Alert archive / Iowa / Special Weather Statements in 2011
Special Weather Statement, NWS Quad Cities, IA
NWS Quad Cities, IA issued this special weather statement at Jul 29, 2011, 4:14 AM CDT for Lee County, Iowa; Hancock County, Illinois; Clark County, Missouri. It was in force for 61 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 29, 2011, 4:14 AM CDT (09:14 UTC)
- Expired
- Jul 29, 2011, 5:15 AM CDT
- In force
- 61 min
- Issued by
- NWS Quad Cities, IA
Counties Lee County, IA, Hancock County, IL, Clark County, MO
The radar
The Quad Cities radar (KDVN), 141 km from the middle of the area, began a volume at 09:17 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.
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 9.2 hours before the alert went out and 146 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
- 4421 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 764 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 63 m²/s²
- 0-3 km storm-relative helicity
- 121 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.8
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>What forecasters said that day
The local office's own words before this special weather statement 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 special weather statement went out at Jul 29, 3:37 AM CDT, 37 minutes earlier.
Area forecast discussion, Jul 29, 3:37 AM CDT, 37 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 337 AM CDT FRI JUL 29 2011 .SYNOPSIS... TROPICAL FEED OF MOISTURE CONTINUES OVER THE REGION WITH PRECIPITABLE WATER VALUES NEAR 2.4 INCHES...WHICH IS CLOSE TO A RECORD FOR DVN. THE SURFACE FRONTAL BOUNDARY HAS STALLED IN THE SOUTHERN THIRD OF THE CWA WITH MID TO UPPER 70 DEW POINTS POOLING ALONG IT. PATCHY DENSE FOG HAS DEVELOPED AT SEVERAL LOCATIONS IN THE NORTHERN CWA WITH VISIBILITIES OF 1/2 MILE OR LESS IN SPOTS. && .SHORT TERM...TODAY AND TONIGHT MAIN CONCERN IN THIS PERIOD IS THE EVOLUTION OF THE LOW-LEVEL BOUNDARY AND SUBSEQUENT CONVECTION. NAM...RUC AND HRRR AGREE IN PUSHING THE BOUNDARY SOUTH OF THE AREA AFTER ONGOING CONVECTION MOVES TO THE EAST LATER THIS MORNING. 850 MB WINDS FROM DVN VAD WIND PROFILE SUPPORT THIS SOUTHWARD PUSH...SO WOULD EXPECT LOWER DEW POINTS (BUT STILL HUMID) TO MOVE INTO THE AREA DURING THE DAY. CONVECTIVE THREAT SHOULD BE TIED TO THE BOUNDARY AND LIMITED MAINLY TO THIS MORNING. AREAS OF DENSE FOG NORTH OF I-80 SHOULD HOPEFULLY REMAIN PATCHY ENOUGH TO NOT REQUIRE AN ADVISORY...BUT THIS WILL CONTINUE TO BE WATCHED. LIGHT WINDS...GENERALLY CLEAR SKIES AND ABUNDANT GROUND MOISTURE WILL LEAD TO A THREAT OF FOG AGAIN TONIGHT. .LONG TERM...SATURDAY THROUGH THURSDAY... MAIN FEATURE OF INTEREST THROUGH THE LONGER RANGE WILL BE THE STRENGTH AND POSITION OF THE UPPER RIDGE. UPPER RIDGE NOW OVER THE SOUTHEASTERN US IS FORECAST TO EXPAND WEST...BUILDING INTO THE SOUTHERN PLAINS AND COVERING THE SOUTHERN TWO-THIRDS OF THE CONUS BY SATURDAY. THE NET EFFECT OF THIS EVOLUTION WILL BE TO SHUNT THE ENERGY NORTH INTO THE NORTHERN PLAINS AND UPPER GREAT LAKES STATES. FORECAST DETAILS DEPEND ON THE STRENGTH OF THE UPPER HIGH AND HOW FAR SOUTH ANY WAVES WOULD TRAVEL AS THEY TOP THE RIDGE. HAVE FAVORED THE ECMWF FOR THIS FORECAST DUE TO ITS OVERALL CONSISTENCY AND BETTER VERIFICATION RELATIVE TO THE GFS. VERY LOW POPS REMAIN IN THE FORECAST FOR EXTREME NORTHERN AREAS FOR SUNDAY AS...PER THE ECMWF...AT THE SOUTHERN EDGE OF A SHORT WAVE BRUSHES THE AREA. NEXT SIGNIFICANT CHANCE FOR RAIN IS TUESDAY WHEN A COLD FRONT PUSHES INTO THE REGION. CONVERGENCE ALONG THE FRONT LOOKS LIKE IT SHOULD BE SUFFICIENT TO GENERATE CONVECTION. WITH 850 MB TEMPS NEAR 25C... MAIN CHALLENGE WILL BE TO OVERCOME THE CAP SO EXPECT CONVECTION TO BE LIMITED TO ALONG AND BEHIND THE FRONT. AS WE HEAD INTO THE END OF NEXT WEEK...RIDGE BEGINS TO FLATTEN WHICH MAY ALLOW ANOTHER WEAKER WAVE TO AFFECT THE AREA THURSDAY AND HAVE KEPT LOW POPS. WITH THE BUILDING RIDGE...MAIN STORY FOR THE WEEKEND MAY WELL BE THE HEAT RETURNING TO THE REGION. HEAT INDICES BY SUNDAY ARE PROGGED TO NEAR 100 IN SOUTHERN PORTIONS OF THE SERVICE AREA AND BY TUESDAY ARE FORECAST TO TOP 105 AS TEMPS CONTINUE TO CLIMB. LOW LEVEL MOISTURE WILL BE READILY AVAILABLE...AND GIVEN THE LACK OF CLOUD COVER AHEAD OF THE FRONT AND AFOREMENTIONED 850MB TEMPS...BELIEVE THESE HEAT INDICES ARE INDEED WITHIN REACH. COLD FRONT LATE TUESDAY WILL GIVE SOME SLIGHT RELIEF BUT THE GREATER RELIEF WILL COME IN THE FORM OF RAIN AND CLOUD COVER PERHAPS LATE TUESDAY AND AGAIN THURSDAY. && .AVIATION... MAIN AVIATION CONCERN THIS FORECAST PERIOD IS LIFR/IFR FOG THIS MORNING AND POTENTIAL FOR FOG AGAIN TONIGHT. COMBINATION OF CLEAR SKIES...LIGHT WINDS AND ABUNDANT GROUND MOISTURE WILL KEEP VSBYS DOWN AT CID AND DBQ UNTIL AFTER SUNRISE. MLI MAY BE IMPACTED BUT PROBABLY NOT TO THE SAME DEGREE AS CID AND DBQ. THUNDERSTORMS IN THE BRL AREA SHOULD HELP LIMIT THE FOG...BUT WILL BE AN ISSUE FOR THE NEXT FEW HOURS AND POSSIBLY AGAIN LATER IN THE DAY. WOLF && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && WOLF/33
Hazardous weather outlook, Jul 28, 5:07 AM CDT, 23 hours 7 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 507 AM CDT THU JUL 28 2011 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-291015- 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- 507 AM CDT THU JUL 28 2011 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 THUNDERSTORMS WITH HEAVY RAIN ARE LIKELY OVER ESPECIALLY THE NORTHERN HALF OF THE OUTLOOK AREA TODAY THROUGH THIS EVENING. THIS MAY LEAD TO FLASH FLOODING...ESPECIALLY ALONG THE HIGHWAY 20 CORRIDOR WHERE CONDITIONS ARE SATURATED FROM OVERNIGHT HEAVY RAINFALL. A FLASH FLOOD WATCH IS IN EFFECT UNTIL MIDNIGHT TONIGHT FOR THE AREA ROUGHLY NORTH OF A LINE FROM STERLING ILLINOIS TO BELLE PLAINE IOWA. THERE WILL ALSO BE A POTENTIAL FOR SEVERE THUNDERSTORMS TODAY AND TONIGHT. THE PRIMARY THREAT WILL BE DAMAGING WINDS UP TO 70 MPH. SOME STORMS MAY ALSO BE CAPABLE OF PRODUCING LARGE HAIL...AND CONDITIONS MAY BE FAVORABLE FOR BRIEF TORNADOES ALONG BOUNDARIES. VERY WARM AND HUMID CONDITIONS WILL REMAIN IN PLACE TODAY... POSSIBLY RESULTING IN AFTERNOON HEAT INDEX VALUES FROM 100 TO NEAR 107 SOUTH OF INTERSTATE 80. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY FRIDAY...THUNDERSTORMS WILL BE POSSIBLE MAINLY SOUTH OF INTERSTATE 80. SEVERE WEATHER IS NOT EXPECTED. THUNDERSTORMS ARE POSSIBLE AGAIN TUESDAY AND WEDNESDAY. IT IS TOO SOON TO DETERMINE THE POTENTIAL FOR SEVERE WEATHER. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT. DLS
In the hours before
Special weather statement, Jul 29, 2:07 AM CDT, 2 hours 7 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE QUAD CITIES IA IL 207 AM CDT FRI JUL 29 2011 IAZ040>042-051>054-063>068-076>078-ILZ001-002-007-009-015>018-024- 290915- BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON- CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JO DAVIESS- STEPHENSON-CARROLL-WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM- MERCER- INCLUDING THE CITIES OF...INDEPENDENCE...MANCHESTER...DUBUQUE... VINTON...CEDAR RAPIDS...ANAMOSA...MAQUOKETA...MARENGO... IOWA CITY...TIPTON...CLINTON...MUSCATINE...BETTENDORF... DAVENPORT...SIGOURNEY...WASHINGTON...WAPELLO...GALENA... FREEPORT...MOUNT CARROLL...STERLING...ROCK FALLS...MOLINE... ROCK ISLAND...KEWANEE...PRINCETON...HENNEPIN...ALEDO 207 AM CDT FRI JUL 29 2011 ...FOG DEVELOPING... WITH CLEAR SKIES...LIGHT WINDS AND ABUNDANT MOISTURE IN THE ATMOSPHERE...FOG HAS BEGUN TO DEVELOP OVER PARTS OF EASTERN IOWA AND NORTHWEST ILLINOIS. IN SOME LOCATIONS SUCH AS DUBUQUE... INDEPENDENCE...VINTON...AND MONTICELLO...VISIBILITIES HAVE ALREADY DROPPED TO ONE-HALF MILE OR LESS. IF YOU ARE OR WILL BE TRAVELING EARLY THIS MORNING...BE PREPARED FOR REDUCED VISIBILITIES. THE FOG WILL CONTINUE TO SPREAD AND BECOME MORE DENSE THROUGH SUNRISE...THEN BEGIN TO BURN OFF BY AROUND 8 AM. WOLF
Special weather statement, Jul 29, 4:14 AM CDT, 0 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE QUAD CITIES IA IL 414 AM CDT FRI JUL 29 2011 IAZ099-ILZ025-034-MOZ010-291015- LEE IA-HENDERSON IL-HANCOCK IL-CLARK MO- 414 AM CDT FRI JUL 29 2011 ...THUNDERSTORM PRODUCING HEAVY RAIN IN NORTHEAST MISSOURI... AT 410 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING HEAVY RAIN IN EXTREME NORTHEAST MISSOURI AND SOUTHEAST IOWA. THE STORM IS MOVING NORTHEAST AROUND 20 MPH AND WILL SOON MOVE INTO WEST CENTRAL ILLINOIS. LOCATIONS THAT HAVE OR WILL RECEIVE HEAVY RAINFALL AT THE RATE OF BETWEEN 1 AND 2 INCHES PER HOUR INCLUDE CLARK COUNTY MISSOURI... SOUTHERN LEE COUNTY IN IOWA...AND HANCOCK COUNTY IN ILLINOIS. THE STORM SHOULD MOVE OUT OF THIS AREA BY 6 AM. EXPECT PONDING OF WATER ON ROADS AND IN LOW-LYING AREAS...AND RISES IN AREA STREAMS AND CREEKS. && LAT...LON 4074 9125 4035 9092 4027 9191 4052 9193 WOLF
The office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 28, 9:50 PM CDT | River Flood Warning | DVN | Clinton, Scott | 37 hr |
| Jul 28, 9:50 PM CDT | River Flood Warning | DVN | Clinton, Scott | 47 hr |
| Jul 29, 8:48 AM CDT | River Flood Warning | DVN | Jackson | 23 hr |
| Jul 29, 11:09 AM CDT | River Flood Warning | DVN | Muscatine, Scott | 23 hr |
| Jul 29, 11:09 AM CDT | River Flood Warning | DVN | Muscatine, Scott | 47 hr |
| Jul 28, 7:13 PM CDT | Flash Flood Warning | DVN | Carroll | 6 hr |
| Jul 29, 4:51 AM CDT | Special Weather Statement | DVN | Henderson, McDonough, Warren | 54 min |
| Jul 29, 2:55 AM CDT | Severe Thunderstorm Warning | DVN | Scotland | 65 min |
Nearby
Special Weather Statements in Iowa, 2011Special Weather Statements in Illinois, 2011Special Weather Statements in Missouri, 2011Every special weather statement in 2011
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.