Alert archive / Colorado / Tornado Warnings in 2026

Tornado Warning 22, NWS Denver/Boulder, CO

June 24, 2026Logan County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 24, 2026, 5:48 PM MDT for Logan County, Colorado. It was in force for 42 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jun 24, 2026, 5:48 PM MDT (23:48 UTC)
Expired
Jun 24, 2026, 6:30 PM MDT
In force
42 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Radar indicated
Hail
2.5 in

County Logan County, CO

The radar

The Cheyenne radar (KCYS), 156 km from the middle of the area, began a volume at 23:51 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.

What was reported inside it

TimeReportWhereRemark
Jun 24, 6:13 PM MDTTORNADO2 Se Proctor, CO
Jun 24, 6:16 PM MDTHAIL 2.51 Sw Proctor, COTime and location estimated from radar.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this tornado warning; the first came 25 minutes after it went out.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 24, 3:50 PM MDTTornado WatchSPC8 hr

The text

As transmitted.

650 
WFUS55 KBOU 242348
TORBOU
COC075-250030-
/O.NEW.KBOU.TO.W.0022.260624T2348Z-260625T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
548 PM MDT Wed Jun 24 2026

The National Weather Service in Denver has issued a

* Tornado Warning for...
  Northeastern Logan County in northeastern Colorado...

* Until 630 PM MDT.

* At 548 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 4 miles north of Proctor, or 20 miles northeast of
  Sterling, moving southeast at 20 mph.

  HAZARD...Tornado and tennis ball size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without
           shelter. Mobile homes will be damaged or destroyed. Damage
           to roofs, windows and vehicles will occur. Tree damage is
           likely.

* Locations impacted include...
  Crook, Proctor and Twin Buttes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.

&&

LAT...LON 4088 10317 4100 10293 4090 10268 4070 10298
TIME...MOT...LOC 2348Z 321DEG 17KT 4087 10298

TORNADO...RADAR INDICATED
MAX HAIL SIZE...2.50 IN

$$

63
5 follow-up statements
647 
WWUS55 KBOU 242356
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
556 PM MDT Wed Jun 24 2026

COC075-250030-
/O.CON.KBOU.TO.W.0022.000000T0000Z-260625T0030Z/
Logan CO-
556 PM MDT Wed Jun 24 2026

...TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR
NORTHEASTERN LOGAN COUNTY...

At 556 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Proctor, or 20 miles northeast of Sterling, moving
southeast at 20 mph.

HAZARD...Tornado and tennis ball size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without
         shelter. Mobile homes will be damaged or destroyed. Damage
         to roofs, windows and vehicles will occur. Tree damage is
         likely.

Locations impacted include...
  Crook, Proctor and Twin Buttes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.

&&

LAT...LON 4085 10310 4098 10288 4090 10268 4070 10298
TIME...MOT...LOC 2348Z 321DEG 17KT 4087 10298

TORNADO...RADAR INDICATED
MAX HAIL SIZE...2.50 IN

$$

63
569 
WWUS55 KBOU 250003
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
603 PM MDT Wed Jun 24 2026

COC075-250030-
/O.CON.KBOU.TO.W.0022.000000T0000Z-260625T0030Z/
Logan CO-
603 PM MDT Wed Jun 24 2026

...TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR
NORTHEASTERN LOGAN COUNTY...

At 603 PM MDT, a severe thunderstorm capable of producing a tornado
was located over Proctor, or 20 miles northeast of Sterling, moving
southeast at 20 mph.

HAZARD...Tornado and baseball size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without
         shelter. Mobile homes will be damaged or destroyed. Damage
         to roofs, windows and vehicles will occur. Tree damage is
         likely.

Locations impacted include...
  Crook, Proctor and Twin Buttes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.

&&

LAT...LON 4082 10307 4096 10283 4090 10268 4070 10298
TIME...MOT...LOC 2356Z 321DEG 17KT 4084 10294

TORNADO...RADAR INDICATED
MAX HAIL SIZE...2.75 IN

$$

63
422 
WWUS55 KBOU 250011
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
611 PM MDT Wed Jun 24 2026

COC075-250030-
/O.CON.KBOU.TO.W.0022.000000T0000Z-260625T0030Z/
Logan CO-
611 PM MDT Wed Jun 24 2026

...TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR
NORTHEASTERN LOGAN COUNTY...

At 611 PM MDT, a confirmed tornado was located near Proctor, or 20
miles northeast of Sterling, moving southeast at 20 mph.

HAZARD...Damaging tornado and baseball size hail.

SOURCE...Law enforcement confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without
         shelter. Mobile homes will be damaged or destroyed. Damage
         to roofs, windows and vehicles will occur. Tree damage is
         likely.

Locations impacted include...
  Crook, Proctor and Twin Buttes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.

&&

LAT...LON 4082 10307 4096 10283 4090 10268 4070 10298
TIME...MOT...LOC 0003Z 321DEG 17KT 4081 10292

TORNADO...OBSERVED
MAX HAIL SIZE...2.75 IN

$$

63
979 
WWUS55 KBOU 250018
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
618 PM MDT Wed Jun 24 2026

COC075-250030-
/O.CON.KBOU.TO.W.0022.000000T0000Z-260625T0030Z/
Logan CO-
618 PM MDT Wed Jun 24 2026

...TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR EAST
CENTRAL LOGAN COUNTY...

At 618 PM MDT, a confirmed tornado was located 5 miles north of
Fleming, or 19 miles northeast of Sterling, moving southeast at 20
mph.

HAZARD...Damaging tornado and baseball size hail.

SOURCE...Law enforcement confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without
         shelter. Mobile homes will be damaged or destroyed. Damage
         to roofs, windows and vehicles will occur. Tree damage is
         likely.

Locations impacted include...
  Crook and Proctor.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.

&&

LAT...LON 4078 10301 4090 10279 4085 10276 4075 10290
      4071 10297
TIME...MOT...LOC 0011Z 325DEG 16KT 4078 10289

TORNADO...OBSERVED
MAX HAIL SIZE...2.75 IN

$$

63
892 
WWUS55 KBOU 250025
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
625 PM MDT Wed Jun 24 2026

COC075-250035-
/O.EXP.KBOU.TO.W.0022.000000T0000Z-260625T0030Z/
Logan CO-
625 PM MDT Wed Jun 24 2026

...TORNADO WARNING WILL EXPIRE AT 630 PM MDT FOR EAST CENTRAL LOGAN
COUNTY...

The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 1100 PM MDT Wednesday for a
portion of northeast Colorado.

&&

LAT...LON 4078 10301 4090 10279 4085 10276 4075 10290
      4071 10297
TIME...MOT...LOC 0018Z 325DEG 16KT 4076 10287

$$

63

What forecasters said that day

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

NWS Denver/Boulder, CO wrote its last area forecast discussion before this tornado warning went out at Jun 24, 2:50 PM MDT, 2 hours 58 minutes earlier. Its key messages:

  • Numerous strong to severe thunderstorms expected today for the lower elevations, particularly late afternoon through tonight. Strongest storms may produce very large hail exceeding 2-3" in diameter.
  • Additional round of strong to severe thunderstorms possible Thursday. Localized flash flood concerns will exist both Wednesday and Thursday.
  • Critical fire weather conditions this afternoon in the mountains given warm, dry and breezy weather and the potential for isolated dry thunderstorms. Notably higher fire danger will develop this weekend as hotter and windier weather returns.
Area forecast discussion, Jun 24, 2:50 PM MDT, 2 hours 58 minutes before
Area Forecast Discussion
National Weather Service Denver/Boulder CO
250 PM MDT Wed Jun 24 2026

.KEY MESSAGES...

- Numerous strong to severe thunderstorms expected today for the
  lower elevations, particularly late afternoon through tonight.
  Strongest storms may produce very large hail exceeding 2-3" in
  diameter.

- Additional round of strong to severe thunderstorms possible Thursday.
  Localized flash flood concerns will exist both Wednesday and
  Thursday.

- Critical fire weather conditions this afternoon in the mountains
  given warm, dry and breezy weather and the potential for
  isolated dry thunderstorms. Notably higher fire danger will
  develop this weekend as hotter and windier weather returns.

&&

.DISCUSSION /Through Wednesday/...
Issued at 147 PM MDT Wed Jun 24 2026

A rather conditional severe weather threat still exists across
most of the I-25 corridor and eastern plains this afternoon.

A broad belt of westerly/west-northwesterly flow aloft is evident
via GOES water vapor imagery and recent RAP analysis data.
Meanwhile, a well-defined surface boundary stretching from KAPA
through KDEN and into southeastern Weld County. While this
boundary has produced more of a shear zone than a true convergence
zone, there's been plenty of differential heating along the
boundary. With the DEN ASOS on the "warm" side of the boundary,
we've seen T/Td reach 89/55F, with temperatures in the upper 70s
to low 80s across the western Denver metro.

At this point, it appears likely that we'll see a first attempt at
convective initiation somewhere along the surface boundary in the
next couple of hours, with better probabilities of sustained
convection closer to Fort Morgan/Sterling. A recent ACARS
sounding, modified to the latest DEN observation suggest only
meager capping at 700-600mb remains, with ACARS and RAP
Mesoanalysis showing a fairly broad area of >3000 MLCAPE
stretching along and south of I-76. Combined with impressive deep
layer shear, any thunderstorms that can develop this afternoon
should quickly become strong to severe, with primarily a large
hail threat. Hodographs have slowly become more curved as the
low-level flow has increased, though overall hodographs are still
relatively straight-line and would favor splitting supercells with
the initial round of convection today. Still, there would be at
least a brief tornado threat, especially closer to any boundary
where sfc vorticity and effective SRH would be maximized.

A second round of thunderstorms is expected to develop in Wyoming
and move into our forecast area sometime between about 6-10 PM.
This should primarily be north and east of the metro (where SPC's
enhanced risk is). I would expect this to be the more significant
of the two waves of convection given a weakening cap and rather
impressive skew-t/hodograph combinations advertised by the WoFS.
While again this threat appears to be mainly north/east of the
I-25 corridor, we can't completely rule out strong to severe
storms this far west. Any sort of additional push of moist outflow
may be enough to break the remaining cap here, which has been
shown on and off by various high resolution models. We'll see if
any more meaningful trends emerge this afternoon but the threat in
the Denver metro is highly conditional.

A more organized round of sub-severe showers and thunderstorms is
likely overnight tonight as a shortwave moves across the region.
There could still be a strong storm or two left depending on how
much instability lingers overnight, but the severe threat should
diminish quickly after midnight. A combination of some showers,
stratus, fog/mist, and haze from wildfire smoke will likely
develop overnight and linger into Thursday morning.

The shortwave should move across the area through Thursday, with a
cooler/more stable airmass behind it. There should still be widely
scattered showers and thunderstorms in the afternoon, though any
severe potential will be determined by how quickly things can
destabilize following the morning stratus/fog.

Drier southwesterly flow aloft should develop by Friday, leading
to less convection across the region. The warming/drying trend is
likely to continue into the weekend as a strong upper trough
advances into the Pacific Northwest region during the weekend.
Strengthening mid/upper level flow is expected to bring gusty
winds to most of the forecast area, with the strongest winds over
the higher elevations. The combination of above normal
temperatures, a dry airmass, and gusty winds will likely lead to
critical fire weather conditions across a large portion of the
forecast area... and Fire Weather Watches may be necessary soon.

Little change is expected in the longer term forecast period as
dry southwesterly flow aloft continues.

&&

.AVIATION /18Z TAFS through 18Z Thursday/...
Issued at 1215 PM MDT Wed Jun 24 2026

Another complicated day is in store for the three airports. A
boundary is positioned just to the east of KDEN, with north to
NNE winds at KDEN. Over the last hour or so, this boundary has
migrated further to the NW. Guidance is having a difficult time
resolving the boundary, but we are currently thinking winds will
turn to the E and SE throughout the afternoon at KDEN as this
boundary moves further west. The timing could be slightly earlier
than what is currently in the TAF given the current position of
the boundary.

The next big focus is the thunderstorm chances this afternoon and
evening. Short-term models remain in pretty good agreement that
precipitation will likely occur at least near all three sites,
but timing is varying across run-to-run and model-to-model. Thus,
have stretched prob30s from about 21z to 8z at all three sites.
The highest chances look to be between about 00z and 04z, so we
may need to add in a tempo group if there is more confidence in
timing this afternoon. Gusty outflow winds of at least 30 kts will
be possible with any storms near KDEN and KAPA especially.

Finally, low ceilings/fog/haze look to develop with northeast to
east flow overnight. Ceilings could drop as low as about 005
generally after 10z. We will need to monitor the wind direction
overnight as the winds could turn more easterly or southeasterly,
which would limit the threat for lower ceilings. By tomorrow
afternoon, showers and thunderstorms will return to the area, but
we will address any needs to add -tsra in the next update.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 6 PM MDT this evening for COZ211>214-217-
218.

&&

DISCUSSION...Hiris
AVIATION...MV

In the hours before

Local storm report, Jun 24, 4:33 PM MDT, 1 hour 15 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
433 PM MDT Wed Jun 24 2026

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

0409 PM     Hail             1 NNE Log Lane Village  40.29N 103.82W
06/24/2026  E1.75 Inch       Morgan             CO   Trained Spotter

            Corrects time of previous hail report from 1
            NNE Log Lane Village. Time estimated from
            radar.

&&

AA
Local storm report, Jun 24, 4:40 PM MDT, 1 hour 8 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
440 PM MDT Wed Jun 24 2026

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

0431 PM     Hail             4 N Adena School        40.18N 103.80W
06/24/2026  M2.50 Inch       Morgan             CO   Trained Spotter

&&
Local storm report, Jun 24, 4:47 PM MDT, 1 hour 1 minute before
Preliminary Local Storm Report
National Weather Service Denver CO
447 PM MDT Wed Jun 24 2026

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

0441 PM     Hail             5 N Adena School        40.19N 103.79W
06/24/2026  E2.00 Inch       Morgan             CO   Public

            Report from mPING: Hen Egg (2.00 in.).

&&

AA
Local storm report, Jun 24, 4:48 PM MDT, 1 hour before
Preliminary Local Storm Report
National Weather Service Denver CO
448 PM MDT Wed Jun 24 2026

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

0414 PM     Hail             1 SW Fort Morgan        40.25N 103.80W
06/24/2026  E1.75 Inch       Morgan             CO   Public

            Report from mPING: Golf Ball (1.75 in.) Time
            estimated from radar.

&&

AA
Local storm report, Jun 24, 5:06 PM MDT, 42 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
506 PM MDT Wed Jun 24 2026

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

0426 PM     Tstm Wnd Gst     3 N Messex              40.46N 103.43W
06/24/2026  M61 MPH          Logan              CO   Public

&&

AA
Local storm report, Jun 24, 5:15 PM MDT, 33 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
515 PM MDT Wed Jun 24 2026

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

0508 PM     Hail             1 SW Gary               40.06N 103.60W
06/24/2026  M1.50 Inch       Morgan             CO   Public

            Report from mPING: Ping Pong Ball (1.50
            in.).

&&

AA

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 23, 6:09 PM MDTSevere Thunderstorm WarningBOUWashington22 min
Jun 23, 6:19 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert, Lincoln41 min
Jun 23, 6:51 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUArapahoe, Elbert, Lincoln, Washington38 min
Jun 23, 7:12 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUWashington18 min
Jun 23, 7:29 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUWashington27 min
Jun 23, 8:31 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUMorgan, Weld44 min
Jun 23, 8:34 PM MDTSevere Thunderstorm WarningBOUElbert41 min
Jun 23, 8:45 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington25 min
Jun 23, 8:52 PM MDTSevere Thunderstorm Warning Destructive damage threatBOUMorgan38 min
Jun 23, 8:58 PM MDTSevere Thunderstorm Warning Destructive damage threatBOUMorgan, Weld47 min
Jun 23, 9:02 PM MDTSevere Thunderstorm WarningBOUElbert43 min
Jun 23, 9:16 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUMorgan32 min
Jun 23, 9:37 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld25 min
Jun 23, 9:38 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln9 min
Jun 23, 9:42 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln17 min
Jun 23, 9:46 PM MDTSevere Thunderstorm WarningBOUPhillips44 min
Jun 23, 10:05 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick25 min
Jun 23, 10:27 PM MDTSevere Thunderstorm WarningBOUPhillips23 min
Jun 23, 10:39 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert, Lincoln, Washington42 min
Jun 23, 11:48 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln27 min
Jun 23, 11:59 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln46 min
Jun 24, 12:26 AM MDTSevere Thunderstorm WarningBOUElbert, Lincoln31 min
Jun 24, 12:40 AM MDTSevere Thunderstorm WarningBOUElbert25 min
Jun 24, 12:42 AM MDTSevere Thunderstorm WarningBOULincoln48 min
Jun 24, 12:47 AM MDTSevere Thunderstorm WarningBOUElbert, Lincoln43 min
Jun 24, 1:02 AM MDTFlash Flood WarningBOULincoln3 hr
Jun 24, 1:21 AM MDTSevere Thunderstorm WarningBOULogan, Morgan, Weld39 min
Jun 24, 1:22 AM MDTFlash Flood WarningBOUArapahoe, Elbert, Lincoln3 hr
Jun 24, 3:21 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUMorgan, Weld39 min
Jun 24, 3:38 PM MDTSevere Thunderstorm Warning Destructive damage threatBOUMorgan, Weld33 min
Jun 24, 3:46 PM MDTSpecial Weather StatementBOUAdams44 min
Jun 24, 3:59 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Washington46 min
Jun 24, 4:06 PM MDTSevere Thunderstorm Warning Destructive damage threatBOUMorgan21 min
Jun 24, 4:21 PM MDTTornado WarningBOULogan, Morgan, Washington39 min
Jun 24, 4:26 PM MDTTornado WarningBOUMorgan34 min
Jun 24, 4:52 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington38 min
Jun 24, 4:55 PM MDTSevere Thunderstorm Warning Considerable damage threatBOUWashington35 min
Jun 24, 5:15 PM MDTSevere Thunderstorm WarningBOUWashington45 min
Jun 24, 5:38 PM MDTSevere Thunderstorm WarningBOULogan, Sedgwick24 min
Jun 24, 5:42 PM MDTSevere Thunderstorm WarningBOUWashington33 min

Nearby

Tornado Warnings in Colorado, 2026Every tornado warning in 2026Tornadoes 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; local storm reports from the same archive; radar from the NEXRAD Level II archive.