Alert archive / Iowa / Flash Flood Watches in 2008

Flash Flood Watch 4, NWS Quad Cities, IA

April 9, 200818 counties in Iowa; 13 counties in Illinois; Clark County, Scotland County, Missouri

NWS Quad Cities, IA issued this flash flood watch at Apr 9, 2008, 3:15 AM CDT for 18 counties in Iowa; 13 counties in Illinois; Clark County, Scotland County, Missouri. It took effect at Apr 10, 2008, 1:00 AM CDT. It was in force for 20 hr.

The area

The counties it named.

The facts

Issued
Apr 9, 2008, 3:15 AM CDT (08:15 UTC)
In effect from
Apr 10, 2008, 1:00 AM CDT
Expired
Apr 10, 2008, 9:07 PM CDT
In force
20 hr
Issued by
NWS Quad Cities, IA
Flood severity
None
All 33 counties

Cedar County, IA, Clinton County, IA, Des Moines County, IA, Dubuque County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Bureau County, IL, Carroll County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, McDonough County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Clark County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 40 km from the middle of the area, began a volume at 08:21 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

Davenport, (KDVN), launched 00:00Z, 8.3 hours before the alert went out and 46 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, Davenport, at 00:00Z on 2008-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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, Davenport, at 00:00Z on 2008-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 289 square meters per square second.19395878Sfc1 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
460 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
289 m²/s²
0-3 km storm-relative helicity
497 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Quad Cities, IA wrote its last area forecast discussion before this flash flood watch went out at Apr 8, 3:11 PM CDT, 12 hours 4 minutes earlier.

Area forecast discussion, Apr 8, 3:11 PM CDT, 12 hours 4 minutes before
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Hazardous weather outlook, Apr 8, 4:49 AM CDT, 22 hours 26 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
449 AM CDT TUE APR 8 2008

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-091000-
BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON-
CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JEFFERSON-
HENRY IA-DES MOINES-VAN BUREN-LEE-JO DAVIESS-STEPHENSON-CARROLL-
WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM-MERCER-HENDERSON-
WARREN-HANCOCK-MCDONOUGH-SCOTLAND-CLARK-
449 AM CDT TUE APR 8 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
ILLINOIS...NORTHWEST ILLINOIS...WEST CENTRAL ILLINOIS...EAST
CENTRAL IOWA...NORTHEAST IOWA...SOUTHEAST IOWA AND NORTHEAST
MISSOURI.

.DAY ONE...TODAY AND TONIGHT

HEAVY RAIN IS EXPECTED TODAY...ESPECIALLY EAST OF A LINE FROM
FAIRFIELD TO DUBUQUE.  PERIODS OF RAIN...HEAVY AT TIMES WILL SPREAD
ACROSS THE ENTIRE OUTLOOK AREA DURING THE DAY TODAY.  THUNDERSTORMS
WILL BE EMBEDDED IN THE RAIN...ESPECIALLY THIS MORNING.  LOCATIONS
MOST LIKELY TO HEAR THUNDER WILL BE SOUTHEAST IOWA...AND ALL
ILLINOIS AND MISSOURI COUNTIES. THUNDERSTORMS ARE NOT EXPECTED TO BE
SEVERE.  WIDESPREAD RAINFALL OF ONE HALF TO ONE INCH IS LIKELY
ACROSS THE ENTIRE OUTLOOK AREA...WITH POTENTIAL FOR GREATER THAN ONE
INCH EAST OF A FAIRFIELD TO DUBUQUE LINE.

MINOR FLOODING CONTINUES ON A FEW TRIBUTARY RIVERS IN EASTERN IOWA
AND NORTHWEST ILLINOIS. PLEASE SEE THE LATEST FLOOD STATEMENT FOR
FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

HEAVY RAINFALL IS LIKELY LATE WEDNESDAY NIGHT INTO THURSDAY
EVENING AS AN STRONG SPRING STORM SYSTEM SLOWLY MOVES INTO THE
AREA. WIDESPREAD RAINFALL AMOUNTS IN THE RANGE OF 1 TO 2 INCHES
ARE EXPECTED THURSDAY...WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
THIS MAY RESULT IN PONDING OF WATER IN LOW LYING AREAS AND LEAD TO
ADDITIONAL RISES AND FLOODING ON AREA RIVERS.

THERE IS A SLIGHT RISK FOR SEVERE STORMS THURSDAY IN THE AREA
ALONG AND SOUTH OF HIGHWAY 30. THE PRIMARY SEVERE WEATHER THREAT
IS LARGE HAIL WITH A SECONDARY THREAT FOR DAMAGING WIND WITH
STORMS IN THE AFTERNOON AND EARLY EVENING HOURS. NON-SEVERE
THUNDERSTORMS ARE POSSIBLE ACROSS MUCH OF THE OUTLOOK AREA FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

ERVIN/SHEETS

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 9, 3:57 AM CDTRiver Flood WarningDVNLee30 hr
Apr 9, 9:52 AM CDTRiver Flood WarningDVNJohnson, Louisa, Washington4 days
Apr 9, 9:52 AM CDTRiver Flood WarningDVNDes Moines, Henry, Lee3 days
Apr 9, 10:15 AM CDTRiver Flood WarningDVNHancock43 days

Nearby

Flash Flood Watches in Iowa, 2008Flash Flood Watches in Illinois, 2008Flash Flood Watches in Missouri, 2008Every flash flood watch 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.