Alert archive / Utah / Flash Flood Warnings in 2026

Flash Flood Warning 2, NWS Salt Lake City, UT

April 11, 2026Emery County, Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Apr 11, 2026, 12:42 PM MDT for Emery County, Wayne County, Utah. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 11, 2026, 12:42 PM MDT (18:42 UTC)
Expired
Apr 11, 2026, 3:45 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Emery County, UT, Wayne County, UT

The radar

The Grand Junction radar (KGJX), 220 km from the middle of the area, began a volume at 18:46 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The text

As transmitted.

288 
WGUS55 KSLC 111842
FFWSLC
UTC015-055-112145-
/O.NEW.KSLC.FF.W.0002.260411T1842Z-260411T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
1242 PM MDT Sat Apr 11 2026

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  South Central Emery County in central Utah...
  North Central Wayne County in southern Utah...

* Until 345 PM MDT.

* At 1242 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.25 and 0.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.25 to 0.5 
  inches are possible in the warned area. Flash flooding is ongoing 
  or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Goblin Valley, Little Wildhorse Canyon, Ding Canyon, Dang Canyon, 
  Bell Canyon, and other adjacent canyons nearby.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. Dry 
washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3887 11064 3891 11045 3882 11032 3850 11076
      3848 11079 3845 11101 3872 11107

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

JCW
2 follow-up statements
280 
WGUS75 KSLC 112020
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
220 PM MDT Sat Apr 11 2026

UTC015-055-112145-
/O.CON.KSLC.FF.W.0002.000000T0000Z-260411T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Emery UT-Wayne UT-
220 PM MDT Sat Apr 11 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM MDT THIS 
AFTERNOON FOR SOUTH CENTRAL EMERY AND NORTH CENTRAL WAYNE COUNTIES...

At 220 PM MDT, Doppler radar indicated thunderstorms produced heavy 
rain across the warned area. Between 0.25 and 0.75 inches of rain 
have fallen. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Goblin Valley, Little Wildhorse Canyon, Ding Canyon, Dang Canyon, 
  Bell Canyon, and other adjacent canyons nearby.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. Dry 
washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3887 11064 3891 11045 3882 11032 3850 11076
      3848 11079 3845 11101 3872 11107

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

CRK
983 
WGUS75 KSLC 112143
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
343 PM MDT Sat Apr 11 2026

UTC015-055-112153-
/O.EXP.KSLC.FF.W.0002.000000T0000Z-260411T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Emery UT-Wayne UT-
343 PM MDT Sat Apr 11 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 345 PM MDT THIS AFTERNOON FOR 
SOUTH CENTRAL EMERY AND NORTH CENTRAL WAYNE COUNTIES...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

&&

LAT...LON 3887 11064 3891 11045 3882 11032 3850 11076
      3848 11079 3845 11101 3872 11107

$$

JCW

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Salt Lake City, UT wrote its last area forecast discussion before this flash flood warning went out at Apr 11, 11:11 AM MDT, 1 hour 31 minutes earlier. Its key messages:

  • A marginal risk for severe thunderstorms (5-10% chance of wind gusts in excess 58 mph) is outlooked for portions of northern and eastern Utah this afternoon and evening.
  • Wind gusts in excess of 45 mph will occur across southwest and west central Utah, the Sevier Valley and Castle Country Sunday afternoon and evening.
  • A storm system will bring unsettled conditions Sunday into Tuesday with periods of valley rain and accumulating mountain snow. The heaviest mountain snow is expected Monday into Tuesday.
  • Freezing conditions will occur in the central and southern valleys Tuesday night into Wednesday morning and across most valleys including the Wasatch Front Thursday night into Friday morning.
Area forecast discussion, Apr 11, 11:11 AM MDT, 1 hour 31 minutes before
Area Forecast Discussion
National Weather Service Salt Lake City UT
1111 AM MDT Sat Apr 11 2026

.UPDATE...Quick update AFD today due to widespread convection
impacting the region.

Looking at the current mesoanalysis, SBCAPE values have increased
through the morning, averaging 500-1000 J/kg based on the latest
mesoanalysis. Deep layer shear is more than sufficient...with a
broad area of 0-6KM shear in excess of 40-50 kts across the
Beehive State. A dry slot will shift north and east with time,
clearing convection across southern Utah by late afternoon.

Main threats today are small hail (less than 5% chance of hail in
quarter size or larger), strong winds in excess of 58 mph with
thunderstorms (5-10% chance across northern and eastern Utah) and
localized flash flooding across portions of south central and
southeastern Utah. The most at risk locations for flash flooding
include Capitol Reef National Park, the Grand Staircase National
Monument, the San Rafael Swell, western Canyonlands and Glen
Canyon National Recreation Area.

The threat of flash flooding will end across southern Utah by 4-5
PM. The threat for organized convection across northern Utah,
Uinta County, WY and eastern Utah will diminish after 5 PM.

Ahead of cold front crossing the region Sunday, expect a greater
than 70% chance of wind gusts in excess of 45 mph across
southwestern and west central Utah, the Sevier Valley and Castle
Country. These areas will likely need wind advisories with this
package.

Key messages and the aviation AFD are updated. The previous AFD
follows for the remainder.

&&

.KEY MESSAGES...

- A marginal risk for severe thunderstorms (5-10% chance of wind
  gusts in excess 58 mph) is outlooked for portions of northern
  and eastern Utah this afternoon and evening.

- Wind gusts in excess of 45 mph will occur across southwest and
  west central Utah, the Sevier Valley and Castle Country Sunday
  afternoon and evening.

- A storm system will bring unsettled conditions Sunday into
  Tuesday with periods of valley rain and accumulating mountain
  snow. The heaviest mountain snow is expected Monday into
  Tuesday.

- Freezing conditions will occur in the central and southern
  valleys Tuesday night into Wednesday morning and across most
  valleys including the Wasatch Front Thursday night into Friday
  morning.

&&

.DISCUSSION (Previous, issued at 1002 PM 04/10)...A broad storm
system is moving onshore along the California coast this evening,
putting Utah and southwest Wyoming under a breezy southwest flow
aloft. This flow is drawing enough moisture northward for the
development of scattered showers and thunderstorms early today,
with many of these storms producing gusty winds, some in excess of
40 mph. A few light showers remain and will continue to dissipate
into the overnight hours.

The California trough is on track to weaken significantly as it
moves onshore, eventually crossing northern Utah Saturday
afternoon and evening. The flow aloft is no longer expected to
increase much with the passage of the trough, so the potential for
wind gusts in excess of 40 mph has dropped to the 20 to 30 percent
range. While it would not be surprising to see isolated gusts in
excess of 40 mph, the areal extent and anticipated duration of
these winds would not warrant a Wind Advisory. Associated showers
and storms will be a bit more widespread compared to the last
couple of days, but the best coverage will be confined to areas
east of I-15, primarily over northern Utah. Still, any storms that
move over rain sensitive areas could bring the threat of flash
flooding.

As the weakening system exits the forecast area, another broad low
will approach the California coast. Guidance appears to be
converging on a solution for this low that would slowly track it
across the Great Basin and eventually into Utah and southwest
Wyoming Sunday into early Tuesday. There is high confidence that
this will bring substantial cooling to the area, with highs below
seasonal normals by Monday. The storm and associated cold front
will also bring unsettled conditions and the potential for
accumulating mountain snow, though totals overall look a bit less
impressive than they have the past couple of days. This is because
the system ultimately becomes a bit moisture starved and more
guidance is showing the system weakening somewhat as it moves
through, though not to the extent of the first system.

A drier zonal flow is expected to develop for the midweek period,
but long range guidance is showing the potential for a colder
storm system impacting the area by late in the work week, bringing
a chance of snow for most valleys as well as the mountains for day
seven.

&&

.AVIATION (Updated as of 1110 AM 4/11)...KSLC...VFR conditions
will prevail with some isolated thunderstorms present into the
afternoon hours. These thunderstorms will cause a brief drop into
MVFR as they pass with increased and more variable wind speeds.
Prevailing winds will be from a southerly direction before
shifting this afternoon. This shift will be a gradual shift to the
southwest then west with continued gusty winds. Winds will calm
overnight, before picking up again along a diurnal trend tomorrow.
More shower and thunderstorm chances again tomorrow, but later in
the day than what we have seen today.

.REST OF UTAH AND SOUTHWEST WYOMING...Broadly VFR with isolated
areas of thunderstorms causing brief drops into MVFR this
afternoon into early evening. Winds will be more southwesterly
across southern Utah with more of a westerly component to the
north. Gusty synoptic winds through the day today falling
overnight along the usual diurnal curve. Winds pick up again
tomorrow from the south. More shower and thunderstorm chances on
Sunday, but generally later in the day than we have seen today.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

Kruse/Carletta

For more information from NOAA's National Weather Service visit...
http://weather.gov/saltlakecity

In the hours before

Special weather statement, Apr 11, 12:03 PM MDT, 39 minutes before
Special Weather Statement
National Weather Service Salt Lake City UT
1203 PM MDT Sat Apr 11 2026

UTZ111>113-117-118-111845-
Sanpete Valley UT-Wasatch Plateau/Book Cliffs UT-
Western Uinta Mountains UT-Central Mountains UT-
Wasatch Mountains South of I-80 UT-
1203 PM MDT Sat Apr 11 2026

...A strong thunderstorm will impact portions of north central
Sanpete, central Wasatch and south central Utah Counties through 1245
PM MDT
...

At 1203 PM MDT, Doppler radar was tracking a strong thunderstorm 14
miles southeast of Woodland Hills, or 17 miles southeast of Payson,
moving northeast at 40 mph.

HAZARD...Wind gusts up to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Birdseye, Strawberry Reservoir, and Indianola.

This includes the following highways...
 US Route 6 between mile markers 183 and 199.
 US Route 40 between mile markers 31 and 47.
 US Route 89 between mile markers 292 and 312.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3972 11144 3981 11166 4034 11138 4035 11136
      4035 11120 4023 11106
TIME...MOT...LOC 1803Z 205DEG 33KT 3984 11151

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

JCW
Local storm report, Apr 11, 12:19 PM MDT, 23 minutes before
Preliminary Local Storm Report
National Weather Service Salt Lake City UT
1219 PM MDT Sat Apr 11 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1218 PM     Hail             2 ESE West Jordan       40.59N 111.96W
04/11/2026  M0.75 Inch       Salt Lake          UT   Trained Spotter

&&

CRK
Special weather statement, Apr 11, 12:19 PM MDT, 23 minutes before
Special Weather Statement
National Weather Service Salt Lake City UT
1219 PM MDT Sat Apr 11 2026

UTZ104-105-108-110-111900-
Salt Lake Valley UT-Wasatch Back UT-Northern Wasatch Front UT-
Wasatch Mountains I-80 North UT-
1219 PM MDT Sat Apr 11 2026

...A strong thunderstorm will impact portions of central Salt Lake,
southeastern Davis and southwestern Morgan Counties through 100 PM
MDT
...

At 1219 PM MDT, Doppler radar was tracking a strong thunderstorm over
Taylorsville, or over Murray, moving north at 45 mph.

HAZARD...Half inch hail.

SOURCE...Observed.

IMPACT...Minor damage to outdoor objects is possible.

Locations impacted include...
Salt Lake City, West Valley City, Sandy, Murray, Bountiful,
Farmington, West Jordan, Taylorsville, South Jordan, Cottonwood
Heights, Midvale, Kaysville, Holladay, South Salt Lake, North Salt
Lake, Centerville, Woods Cross, West Bountiful, Millcreek, and
Kearns.

This includes the following highways...
 Interstate 15 between mile markers 294 and 325.
 Interstate 80 in Utah between mile markers 115 and 131.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4100 11158 4070 11177 4070 11179 4068 11178
      4055 11186 4060 11206 4108 11190
TIME...MOT...LOC 1819Z 198DEG 38KT 4065 11193

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...<40 MPH

JCW
Special weather statement, Apr 11, 12:31 PM MDT, 11 minutes before
Special Weather Statement
National Weather Service Salt Lake City UT
1231 PM MDT Sat Apr 11 2026

UTZ101-103-104-110-111915-
Eastern Box Elder County UT-Northern Wasatch Front UT-
Wasatch Mountains I-80 North UT-
Great Salt Lake Desert and Mountains UT-
1231 PM MDT Sat Apr 11 2026

...A strong thunderstorm will impact portions of southwestern Weber,
west central Cache and southeastern Box Elder Counties through 115 PM
MDT
...

At 1231 PM MDT, Doppler radar was tracking a strong thunderstorm 11
miles west of Hooper, or 18 miles west of Hill Air Force Base, moving
north at 35 mph.

HAZARD...Wind gusts up to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Brigham City, Perry, Wellsville, Willard, Bear River City, Corinne,
Honeyville, Elwood, and Bear River.

This storm will be capable of producing strong gusty winds on the
Great Salt Lake. This will lead to a sudden increase in waves and
very choppy waters which will result in hazardous boating conditions.
Boaters are urged to seek safe harbor if possible.

This includes Interstate 15 between mile markers 358 and 373.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

If on or near the Great Salt Lake, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4113 11223 4119 11246 4169 11228 4160 11194
TIME...MOT...LOC 1831Z 199DEG 31KT 4121 11233

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

JCW
Special weather statement, Apr 11, 12:35 PM MDT, 7 minutes before
Special Weather Statement
National Weather Service Salt Lake City UT
1235 PM MDT Sat Apr 11 2026

UTZ101-102-104-105-111915-
Salt Lake Valley UT-Northern Wasatch Front UT-
Tooele and Rush Valleys UT-Great Salt Lake Desert and Mountains UT-
1235 PM MDT Sat Apr 11 2026

...A strong thunderstorm will impact portions of northwestern Salt
Lake, central Davis and east central Tooele Counties through 115 PM
MDT
...

At 1235 PM MDT, Doppler radar was tracking a strong thunderstorm near
Grantsville, moving northeast at 50 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch hail.

SOURCE...Observed.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Layton, Tooele, Grantsville, Kaysville, Syracuse, Stansbury Park,
Tooele Army Depot, Great Salt Lake South of the Causeway, Lake Point,
Erda, and Antelope Island State Park.

This includes the following highways...
 Interstate 15 between mile markers 327 and 328.
 Interstate 80 in Utah between mile markers 84 and 106.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4049 11241 4058 11261 4114 11224 4102 11192
TIME...MOT...LOC 1835Z 210DEG 41KT 4065 11243

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

JCW
Special weather statement, Apr 11, 12:37 PM MDT, 5 minutes before
Special Weather Statement
National Weather Service Salt Lake City UT
1237 PM MDT Sat Apr 11 2026

UTZ121-130-111915-
San Rafael Swell UT-Western Canyonlands UT-
1237 PM MDT Sat Apr 11 2026

...A strong thunderstorm will impact portions of north central Wayne
and southern Emery Counties through 115 PM MDT
...

At 1234 PM MDT, Doppler radar was tracking a strong thunderstorm 26
miles north of Hanksville, moving northeast at 45 mph.

HAZARD...Wind gusts of 50 to 55 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible. Very heavy rain is falling with this storm over
         flash flood prone areas such as Little Wildhorse and Ding
         and Dang Canyons. If near or in these areas, seek higher
         ground now outside of the slot canyons. Consider altering
         plans for this afternoon if they included any of these slot
         canyons near Goblin Valley State Park.

Locations impacted include...
Goblin Valley.

This includes the following highways...
 Interstate 70 between mile markers 114 and 155.
 Utah Route 24 between mile markers 132 and 160.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3835 11105 3873 11111 3917 11052 3888 11018
      3851 11069
TIME...MOT...LOC 1834Z 224DEG 41KT 3876 11073

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...55 MPH

CRK

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 7:16 PM MDTSpecial Weather StatementSLCUtah44 min
Apr 11, 10:19 AM MDTSpecial Weather StatementSLCSalt Lake26 min
Apr 11, 10:37 AM MDTSpecial Weather StatementSLCSanpete38 min
Apr 11, 10:41 AM MDTSpecial Weather StatementSLCWeber49 min
Apr 11, 11:17 AM MDTWind AdvisorySLCBeaver, Carbon, Emery, Garfield, Iron, Juab and 7 more33 hr
Apr 11, 11:59 AM MDTSpecial Weather StatementSLCRich31 min
Apr 11, 12:03 PM MDTSpecial Weather StatementSLCUtah42 min
Apr 11, 12:19 PM MDTSpecial Weather StatementSLCSalt Lake41 min
Apr 11, 12:31 PM MDTSpecial Weather StatementSLCWeber44 min
Apr 11, 12:35 PM MDTSpecial Weather StatementSLCDavis40 min
Apr 11, 12:37 PM MDTSpecial Weather StatementSLCEmery38 min
Apr 11, 12:51 PM MDTSpecial Weather StatementSLCCache39 min
Apr 11, 1:08 PM MDTSevere Thunderstorm WarningSLCBox Elder, Davis, Weber37 min
Apr 11, 1:14 PM MDTSpecial Weather StatementSLCDavis46 min
Apr 11, 1:15 PM MDTSpecial Weather StatementSLCEmery45 min
Apr 11, 1:33 PM MDTSevere Thunderstorm WarningSLCBox Elder, Cache42 min
Apr 11, 1:50 PM MDTSpecial Weather StatementSLCDuchesne40 min
Apr 11, 1:55 PM MDTSpecial Weather StatementSLCDavis50 min
Apr 11, 1:55 PM MDTSpecial Weather StatementSLCEmery20 min
Apr 11, 1:56 PM MDTSpecial Weather StatementSLC49 min
Apr 11, 2:13 PM MDTSevere Thunderstorm WarningSLCCache, Rich47 min
Apr 11, 2:42 PM MDTSpecial Weather StatementSLCTooele33 min
Apr 11, 3:02 PM MDTSpecial Weather StatementSLCMorgan43 min
Apr 11, 3:12 PM MDTSpecial Weather StatementSLCSummit33 min

Nearby

Flash Flood Warnings in Utah, 2026Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.