Alert archive / Iowa / Flash Flood Warnings in 2008

Flash Flood Warning 117, NWS Des Moines, IA

July 7, 2008Cerro Gordo County, Worth County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jul 7, 2008, 3:15 PM CDT for Cerro Gordo County, Worth County, Iowa. It was in force for 76 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 7, 2008, 3:15 PM CDT (20:15 UTC)
Expired: Jul 7, 2008, 4:31 PM CDT
In force: 76 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Flood severity: None

Counties Cerro Gordo County, IA, Worth County, IA

The radar

The La Crosse radar (KARX), 169 km from the middle of the area, began a volume at 20:17 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.3 hours before the alert went out and 183 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: 1467 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: -31 m²/s²
0-3 km storm-relative helicity: 21 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS53 KDMX 072017
FFWDMX
IAC033-195-080215-
/O.NEW.KDMX.FF.W.0117.080707T2015Z-080708T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
315 PM CDT MON JUL 7 2008

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN CERRO GORDO COUNTY IN NORTH CENTRAL IOWA...
  THIS INCLUDES THE CITY OF MASON CITY...
  SOUTHEASTERN WORTH COUNTY IN NORTH CENTRAL IOWA...

* UNTIL 915 PM CDT

* AT 309 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MANLY... 
MASON CITY...PLYMOUTH AND GRAFTON.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN DES
MOINES.

LAT...LON 4331 9302 4306 9303 4301 9344 4332 9331
      4334 9302 4333 9302

$$

TEACHOUT

2 follow-up statements

000 
WGUS73 KDMX 072101
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
401 PM CDT MON JUL 7 2008

IAC033-195-080215-
/O.CON.KDMX.FF.W.0117.000000T0000Z-080708T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WORTH IA-CERRO GORDO IA-
401 PM CDT MON JUL 7 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR
NORTHERN CERRO GORDO AND SOUTHEASTERN WORTH COUNTIES...

AT 354 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A THUNDERSTORM PRODUCING FLASH FLOODING OVER THE WARNED
AREA.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MANLY

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN DES
MOINES.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT MONDAY
EVENING FOR NORTHERN IOWA.

LAT...LON 4331 9302 4306 9303 4301 9344 4332 9331
      4334 9302 4333 9302

$$

TEACHOUT

000 
WGUS73 KDMX 072131
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
431 PM CDT MON JUL 7 2008

IAC033-195-072141-
/O.CAN.KDMX.FF.W.0117.000000T0000Z-080708T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WORTH IA-CERRO GORDO IA-
431 PM CDT MON JUL 7 2008

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHERN CERRO
GORDO AND SOUTHEASTERN WORTH COUNTIES...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT MONDAY
EVENING FOR NORTHERN IOWA.

LAT...LON 4331 9302 4306 9303 4301 9344 4332 9331
      4334 9302 4333 9302

$$

RUSSELL

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 Des Moines, IA wrote its last area forecast discussion before this flash flood warning went out at Jul 7, 12:50 PM CDT, 2 hours 25 minutes earlier.

Area forecast discussion, Jul 7, 12:50 PM CDT, 2 hours 25 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1250 PM CDT MON JUL 7 2008

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...
NUMEROUS LOW LEVEL BOUNDARIES STILL LINGERING OVER IOWA THIS MORNING
FROM PREVIOUS CONVECTION THOUGH THE SFC FLOW IS RATHER WEAK. WARM
FRONT MOVING NORTH AND NOW LOCATED NEAR INTERSTATE 80 SHOULD
CONTINUE TO LIFT INTO NORTHERN IOWA TODAY. THE RUC AND NAM BOTH
HANDLING THIS SCENARIO WELL WITH SFC AND 850 MB BOUNDARY LIFTING
NORTH EARLY THIS MORNING WITH GOOD CONVERGENCE ALONG THE BOUNDARY.
SECONDARY BRANCH OF THE LOW LEVEL JET ALSO FEEDING MOISTURE INTO THE
REGION AND FIRING STORMS NORTH OF HIGHWAY 30 WITH ENTIRE LINE
LIFTING NORTH. STORMS MAY PERCOLATE OVER NORTHERN IOWA ALL MORNING
THOUGH THE GREATER FOR STORMS WILL ARRIVE THIS AFTERNOON. MCV OVER
SOUTH CENTRAL NEBRASKA IS EXPECTED TO LIFT NORTHEAST THROUGH THE
FLOW THIS MORNING AND BEGIN TO OVERRIDE THE WARM FRONT BY THIS
AFTERNOON. STORMS THIS MORNING WILL BE PULSY WITH LACK OF OVERALL
SHEAR AND DESPITE BRIEF UPDRAFT INTENSIFICATIONS...HAIL HAS BEEN
DIFFICULT TO REALIZE AT THE SFC WITH STORMS NEAR VERTICAL AND HAIL
TRYING TO FALL THROUGH THE HEAVY RAIN CORE RESULTING IN ENHANCED
MELTING. SHEAR WILL HOWEVER BE INCREASING TODAY AHEAD OF THE
APPROACHING MCV WITH EFFECTIVE SHEAR VALUES AROUND 40 KTS SUGGESTING
A FEW SUPERCELLS WILL BE POSSIBLE. IN THIS HIGHER SHEAR
ENVIRONMENT...HAIL WILL BE EASIER TO PRODUCE WITH SIMILAR CORE
HEIGHTS THAT HAVE OCCURRED OVERNIGHT BECAUSE THE HAIL WILL BE
DISPLACED FROM THE HEAVY RAIN. NEAR UNIDIRECTIONAL SHEAR WILL
PROMOTE DAMAGING WIND POTENTIAL. AN ENHANCED TORNADIC THREAT ALSO
POSSIBLE THIS AFTERNOON AND EARLY EVENING WITH EFFECTIVE LOW LEVEL
HELICITY NEAR 200 M2/S2. AFTER EARLY POTENTIAL FOR
SUPERCELLS...STORMS LIKELY WILL CONGEAL INTO A LINEAR MCS WITH
POTENTIAL FOR A QUASI LINEAR (QLCS) TYPE EVENT AS LOW LEVEL SR
HELICITIES REMAIN HIGH.

ANY STORMS THAT DO DEVELOP TODAY AND TONIGHT WILL BE EFFICIENT RAIN
PRODUCERS AS HAS BEEN THE CASE THE PAST 24 HRS. A SEASONAL WARM
LAYER DEPTH NEAR 14 KFT...SLOW MOVING STORMS AND PWATS AOA 2 INCHES
WITH SUSTAINED MOISTURE ADVECTION WOULD SUGGEST THREAT FOR 2 TO 4
INCHES WITH LOCALLY HIGHER AMOUNTS REMAINS. WILL HOLD OFF ON ISSUING
HEADLINES THROUGH WITH MUCH OF THE AREA ESCAPING HEAVY RAINFALL ON
SUNDAY AND OVERNIGHT. LOCATIONS THAT DID RECEIVE HEAVY AMOUNTS THE
PAST 24 HOURS WERE ABLE TO HANDLE IT FAIRLY WELL WITH A FEW
EXCEPTIONS.

THE FRONTAL BOUNDARY WILL BE OVER SOUTHERN IOWA EARLY TUESDAY AND
WILL SLIDE SLOWLY SOUTH DURING THE DAY. A SECONDARY BOUNDARY IS
EXPECTED TO FOLLOW AND MOVE THROUGH LATE TUESDAY. STILL SOME
UNCERTAINTY ABOUT CONVECTIVE POTENTIAL TUESDAY NIGHT AND HAVE
MAINTAINED DRY FOR NOW BUT THIS MAY NEED TO BE REVISITED. NEXT
SYSTEM EXPECTED TO MOVE ACROSS THE NORTHERN PLAINS WED NIGHT AND
THURSDAY. THIS SYSTEM MAY CLIP NORTHERN IOWA WITH PRECIPITATION IF
IT DROPS FARTHER SOUTH THAN EXPECTED.

&&

.AVIATION...07/18Z
THUNDERSTORMS WILL DEVELOP LATE THIS AFTERNOON AND EVENING IN
NORTHERN AND CENTRAL IOWA...MOVING SOUTHEASTWARD THROUGH
SOUTHEASTERN IOWA TONIGHT. THIS WILL RESULT IN PERIODS OF MVFR OR
LOWER CONDITIONS AT ALL OF OUR TERMINALS...PRIMARILY THROUGH LATE
AFTERNOON AT KFOD AND KMCW...DURING THE EVENING AT KALO KDMX...AND
TONIGHT AT KOTM. VFR CONDITIONS WILL PREVAIL AHEAD OF THE
TSTORMS...ESPECIALLY AT KALO...KDMX...AND KOTM...WITH ONLY A FEW
BRIEF MVFR CIGS AT THOSE TERMINALS THIS AFTERNOON. LATER TONIGHT
SOME MVFR CIGS WILL LINGER AT MOST TERMINALS BEHIND THE
STORMS...WITH THESE CLEARING OUT BY TOMORROW MORNING.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

AVIATION...LEE
PUBLIC...DONAVON

Hazardous weather outlook, Jul 7, 5:48 AM CDT, 9 hours 27 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
548 AM CDT MON JUL 7 2008

IAZ004>007-015>017-023>028-033>039-044>046-081100-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE-
548 AM CDT MON JUL 7 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
IOWA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE WEATHER TODAY. SCATTERED
THUNDERSTORMS ARE POSSIBLE THIS MORNING THEN BECOMING MORE
WIDESPREAD THIS AFTERNOON AND INTO THE EARLY EVENING HOURS. AN
ISOLATED SEVERE STORM WITH NICKEL SIZED HAIL AND 60 MPH WINDS IS
POSSIBLE THIS MORNING. MORE SIGNIFICANT WEATHER IS EXPECTED THIS
AFTERNOON WHEN MORE INTENSE STORMS ARE ANTICIPATED TO DEVELOP.
GOLF BALL SIZED HAIL...65 MPH WINDS AND A FEW TORNADOES ARE ALL
POSSIBLE WITH THE ACTIVITY THIS AFTERNOON AND EVENING.

HEAVY RAINFALL IS EXPECTED ACROSS PORTIONS OF THE AREA TODAY AND
INTO THIS EVENING. RAINFALL AMOUNTS OF 2 TO 4 INCHES WITH LOCALLY
HIGHER AMOUNTS IS POSSIBLE AND MAY CAUSE FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A FEW THUNDERSTORMS ARE POSSIBLE ON TUESDAY ALONG WITH AN ISOLATED
SEVERE STORM. ANOTHER CHANCE FOR THUNDERSTORMS ARRIVES SATURDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY THROUGH THIS EVENING
ESPECIALLY BETWEEN 2 PM AND 8 PM. RAINFALL REPORTS WOULD BE
APPRECIATED DURING THIS TIME.

IAZ047>050-057>062-070>073-081-082-092-081100-
BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-
POWESHIEK-CASS-ADAIR-MADISON-WARREN-ADAMS-UNION-TAYLOR-
548 AM CDT MON JUL 7 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE WEATHER TODAY. ISOLATED THUNDERSTORMS
ARE POSSIBLE THIS MORNING THEN BECOMING MORE WIDESPREAD BY LATE AFTERNOON
AND CONTINUE INTO THE EVENING HOURS. AN ISOLATED SEVERE STORM
WITH NICKEL SIZED HAIL AND 60 MPH WINDS IS POSSIBLE THIS MORNING.
MORE SIGNIFICANT WEATHER IS EXPECTED THIS AFTERNOON WHEN MORE
INTENSE STORMS ARE ANTICIPATED TO DEVELOP. GOLF BALL SIZED
HAIL...65 MPH WINDS AND A FEW TORNADOES ARE ALL POSSIBLE WITH THE
ACTIVITY THIS AFTERNOON AND EVENING.

HEAVY RAINFALL IS EXPECTED ACROSS PROTONS OF THE AREA. RAINFALL
AMOUNTS OF 1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS IS POSSIBLE
AND MAY CAUSE FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A FEW THUNDERSTORMS ARE POSSIBLE ON TUESDAY ALONG WITH AN ISOLATED
SEVERE STORM.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY THROUGH THIS EVENING
ESPECIALLY BETWEEN 4 PM AND MIDNIGHT. RAINFALL REPORTS WOULD BE
APPRECIATED DURING THIS TIME.

IAZ074-075-083>086-093>097-081100-
MARION-MAHASKA-CLARKE-LUCAS-MONROE-WAPELLO-RINGGOLD-DECATUR-WAYNE-
APPANOOSE-DAVIS-
548 AM CDT MON JUL 7 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
IOWA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE WEATHER TONIGHT. THUNDERSTORMS
WILL DEVELOP TO THE NORTHWEST THIS AFTERNOON THEN MOVE SOUTHEAST
INTO THE REGION THIS EVENING. QUARTER SIZED HAIL AND 65 MPH WINDS
ARE THE PRIMARY THREATS ALONG WITH AN ISOLATED TORNADO.

HEAVY RAINFALL IS EXPECTED ACROSS PROTONS OF THE AREA. RAINFALL
AMOUNTS OF 1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS IS POSSIBLE
AND MAY CAUSE FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A SLIGHT RISK FOR SEVERE STORMS CONTINUES ON TUESDAY FEW THUNDERSTORMS
ARE POSSIBLE ON TUESDAY ALONG WITH AN ISOLATED SEVERE STORM.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT BETWEEN 7 PM AND 3 AM
AND AGAIN TUESDAY AFTERNOON.

DONAVON

In the hours before

Local storm report, Jul 7, 2:09 PM CDT, 1 hour 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
209 PM CDT MON JUL 07 2008

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

0155 PM     TSTM WND GST     7 ENE NORTHWOOD         43.49N 93.10W
07/07/2008  E60 MPH          WORTH              IA   TRAINED SPOTTER

&&

JJOHNSON

Local storm report, Jul 7, 2:41 PM CDT, 34 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
241 PM CDT MON JUL 07 2008

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

0233 PM     TSTM WND DMG     5 E MANLY               43.30N 93.09W
07/07/2008                   WORTH              IA   TRAINED SPOTTER

            NUMEROUS LARGE TREE LIMBS DOWN OF GREATER THAN SIX INCH
            IN DIAMETER.

&&

JJOHNSON

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 11:32 PM CDT	Areal Flood Advisory	DMX	Mahaska	118 min
Jul 7, 12:04 AM CDT	Severe Thunderstorm Warning	DMX	Wapello	39 min
Jul 7, 1:43 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Worth	47 min
Jul 7, 2:27 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Worth	17 min
Jul 7, 3:24 PM CDT	Tornado Warning	DMX	Cerro Gordo	20 min
Jul 7, 3:35 PM CDT	Flash Flood Watch	DMX	Black Hawk, Bremer, Butler, Calhoun, Cerro Gordo, Emmet and 14 more	5 hr
Jul 7, 3:58 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll	47 min
Jul 7, 4:02 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Greene, Webster	43 min
Jul 7, 4:10 PM CDT	Severe Thunderstorm Warning	DMX	Carroll, Greene	35 min
Jul 7, 4:19 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	41 min
Jul 7, 4:42 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Greene, Webster	48 min
Jul 7, 4:49 PM CDT	Areal Flood Advisory	DMX	Greene	119 min
Jul 7, 4:49 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Franklin	56 min
Jul 7, 4:51 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass	39 min
Jul 7, 4:57 PM CDT	Tornado Warning	DMX	Hamilton, Webster	33 min
Jul 7, 4:59 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Webster	46 min
Jul 7, 5:05 PM CDT	Areal Flood Advisory	DMX	Webster	2 hr
Jul 7, 5:12 PM CDT	Severe Thunderstorm Warning	DMX	Boone	17 min
Jul 7, 5:49 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Butler	56 min
Jul 7, 5:53 PM CDT	Areal Flood Advisory	DMX	Bremer, Butler	2 hr
Jul 7, 6:18 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Franklin, Grundy, Hardin	22 min
Jul 7, 6:39 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Butler, Grundy	66 min
Jul 7, 6:51 PM CDT	Areal Flood Advisory	DMX	Black Hawk	76 min
Jul 7, 6:58 PM CDT	Areal Flood Advisory	DMX	Grundy	69 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.