HAS CONFIRMED A MICROBURST /STRAIGHT LINE WIND DAMAGE/ 4 SE OF UNION CITY IN DARKE COUNTY OHIO ON JULY 20 2011. DAMAGE FROM STRAIGHT LINE WINDS WAS EVIDENT ACROSS THIS AREA. BARNS WERE DAMAGED EXTENSIVELY BY A MICROBURST. AN AGRICULTURAL HOPPER MOVED APPROXIMATELY 1000 FEET. LARGE TREES OR TREE LIMBS WERE SNAPPED IN FIVE LOCATIONS WITHIN THE AREA THAT RECEIVED WIND DAMAGE. CORN FIELDS WERE FLATTENED. VEGETATION WAS REMOVED FROM A 30 FOOT WIDE CIRCULAR AREA OF A FARM FIELD. ALL OF THIS DAMAGE WAS DETERMINED TO HAVE BEEN CAUSED BY STRAIGHT LINE WINDS AND EMBEDDED MICROBURSTS. FOR REFERENCE... A MICROBURST IS A CONVECTIVE DOWNDRAFT WITH AN AFFECTED OUTFLOW AREA OF LESS THAN 2 1/2 MILES WIDE AND PEAK WINDS LASTING LESS THAN 5 MINUTES. MICROBURSTS MAY INDUCE DANGEROUS HORIZONTAL/VERTICAL WIND SHEARS...WHICH CAN ADVERSELY AFFECT AIRCRAFT PERFORMANCE AND CAUSE PROPERTY DAMAGE. STRAIGHT-LINE WINDS ARE GENERALLY ANY WIND THAT IS NOT ASSOCIATED WITH ROTATION...USED MAINLY TO DIFFERENTIATE THEM FROM TORNADIC WINDS. $$