Damaging Winds in Iowa, July 6, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
334 AM CDT SUN JUL 6 2003

LARGE MCS MOVING OVER WESTERN HALF IA TO MOVE ACROSS CWFA THIS
MORNING IN RAPIDLY DECAYING MODE. SEVERE THREAT LOOKS MINIMAL AS IR
IMAGERY SHOWS COOLING TOPS AND 88D MOSAIC SHOWS SYSTEM BECOMING MORE
DISORGANIZED AT LEADING EDGE. ALSO...COMPLEX IS MOVING INTO AIRMASS
OVER SOUTHERN IA AND SOUTHERN HALF DVN CWA ALREADY WORKED OVER BY
EVENING MCS. INITIAL FORECAST CHALLENGE IS HANDLING OF POPS THIS
MORNING...THEN CHANCES FOR ADDITIONAL MAINLY NOCTURNAL COMPLEXES
NEXT SEVERAL DAYS BEFORE PATTERN CHANGE PUSHES FRONT SOUTH OF AREA
MID TO LATE WEEK.

AT 06Z...SURFACE ANALYSIS SHOWED MESO HIGH OVER WESTERN IA. EARLIER
CONVECTION HAD PUSHED SYNOPTIC BOUNDARY TO AXIS FROM CENTRAL IA TO
JUST SOUTH OF QUAD CITIES TO NEAR KPIA. SOME FLARE UP OF NEAR SEVERE
WIND PRODUCERS POSSIBLE AROUND AM PACKAGE ISSUANCE TIME ALONG NW
EDGE OF THIS FRONT THAT HAS SINCE LIFTED NORTH TO NEAR KALO
SOUTHEAST THROUGH QUAD CITIES. EXPECTING WIDESPREAD RAIN AND FEW
CONTINUED LIGHTNING STRIKES AS SYSTEM DECAYS AS IT PUSHES EAST AND
THUS RAISED TO CATEGORICAL POPS OVER EASTERN IA AND NORTHEAST MO
UNTIL MID MORNING...KEEPING SCATTERED WORDING FURTHER EAST THROUGH
LATE MORNING. SHOULD THEN SEE RAPID CLEARING WITH MORE HEAT AND
HUMIDITY THROUGH AFTERNOON. KEPT SLIGHT CHANCES FOR MAINLY LATE
AFTERNOON CONVECTION ALONG BOUNDARY IN FAR NORTH BUT MOST OF CWFA
WILL BE CAPPED. MODELWISE...MAINLY FOLLOWED GFS AS ETA HAD POOR
HANDLE ON THIS MORNINGS MCS.

CHANCE POPS KEPT IN NORTHERN THIRD FOR TONIGHT WHERE NEXT COMPLEX
SET OFF BY MT SHORTWAVE EXPECTED TO MOVE ALONG FRONT. MODELS TRY TO
PUSH FRONT BACK SOUTHEAST IN RESPONSE TO STRONG MID LEVEL VORTEX
MOVING ACROSS SOUTHERN CANADA...BUT DO NOT ANTICIPATE THE FRONT TO
MAKE MUCH PROGRESS UNTIL LATE WED/WED NIGHT WHEN H5 RIDGE BEGINS TO
BUILD OVER WESTERN CONUS. HAVE THUS CONTINUED SCATTERED POPS THROUGH
PERIOD WITH TOO MUCH UNCERTAINTY ON BOUNDARY LOCATION TO GET TOO
DETAILED. DID EXTEND LOW POPS INTO WED NIGHT...BUT THINK GFS MAY BE
SUFFERING FROM FEEDBACK AND OVERDOING SURFACE LOW PASSING OVERHEAD
IN THAT TIMEFRAME. LATER FORECASTS WILL NEED TO WATCH FOR FLASH
FLOOD POTENTIAL IN AREAS OF MAINLY FAR NORTH AND FAR SOUTH THAT HAVE
BEEN RECENTLY SATURATED. VERY FEW CHANGES MADE TO GRIDS THURSDAY AND
BEYOND AS MEDIUM RANGE GUIDANCE SHOWS UPPER LEVEL RIDGE OVER ROCKIES
RESULTING IN NW FLOW OVER REGION TO RESULT IN DRIER AIRMASS AND
COOLER TEMPERATURES.

.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

SHEETS

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-071100-

HAZARDOUS WEATHER OUTLOOK...CORRECTED DAY 2...
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
758 AM CDT SUN JUL 6 2003

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

.DAY ONE...TONIGHT...

THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON.  DUE TO THE
VERY MOIST AND UNSTABLE AIR...SOME OF THESE STORMS MAY REACH SEVERE
LEVELS LATE THIS AFTERNOON AND THIS EVENING.  THE HIGHEST RISKS WILL
BE FOR DAMAGING WINDS UP TO 80 MPH ALONG AND NORTH OF HIGHWAY 34.
LARGE HAIL UP TO THE SIZE OF QUARTERS IN THE STRONGEST STORMS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY...

ANOTHER ROUND OF STRONG TO SEVERE STORMS IS ANTICIPATED MONDAY NIGHT
AS A COMPLEX OF THUNDERSTORMS DROPS OUT OF SOUTHWEST MINNESOTA...
THROUGH THE MID MISSISSIPPI RIVER VALLEY.  THE GREATEST POTENTIAL FOR
SEVERE STORMS WILL BE NORTH OF INTERSTATE 80 WITH THE GREATEST RISK
OF SEVERE WEATHER IN THE FORM OF DAMAGING WINDS AND ISOLATED
TORNADOES.

THUNDERSTORMS WILL CONTINUE TO THREATEN THE REGION TUESDAY THROUGH
WEDNESDAY...AS A FRONTAL BOUNDARY STALLS ACROSS SOUTHERN IOWA AND
NORTHERN MISSOURI.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS EXPECTED LATER THIS AFTERNOON INTO THE
EVENING...MAINLY NORTH OF HIGHWAY 34. SPOTTER ACTIVATION MAY ALSO BE
NEEDED MONDAY AND TUESDAY NIGHT.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:
HTTP://WWW.CRH.NOAA.GOV/DVN

NICHOLS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
122 PM CDT SUN JUL 06 2003

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

0113 PM    WEST LIBERTY              IA   40 MPH TSTM GUST
07/06/03   MUSCATINE                      HEAVY RAIN CAUSING SOME
                                          STREET FLOODING
                                          REPORTED BY STORM
                                          SPOTTER.