Alert archive / Illinois / Special Weather Statements in 2011

Special Weather Statement, NWS Quad Cities, IA

April 15, 2011Henderson County, Illinois

NWS Quad Cities, IA issued this special weather statement at Apr 15, 2011, 4:29 PM CDT for Henderson County, Illinois. It was in force for 46 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: Apr 15, 2011, 4:29 PM CDT (21:29 UTC)
Expired: Apr 15, 2011, 5:15 PM CDT
In force: 46 min
Issued by: NWS Quad Cities, IA

County Henderson County, IL

The radar

The Quad Cities radar (KDVN), 137 km from the middle of the area, began a volume at 21:31 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 12:00Z, 9.5 hours before the alert went out and 139 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: 1048 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 459 m²/s²
0-3 km storm-relative helicity: 465 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.

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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 Apr 15, 2:51 PM CDT, 1 hour 38 minutes earlier.

Area forecast discussion, Apr 15, 2:51 PM CDT, 1 hour 38 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
251 PM CDT FRI APR 15 2011

.DISCUSSION...
THE DEEP SYNOPTIC STORM OVER MO WILL MOVE NORTHEAST THIS EVENING
INTO SATURDAY...AND SHOULD DRAG AN OCCLUDING SURFACE LOW VERY NEAR
THE QUAD CITIES DURING THE OVERNIGHT HOURS. THIS WILL PROVIDE
CONTINUOUS LOW LEVEL CONVERGENCE OVER THE CWA...AND COMBINED WITH
THE VERTICALLY STACKED UPPER LOW...WE WILL SEE PERIODIC SHOWERS
AND THUNDERSTORMS THIS EVENING...THEN THIS ACTIVITY SHOULD
CONSOLIDATE INTO A NEW DEFORMATION ZONE OVER THE CENTRAL CWA BY
LATE EVENING. THIS DEFORMATION ZONE RAIN IS LIKELY TO LAST INTO
SATURDAY MORNING BEFORE MOVING EAST AND ENDING OUR RAIN EVENT. DUE
TO THE STORM SYSTEM IMPACTS OCCURRING AS OF EARLY AFTERNOON...THIS
AFD WILL BE CONCISE.

WIND ADVISORY WILL BE CONTINUED THROUGH THE END OF THE AFTERNOON
IN THE NORTH...AT SOMETIME BEFORE 7 PM...WE WILL LIKELY CANCEL
IT...BUT IT IS TOO EARLY TO THAT AS OF 3 PM AS ISSUANCE TIME.
WINDS OVERNIGHT SHOULD ACTUALLY GO RATHER LIGHT AND VARIABLE FOR A
TIME...AS THE LOW PASSES UP ALONG THE MISSISSIPPI RIVER DURING THE
NIGHT. IF WE ARE NOT SEEING RAIN OVER THE CENTRAL CWA DURING THAT
PERIOD...A SIGNIFICANT DRIZZLE MAY TAKE PLACE...ALONG WITH SOME
FOG. HOWEVER...RAIN APPEARS LIKELY AT THIS TIME AND WILL KEEP THE
FORECAST SIMPLE.

SATURDAY...AFTER THE RAIN MOVES OUT...THE NORTHWEST WINDS WILL
INCREASE AS THE DEPTH OF THE MIXING INCREASES. THIS WILL BUMP UP
TEMPS TO THE LOWER 50S...BUT SHOULD ALSO POTENTIALLY BRING WINDS
UP NEAR ADVISORY LEVELS ONCE AGAIN FOR A FEW HOURS.

SATURDAY NIGHT SHOULD SEE LIGHTER WINDS AND COOL TEMPS IN THE
LOWER TO UPPER 30S.

THE DRY WEATHER IS SHORT LIVED AS WE MOVE TOWARDS SUNDAY AND
SUNDAY NIGHT. RAIN SHOWERS SHOULD FIRE ALONG AN ELEVATED WARM
FRONT...AND BY EVENING...AS THE FORCING INCREASING AND LAPSE RATES
STEEPEN...WE COULD SEE SOME LIGHTNING AS WELL.

MONDAY WILL SEE THIS FRONT BEGIN TO TIGHTEN AGAIN AS ANOTHER
STRONG SURGE OF WAA DRIVEN PCPN GETS GOING MONDAY AFTERNOON
THROUGH MONDAY NIGHT. THIS COULD POSE A MODERATE TO HEAVY RAIN
RISK. TUESDAY INTO WEDNESDAY...THE MAIN SURFACE LOW SHOULD PASS
NEAR THE CWA...WITH A CHALLENGE TO TEMPERATURES FORECASTS AS WELL
AS ANOTHER MODERATE TO HEAVY RAIN RISK.
..ERVIN...

&&

.AVIATION...
STRONG EAST WINDS FROM 20 TO 30 KTS WILL DIMINISH THIS AFTERNOON
INTO EVENING AS THE INTENSE LOW PRESSURE SYSTEM OVER MO LIFTS
NORTHEAST THROUGH SE IA...REACHING SOUTHERN WI BY SATURDAY MORNING.
A LARGE SWATH OF RAIN AND MVFR CRITERIA CIGS AND VSBYS WILL CONTINUE
TO AFFECT MUCH OF THE AREA UNTIL THE LOW PASSES...THEN HAVE TRENDED
FORECASTS DOWNWARD WITH IFR CONDITIONS SETTING IN OVERNIGHT.
THUNDERSTORMS WILL MOST LIKELY REMAIN CONFINED TO THE MLI AND BRL
TERMINALS BETWEEN 21Z AND 03Z. WINDS WILL WEAKEN AND BECOME
LIGHT AND VARIABLE FOR A PERIOD THIS EVENING...THEN VEER TO THE WEST
AND THEN NW AND INCREASE BACK TO 20 TO 30 MPH SATURDAY MORNING WITH
CONDITIONS IMPROVING TO MVFR BY MIDDAY.
..SHEETS..

&&

.HYDROLOGY...
MISSISSIPPI RIVER LEVELS WILL CONTINUE TO RISE AS A RESULT OF SNOW
MELT AND RUNOFF FROM RECENT RAINFALL. MAJOR SEVERITY FLOODING IS
FORECAST OVER THE NEXT WEEK FOR PORTIONS OF THE MISSISSIPPI RIVER
FROM DUBUQUE DOWNSTREAM TO BURLINGTON.

THE MISSISSIPPI RIVER IS FORECAST TO CREST BY THE MIDDLE OF NEXT
WEEK FROM DUBUQUE DOWNSTREAM TO BELLEVUE...FROM MID TO LATE NEXT
WEEK DOWNSTREAM OF BELLEVUE TO NEW BOSTON...AND DOWNSTREAM OF NEW
BOSTON TOWARD GREGORY LANDING NEXT WEEKEND.

THE LATEST RIVER FORECASTS INCLUDE PAST PRECIPITATION AND FORECAST
PRECIPITATION FOR THE NEXT 24 HOURS. THIS INCLUDES ANTICIPATED ONE
HALF TO ONE INCH RAINFALL AMOUNTS FROM THE SHOWER AND THUNDERSTORM
ACTIVITY TONIGHT INTO SATURDAY MORNING.

ANOTHER STORM SYSTEM IS FORECAST TO BRING ROUNDS OF PRECIPITATION TO
THE AREA MONDAY AND TUESDAY. DEPENDING ON HOW MUCH PRECIPITATION
THIS SYSTEM BRINGS AND WHERE THE HEAVIEST AMOUNTS FALL...THERE IS
THE POTENTIAL FOR ADDITIONAL RISES ON THE MISSISSIPPI RIVER BEYOND
WHAT IS CURRENTLY FORECAST.
..STOFLET..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BENTON-BUCHANAN-
     CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JOHNSON-JONES-
     LINN.

IL...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-JO DAVIESS-
     STEPHENSON-WHITESIDE.

MO...NONE.
&&

ERVIN/SHEETS/STOFLET

Hazardous weather outlook, Apr 15, 9:16 AM CDT, 7 hours 13 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
916 AM CDT FRI APR 15 2011

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-161430-
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-
916 AM CDT FRI APR 15 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

VERY STRONG WINDS WILL CONTINUE ACROSS MOST OF THE OUTLOOK AREA
TODAY AS A STRONG SPRING STORM SYSTEM TRACKS FROM EASTERN KANSAS
TO CENTRAL ILLINOIS. EAST WINDS FROM 25 TO 35 MPH...WITH GUSTS TO
NEAR 50 MPH WILL CONTINUE THROUGH EARLY AFTERNOON...THEN DIMINISH
TO 20 TO 30 MPH. A WIND ADVISORY HAS BEEN ISSUED FOR MUCH OF THE
OUTLOOK AREA FOR TODAY. PLEASE SEE THE LATEST WIND ADVISORY MESSAGE FOR
MORE COMPLETE INFORMATION.

THERE WILL BE A HIGH THREAT OF GRASS FIRES DUE TO DRIED
VEGETATION...LOW RELATIVE HUMIDITY AND VERY STRONG WINDS. THIS
THREAT WILL END AS RAIN OVERSPREADS THE AREA FROM SOUTH TO NORTH
TODAY.

ISOLATED SEVERE STORMS WILL BE POSSIBLE...ESPECIALLY IN FAR
NORTHEAST MISSOURI AND PORTIONS OF WEST CENTRAL ILLINOIS THIS
AFTERNOON INTO EARLY EVENING. THE MAIN SEVERE WEATHER THREAT WILL
BE HAIL UP TO 1 INCH IN DIAMETER AND WIND GUSTS UP TO 60 MPH.

THE MISSISSIPPI RIVER IS EXPERIENCING FLOODING. PLEASE SEE THE
LATEST FLOOD STATEMENTS AND FLOOD WARNINGS FOR DETAILS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

ANOTHER STORM SYSTEM WILL MOVE THROUGH THE REGION EARLY NEXT WEEK.
THE SYSTEM WILL BRING RAIN AND SOME THUNDERSTORMS TO THE REGION
MONDAY INTO TUESDAY. THE RAINFALL MAY BE ENOUGH TO AGGRAVATE THE
ALREADY SWOLLEN MISSISSIPPI RIVER.

.SPOTTER INFORMATION STATEMENT...

THERE IS A LOW CHANCE THAT SPOTTER ACTIVATION WILL BE NEEDED ACROSS
PORTIONS OF WEST CENTRAL ILLINOIS THIS AFTERNOON AND EVENING.

SHEETS

In the hours before

Special weather statement, Apr 15, 2:21 PM CDT, 2 hours 8 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
221 PM CDT FRI APR 15 2011

IAZ099-ILZ034-035-MOZ010-152045-
CLARK-HANCOCK-LEE-MCDONOUGH-
221 PM CDT FRI APR 15 2011

...STRONG THUNDERSTORMS WITH GUSTY WINDS AND SMALL HAIL MOVING INTO
THE AREA...

AT 220 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
CLUSTER OF STRONG THUNDERSTORMS ROUGHLY 40 MILES SOUTHWEST OF WEST
POINT...OR 28 MILES SOUTH OF CANTON...MOVING NORTH AT 30 MPH.

* THE THUNDERSTORM WILL BE NEAR...
  ST PATRICK...WINCHESTER...GREGORY LANDING...TIOGA...WEST POINT AND
  STILLWELL BETWEEN 3 PM AND 330 PM THIS AFTERNOON.

HAIL UP TO ONE HALF INCH IN DIAMETER AND WIND GUSTS OVER 30 MPH ARE
POSSIBLE WITH THESE STORMS.

LAT...LON 4019 9150 4024 9151 4026 9187 4056 9189
      4059 9070 4028 9077 4028 9090 4019 9091
TIME...MOT...LOC 1914Z 188DEG 26KT 3976 9156

SHEETS

Special weather statement, Apr 15, 3:58 PM CDT, 31 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
358 PM CDT FRI APR 15 2011

ILZ026-034-035-152200-
HANCOCK-MCDONOUGH-WARREN-
358 PM CDT FRI APR 15 2011

...STRONG THUNDERSTORMS MOVING INTO WEST CENTRAL ILLINOIS...

AT 353 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 11 MILES SOUTH OF BOWEN...OR 24 MILES SOUTH OF
CARTHAGE...MOVING NORTH AT 30 MPH.

* THE THUNDERSTORM WILL BE NEAR...
  AUGUSTA AND BOWEN AROUND 415 PM CDT...
  COLMAR AROUND 435 PM CDT...
  COLCHESTER AROUND 445 PM CDT...

ONE HALF INCH DIAMETER HAIL...WINDS GREATER THAN 35 MPH AND BRIEF
HEAVY RAIN ARE EXPECTED WITH THIS STORM.

LAT...LON 4019 9117 4063 9111 4064 9044 4046 9044
      4027 9059 4028 9090 4019 9091
TIME...MOT...LOC 2055Z 199DEG 27KT 4009 9107

SHEETS

Local storm report, Apr 15, 4:16 PM CDT, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
416 PM CDT FRI APR 15 2011

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

0414 PM     HAIL             1 S WEST POINT          40.24N 91.18W
04/15/2011  E0.25 INCH       HANCOCK            IL   LAW ENFORCEMENT

            COVERING THE GROUND.

&&

14

Special weather statement, Apr 15, 4:29 PM CDT, 0 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
429 PM CDT FRI APR 15 2011

ILZ025-026-034-035-152215-
HANCOCK-HENDERSON-MCDONOUGH-WARREN-
429 PM CDT FRI APR 15 2011

...THUNDERSTORMS WITH PENNY SIZE HAIL MOVING ACROSS HANCOCK AND
MCDONOUGH COUNTIES...

AT 419 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF STRONG THUNDERSTORMS EXTENDING FROM CARTHAGE TO AUGUSTA
MOVING NORTHEAST AT 25 MPH.

* THE THUNDERSTORM WILL BE NEAR...
  WEBSTER..COLCHESTER...COLMAR AND INDUSTRY AROUND 445 PM CDT.. .
  MACOMB AROUND 5 PM CDT...

HAIL UP TO THE SIZE OF PENNIES...WINDS GREATER THAN 35 MPH AND BRIEF
HEAVY RAIN ARE EXPECTED WITH THIS STORM. AROUND 4 PM...THESE STORMS
PRODUCED PEA TO PENNY SIZE HAIL COVERING THE GROUND NEAR GOLDEN.

LAT...LON 4037 9118 4085 9096 4067 9050 4028 9088
      4028 9090 4025 9090 4022 9093
TIME...MOT...LOC 2122Z 206DEG 23KT 4034 9105

SHEETS

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 15, 4:30 AM CDT	Wind Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 13 more	15 hr
Apr 15, 2:21 PM CDT	Special Weather Statement	DVN	Hancock	84 min
Apr 15, 3:58 PM CDT	Special Weather Statement	DVN	McDonough	62 min
Apr 15, 4:56 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, McDonough	34 min

Nearby

Special Weather Statements in Illinois, 2011 Every 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.