S. S.
Every event with a place to put it. 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 DMX wrote it up.
The seasons first major severe weather event took place as a strong upper level low pressure lifted north into the central U.S. This was ahead of a strong upper level low pressure system over the southwest U.S. A warm front lifted north across the Des Moines CWA with moist and unstable air pushing into the state. There were several rounds of convection. The first developed over northern Iowa during the mid afternoon hours and moved north into Minnesota. A break in the thunderstorm activity took place before the next round moved into southwest Iowa and spread north and east during the evening. The atmosphere became unstable with highs in the 80s and dewpoints in the low to mid 60s by afternoon. CAPE, though not excessive, was sufficient with 1000 to 3000 J/kg available. CAPE in the -10 to -30 C layer of the atmosphere was between 300 and 600 J/kg. In the late afternoon hours around 500 J/kg of downdraft CAPE was present, and it increased to around 900 to 1100 J/kg during the evening hours. The shear increased as well with 25 to 40 kts available at the beginning of the event, and 50 to 60 kts by the end. Precipitable water values increased to 1.2 to 1.5 inches. The LCL was relatively low, around 1000 meters. The freezing level was relatively low, around 11,900 feet. The storms produced heavy rain and large hail initially. Flash flooding occurred first in Crawford County in western Iowa with over two inches of rainfall in about an hour, causing water to flow over Highway 141. The event became a wind and hail event for the most part with winds gusting to 60 to 80 MPH across a large part of the CWA and hail up to 3 inches in diameter in Adams County. The largest hail was northwest of Carbon in Adams County, where 2 to 3 inch diameter hail fell. Reports indicated enough hail fell to completely cover the ground. Numerous reports of 1.5 inch hail were received. Three tornadoes touched down in central Iowa. Numerous reports of winds of 60 to 80 MPH were received all along the line of thunderstorms. High winds blew a semi truck off the highway and blew it over west of Earlham in Madison County. There was considerable tree damage reported with some damage to outbuilding, barns, and a few houses.
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 Des Moines, IA wrote its last area forecast discussion before the first event at May 19, 11:25 AM CST, 1 hour 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1225 PM CDT SUN MAY 19 2013 .UPDATE ISSUED AT 1122 AM CDT SUN MAY 19 2013 BRIEF RESPITE FROM CONVECTION OVER OUR AREA CONTINUES...WITH INSTABILITY CURRENTLY CONFINED TO SOUTHEAST IOWA. TEMPS AND DEW POINTS ON THE RISE AND SOUTHERLY WINDS PICKING UP ACROSS THE REGION UP TO 15 TO 30 MPH. BRIEF WIND SPEED JUMP ALONG WARM FRONT IN NORTHERN IOWA WITH GUSTS TO NEAR 45 MPH PAST FEW HOURS...HAS NOW MOVED NORTH INTO SOUTHERN MINNESOTA. PROGGED UPPER LEVEL WINDS EXPECTED TO INCREASE RAPIDLY THIS AFTERNOON AND WITH INSOLATION INCREASING ACROSS THE AREA...EXPECTING LINE INITIATION OVER KS/NE TO MOST LIKELY BE THE MAIN AREA OF CONVECTION THIS AFTERNOON AND EVENING. WATCHING OLD MCV OVER WESTERN IOWA NOW...WHICH TRYING TO SPIN UP CONVECTION NOW...MAY SEE ISOLATED STRONG STORM IF INSTABILITY CATCHES UP WITH FEATURE PRIOR TO EXITING NORTHERN IOWA. .SYNOPSIS... ISSUED AT 407 AM CDT SUN MAY 19 2013 AMPLE WEATHER DURING THE FORECAST PERIOD WITH ONGOING CONVECTION PASSING THROUGH THE FORECAST AREA. THIS ARC OF THUNDERSTORMS IS EXPECTED TO PROGRESS NORTHEAST OUT OF THE AREA TOWARD 12Z. THERE MAY BE SOME LINGERING CONVECTION...HOWEVER IT APPEARS THERE WILL BE SOME DOWN TIME DURING THE DAY WITH WEAK SUBSIDENCE ON THE BACKSIDE OF THIS CONVECTION THIS MORNING. THIS SHOULD ALLOW DAYTIME HEATING TO PROGRESS WITH INSTABILITY INCREASING THROUGHOUT THE DAY. WILL ALSO SEE SHEAR BEGIN TO INCREASE AS MID LEVEL SPEED MAX APPROACHES LATE IN THE DAY. POTENTIAL FOR SEVERE WEATHER LOOKS GOOD BY LATE AFTERNOON INTO THE EVENING WITH BEST PARAMETERS ACROSS THE SOUTH. ALL MODES OF SEVERE WEATHER WILL BE POSSIBLE INCLUDING LARGE HAIL...DAMAGING WINDS WITH A FEW TORNADOES ALSO POSSIBLE...ESPECIALLY IN THE SOUTH AND WEST. THE CONVECTION WILL PULL NORTHEAST ACROSS CENTRAL IOWA TONIGHT AS SHORTWAVE MOVES QUICKLY THROUGH THE STATE. WILL LIKELY SEE CONVECTION DIMINISH OVER THE FORECAST AREA LATE TONIGHT AS DRIER AIR ALOFT MOVES ACROSS THE STATE. EXCEPTION WOULD BE IN THE FAR NORTH WHERE FORCING LINGERS AND CONVECTION MAY PERSIST FOR MUCH OF THE NIGHT. WILL CONTINUE TO MONITOR THIS AREA FOR POTENTIAL HEAVY RAINFALL AND THE POSSIBILITY OF FLASH FLOODING GIVEN THE PREVIOUS HEAVY RAINS OF EARLIER IN THE WEEK. UPPER LOW WILL SIT AND SPIN FOR THE EARLY PART OF THE WEEK BRINGING CHANCES OF CONVECTION ON MONDAY INTO TUESDAY WITH ADDITIONAL THREAT OF SEVERE WEATHER...MAINLY EAST DURING THIS TIME AS MOISTURE AND SHEAR REMAIN IN PLACE. UPPER SYSTEM WILL EVENTUALLY PULL AWAY LATER IN THE WEEK WITH DRIER WEATHER INTO THURSDAY AND FRIDAY. HOWEVER...THE BREAK APPEARS SHORT LIVED AS WARM ADVECTION AND MOISTURE TRANSPORT INCREASE LATE FRIDAY INTO SATURDAY. THIS WILL BRING ADDITIONAL CHANCES FOR THUNDERSTORMS LATE IN THE PERIOD. && .AVIATION...19/18Z ISSUED AT 1225 PM CDT SUN MAY 19 2013 OLD MCV CONTINUES TO PRODUCE SHOWERS AND ISO THUNDER WEST EARLY THIS PERIOD AS IT DRIFTS NORTH. MAIN CONCERNS WILL BE APPROACHING SHORTWAVE LATE AFTERNOON AND EVENING WHICH SHOULD SET INSTABILITY OFF. WINDS COMPLICATED THIS AFTERNOON WITH GUSTY SOUTH WINDS ALONG AND BEHIND WARM FRONT WHILE CIRCULATION OVER WESTERN SECTIONS BRINGING VRBL WIND DIRECTION/SPEED NEXT SEVERAL HOURS. LIKELY TO SEE +TSRA OVER THE REGION AFT 00Z SPREADING FROM WEST TO EAST DURING THE EVENING...TIMED PERIOD ABOUT 4 HOURS. MESO MODELS SUGGEST LINE MAINLY PRIOR TO 06Z...WILL MONITOR FOR TIMING AND MAKE APPROPRIATE UPDATES AS NECESSARY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && UPDATE...REV SYNOPSIS...COGIL AVIATION...REV
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 503 AM CDT SUN MAY 19 2013 IAZ033>035-044>049-057>062-070>075-081>086-092>097-201100- SAC-CALHOUN-WEBSTER-CRAWFORD-CARROLL-GREENE-BOONE-STORY-MARSHALL- AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-POWESHIEK-CASS-ADAIR-MADISON- WARREN-MARION-MAHASKA-ADAMS-UNION-CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR- RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS- 503 AM CDT SUN MAY 19 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED DURING THE DAY WITH A SEVERE STORM POSSIBLE PRODUCING LARGE HAIL OR A DAMAGING WIND GUST. HOWEVER...MUCH MORE WIDESPREAD THUNDERSTORM ACTIVITY IS EXPECTED TO DEVELOP BY MID TO LATE AFTERNOON AND SPREAD NORTHEAST ACROSS THE AREA INTO TONIGHT. SIGNIFICANT SEVERE WEATHER IS EXPECTED WITH THESE STORMS LATER THIS AFTERNOON INTO THE EVENING WITH ALL MODES OF SEVERE WEATHER POSSIBLE. GOLF BALL HAIL...DAMAGING SURFACE WINDS IN EXCESS OF 60MPH AND A FEW TORNADOES WILL BE POSSIBLE DURING THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SCATTERED THUNDERSTORMS ARE EXPECTED FROM TIME TO TIME ON MONDAY INTO EARLY WEDNESDAY. THERE IS THE THREAT FOR SEVERE WEATHER MONDAY AFTERNOON INTO THE EVENING AS WELL AS AGAIN ON TUESDAY AFTERNOON AND EVENING. MAIN THREAT WILL BE FROM LARGE HAIL AND DAMAGING WINDS ALTHOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE NEEDED LATER THIS AFTERNOON INTO THE EVENING FOR THE OUTLOOK AREA. ADDITIONAL SPOTTER ACTIVATION MAY BE NEEDED FROM TIME TO TIME EARLY IN THE WORK WEEK. IAZ004>007-015>017-023>028-036>039-050-201100- EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO- POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-HAMILTON-HARDIN- GRUNDY-BLACK HAWK-TAMA- 503 AM CDT SUN MAY 19 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TODAY AND TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED DURING THE DAY WITH A SEVERE STORM POSSIBLE PRODUCING LARGE HAIL OR A DAMAGING WIND GUST. HOWEVER...THUNDERSTORM ACTIVITY WILL BECOME MORE NUMEROUS BY LATE THIS AFTERNOON INTO TONIGHT. SEVERE WEATHER IS EXPECTED WITH THESE STORMS LATE THIS AFTERNOON INTO THE EVENING WITH LARGE HAIL UP TO GOLF BALL SIZE AND DAMAGING SURFACE WINDS IN EXCESS OF 60MPH. AN ISOLATED TORNADO WILL BE POSSIBLE DURING THIS TIME. IN ADDITION...LOCALIZED HEAVY RAIN IS EXPECTED LATE TODAY INTO TONIGHT WHICH MAY PRODUCE PONDING OF WATER. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SCATTERED THUNDERSTORMS ARE EXPECTED FROM TIME TO TIME ON MONDAY INTO EARLY WEDNESDAY. THERE IS THE THREAT FOR SEVERE WEATHER MONDAY AFTERNOON INTO THE EVENING AS WELL AS AGAIN ON TUESDAY AFTERNOON AND EVENING. MAIN THREAT WILL BE FROM LARGE HAIL AND DAMAGING WINDS ALTHOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS EXPECTED LATER THIS AFTERNOON INTO THE EVENING. ADDITIONAL SPOTTER ACTIVATION MAY BE NEEDED FROM TIME TO TIME EARLY IN THE WORK WEEK. CC
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 1014 AM CDT SUN MAY 19 2013 IAZ005>007-016-017-024>026-035>037-191715- KOSSUTH-WINNEBAGO-WORTH-HANCOCK-CERRO GORDO-HUMBOLDT-WRIGHT- FRANKLIN-WEBSTER-HAMILTON-HARDIN- INCLUDING THE CITIES OF...ALGONA...FOREST CITY...NORTHWOOD... GARNER...MASON CITY...HUMBOLDT...CLARION...HAMPTON...FORT DODGE... WEBSTER CITY...ELDORA 1014 AM CDT SUN MAY 19 2013 ...BRIEF PERIOD OF GUSTY WINDS THIS MORNING... GUSTY EAST SOUTHEASTERLY WINDS HAVE DEVELOPED IN RESPONSE TO THE PASSING OF A LINE OF THUNDERSTORMS EARLIER THIS MORNING AND A WARM FRONT NEAR THE AREA NOW. THE WINDS MAY BRIEFLY REACH 30 TO NEAR 45 MPH AT TIMES FOR THE NEXT COUPLE OF HOURS BEFORE BECOMING MORE SOUTHERLY THIS AFTERNOON. WINDS THIS AFTERNOON WILL STILL BE BREEZY FROM THE SOUTH AT 15 TO 30 MPH. REV
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1215 PM CDT SUN MAY 19 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0305 AM HAIL 6 SE MONROE 41.47N 93.02W
05/19/2013 E1.00 INCH MARION IA TRAINED SPOTTER
QUARTER SIZE HAIL. DID DAMAGE TO CAR.
&&SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 134 PM CDT SUN MAY 19 2013 IAZ006-007-016-017-191900- CERRO GORDO-HANCOCK-WINNEBAGO-WORTH- 134 PM CDT SUN MAY 19 2013 ...RAPIDLY DEVELOPING THUNDERSTORM CAPABLE OF PRODUCING HAIL... AT 128 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A RAPIDLY DEVELOPING THUNDERSTORM OVER EXTREME WEST CENTRAL CERRO GORDO COUNTY...MOVING NORTH AT 30 MPH. PENNY SIZE HAIL...WINDS UP TO 50 MPH...OCCASIONAL CLOUD TO GROUND LIGHTNING...ARE POSSIBLE WITH THIS STORM. LOCATIONS IMPACTED INCLUDE... HANLONTOWN... FERTILE... FOREST CITY AIRPORT... FOREST CITY... CRYSTAL LAKE... JOICE... LELAND... GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE OBJECTS TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED. KOTENBERG
The Des Moines radar (KDMX), 157 km away, was scanning. The volume nearest the first event began at 19:10 UTC.
46 thunderstorm wind, 16 hail, 4 tornado, 3 funnel cloud, 1 heavy rain, 1 flash flood. Local standard time, as filed.
Damage just north of Highway 18 along Nash Ave and 260th Street. Lots of 6 inches or larger branches down and a few power poles leaning. Damage to a couple of grain bins and a few metal shed roofs peeled.
Estimate of 2 inches of rain in the past hour. On Highway 141 east of Charter Oak, a spotter saw water pouring out of the fields into ditches, but no flood impacts at that time.
Hail completely covered the ground.
Two to three inch hail received via social media.
The Sac County Deputy reported a funnel cloud near the town of Ulmer, or 4 miles east and 3 miles south of Lake View.
Numerous 6 inch tree limbs down with hail damage to a house. Siding and roof damage. Hail size unknown but dents in aluminum were quarter to half dollar size.
Hail dented aluminum siding of a house near Bridgewater.
The Crawford County dispatch reported water briefly over Highway 141 and some gravel roads in the area due to over 2 inches of rainfall. Conditions improved quickly after the rain ended.
Large tree limbs broken and blown 100 yards.
A trailer park west to southwest of Earlham with 6 to 8 units was damaged. One unit had a missing roof. Multiple trees were down throughout town.
Trees and power lines were down west of Earham. Two to three poles were snapped. A shed was blown over with about 30 small pieces of wood spread across the field.
Roof blown off of a house.
Power lines were down with large tree limbs broken.
Several 6 to 8 inch diameter tree limbs were down near the high school.
Weak tornado with a very broad circulation. Track was intermittent.
Semi blown over by high winds.
Pea to marble size hail as well.
Quarter size hail with zero visibility. Strong winds taking down numerous tree limbs.
A roof was damaged with structural damage to a building was reported.
A house lost about three-quarters of its roof on County Highway R22 south of Highway 44.
Circulation was embedded within the straight line winds. There was significant tree and some structural wind damage to one residence along 250th street. Track was intermittent.
Eighteen inch diameter tree limbs were blown down in Highway 44 and S Avenue east of Dallas Center.
A new machine shed had over half of the roof blown off.
Twelve inch diameter tree limbs blown down.
From a Schoolnet site.
Power lines and 18 inch trees down.
From a Schoolnet site.
A tree was blown down onto a power line.
Large trees were down or snapped off around town.
Ten inch diameter tree branches blown down in Polk City.
From a Schoolnet site.
Shingles and siding torn from some homes by the high wind.
Tornado exhibited an intermittent track as it moved across northern Polk County into Story County. Peak damage included garage and a living room roof removed from a manufactured home. Tornado continued into Story County.
A gas station canopy was torn off near 36th and Ankeny Blvd.
Six inch diameter trees blown down by high winds.
Top of grain bin crushed.
Tornado exhibited an intermittent track as it moved across northern Polk County into Story County. Peak damage included garage and a living room roof removed from a manufactured home. Tornado moved in from Polk County.
A few large 8 inch diameter and 20 feet long tree limbs down.
Power line were blown down along Highway 69 east of Alleman.
Four to six inch tree branches down with power outages.
Trees were blown down in town. Relayed by the Waterloo Courier.
Wind gust estimated by the Emergency Manager.
Trees were snapped off by high winds.
Public estimate of 60 MPH winds.
Eight inch diameter tree branches were snapped at Bremer Ave and 8th St.
Wind damage with a tree blocking the road.
Numerous tree limbs down, some 3 inches or more with winds estimated at 65 MPH.
Strong winds with tree damage. Tin was blown off of a house. Heavy rain as well.
A pole barn was blown onto the road.
A light pole was blown down on Ferry Street.
A power pole and tree was blown down along County Road 918.
Tin blown off barns and sheds blown down.
Trees were blocking the road on Ashland Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2013Every state in 2013This day in weather historyThe tornado archive for Iowa, 2013Warnings in Iowa, May 2013
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: 440778, 452168, 440746, 440756, 440757, 440743, 441169, 441171, 440742, 440760, 440776, 440758, 440771, 440772, 440789, 440798, 440773, 440819, 440770, 440788, 440759, 440761, 440785, 440787, 440821, 440769, 440786, 440794, 440763, 440795, 440768, 440750, 440792, 440752, 440808, 440813, 440796, 440751, 440811, 440747, and more.