Flash Flood Warning 12, NWS Quad Cities, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
250 AM CDT TUE JUN 4 2002

NONLINEAR PROCESSES DOMINATING FOR THE FIRST TWO PERIODS OF THIS
PACKAGE WHICH THE MODELS DO NOT UNDERSTAND. EACH MODEL IS ALSO OFFERING
DIFFERENT SOLUTIONS ON WHAT WILL HAPPEN. THE ONE THING THAT THE MODELS
DO AGREE ON IS PWS GREATER THAN 1.5 INCHES OVER THE ENTIRE CWFA TODAY
AND THIS EVENING. THIS COMBINED WITH A LLJ...THETA E RIDGE...H3
DIFFLUENCE...AND PLENTY OF OMEGA POINTS TO A HEAVY RAIN THREAT. THUS
WILL APPLY NOWCASTING TOOLS AGAINST THE MODELS TO FIGURE OUT WHAT WILL
HAPPEN FOR PERIOD 1 AND EARLY PERIOD 2. OMEGA...SURFACE...AND 300 MB
HEIGHT FIELDS INDICATE CONVECTION OVER NORTHERN CWFA TO CONTINUE
THROUGH 12Z WHICH WILL HELP HOLD BOUNDARY ACROSS SOUTHERN CWFA IN
PLACE. BASED ON RADAR TRENDS AND PREVIOUS MENTIONED FIELDS...
CONVECTION ACROSS WESTERN HALF OF IOWA NOT TO AMOUNT TO MUCH THROUGH
12Z...BUT NEW CONVECTION TO FIRE ACROSS NORTHEAST IOWA WHICH RADAR
TRENDS INDICATE IS HAPPENING.

AFTER 12Z OMEGA FIELDS EXPLODE OVER CWFA INDICATING A RAPID INCREASE
IN CONVECTION DURING THE MORNING HOURS. GIVEN APPROACHING SHORTWAVE AND
INFLECTION ON THE SURFACE THIS WOULD BE REASONABLE. OMEGA MAXIMIZES
OVER ABOUT THE NORTHERN HALF OF CWFA THROUGH MID-DAY BEFORE REALIGNING
ALONG THE FRONT THIS AFTERNOON. STRONG 925 MB FLOW SHOULD EVENTUALLY
HELP PUSH THE BOUNDARY INTO THE NORTHERN PART OF CWFA BUT POTENTIAL
MESO HIGHS MAY SLOW NORTHWARD MOVEMENT. HEATING TO THE SOUTH AND
MOISTURE POOLING TO ALLOW EXTREME DESTABLIZATION TO OCCUR ALLOWING
CONVECTION TO EXPLODE ALONG THE FRONT. CAP TO BE NONE EXISTENT AND PWS
REMAINING HIGH SO TSRA DEVELOPMENT TO PRODUCE R+ AND LIKELY SVR WX.
FLOOD WATCH TO BE ISSUED FOR AT LEAST NORTHERN HALF OF CWFA AND MAY BE
NORTHERN TWO THIRDS.

OMEGA FIELDS MAXIMIZE ALONG THE FRONT AT 00Z WITH OMEGA BECOMING
NEUTRAL TO NEGATIVE BY 03Z AS SHORTWAVE MOVES NORTHEAST. THIS SUGGESTS
THAT STRONG CONVECTION SHOULD STRATIFORM OUT DURING THE EVENING WITH
IT LIKELY ENDING AROUND 06Z. HOWEVER POTENTIAL FOR A WEAK SURFACE TROF
TO EXTEND ACROSS NORTHERN THIRD OF CWFA WHICH MAY EXTEND PRECIP PAST
06Z. NORTHERLY AND EVENTUALLY NORTHEAST WINDS KICK IN BY 05/12Z AND
CONTINUE DURING THE DAY WEDNESDAY. POTENTIAL FOR LAKE INDUCED CLOUDS AS
DELTA T IS 15. QUIET WX THEN EXPECTED WEDNESDAY NIGHT AS SURFACE RIDGE
BUILDS IN.

TEMPS TODAY ALL DEPENDENT ON WHERE THE SURFACE FRONT WILL BE.
POTENTIAL FOR A 25 DEGREE SPREAD ACROSS CWFA TODAY. NOT MUCH DIFFERENCE
BETWEEN FWC/MAV BUT WILL BE MAKING ADJUSTMENTS. NO CHANGES TO EXTENDED
DUE TO LACK OF TIME.

COORDINATED WITH DSM...LSE...CHI...ILX...AND STL. THANKS.

.DVN...FLOOD WATCH TODAY AND THIS EVENING.
IA...IAZ040>042-051>054-063>068-076>078.
IL...ILZ001-002-007-009-015>018-024.
MO...NONE.

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PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
129 AM CDT TUE JUN 04 2002

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0610 PM    DEWITT                    IA   45 MPH TSTM GUST
06/03/02   CLINTON                        40 TO 45 MPH WINDS
                                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

0620 PM    1 W ANDALUSIA             IL   1 INCH HAIL
06/03/02   ROCK ISLAND                    REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

0630 PM    BUFFALO                   IA   .25 INCH HAIL
06/03/02   SCOTT                          .25 INCH HAIL REPORTED
                                          BY FIRE AND RESCUE AND
                                          RELAYED THROUGH
                                          SHERIFFS DEPARTMENT.

0700 PM    MILAN                     IL   .25 INCH HAIL
06/03/02   ROCK ISLAND                    REPORTED BY STORM
                                          SPOTTER.

0705 PM    MILAN                     IL   URBAN FLOODING
06/03/02   ROCK ISLAND                    SOME STREETS REPORTED
                                          TO BE CURB FULL AND
                                          SOME STREET LIGHTS WERE
                                          NOT WORKING.  .
                                          REPORTED BY STORM
                                          SPOTTER.

0710 PM    5 W FREEPORT              IL   URBAN FLOODING
06/03/02   STEPHENSON                     MAINLY RURAL FLOODING
                                          WITH WATER REPORTED IN
                                          FIELDS AND SOME DITCHS
                                          FULL OF WATER.
                                          REPORTED BY EMERGENCY
                                          MANAGEMENT.

0723 PM    STERLING ARPT             IL   53 MPH TSTM GUST
06/03/02   WHITESIDE                      RECORDED BY AUTOMATED
                                          OBSERVING EQUIPMENT AT
                                          THE AIRPORT.

1000 PM    MORRISON                  IL   URBAN FLOODING
06/03/02   WHITESIDE                      STREETS IN MORRISON
                                          REPORTED TO BE ABOUT
                                          CURB FULL OF WATER DUE
                                          TO HEAVY RAIN.  .
                                          REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

1029 PM    1 N DUBUQUE               IA   .88 INCH HAIL
06/03/02   DUBUQUE                        REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

1054 PM    5 E INDEPENDENCE          IA   SMALL STREAM FLOODING
06/03/02   BUCHANAN                       REPORTED BY PUBLIC ON
                                          OLD HIGHWAY 20.

1100 PM    INDEPENDENCE              IA   HEAVY RAIN
06/03/02   BUCHANAN                       REPORTED BY KWWL, 1.37
                                          INCHES OF RAIN IN 1 HOUR.

1100 PM    WINTHROP                  IA   HEAVY RAIN
06/03/02   BUCHANAN                       REPORTED BY KWWL, 1.78
                                          INCHES IN 1 HOUR.

1100 PM    3 E MORRISON              IL   FLOOD
06/03/02   WHITESIDE                      REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.
                                          UNION PACIFIC TRAIN
                                          BRIDGE BUCKLED AT
                                          LYNDON RD.

1122 PM    JESUP                     IA   HEAVY RAIN
06/03/02   BUCHANAN                       REPORTED BY STORM
                                          SPOTTER, 1.7 INCHES OF
                                          RAIN - EVENING STORM
                                          TOTAL.

1146 PM    4 W MANCHESTER            IA   FLOOD
06/03/02   DELAWARE                       REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL,
                                          145TH AVENUE FLOODED.
                                          REOPENED AT 1215 A.M.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
132 AM CDT TUE JUN 04 2002

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0130 AM    FREEPORT                  IL   URBAN FLOODING
06/04/02   STEPHENSON                     PONDING OF WATER ON
                                          ROADWAYS ESPECIALLY
                                          SIDES AND CURBS.  .
                                          REPORTED BY STORM
                                          SPOTTER.

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-009-
015>018-024>026-034-035-MOZ009-010-051000-

SIGNIFICANT WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
508 AM CDT TUE JUN 4 2002

...THUNDERSTORMS WITH HEAVY RAIN AND POSSIBLY SEVERE...

A STATIONARY FRONT ACROSS SOUTHERN IOWA AND CENTRAL ILLINOIS WILL MOVE
NORTH AGAIN TODAY AS LOW PRESSURE MOVES UP FROM THE CENTRAL PLAINS.
BEHIND THE FRONT A LOW LEVEL JET WAS TRANSPORTING WARM AND HUMID AIR
FROM THE GULF OF MEXICO. THIS IS INDICATED BY DEW POINTS IN THE UPPER
60S AND LOWER 70S IN EASTERN KANSAS AND NORTHERN MISSOURI.

THUNDERSTORM COMPLEXES ACROSS NORTHEAST IOWA AND NORTHWEST ILLINOIS
ARE EXPECTED TO CONTINUE DURING THE DAYTIME HOURS AND INCREASE IN
COVERAGE. HEAVY RAINFALL IS LIKELY DUE TO THE HIGH MOISTURE CONTENT OF
THE AIR AND EXPECTED TRAINING OF THE THUNDERSTORMS. AT THIS TIME IT
APPEARS THAT A GENERAL 1 TO 1.5 INCH RAINFALL CAN BE EXPECTED WITH
LOCALLY HIGHER AMOUNTS OF 2.5 INCHES OR MORE. THE MOST LIKELY AREA
FOR THE HIGHER RAINFALL AMOUNTS IS NORTH OF AN OSKALOOSA IOWA TO
GALESBURG ILLINOIS LINE...HOWEVER HEAVY RAINFALL CANNOT BE RULED OUT
ACROSS SOUTHEAST IOWA...WEST CENTRAL ILLINOIS...AND FAR NORTHEAST
MISSOURI.

AN UPPER LEVEL DISTURBANCE MOVING THROUGH THE REGION DURING MAXIMUM
HEATING THIS AFTERNOON IS FORECAST TO INCREASE DIRECTIONAL WIND SHEAR
IN THE ATMOSPHERE. THUNDERSTORMS DEVELOPING AHEAD OF THE APPROACHING
COLD FRONT THIS AFTERNOON WILL BE IN A REGION OF VERY UNSTABLE AIR.
SEVERE STORMS ARE POSSIBLE LATE THIS AFTERNOON AND EVENING EAST OF A
LINE FROM OTTUMWA IOWA TO STERLING ILLINOIS. AT THIS TIME THE PRIMARY
THREAT WOULD BE LARGE HAIL...WITH DAMAGING WINDS ALSO POSSIBLE ALONG AND
SOUTH OF HIGHWAY 34.

IF SEVERE WEATHER DEVELOPS...THE MOSTLY LIKELY TIME PERIOD WOULD BE
FROM 4 TO 9 PM. THE RAIN AND THUNDERSTORMS ARE FORECAST TO END AROUND
MIDNIGHT AS HIGH PRESSURE BUILDS INTO THE REGION.

EMERGENCY MANAGERS AND SPOTTERS SHOULD PREPARE FOR HEAVY
RAINFALL TODAY...AND POSSIBLE ACTIVATION FOR SEVERE WEATHER THIS
AFTERNOON AND EVENING.

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