Alert archive / Iowa / Flash Flood Warnings in 2018

Flash Flood Warning 39, NWS Des Moines, IA

September 19, 2018Franklin County, Wright County, Iowa

NWS Des Moines, IA issued this flash flood warning at Sep 19, 2018, 10:22 PM CDT for Franklin County, Wright County, Iowa. It was in force for 6 hr. 3 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
Sep 19, 2018, 10:22 PM CDT (03:22 UTC)
Expired
Sep 20, 2018, 4:15 AM CDT
In force
6 hr
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Flood severity
None

Counties Franklin County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 115 km from the middle of the area, began a volume at 03:22 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
Sep 19, 10:40 PM CDTHEAVY RAIN 3.25Dows, IATOTAL AS OF 10PM, RAIN IS STILL FALLING - VIA SOCIAL MEDIA.
Sep 20, 12:01 AM CDTHEAVY RAIN 3.284 Ssw Hampton, IA24HR TOTAL - STILL RAINING - VIA BROADCAST MEDIA.
Sep 20, 4:15 AM CDTFLASH FLOODHampton, IAFRANKLIN COUNTY SHERIFFS OFFICE REPORTED A NUMBER OF ROADS ACROSS THE COUNTY WITH WATER RUNNING OVER THEM, INCLUDING A FEW IMPASSABLE AT THE TIME OF THE CALL.

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 3.4 hours before the alert went out and 242 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.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2018-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2018-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
616 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

878 
WGUS53 KDMX 200322
FFWDMX
IAC069-197-200915-
/O.NEW.KDMX.FF.W.0039.180920T0322Z-180920T0915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Des Moines IA
1022 PM CDT WED SEP 19 2018

The National Weather Service in Des Moines  has issued a

* Flash Flood Warning for...
  Eastern Wright County in north central Iowa...
  Franklin County in north central Iowa...

* Until 415 AM CDT.

* At 1021 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 2 to 3 inches of rain have 
  fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Hampton, Belmond, Ackley, Sheffield, Big Wall Lake, Elm Lake, Dows,
  Latimer, Coulter, Alexander, Geneva, Rowan, Bradford, Hansell,
  Chapin, Popejoy, Galt, Beeds Lake State Park, Hampton Municipal
  Airport and Belmond Municipal Airport.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area as more thunderstorms move over the region in the next 2 
hours.  Emergency management reports that several roads are being 
impacted near the Dows area at this time.  

This includes Interstate 35 between mile markers 151 and 175.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4266 9303 4266 9302 4256 9303 4256 9368
      4285 9368 4289 9303

$$

REV
1 follow-up statement
542 
WGUS73 KDMX 200916
FFSDMX

Flash Flood Statement
National Weather Service Des Moines IA
416 AM CDT THU SEP 20 2018

IAC069-197-200925-
/O.EXP.KDMX.FF.W.0039.000000T0000Z-180920T0915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wright IA-Franklin IA-
416 AM CDT THU SEP 20 2018

...THE FLASH FLOOD WARNING FOR EASTERN WRIGHT AND FRANKLIN COUNTIES
HAS EXPIRED...

The flash flood warning has been replaced by an areal flood warning. 
Please see that warning for details. Please continue to use caution 
when traveling. 

LAT...LON 4266 9303 4266 9302 4256 9303 4256 9368
      4285 9368 4289 9303

$$

Curtis

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 8:49 PM CDTSevere Thunderstorm WarningDMXPalo Alto, Pocahontas25 min
Sep 19, 9:54 PM CDTRiver Flood WarningDMXCerro Gordo, Floyd, Worth3 days
Sep 19, 9:54 PM CDTRiver Flood WarningDMXEmmet15 days
Sep 19, 9:57 PM CDTRiver Flood WatchDMXHumboldt, Kossuth7 days
Sep 20, 4:14 AM CDTAreal Flood WarningDMXFranklin, Wright24 hr
Sep 20, 4:55 AM CDTRiver Flood WarningDMXWright6 days
Sep 20, 4:55 AM CDTRiver Flood WarningDMXHumboldt9 days
Sep 20, 4:57 AM CDTRiver Flood WatchDMXWebster24 hr
Sep 20, 4:57 AM CDTRiver Flood WatchDMXPalo Alto, Pocahontas6 days
Sep 20, 8:51 AM CDTAreal Flood WarningDMXCerro Gordo, Emmet, Hancock, Kossuth, Palo Alto, Winnebago and 1 more48 hr
Sep 20, 10:46 AM CDTRiver Flood WatchDMXTama3 days
Sep 20, 11:23 AM CDTRiver Flood WarningDMXWebster7 days
Sep 20, 11:23 AM CDTRiver Flood WarningDMXPalo Alto, Pocahontas5 days
Sep 20, 11:23 AM CDTRiver Flood WarningDMXHumboldt, Kossuth8 days
Sep 20, 5:13 PM CDTSevere Thunderstorm WarningDMXEmmet47 min
Sep 20, 5:19 PM CDTSpecial Weather StatementDMXCalhoun, Crawford, Kossuth, Palo Alto, Pocahontas, Sac56 min
Sep 20, 5:41 PM CDTSevere Thunderstorm WarningDMXEmmet, Kossuth, Palo Alto34 min
Sep 20, 5:43 PM CDTSevere Thunderstorm WarningDMXCalhoun, Carroll, Crawford, Pocahontas, Sac47 min
Sep 20, 5:49 PM CDTSevere Thunderstorm WarningDMXHumboldt, Kossuth, Palo Alto, Pocahontas26 min
Sep 20, 5:52 PM CDTSevere Thunderstorm WarningDMXHancock, Kossuth, Winnebago, Worth38 min
Sep 20, 6:17 PM CDTSpecial Weather StatementDMXHumboldt, Pocahontas58 min
Sep 20, 6:25 PM CDTSevere Thunderstorm WarningDMXCalhoun, Hancock, Humboldt, Kossuth, Pocahontas, Webster and 1 more50 min
Sep 20, 6:28 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock, Kossuth, Winnebago, Worth47 min
Sep 20, 6:41 PM CDTSevere Thunderstorm WarningDMXCalhoun, Hamilton, Webster, Wright34 min
Sep 20, 6:59 PM CDTSpecial Weather StatementDMXBoone, Greene61 min

Nearby

Flash Flood Warnings in Iowa, 2018Every flash flood warning in 2018

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.