Alert archive / Iowa / Flash Flood Warnings in 2008

Flash Flood Warning 25, NWS Omaha, NE

June 11, 2008Pottawattamie County, Iowa

NWS Omaha, NE issued this flash flood warning at Jun 11, 2008, 6:59 AM CDT for Pottawattamie County, Iowa. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jun 11, 2008, 6:59 AM CDT (11:59 UTC)
Expired: Jun 11, 2008, 11:22 AM CDT
In force: 4 hr
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Flood severity: None

County Pottawattamie County, IA

The radar

The Omaha radar (KOAX), 69 km from the middle of the area, began a volume at 12:02 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 12.0 hours before the alert went out and 69 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2373 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 91 m²/s²
0-3 km storm-relative helicity: 284 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

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 Omaha, NE wrote its last area forecast discussion before this flash flood warning went out at Jun 11, 6:59 AM CDT, 0 minutes earlier.

Area forecast discussion, Jun 11, 6:59 AM CDT, 0 minutes before

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Hazardous weather outlook, Jun 11, 5:45 AM CDT, 1 hour 14 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
545 AM CDT WED JUN 11 2008

IAZ043-055-056-069-079-080-090-091-NEZ015-032>034-042>045-050>053-
065>068-078-088>093-120045-
MONONA-HARRISON-SHELBY-POTTAWATTAMIE-MILLS-MONTGOMERY-FREMONT-
PAGE-THURSTON-STANTON-CUMING-BURT-PLATTE-COLFAX-DODGE-WASHINGTON-
BUTLER-SAUNDERS-DOUGLAS-SARPY-SEWARD-LANCASTER-CASS-OTOE-SALINE-
JEFFERSON-GAGE-JOHNSON-NEMAHA-PAWNEE-RICHARDSON-
545 AM CDT WED JUN 11 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST IOWA
AND EASTERN NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
THE OUTLOOK AREA...MAINLY THIS AFTERNOON AND EVENING. SCATTERED
THUNDERSTORMS SHOULD BE DECREASING OR ENDING ACROSS THE AREA THIS
MORNING...WITH REDEVELOPMENT EXPECTED LATER THIS AFTERNOON.
THUNDERSTORMS THIS MORNING COULD PRODUCE ISOLATED MARGINALLY
SEVERE SIZE HAIL. THUNDERSTORMS THIS AFTERNOON COULD PRODUCE
LARGE HAIL...DAMAGING WINDS AS WELL AS TORNADOES. ANY THUNDERSTORM
ALSO HAS THE POTENTIAL TO PRODUCE VERY HEAVY RAIN.

A COLD FRONT WILL BE MOVING INTO EASTERN NEBRASKA DURING THE
AFTERNOON. IN ADVANCE OF THE FRONT VERY STRONG SOUTH WINDS
CAN BE EXPECTED. AS TEMPERATURES WARM INTO THE 80S THIS AFTERNOON...
THE COMBINATION OF THESE WARM TEMPERATURES AND DEWPOINTS OF 65 TO
70 DEGREES WILL CREATE HIGH INSTABILITY. IN ADDITION...WIND SHEAR
WILL INCREASE THROUGH THE AFTERNOON...SETTING THE STAGE FOR
SUPERCELL STORMS TO FORM BY THIS AFTERNOON. THE CHANCE FOR SEVERE
STORMS WILL CONTINUE WELL INTO THE EVENING...BUT HEAVY RAIN WILL
BECOME INCREASINGLY LIKELY BY LATE EVENING AND OVERNIGHT.

A CONFERENCE CALL WITH EMERGENCY MANAGEMENT AND MEDIA WILL MOST
LIKELY BE SCHEDULED FOR EARLY AFTERNOON. THE LATE MORNING
HAZARDOUS WEATHER UPDATE WILL PROVIDE MORE INFORMATION.

FLOODING CONTINUES ON SEVERAL RIVERS AND STREAMS FROM RECENT
HEAVY RAIN. CHECK THE LATEST FLOOD WARNINGS OR STATEMENTS FOR
DETAILS REGARDING FLOODING. IN ADDITION...A FLASH FLOOD WATCH HAS
BEEN POSTED FOR THE AREA UNTIL THURSDAY MORNING. THE FLASH FLOOD
WATCH BEGINS THIS MORNING FOR LOCATIONS NORTH THROUGH SOUTHEAST OF
OMAHA AND BEGINS AT 400 PM FOR THE REST OF THE REGION.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THUNDERSTORMS MAY LINGER INTO THURSDAY AND THURSDAY NIGHT IN
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. IT APPEARS THE MAIN THREAT
OF SEVERE STORMS DURING THAT TIME WILL BE SOUTHEAST OF THE REGION.

THUNDERSTORMS ARE AGAIN POSSIBLE SUNDAY AND MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS SHOULD PREPARE FOR ACTIVATION THIS AFTERNOON...PERHAPS AS
EARLY AS 1 OR 2 PM...BUT ESPECIALLY BY LATE AFTERNOON AND THIS EVENING.

NEZ011-012-016>018-030-031-120030-
KNOX-CEDAR-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON-
545 AM CDT WED JUN 11 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE REGION...MAINLY THIS
AFTERNOON THROUGH LATE EVENING. THE STORMS MAY BE SEVERE WITH LARGE
HAIL...DAMAGING WINDS AND EVEN A TORNADO OR TWO POSSIBLE. ANY STORM COULD
ALSO PRODUCE AREAS OF HEAVY RAIN. THE STRONGER THUNDERSTORMS AND
HEAVIEST RAIN THREAT APPEARS THAT IT WILL SHIFT SOUTHEAST OF THE
REGION BY EARLY TO MID EVENING.

A COLD FRONT WILL BE MOVING INTO EASTERN NEBRASKA DURING THE
AFTERNOON. VERY WARM AND MOIST AIR AHEAD OF THE FRONT WILL BRING
HIGH INSTABILITY. WIND SHEAR WILL ALSO INCREASE THROUGH THE
AFTERNOON...SETTING THE STAGE FOR SUPERCELL STORMS TO FORM.

A CONFERENCE CALL WITH EMERGENCY MANAGEMENT AND MEDIA WILL MOST
LIKELY BE SCHEDULED FOR EARLY AFTERNOON. THE LATE MORNING
HAZARDOUS WEATHER UPDATE WILL PROVIDE MORE INFORMATION.

FLOODING CONTINUES ON SEVERAL RIVERS AND STREAMS FROM RECENT
HEAVY RAIN. CHECK THE LATEST FLOOD WARNINGS OR STATEMENTS FOR
DETAILS REGARDING FLOODING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS THURSDAY. IF
THEY DEVELOP THEY COULD PRODUCE SMALL HAIL AND GUSTY WINDS.

THUNDERSTORMS ARE AGAIN POSSIBLE SUNDAY AND MONDAY.

.SPOTTER INFORMATION STATEMENT...

THERE IS A GOOD CHANCE THAT STORM SPOTTER ACTIVATION WILL BE
NEEDED BY EARLY TO MID AFTERNOON OVER MUCH OF THE AREA.

CHERMOK

In the hours before

Local storm report, Jun 11, 3:43 AM CDT, 3 hours 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
343 AM CDT WED JUN 11 2008

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

0325 AM     HAIL             LOUISVILLE              41.00N 96.16W
06/11/2008  E0.75 INCH       CASS               NE   TRAINED SPOTTER

            NEAR THE INTERSECTION OF 120TH AND CHURCH

&&

JREESE

Local storm report, Jun 11, 3:46 AM CDT, 3 hours 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
346 AM CDT WED JUN 11 2008

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

0340 AM     HAIL             OMAHA                   41.26N 96.01W
06/11/2008  M0.50 INCH       DOUGLAS            NE   NWS EMPLOYEE

            156TH AND BLONDO

&&

JREESE

Local storm report, Jun 11, 3:48 AM CDT, 3 hours 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
348 AM CDT WED JUN 11 2008

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

0340 AM     HAIL             PAPILLION               41.16N 96.04W
06/11/2008  E1.00 INCH       SARPY              NE   TRAINED SPOTTER

&&

JREESE

Local storm report, Jun 11, 3:50 AM CDT, 3 hours 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
350 AM CDT WED JUN 11 2008

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

0343 AM     HAIL             OMAHA                   41.26N 96.01W
06/11/2008  E1.00 INCH       DOUGLAS            NE   LAW ENFORCEMENT

            NEAR THE INTERSECTION OF MAPLE ST. AND 156TH.

&&

JREESE

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 11, 2:34 AM CDT	Severe Thunderstorm Warning	OAX	Johnson	41 min
Jun 11, 2:50 AM CDT	Severe Thunderstorm Warning	OAX	Colfax, Platte, Stanton	40 min
Jun 11, 2:59 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Sarpy	46 min
Jun 11, 3:26 AM CDT	Severe Thunderstorm Warning	OAX	Colfax, Dodge	49 min
Jun 11, 3:37 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Sarpy	38 min
Jun 11, 3:43 AM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy, Washington	47 min
Jun 11, 4:17 AM CDT	Severe Thunderstorm Warning	OAX	Burt, Dodge, Washington	43 min
Jun 11, 4:25 AM CDT	Severe Thunderstorm Warning	OAX	Cedar	22 min
Jun 11, 4:28 AM CDT	Severe Thunderstorm Warning	OAX	Burt, Cuming, Thurston	47 min
Jun 11, 4:44 AM CDT	Flash Flood Watch	OAX	Burt, Butler, Cass, Colfax, Cuming, Dodge and 17 more	26 hr
Jun 11, 6:26 AM CDT	Wind Advisory	OAX	Antelope, Boone, Burt, Butler, Cass, Cedar and 23 more	10 hr
Jun 11, 11:14 AM CDT	Areal Flood Warning	OAX	Platte	24 hr
Jun 11, 4:26 PM CDT	Severe Thunderstorm Warning	OAX	Cuming, Thurston	27 min
Jun 11, 4:32 PM CDT	Severe Thunderstorm Warning	OAX	Saunders	43 min
Jun 11, 5:02 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Cuming	28 min
Jun 11, 5:25 PM CDT	Severe Thunderstorm Warning	OAX	Thurston	50 min
Jun 11, 5:36 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Dodge, Douglas, Lancaster, Saunders, Seward and 1 more	54 min
Jun 11, 5:49 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Dodge, Washington	26 min
Jun 11, 5:56 PM CDT	Tornado Warning	OAX	Saunders	49 min
Jun 11, 6:03 PM CDT	Flash Flood Warning	OAX	Saunders	3 hr
Jun 11, 6:13 PM CDT	Severe Thunderstorm Warning	OAX	Burt	47 min
Jun 11, 6:16 PM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Saline, Seward	59 min
Jun 11, 6:23 PM CDT	Tornado Warning	OAX	Burt	37 min
Jun 11, 6:27 PM CDT	Tornado Warning	OAX	Dodge, Douglas, Saunders, Washington	63 min
Jun 11, 6:40 PM CDT	Flash Flood Warning	OAX	Burt, Washington	3 hr
Jun 11, 6:58 PM CDT	Tornado Warning	OAX	Cass, Lancaster, Otoe, Saline, Seward	62 min
Jun 11, 5:55 AM CDT	Severe Thunderstorm Warning	OAX	Harrison, Shelby	39 min
Jun 11, 12:29 PM CDT	River Flood Warning	OAX	Harrison	21 hr
Jun 11, 6:08 PM CDT	Severe Thunderstorm Warning	OAX	Monona	37 min
Jun 11, 6:13 PM CDT	Flash Flood Warning	OAX	Monona	3 hr
Jun 11, 6:57 PM CDT	Tornado Warning	OAX	Harrison, Monona	23 min

Nearby

Flash Flood Warnings in Iowa, 2008 Every flash flood warning in 2008

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.