Temperatures that reached the lower to mid 90s over southwest Iowa combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
Every event with a place to put it; 6 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 OAX wrote it up.
Temperatures that reached the lower to mid 90s over southwest Iowa combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
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 Omaha, NE wrote its last area forecast discussion before the first event at Jun 30, 2:23 AM CST, 11 hours 37 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
323 AM CDT THU JUN 30 2011
.DISCUSSION...TODAY THROUGH SATURDAY NIGHT.
WATER VAPOR IMAGERY THIS MORNING SHOWING WELL AMPLIFIED UPPER LEVEL
RIDGE OVER THE PLAINS EXTENDING INTO SRN CANADA WITH PLUME OF
TROPICAL MOISTURE ADVECTING NWD THRU THE ROCKIES. MEANWHILE UPSTREAM
TROF WAS SITUATED OVER THE WRN CONUS WITH CLOSED SEGMENT IN THE
GREAT BASIN. AT THE SFC NARROW WEDGE OF INCREASED LLVL MOISTURE WAS
RUNNING ALL ALONG THE MO RIVER VALLEY. HEAT AND HUMIDITY TODAY
WILL RESULT IN QUITE MUGGY CONDITIONS TODAY ACROSS THE REGION.
EXPECT HEAT INDICES WILL HOVER AROUND 105 OVER THE MAJORITY OF THE
CWA...AND A HEAT ADV IS IN PLACE THRU THIS AFTN FOR THIS. LATER
TONIGHT...GREAT BASIN SHORTWAVE TROF LIFTS THRU THE ROCKIES AND
KICKED THE UPPER LEVEL RIDGE EAST WHILE BRINGING A COLD FRONT INTO
THE CNTRL PLAINS. THE MODELS INDICATE THE BNDRY WILL STALL OUT AND
REMAIN IN THE VICINITY OF THE CWA AT LEAST THRU SATURDAY DUE TO
ZONAL FLOW DEVELOPING ALOFT. APPEARS THAT CAPPING...PER 700MB
TEMPS/MLCINH...WILL BE SIGNIFICANT DURING FROPA...SO WILL HOLD POPS
TO SLGT CAT. NOTE...SRN SECTIONS OF THE CWA MAY SEE HIGH HEAT
INDICES FRIDAY AFTN AHEAD OF APPROACHING BNDRY. WILL LEAVE TO LATER
SHIFTS TO DETERMINE IN HEADLINE WILL BE NEEDED.
DEE
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY MORNING. SOUTH WINDS
GUSTING TO 25KTS WILL PREVAIL DURING THE DAY BEFORE DIMINISHING TO
NEAR 12KTS THIS EVENING. A COLD FRONT WILL APPROACH NORTHEAST
NEBRASKA BY 12Z FRIDAY...BUT ANY CLOUDS OR PRECIPITATION WILL REMAIN
WELL NORTHWEST OF THE KOFK AREA.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-
088>093.
IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
IAZ043-055-056-069-079-080-090-091.
&&HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1136 AM CDT THU JUN 30 2011 IAZ043-055-069-079-090-NEZ011-012-015-034-045-052-053-067-068-091- 093-010645- MONONA-HARRISON-POTTAWATTAMIE-MILLS-FREMONT-KNOX-CEDAR-THURSTON- BURT-WASHINGTON-DOUGLAS-SARPY-CASS-OTOE-NEMAHA-RICHARDSON- 1136 AM CDT THU JUN 30 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA...NORTHEAST NEBRASKA AND SOUTHEAST NEBRASKA. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS OVER PORTIONS OF NORTHEAST NEBRASKA TONIGHT. WIDESPREAD FLOODING WILL CONTINUE ALONG THE MISSOURI RIVER. THE COMBINATION OF HEAT AND HUMIDITY WILL RESULT IN HEAT INDICES OF 105 TO 110 DEGREES ACROSS THE AREA THIS AFTERNOON. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THUNDERSTORM CHANCES CONTINUE FRIDAY AFTERNOON THROUGH SATURDAY NIGHT...AS WELL AS ON TUESDAY AND WEDNESDAY. MODERATE TO MAJOR FLOODING WILL CONTINUE ALONG THE MISSOURI RIVER THROUGH THE SUMMER. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT. IAZ056-080-091-NEZ016>018-030>033-042>044-050-051-065-066-078- 088>090-092-010645- SHELBY-MONTGOMERY-PAGE-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON- STANTON-CUMING-PLATTE-COLFAX-DODGE-BUTLER-SAUNDERS-SEWARD- LANCASTER-SALINE-JEFFERSON-GAGE-JOHNSON-PAWNEE- 1136 AM CDT THU JUN 30 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST IOWA...EAST CENTRAL NEBRASKA...NORTHEAST NEBRASKA AND SOUTHEAST NEBRASKA. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS OVER PORTIONS OF NORTHEAST NEBRASKA TONIGHT. THE COMBINATION OF HEAT AND HUMIDITY WILL RESULT IN HEAT INDICES OF 105 TO 110 DEGREES ACROSS THE AREA THIS AFTERNOON. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THUNDERSTORM CHANCES CONTINUE FRIDAY AFTERNOON THROUGH SATURDAY NIGHT...AS WELL AS ON TUESDAY AND WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT. FOBERT
The national radar mosaic for the moment the first event began.
6 heat. Local standard time, as filed.
Temperatures that reached the lower to mid 90s combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
Temperatures that reached the lower to mid 90s combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
Temperatures that reached the lower to mid 90s combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
Temperatures that reached the lower to mid 90s combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
Temperatures that reached the lower to mid 90s combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
Temperatures that reached the lower to mid 90s combined with dew point temperatures in the mid to upper 70s and produced heat index values that climbed into the 105 to 110 degree range during the afternoon and early evening of June 30th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2011Every state in 2011This day in weather historyWarnings in Iowa, June 2011
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: 305995, 305996, 305997, 305998, 305999, 306000.