Alert archive / Iowa / Severe Thunderstorm Warnings in 2019
Severe Thunderstorm Warning 150, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jul 20, 2019, 11:04 AM CDT for 4 counties in Iowa. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 20, 2019, 11:04 AM CDT (16:04 UTC)
- Expired
- Jul 20, 2019, 11:45 AM CDT
- In force
- 41 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Cerro Gordo County, IA, Hancock County, IA, Winnebago County, IA, Worth County, IA
The radar
The Des Moines radar (KDMX), 168 km from the middle of the area, began a volume at 16:06 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 20, 9:05 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 4.1 hours before the alert went out and 180 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1482 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 101 m²/s²
- 0-3 km storm-relative helicity
- 291 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.1
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at Jul 20, 5:45 AM CDT, 5 hours 19 minutes earlier.
Area forecast discussion, Jul 20, 5:45 AM CDT, 5 hours 19 minutes before
Area Forecast Discussion National Weather Service Des Moines IA 545 AM CDT Sat Jul 20 2019 .DISCUSSION.../Today through Friday/ Issued at 353 AM CDT Sat Jul 20 2019 Main focus today will be on precipitation chances, temperatures and the progression of the cold front across Iowa through Sunday. Currently have the surface cold front stretching across southern Minnesota back southwestward into northwest Iowa and is right near the IA/MN border across north central Iowa. A few storms have fired along the boundary through the overnight hours, but have not been able to sustain themselves and have since dissipated completely. The boundary is expected to waffle around southern MN/northern Iowa through the morning into the early afternoon hours. An ongoing MCS is moving through SD currently and is expected to continue push east along the 850mb moisture gradient especially into the morning hours as the moisture transport becomes more oriented into southern MN. Expect the majority of this activity to remain across southern MN, but could scrape the northern counties this morning, therefore have reduced pops across the north. This system will reinforce the cold front with additional activity expected to fire along the front into this afternoon as it begins to push further south again and becomes stalled out across central Iowa this evening. Mean flow will be parallel to the front across central Iowa tonight, with storms expected to backbuild and then likely train across the area. Given the hot and humid conditions, large amounts of instability present however bulk shear values will be limited. However given the large instability, some severe storms are still likely across the area with large hail, damaging winds and possibly even a tornado the main threats. However the threat for heavy rainfall appears to be even larger given the tremendous moisture in place with precipitable water values around 2 inches or higher across the area later today into tonight. Freezing levels will be up around 15-16kft yielding deep warm cloud depths, and efficient rain production. These parameters and the training storms expected, the potential for heavy rainfall also seems likely. Overall given the dryness in many areas the past few weeks to a month and full, mature crops in place the threat of flash flooding will be somewhat dampened so will not issue any flood headlines at the moment. However the threat will still have to be assessed during the dayshift for a possibility. The main worries would be heavy rainfall in a more urban areas and towns. The majority of FFG across the area has 1,3,6 hour rainfall amounts of 2- 3 inches or higher, with some areas in the far south central pushing 5" FFG amounts for 6 hours. Into Sunday, much cooler temperatures are anticipated as the frontal boundary is expected to stall across central/southern Iowa with continued chances for showers and storms. Highs are expected to top out in the 70s to around 80. Some lingering storms still possible as the front moves south Sunday night across far southern Iowa, however a large, high amplitude upper ridge to build into the western/central US early next week. This upper ridge will slowly breakdown and shift east through the week which will allow for cooler northwesterly upper level flow across the state and dry conditions through much of the week. An upper wave will move through the Canadian Rockies toward Thursday and will bring a frontal boundary through the state by the end of next week/weekend which will bring a return to some storm chances toward that time period. Otherwise temperatures to remain cooler than the seasonal averages through mid week and begin to moderate toward the seasonal averages by the end of next week. && .AVIATION.../For the 12Z TAFS through 12Z Sunday morning/ Issued at 545 AM CDT Sat Jul 20 2019 Still have southerly winds today becoming more northerly to northeasterly by late today and tonight as a cold front drops south through Iowa. Some storms have fired across southern MN and expect them to remain up there north of the Iowa border through the mid morning hours before starting to sink southward into Iowa toward mid-day. Entire boundary to then continue southward with additional development along and ahead of the boundary into the afternoon/evening hours. && .DMX WATCHES/WARNINGS/ADVISORIES... Excessive Heat Warning until 7 PM CDT this evening for IAZ026>028-035>039-044>050-057>062-070>075-081>086-092>097. && DISCUSSION...Beerends AVIATION...Beerends
Hazardous weather outlook, Jul 20, 4:04 AM CDT, 7 hours before
Hazardous Weather Outlook National Weather Service Des Moines IA 404 AM CDT Sat Jul 20 2019 IAZ026>028-035>039-044>050-057>062-070>075-081>086-092>097-210915- Franklin-Butler-Bremer-Webster-Hamilton-Hardin-Grundy-Black Hawk- Crawford-Carroll-Greene-Boone-Story-Marshall-Tama-Audubon-Guthrie- Dallas-Polk-Jasper-Poweshiek-Cass-Adair-Madison-Warren-Marion- Mahaska-Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold- Decatur-Wayne-Appanoose-Davis- 404 AM CDT Sat Jul 20 2019 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight An Excessive Heat Warning is in effect for the area. Please refer to the National Weather Service website at weather.gov/desmoines for further details. Thunderstorm chances return today into tonight. A few severe storms are possible late this afternoon into this evening. Locally heavy rainfall seems likely, especially over southern and central Iowa tonight. .DAYS TWO THROUGH SEVEN...Sunday through Friday Thunderstorms are possible over southern Iowa on Sunday. A few storms could be strong to perhaps severe with locally heavy rain less of a concern than Saturday night. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated. IAZ004>007-015>017-023>025-033-034-210915- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Sac-Calhoun- 404 AM CDT Sat Jul 20 2019 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight Thunderstorm chances return today into tonight. A few severe storms are possible late this afternoon into this evening. Locally heavy rainfall seems likely, especially over southern and central Iowa tonight. .DAYS TWO THROUGH SEVEN...Sunday through Friday Thunderstorms are possible over southern Iowa on Sunday. A few storms could be strong to perhaps severe with locally heavy rain less of a concern than Saturday night. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated. Ansorge
In the hours before
Local storm report, Jul 20, 10:04 AM CDT, 1 hour before
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</html>Local storm report, Jul 20, 10:06 AM CDT, 58 minutes before
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</html>Local storm report, Jul 20, 10:43 AM CDT, 21 minutes before
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</html>Special weather statement, Jul 20, 10:53 AM CDT, 11 minutes before
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</html>Local storm report, Jul 20, 11:03 AM CDT, 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1103 AM CDT SAT JUL 20 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1058 AM TSTM WND DMG 1 NNE FOREST CITY 43.27N 93.64W
07/20/2019 WINNEBAGO IA TRAINED SPOTTER
MULTIPLE SPOTTERS HAVE REPORTED TREE LIMBS,
ABOUT 3 TO 4 INCHES IN DIAMETER HAVE BEEN
DOWNED.
&&
AKThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 9:42 AM CDT | Severe Thunderstorm Warning | DMX | Emmet, Palo Alto | 48 min |
| Jul 20, 10:15 AM CDT | Severe Thunderstorm Warning | DMX | Humboldt, Kossuth, Palo Alto, Pocahontas | 60 min |
| Jul 20, 10:37 AM CDT | Special Weather Statement | DMX | Emmet, Palo Alto | 53 min |
| Jul 20, 10:53 AM CDT | Special Weather Statement | DMX | Cerro Gordo, Franklin, Hancock, Humboldt, Winnebago, Worth and 1 more | 52 min |
| Jul 20, 11:24 AM CDT | Special Weather Statement | DMX | Boone, Butler, Grundy, Hamilton, Hardin, Story | 51 min |
| Jul 20, 11:35 AM CDT | Severe Thunderstorm Warning | DMX | Butler, Franklin, Grundy, Hamilton, Hardin | 40 min |
| Jul 20, 12:18 PM CDT | Special Weather Statement | DMX | Black Hawk, Grundy, Marshall, Story, Tama | 57 min |
| Jul 20, 12:43 PM CDT | Special Weather Statement | DMX | Kossuth, Palo Alto | 62 min |
| Jul 20, 3:56 PM CDT | Special Weather Statement | DMX | Greene | 49 min |
| Jul 20, 4:14 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Greene | 46 min |
| Jul 20, 4:28 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Polk | 47 min |
| Jul 20, 4:59 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Polk, Story, Warren | 46 min |
| Jul 20, 5:29 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marion, Polk, Warren | 46 min |
| Jul 20, 5:58 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Lucas, Mahaska, Marion, Monroe, Poweshiek and 2 more | 47 min |
| Jul 20, 6:27 PM CDT | Severe Thunderstorm Warning | DMX | Appanoose, Davis, Lucas, Mahaska, Monroe, Wapello and 1 more | 63 min |
| Jul 20, 6:41 PM CDT | Severe Thunderstorm Warning | DMX | Adair, Dallas, Guthrie, Madison | 49 min |
| Jul 20, 6:48 PM CDT | Severe Thunderstorm Warning | DMX | Mahaska, Poweshiek | 42 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2019Every severe thunderstorm warning in 2019
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.