Convection on August 19th sufficiently saturated the low level atmosphere, and gusty southerly winds that prevailed across northeast Kansas during the morning and afternoon hours of the 20th helped to reinforce the hot and humid air mass in place over the region, south of a surface stationary boundary over Nebraska. Temperatures over the western half of the county warning area quickly warmed…
Every event with a place to put it; 23 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS TOP wrote it up.
Convection on August 19th sufficiently saturated the low level atmosphere, and gusty southerly winds that prevailed across northeast Kansas during the morning and afternoon hours of the 20th helped to reinforce the hot and humid air mass in place over the region, south of a surface stationary boundary over Nebraska. Temperatures over the western half of the county warning area quickly warmed under sunny skies early in the day. Sites further east followed suit after debris clouds from the overnight convection dissipated. Heat indicies from 105 to 109 degrees were recorded across norhteast Kansas between 11am and 4pm CST, and between 12pm and 5pm CST further east.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Topeka, KS wrote its last area forecast discussion before the first event at Aug 20, 2:26 AM CST, 8 hours 34 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 326 AM CDT MON AUG 20 2007 .DISCUSSION... LOW STRATUS AND FOG MOVING SLOWLY NORTH AND EAST OVER THE EASTERN HALF OF THE FA ATTM. SOME LOCATIONS REPORTING LOCALLY DENSE FOG IN SOUTHWESTERN COUNTIES. SHRA/TS MOVING NORTHEAST TO THE SOUTH OF THE CWA. EXPECT LOW CLOUDS TO CLEAR UP LATER THIS MORNING. 850MB WINDS BEHIND DEPARTING SHORTWAVE TAKE UNTIL LATE DAY TO STRENGTHEN AND COME BACK AROUND TO THE SOUTHWEST...SO MAY NOT GET QUITE AS MUCH MIXING TODAY. STILL WOULD EXPECT HIGHS TO MAKE IT TO THE LOW 90S EAST TO MID 90S WEST. TONIGHT BECOMES MUCH TRICKER. BOTH GFS AND NAM INDICATING MCS MOVING OUT OF NEBRASKA INTO OUR NORTHERN CWA AS EARLY AS 3Z. CONVECTION IN ND ATTM AND ASSOCIATED FRONTAL BOUNDARY MOVES INTO SOUTHERN NEBRASKA BY LATE AFTERNOON. CAPE VALUES RUNNING 2-4K J/KG OVER OUR AREA...WITH SHEAR VALUES RISING TO AROUND 30KTS IN THE SAME TIME PERIOD. ONLY UP SIDE IS LLJ VEERS QUICKLY AND BECOMES WEST SOUTHWEST BY 6Z...FAVORING DEVELOPMENT ON THE NORTH AND EAST FLANK AS CONVECTION MOVES INTO THE CWA. CORFIDI VECTORS ARE NORTHWEST...SO EXPECT STORMS TO PROPAGATE SE. FLY IN THE OINTMENT MAY BE ANY CONVECTION WHICH DEVELOPS IN WESTERN KS AND COULD ALSO PROPAGATE EASTWARD...WHICH WOULD IMPACT MORE OF OUR WESTERN AND CENTRAL ZONES. WILL CARRY CHANCE POPS ALONG AND NORTH OF I70 WITH ISOLATED FARTHER SOUTH...ALTHOUGH IF A LINE SETS UP POPS COULD CERTAINLY BE INCREASED. PW VALUES ARE STILL AROUND 1.5 INCHES SO LOCALLY HEAVY RAINFALL COULD BE A PROBLEM...BUT EXPECT 30-40KT 500MB WINDS TO KEEP STORMS MOVING. MAIN THREAT WOULD BE STRONG WINDS...BUT WITH STRONG INSTABILITY AND SUFFICIENT SHEAR COULDNT RULE OUT AN ISOLD TORNADO AS WELL. TUES-THURS...NAM RETREATS FRONT BACK NORTHWARD THROUGH THE DAY TUESDAY THEN BRINGS ANOTHER ROUND OF PRECIP ALONG THE NEBRASKA BORDER BY LATE AFTERNOON. HOWEVER LLJ CONTINUES TO NOSE NORTHWARD...AND PRIMARY DEVELOPMENT IS FARTHER NORTH THAN PREVIOUS NIGHT. GFS IS FARTHER SOUTH WITH SURFACE FRONT...AND BLOWS UP MCS OVER SOUTH CENTRAL NEBRASKA JUST AFTER MIDNIGHT. HAVE KEPT POPS MAINLY ALONG AND NORTH OF I70 AS OUTFLOWS FROM PREVIOUS NIGHT WILL HAVE SOME INFLUENCE ON WHERE AND HOW CONVECTION DEVELOPS ON WED. BOTH NAM AND GFS MOVE UPPER LOW ACROSS SOUTHERN CANADA...WHICH DRAWS SYNOPTIC FRONT FURTHER SOUTH INTO SOUTHERN NEBRASKA SOMETIME THURSDAY WITH SOME TIMING DIFFERENCES. FRI-SUN...ANOTHER SHORTWAVE PROGGED TO MOVE ACROSS THE AREA FRIDAY INTO SATURDAY. HAVE NOT MADE CHANGES TO GRIDS WHICH ALREADY REFLECT THIS WITH POPS FRIDAY INTO EARLY SAT AND TEMPERATURES SLIGHTLY COOLER AND MORE TOWARDS CLIMATOLOGICAL VALUES. 67 && .AVIATION... STRATUS HAS FORMED ACROSS MUCH OF THE AREA SINCE LATE EVENING IN THE WAKE OF DEPARTING REMNANTS OF ERIN. CEILINGS DOWN TO 500-800 FT IN THE TAF SITE...HOWEVER WITH VEERING FLOW IN THIS LAYER THROUGH SUNRISE AND DRIER AIR ADVECTING IN...EXPECT CEILINGS TO IMPROVE IN THE 12-14Z TIMEFRAME. HOWEVER...DENSE FOG HAS DEVELOPED ACROSS PORTIONS OF EAST CENTRAL KANSAS SINCE 06Z...AND SATELLITE INDICATES THAT SOME OF THIS MAY BE SPREADING NORTHWARD TOWARDS THE TAF SITES BY 10-12Z TIMEFRAME...ALTHOUGH BUFKIT SHOWS MORE FAVORABLE LOW LEVEL INVERSION IN EAST CENTRAL AREAS THAN NORTHWARD ALONG I 70 WITH DEEPER INVERSION JUST ABOVE FOG DECK BEING HARDER TO MIX OUT IN THE EAST CENTRAL. EITHER WAY IF IT DOES MAKE IT INTO TAF SITES...WOULD EXPECT IFR/LIFR VIS/CIGS THROUGH 13Z THEN RAPIDLY IMPROVING TO VFR BY 14Z-15Z. WILL CONTINUE TO MONITOR SATELLITE AND OB TRENDS FOR AMDTS. WILL THEN ONLY CARRY SCT STRATACU AROUND 4-5KFT THROUGH THE DAY WITH SOUTHERLY 8-10KT WINDS. ANY PRECIPITATION NEAR TAF SITES TONIGHT WOULD OCCUR BEYOND THE 06Z TIMEFRAME WITH VFR CONDITIONS CONTINUING UNTIL THEN. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TOPEKA KS 549 AM CDT MON AUG 20 2007 KSZ008>012-020>024-026-034>040-054>056-058-059-211100- REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY- POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS- WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON- 549 AM CDT MON AUG 20 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL...NORTH CENTRAL AND NORTHEAST KANSAS. .DAY ONE...TODAY AND TONIGHT THERE IS A CHANCE FOR THUNDERSTORMS LATE THIS AFTERNOON OVER NORTH CENTRAL KANSAS...SPREADING INTO NORTHEAST KANSAS THIS EVENING AND OVERNIGHT. THESE STORMS MAY BE SEVERE...WITH STRONG WINDS THE PRIMARY HAZARD. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THERE IS A CHANCE FOR THUNDERSTORMS TUESDAY NIGHT THROUGH SATURDAY ACROSS MUCH OF THE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTERS MAY BE NEEDED TONIGHT...MAINLY NORTH OF INTERSTATE 70.
The national radar mosaic for the moment the first event began.
23 heat. Local standard time, as filed.
The heat indicies calculated by the ASOS at Concordia recorded readings at or above 105 degrees from 11am to 2pm CST.
The heat indicies calculated by the ASOS at Lawrence recorded readings at or above 105 degrees from 2pm to 6pm CST. The highest recorded heat index was 109 degrees at 3pm.
The heat indicies calculated by the ASOS at Emporia recorded readings at or above 105 degrees at 2pm, 4pm, and 5pm CST. Heat indicies were above 103 degrees at 3pm and 6pm.
The heat indicies calculated by the ASOS at Concordia recorded readings at or above 105 degrees from 1pm to 5pm CST. The peak heat index reading was 109 degrees at 2pm.
The heat indicies calculated by the ASOS at Topeka's Billard Airport recorded readings at or above 105 degrees from 2pm to 5pm CST. The heat indicies calculated by the ASOS at Topeka's Forbes Field recorded readings at or above 105 degrees from 2pm to 5pm CST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Kansas in 2007Every state in 2007This day in weather historyWarnings in Kansas, August 2007
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 56438, 56453, 56455, 56437, 56440, 56460, 56435, 56436, 56439, 56441, 56442, 56443, 56444, 56445, 56447, 56448, 56449, 56450, 56451, 56454, 56456, 56457, 56459.